Quectel Wireless Solutions 201605M35 GSM/GPRS Module User Manual

Quectel Wireless Solutions Company Limited GSM/GPRS Module

User manual

M35 User Manual GSM/GPRS Module Series Rev. M35_User_Manual_V3.1 Date: 2014-11-26 www.quectel.com
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 1 / 85 Our aim is to provide customers with timely and comprehensive service. For any assistance, please contact our company headquarters: Quectel Wireless Solutions Co., Ltd. Office 501, Building 13, No.99, Tianzhou Road, Shanghai, China, 200233 Tel: +86 21 5108 6236 Mail: info@quectel.com Or our local office, for more information, please visit: http://www.quectel.com/support/salesupport.aspx For technical support, to report documentation errors, please visit: http://www.quectel.com/support/techsupport.aspx GENERAL NOTES QUECTEL OFFERS THIS INFORMATION AS A SERVICE TO ITS CUSTOMERS. THE INFORMATION PROVIDED IS BASED UPON CUSTOMERS’ REQUIREMENTS. QUECTEL MAKES EVERY EFFORT TO ENSURE THE QUALITY OF THE INFORMATION IT MAKES AVAILABLE. QUECTEL DOES NOT MAKE ANY WARRANTY AS TO THE INFORMATION CONTAINED HEREIN, AND DOES NOT ACCEPT ANY LIABILITY FOR ANY INJURY, LOSS OR DAMAGE OF ANY KIND INCURRED BY USE OF OR RELIANCE UPON THE INFORMATION. ALL INFORMATION SUPPLIED HEREIN IS SUBJECT TO CHANGE WITHOUT PRIOR NOTICE. COPYRIGHT THIS INFORMATION CONTAINED HERE IS PROPRIETARY TECHNICAL INFORMATION OF QUECTEL CO., LTD. TRANSMITTABLE, REPRODUCTION, DISSEMINATION AND EDITING OF THIS DOCUMENT AS WELL AS UTILIZATION OF THIS CONTENTS ARE FORBIDDEN WITHOUT PERMISSION. OFFENDERS WILL BE HELD LIABLE FOR PAYMENT OF DAMAGES. ALL RIGHTS ARE RESERVED IN THE EVENT OF A PATENT GRANT OR REGISTRATION OF A UTILITY MODEL OR DESIGN. Copyright © Quectel Wireless Solutions Co., Ltd. 2015. All rights reserved.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 2 / 85 About the Document History Revision Date Author Description 1.0 2011-12-29 Luka WU Initial 1.1 2012-05-18 Luka WU 1. Added current consumption in GPRS communication mode. 2. Modified AT command AT+QAUDCH in Chapter 3.10. 3. Modified the Footprint of recommendation. 4. Updated module package type. 1.2 2012-09-19 Luka WU 1. Updated module functional diagram. 2. Updated Voltage ripple during transmitting. 3. Modified level match reference circuits for 5V peripheral system. 4. Updated SIM card reference circuit. 5. Added module current consumption. 1.3 2013-09-03 Winter CHEN 1. Updated information on module’s packaging. 2. Used the new technical document template. 1.4 2013-11-04 Felix YIN Optimized the parameters of VBAT ripple in Table 24. 3.0 2014-07-25 Winter CHEN 1. Added information for SIM2 interface, DTR and DCD pin. 2. Added information for Multi UART. 3. Modified module’s current consumption. 4. Modified module’s pin definition. 5. Modified DC characteristics of module pin. 3.1 2014-11-26 Winter CHEN 1. Added information for PCM interface. 2. Updated Figure 5: Reference Circuit for Power Supply. 3. Modified over-voltage or under-voltage automatic shutdown in Section 3.4.2 4. Modified RTC backup in Section 3.6
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 3 / 85 5. Modified UART application in Section 3.7.3 6. Modified SIM card interface in Section 3.10 7. Added antenna requirement in Section 4.5
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 4 / 85 Contents About the Document ................................................................................................................................... 2 Contents ....................................................................................................................................................... 4 Table Index ................................................................................................................................................... 7 Figure Index ................................................................................................................................................. 8 1 Introduction ........................................................................................................................................ 10 1.1. Safety Information ................................................................................................................. 11 2 Product Concept ................................................................................................................................ 12 2.1. General Description ............................................................................................................... 12 2.2. Directives and Standards ...................................................................................................... 12 2.2.1. FCC Radiation Exposure Statement .............................................................................. 12 2.3. Key Features ......................................................................................................................... 13 2.4. Functional Diagram ............................................................................................................... 15 2.5. Evaluation Board ................................................................................................................... 16 3 Application Interface ......................................................................................................................... 17 3.1. Pin of Module ......................................................................................................................... 18 3.1.1. Pin Assignment .............................................................................................................. 18 3.1.2. Pin Description ............................................................................................................... 19 3.2. Operating Modes ................................................................................................................... 23 3.3. Power Supply ........................................................................................................................ 25 3.3.1. Power Features of Module ............................................................................................. 25 3.3.2. Decrease Supply Voltage Drop ...................................................................................... 25 3.3.3. Reference Design for Power Supply .............................................................................. 26 3.3.4. Monitor Power Supply .................................................................................................... 27 3.4. Power On and Down Scenarios ............................................................................................ 27 3.4.1. Power On ....................................................................................................................... 27 3.4.2. Power Down ................................................................................................................... 29 3.4.2.1. Power Down Module Using the PWRKEY Pin .................................................. 29 3.4.2.2. Power Down Module Using AT Command ........................................................ 30 3.4.2.3. Over-voltage or Under-voltage Automatic Shutdown ........................................ 30 3.4.2.4. Emergency Shutdown Using EMERG_OFF Pin ............................................... 31 3.4.3. Restart ............................................................................................................................ 32 3.5. Power Saving ........................................................................................................................ 33 3.5.1. Minimum Functionality Mode ......................................................................................... 33 3.5.2. SLEEP Mode .................................................................................................................. 34 3.5.3. Wake Up Module from SLEEP Mode ............................................................................. 34 3.5.4. Summary of State Transition .......................................................................................... 35 3.6. RTC Backup .......................................................................................................................... 35 3.7. Serial Interfaces ..................................................................................................................... 37
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 5 / 85 3.7.1. UART Port ...................................................................................................................... 39 3.7.1.1. The Features of UART Port ............................................................................... 39 3.7.1.2. The Connection of UART .................................................................................. 40 3.7.1.3. Firmware Upgrade ............................................................................................. 42 3.7.2. Debug Port ..................................................................................................................... 42 3.7.3. UART Application ........................................................................................................... 43 3.8. Audio Interfaces ..................................................................................................................... 44 3.8.1. Decrease TDD Noise and Other Noise .......................................................................... 46 3.8.2. Microphone Interfaces Design ....................................................................................... 46 3.8.3. Receiver Interface Design .............................................................................................. 47 3.8.4. Earphone Interface Design ............................................................................................ 47 3.8.5. Loud Speaker Interface Design ..................................................................................... 48 3.8.6. Audio Characteristics ..................................................................................................... 48 3.9. PCM Interface ........................................................................................................................ 49 3.9.1. Configuration .................................................................................................................. 50 3.9.2. Timing ............................................................................................................................. 50 3.9.3. Reference Design .......................................................................................................... 52 3.9.4. AT Command ................................................................................................................. 52 3.10. SIM Card Interfaces .............................................................................................................. 53 3.10.1. SIM Card Application ...................................................................................................... 53 3.11. Behaviors of The RI ............................................................................................................... 57 3.12. Network Status Indication ...................................................................................................... 58 3.13. Operating Status Indication ................................................................................................... 59 4 Antenna Interface ............................................................................................................................... 61 4.1. RF Reference Design ............................................................................................................ 61 4.2. RF Output Power ................................................................................................................... 62 4.3. RF Receiving Sensitivity ........................................................................................................ 62 4.4. Operating Frequencies .......................................................................................................... 63 4.5. Antenna Requirement ........................................................................................................... 63 4.6. RF Cable Soldering ............................................................................................................... 64 5 Electrical, Reliability and Radio Characteristics ............................................................................ 65 5.1. Absolute Maximum Ratings................................................................................................... 65 5.2. Operating Temperature ......................................................................................................... 65 5.3. Power Supply Ratings ........................................................................................................... 66 5.4. Current Consumption ............................................................................................................ 67 5.5. Electro-static Discharge ........................................................................................................ 68 6 Mechanical Dimensions .................................................................................................................... 70 6.1. Mechanical Dimensions of Module ....................................................................................... 70 6.2. Recommended Footprint ....................................................................................................... 72 6.3. Top View of the Module ......................................................................................................... 73 6.4. Bottom View of the Module ................................................................................................... 73 7 Storage and Manufacturing .............................................................................................................. 74
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 6 / 85 7.1. Storage .................................................................................................................................. 74 7.2. Soldering ............................................................................................................................... 74 7.3. Packaging .............................................................................................................................. 75 7.3.1. Tape and Reel Packaging .............................................................................................. 75 8 Appendix A Reference ....................................................................................................................... 78 9 Appendix B GPRS Coding Scheme ................................................................................................. 83 10 Appendix C GPRS Multi-slot Class .................................................................................................. 85
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 7 / 85 Table Index TABLE 1: MODULE KEY FEATURES ............................................................................................................... 13 TABLE 2: CODING SCHEMES AND MAXIMUM NET DATA RATES OVER AIR INTERFACE ........................ 15 TABLE 3: PIN DESCRIPTION ........................................................................................................................... 19 TABLE 4: MULTIPLEXED FUNCTIONS ............................................................................................................ 23 TABLE 5: OVERVIEW OF OPERATING MODES ............................................................................................. 23 TABLE 6: SUMMARY OF STATE TRANSITION ............................................................................................... 35 TABLE 7: LOGIC LEVELS OF THE UART INTERFACES ................................................................................ 38 TABLE 8: PIN DEFINITION OF THE UART INTERFACES .............................................................................. 38 TABLE 9: PIN DEFINITION OF AUDIO INTERFACE ....................................................................................... 44 TABLE 10: AOUT2 OUTPUT CHARACTERISTICS .......................................................................................... 45 TABLE 11: TYPICAL ELECTRET MICROPHONE CHARACTERISTICS ......................................................... 48 TABLE 12: TYPICAL SPEAKER CHARACTERISTICS .................................................................................... 48 TABLE 13: PIN DEFINITION OF PCM INTERFACE ......................................................................................... 49 TABLE 14: CONFIGURATION ........................................................................................................................... 50 TABLE 15: QPCMON COMMAND DESCRIPTION .......................................................................................... 53 TABLE 16: QPCMVOL COMMAND DESCRIPTION ......................................................................................... 53 TABLE 17: PIN DEFINITION OF THE SIM INTERFACES ................................................................................ 54 TABLE 18: BEHAVIORS OF THE RI ................................................................................................................. 57 TABLE 19: WORKING STATE OF THE NETLIGHT .......................................................................................... 58 TABLE 20: PIN DEFINITION OF THE STATUS ................................................................................................ 59 TABLE 21: PIN DEFINITION OF THE RF_ANT ................................................................................................ 61 TABLE 22: THE MODULE CONDUCTED RF OUTPUT POWER .................................................................... 62 TABLE 23: THE MODULE CONDUCTED RF RECEIVING SENSITIVITY ....................................................... 62 TABLE 24: THE MODULE OPERATING FREQUENCIES ................................................................................ 63 TABLE 25: ANTENNA CABLE REQUIREMENTS ............................................................................................. 63 TABLE 26: ANTENNA REQUIREMENTS .......................................................................................................... 63 TABLE 27: ABSOLUTE MAXIMUM RATINGS .................................................................................................. 65 TABLE 28: OPERATING TEMPERATURE ........................................................................................................ 65 TABLE 29: THE MODULE POWER SUPPLY RATINGS .................................................................................. 66 TABLE 30: THE MODULE CURRENT CONSUMPTION .................................................................................. 67 TABLE 31: THE ESD ENDURANCE (TEMPERATURE: 25ºC, HUMIDITY: 45%) ............................................ 69 TABLE 32: REEL PACKING .............................................................................................................................. 77 TABLE 33: RELATED DOCUMENTS ................................................................................................................ 78 TABLE 34: TERMS AND ABBREVIATIONS ...................................................................................................... 79 TABLE 35: DESCRIPTION OF DIFFERENT CODING SCHEMES .................................................................. 83 TABLE 36: GPRS MULTI-SLOT CLASSES ...................................................................................................... 85
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 8 / 85 Figure Index FIGURE 1: MODULE FUNCTIONAL DIAGRAM ............................................................................................... 16 FIGURE 2: PIN ASSIGNMENT ......................................................................................................................... 18 FIGURE 3: VOLTAGE RIPPLE DURING TRANSMITTING .............................................................................. 25 FIGURE 4: REFERENCE CIRCUIT FOR THE VBAT INPUT ........................................................................... 26 FIGURE 5: REFERENCE CIRCUIT FOR POWER SUPPLY ............................................................................ 26 FIGURE 6: TURN ON THE MODULE WITH AN OPEN-COLLECTOR DRIVER .............................................. 27 FIGURE 7: TURN ON THE MODULE WITH A BUTTON .................................................................................. 28 FIGURE 8: TURN-ON TIMING .......................................................................................................................... 28 FIGURE 9: TURN-OFF TIMING ........................................................................................................................ 29 FIGURE 10: AN OPEN-COLLECTOR DRIVER FOR EMERG_OFF ................................................................ 31 FIGURE 11: REFERENCE CIRCUIT FOR EMERG_OFF BY USING BUTTON .............................................. 32 FIGURE 12: TIMING OF RESTARTING SYSTEM ............................................................................................ 32 FIGURE 13: TIMING OF RESTARTING SYSTEM AFTER EMERGENCY SHUTDOWN ................................ 33 FIGURE 14: VRTC IS SUPPLIED BY A NON-CHARGEABLE BATTERY ........................................................ 36 FIGURE 15: VRTC IS SUPPLIED BY A RECHARGEABLE BATTERY ............................................................ 36 FIGURE 16: VRTC IS SUPPLIED BY A CAPACITOR ...................................................................................... 36 FIGURE 17: REFERENCE DESIGN FOR FULL-FUNCTION UART ................................................................ 40 FIGURE 18: REFERENCE DESIGN FOR UART PORT ................................................................................... 41 FIGURE 19: REFERENCE DESIGN FOR UART PORT WITH HARDWARE FLOW CONTROL .................... 41 FIGURE 20: REFERENCE DESIGN FOR FIRMWARE UPGRADE ................................................................. 42 FIGURE 21: REFERENCE DESIGN FOR DEBUG PORT ............................................................................... 43 FIGURE 22: LEVEL MATCH DESIGN FOR 3.3V SYSTEM .............................................................................. 43 FIGURE 23: SKETCH MAP FOR RS-232 INTERFACE MATCH ...................................................................... 44 FIGURE 24: REFERENCE DESIGN FOR AIN1&AIN2 ..................................................................................... 46 FIGURE 25: REFERENCE INTERFACE DESIGN OF AOUT1 ......................................................................... 47 FIGURE 26: EARPHONE INTERFACE DESIGN .............................................................................................. 47 FIGURE 27: LOUD SPEAKER INTERFACE DESIGN ...................................................................................... 48 FIGURE 28: LONG SYNCHRONIZATION & SIGN EXTENSION DIAGRAM ................................................... 51 FIGURE 29: LONG SYNCHRONIZATION & ZERO PADDING DIAGRAM....................................................... 51 FIGURE 30: SHORT SYNCHRONIZATION & SIGN EXTENSION DIAGRAM ................................................. 51 FIGURE 31: SHORT SYNCHRONIZATION & ZERO PADDING DIAGRAM .................................................... 52 FIGURE 32: REFERENCE DESIGN FOR PCM ............................................................................................... 52 FIGURE 33: REFERENCE CIRCUIT FOR SIM1 INTERFACE WITH 8-PIN SIM CARD HOLDER ................. 55 FIGURE 34: REFERENCE CIRCUIT FOR SIM1 INTERFACE WITH THE 6-PIN SIM CARD HOLDER ......... 55 FIGURE 35: REFERENCE CIRCUIT FOR SIM2 INTERFACE WITH THE 6-PIN SIM CARD HOLDER ......... 56 FIGURE 36: RI BEHAVIOR OF VOICE CALLING AS A RECEIVER ................................................................ 57 FIGURE 37: RI BEHAVIOR AS A CALLER ....................................................................................................... 58 FIGURE 38: RI BEHAVIOR OF URC OR SMS RECEIVED ............................................................................. 58 FIGURE 39: REFERENCE DESIGN FOR NETLIGHT ..................................................................................... 59 FIGURE 40: REFERENCE DESIGN FOR STATUS .......................................................................................... 60 FIGURE 41: REFERENCE DESIGN FOR RF .................................................................................................. 61
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 9 / 85 FIGURE 42: RF SOLDERING SAMPLE ........................................................................................................... 64 FIGURE 43: M35 MODULE TOP AND SIDE DIMENSIONS (UNIT: MM) ......................................................... 70 FIGURE 44: M35 MODULE BOTTOM DIMENSIONS (UNIT: MM) ................................................................... 71 FIGURE 45: RECOMMENDED FOOTPRINT (UNIT: MM) ................................................................................ 72 FIGURE 46: TOP VIEW OF THE MODULE ...................................................................................................... 73 FIGURE 47: BOTTOM VIEW OF THE MODULE .............................................................................................. 73 FIGURE 48: RAMP-SOAK-SPIKE REFLOW PROFILE .................................................................................... 75 FIGURE 49: TAPE AND REEL SPECIFICATION .............................................................................................. 76 FIGURE 50: DIMENSIONS OF REEL ............................................................................................................... 77 FIGURE 51: RADIO BLOCK STRUCTURE OF CS-1, CS-2 AND CS-3 ........................................................... 83 FIGURE 52: RADIO BLOCK STRUCTURE OF CS-4 ....................................................................................... 84
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 10 / 85 1 Introduction This document defines the M35 module and describes its hardware interface which are connected with your application and the air interface. This document can help you quickly understand module interface specifications, electrical and mechanical details. Associated with application notes and user guide, you can use M35 module to design and set up mobile applications easily.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 11 / 85 1.1. Safety Information The following safety precautions must be observed during all phases of the operation, such as usage, service or repair of any cellular terminal or mobile incorporating M35 module. Manufacturers of the cellular terminal should send the following safety information to users and operating personnel and to incorporate these guidelines into all manuals supplied with the product. If not so, Quectel does not take on any liability for your failure to comply with these precautions. Full attention must be given to driving at all times in order to reduce the risk of an accident. Using a mobie while driving (even with a handsfree kit) cause distraction and can lead to an accident. You must comply with laws and regulations restrcting the use of wireless devices while driving. Switch off the cellular terminal or mobile before boarding an aircraft. Make sure it switched off. The operation of wireless appliances in an aircraft is forbidden to prevent interference with communication systems. Consult the airline staff about the use of wireless devices on boarding the aircraft. If your device offers a Flight Mode which must be enabled prior to boarding an aircraft. Switch off your wireless device when in hospitals or clinics or other health care facilities. These requests are desinged to prevent possible interference with sentitive medical equipment. Cellular terminals or mobiles operate over radio frequency signal and cellular network and cannot be guaranteed to connect in all conditions, for example no mobile fee or an invalid SIM card. While you are in this condition and need emergent help, please remember using emergency call. In order to make or receive call, the cellular terminal or mobile must be switched on and in a service area with adequate cellular signal strength. Your cellular terminal or mobile contains a transmitter and receiver. When it is ON , it receives and transmits radio frequency energy. RF interference can occur if it is used close to TV set, radio, computer or other electric equipment. In locations with potencially explosive atmospheres, obey all posted signs to turn off wireless devices such as your phone or other cellular terminals. Areas with potencially exposive atmospheres including fuelling areas, below decks on boats, fuel or chemical transfer or storage facilities, areas where the air contains chemicals or particles such as grain, dust or metal powders.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 12 / 85 2 Product Concept 2.1. General Description M35 is a Quad-band GSM/GPRS engine that works at frequencies of GSM850MHz, EGSM900, DCS1800 and PCS1900MHz. The M35 features GPRS multi-slot class 12 and supports the GPRS coding schemes CS-1, CS-2, CS-3 and CS-4. For more details about GPRS multi-slot classes and coding schemes, please refer to the Appendix B & C. With a tiny profile of 19.9mm × 23.6mm × 2.65mm, the module can meet almost all the requirements for M2M applications, including Vehicles and Personal Tracking, Security System, Wireless POS, Industrial PDA, Smart Metering, and Remote Maintenance & Control, etc. M35 is an SMD type module with LCC package, which can be easily embedded into applications. It provides abundant hardware interfaces like Audio and UART Interface. Designed with power saving technique, the current consumption of M35 is as low as 1.3 mA in SLEEP mode when DRX is 5. M35 is integrated with Internet service protocols, such as TCP/UDP, FTP and PPP. Extended AT commands have been developed for you to use these Internet service protocols easily. The module fully complies with the RoHS directive of the European Union. 2.2. Directives and Standards The M35 module is designed to comply with the FCC statements. FCC ID: XMR201512M35 The Host system using M35, should have label indicated FCC ID: XMR201512M35. 2.2.1. FCC Radiation Exposure Statement This equipment complies with FCC radiation exposure limits set forth for an uncontrolled environment. This equipment should be installed and operated with minimum distance 20cm between the radiator and your body as well as kept minimum 20cm from radio antenna depending on the Mobile status of this
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 13 / 85 module usage. This module should NOT be installed and operating simultaneously with other radio. The manual of the host system, which uses M35 must include RF exposure warning statement to advice user should keep minimum 20cm from the radio antenna of M35 module depending on the Mobile status. Note: If a portable device (such as PDA) uses M35 module, the device needs to do permissive change and SAR testing. The following list of antenna is indicating the maximum permissible antenna gain. Part Number Frequency Range (MHz) Peak Gain (XZ-V) Average Gain (XZ-V) VSWR Impedance 3R007A GSM850: TX 824-849MHz RX 869-894MHz PCS1900： TX 1850-1910MHz RX 1930-1990MHz 1 dBi typ. 1 dBi typ. 3 max 50Ω Antenna gain including cable loss must not exceed 4.95 dBi of GSM 850 and 2.5 dBi of PCS 1900 for the purpose of satisfying the requirements of 2.1043 and 2.1091. The antenna(s) used for this transmitter must be installed to provide a separation distance of at least 20cm from all persons and must not be co-located or operated in conjunction with any antenna or transmitter not described under this FCC ID. The final product operating with this transmitter must include operating instructions and antenna installation instructions, for end-users and installers to satisfy RF exposure compliance requirements. Compliance of this device in all final product configurations is the responsibility of the Grantee. Installation of this device into specific final products may require the submission of a Class II permissive change application containing data pertinent to RF Exposure, spurious emissions, ERP/EIRP, and host/module authentication, or new application if appropriate. Installation of this device into specific final products may require the submission of a Class II permissive change application containing data pertinent to RF Exposure, spurious emissions, ERP/EIRP, and host/module authentication, or new application if appropriate. 2.3. Key Features The following table describes the detailed features of M35 module. Table 1: Module Key Features Feature Implementation
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 14 / 85 Power Supply Single supply voltage: 3.3V ~ 4.6V Typical supply voltage: 4V Power Saving Typical power consumption in SLEEP mode: 1.3 mA @DRX=5 1.2 mA @DRX=9 Frequency Bands  Quad-band: GSM850, EGSM900, DCS1800, PCS1900  The module can search these frequency bands automatically  The frequency bands can be set by AT command  Compliant to GSM Phase 2/2+ GSM Class Small MS Transmitting Power  Class 4 (2W) at GSM850 and EGSM900  Class 1 (1W) at DCS1800 and PCS1900 GPRS Connectivity  GPRS multi-slot class 10 (default)  GPRS multi-slot class 1~10 (configurable)  GPRS mobile station class B DATA GPRS  GPRS data downlink transfer: max. 85.6kbps  GPRS data uplink transfer: max. 85.6kbps  Coding scheme: CS-1, CS-2, CS-3 and CS-4  Support the protocols PAP (Password Authentication Protocol) usually used for PPP connections  Internet service protocols : TCP/UDP/FTP/PPP/HTTP/NTP/MMS/SMTP/PING  Support Packet Broadcast Control Channel (PBCCH)  Support Unstructured Supplementary Service Data (USSD) Temperature Range  Normal operation: -35°C ~ +80°C  Restricted operation: -40°C ~ -35°C and +80°C ~ +85°C 1)  Storage temperature: -45°C ~ +90°C SMS  Text and PDU mode  SMS storage: SIM card SIM Interfaces Support SIM card: 1.8V, 3V Audio Features Speech codec modes:  Half Rate (ETS 06.20)  Full Rate (ETS 06.10)  Enhanced Full Rate (ETS 06.50/06.60/06.80)  Adaptive Multi-Rate (AMR)  Echo Suppression  Noise Reduction  Embedded one amplifier of class AB with maximum driving power up to 870mW UART Interfaces UART Port:  Seven lines on UART port interface  Used for AT command, GPRS data  Multiplexing function
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 15 / 85 1) When the module works within this temperature range, the deviations from the GSM specification may occur. For example, the frequency error or the phase error will be increased. Table 2: Coding Schemes and Maximum Net Data Rates over Air Interface 2.4. Functional Diagram The following figure shows a block diagram of M35 and illustrates the major functional parts.  Radio frequency part  Power management  The Peripheral interface —Power supply  Support autobauding from 4800bps to 115200bps Debug Port:  Two lines on debug port interface DBG_TXD and DBG_RXD  Debug Port can used for firmware debugging Phonebook Management Support phonebook types: SM, ME, FD, ON, MT SIM Application Toolkit Support SAT class 3, GSM 11.14 Release 99 Real Time Clock Supported Physical Characteristics Size: 19.9±0.15 × 23.6±0.15 × 2.65±0.2mm Weight: Approx. 2.5g Firmware Upgrade Firmware upgrade via UART Port Antenna Interface Connected to antenna pad with 50 Ohm impedance control Coding Scheme 1 Timeslot 2 Timeslot 4 Timeslot CS-1 9.05kbps 18.1kbps 36.2kbps CS-2 13.4kbps 26.8kbps 53.6kbps CS-3 15.6kbps 31.2kbps 62.4kbps CS-4 21.4kbps 42.8kbps 85.6kbps NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 16 / 85 —Turn-on/off interface —UART interfaces —RTC interface —Audio interfaces —PCM interface —SIM interfaces —RF interface BB&RFRF PAM26MHzRF TransceiverRTCGPIO&PWMSerial InterfaceSIM InterfaceRF_ANTVBATPWRKEYEMERG_OFFVRTCStatus&NetlightUARTSIM Interfaces ResetESDPMUMEMORY Audio AudioPCM Interface PCM Figure 1: Module Functional Diagram 2.5. Evaluation Board In order to help you to develop applications with M35, Quectel supplies an evaluation board (EVB), RS-232 to USB cable, power adapter, earphone, antenna and other peripherals to control or test the module. For details, please refer to the document [4].
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 17 / 85 3 Application Interface The module adopts LCC package and has 42 pins. The following chapters provide detailed descriptions about these pins below:  Power supply  Power on/down  RTC  Serial interfaces  Audio interfaces  PCM interface  SIM interfaces  RI  NETLIGHT  STATUS
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 18 / 85 3.1. Pin of Module 3.1.1. Pin Assignment VBAT RFOtherGND UART AudioPowerSIM SIM_GND31 SIM1_CLK30 SIM1_DATA29 SIM1_RST28 SIM1_VDD27PCM_OUT41PCM_IN42SIM2_VDD18SIM2_CLK17SIM2_DATA16 19VDD_EXTPWRKEY 10EMERG_OFF 11STATUS/ PCM_SYNC12NETLIGHT13Top view37GND39RF_ANT34VBAT1AGND32VRTC38GND40GND36GND35GND33VBAT25 DCD/SIM2_RST24 RTS23 CTS22 TXD21 RXD26 RI/PCM_CLK2MIC2P3MIC2N4MIC1P5MIC1N6SPK1N7SPK1P8LOUDSPKN9LOUDSPKP14DBG_RXD15DBG_TXD20DTR/SIM1_PRESENCEPCM Figure 2: Pin Assignment
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 19 / 85 3.1.2. Pin Description Table 3: Pin Description Power Supply PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT VBAT 33, 34 I Main power supply of module: VBAT=3.3V~4.6V Vmax=4.6V Vmin=3.3V Vnorm=4.0V Make sure that supply sufficient current in a transmitting burst typically rises to 1.6A. VRTC 32 I/O Power supply for RTC when VBAT is not supplied for the system. Charging for backup battery or golden capacitor when the VBAT is applied. VImax=3.3V VImin=1.5V VInorm=2.8V VOmax=3V VOmin=2V VOnorm=2.8V Iout(max)=2mA Iin≈10uA If unused, keep this pin open. VDD_ EXT 19 O Supply 2.8V voltage for external circuit. Vmax=2.9V Vmin=2.7V Vnorm=2.8V Imax=20mA 1. If unused, keep this pin open. 2. Recommend to add a 2.2~4.7uF bypass capacitor, when using this pin for power supply. GND 35,36,37,38, 40 Ground Turn on/off PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT PWRKEY 10 I Power on/off key. PWRKEY should be pulled down for a moment to turn on or turn off the system. VILmax= 0.1×VBAT VIHmin= 0.6×VBAT VImax=3.1V Emergency Shutdown
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 20 / 85 PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT EMERG_ OFF 11 I Emergency off. Pulled down for at least 40ms, which will turn off the module in case of emergency. Use it only when shutdown via PWRKEY or AT command cannot be achieved. VILmax=0.45V VIHmin=1.35V Vopenmax=1.8V Open drain/collector driver required in cellular device application. If unused, keep this pin open. Module Indicator PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT STATUS 12 O Indicate module’s operating status. Output high level when module turns on, while output low level when module turns off. VOHmin= 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT If unused, keep these pins open. Audio Interfaces PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT MIC1P MIC1N 4,5 I Channel 1 positive and negative voice input Refer to Section 3.8 If unused, keep these pins open. MIC2P MIC2N 2,3 I Channel 2 positive and negative voice input SPK1P SPK1N 7,6 O Channel 1 positive and negative voice output 1. If unused, keep these pins open. 2. Support both voice and ringtone output. AGND 1 Analog ground. Separate ground connection for external audio circuits. If unused, keep this pin open. LOUD SPKN LOUD SPKP 8,9 O Channel 3 positive and negative voice output 1. If unused, keep these pins open. 2. Integrate a Class- AB amplifier internally. 3. Support both voice and ringtone output.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 21 / 85 Network Status Indicator PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT NETLIGHT 13 O Network status indication VOHmin= 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT If unused, keep this pin open. UART Port PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT DTR 20 I Data terminal ready VILmin=0V VILmax= 0.25×VDD_EXT VIHmin= 0.75×VDD_EXT VIHmax= VDD_EXT+0.2 VOHmin= 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT If only use TXD, RXD and GND to communicate, recommended connecting RTS to GND via 0R resistor and keeping other pins open. RXD 21 I Receive data TXD 22 O Transmit data RTS 24 I Request to send CTS 23 O Clear to send RI 26 O Ring indication DCD 25 O Data carrier detection Debug Port PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT DBG_ TXD 15 O Transmit data Same as above If unused, keep these pins open. DBG_ RXD 14 I Receive data SIM Interfaces PIN NAME PIN NO I/O DESCRIPTION DC CHARACTERISTICS COMMENT SIM1_ VDD 27 O Power supply for SIM1 card The voltage can be selected by software automatically. Either 1.8V or 3V. All signals of SIM interfaces should be protected against ESD with a TVS diode array. Maximum trace length is 200mm from the module SIM1_ CLK 30 O SIM1 clock VOLmax= 0.15×SIM1_VDD VOHmin= 0.85×SIM1_VDD
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 22 / 85 SIM1_ DATA 29 I/O SIM1 data VOLmax= 0.15×SIM1_VDD VOHmin= 0.85×SIM1_VDD pad to SIM card holder. SIM1_ RST 28 O SIM1 reset VOLmax= 0.15×SIM1_VDD VOHmin= 0.85×SIM1_VDD SIM1_ PRESENCE 20 I SIM1 card detection. VILmin=0V VILmax= 0.25×VDD_EXT VIHmin= 0.75×VDD_EXT VIHmax= VDD_EXT+0.2 SIM_ GND 31 SIM ground SIM2_ VDD 18 O Power supply for SIM2 card The voltage can be selected by software automatically. Either 1.8V or 3V. SIM2_ CLK 17 O SIM2 clock VOLmax= 0.15×SIM2_VDD VOHmin= 0.85×SIM2_VDD SIM2_ DATA 16 I/O SIM2 data VOLmax= 0.15×SIM2_VDD VOHmin= 0.85×SIM2_VDD SIM2_ RST 25 O SIM2 reset VOLmax= 0.15×SIM2_VDD VOHmin= 0.85×SIM2_VDD RF Interface PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT RF_ANT 39 I/O RF antenna pad Impedance of 50Ω PCM Interface PIN NAME PIN NO. I/O DESCRIPTION DC CHARACTERISTICS COMMENT
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 23 / 85 Table 4: Multiplexed Functions 1) The alternate function can be configured through AT command. For details, please refer to the section 3.9 and section 3.10. 3.2. Operating Modes The table below briefly summarizes the various operating modes in the following chapters. Table 5: Overview of Operating Modes PCM_ SYNC 12 O PCM sync signal VILmin=-0.3V VILmax= 0.25×VDD_EXT VIHmin= 0.75×VDD_EXT VIHmax= VDD_EXT+0.2 VOHmin= 0.85×VDD_EXT VOLmax= 0.15×VDD_EXT The default function is STATUS after startup. PCM_ CLK 26 O PCM clock signal The default function is RI after startup. PCM_ OUT 41 O PCM serial data output If unused, keep these pins open. PCM_IN 42 I PCM serial data input PIN NAME PIN NO. Function After Reset Alternate Function1) STATUS/PCM_SYNC 12 STATUS PCM_SYNC DTR/SIM1_PRESENCE 20 DTR SIM1_PRESENCE DCD/SIM2_RST 25 DCD SIM2_RST RI/PCM_CLK 26 RI PCM_CLK Mode Function Normal Operation GSM/GPRS Sleep After enabling sleep mode by ―AT+QSCLK=1‖, the module will automatically go into Sleep Mode if DTR is set to high level and there is no interrupt (such as GPIO interrupt or data on UART port). In this case, the current consumption of module will be reduced to the minimal level. During NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 24 / 85 1) Use the EMERG_OFF pin only when failing to turn off the module by the command ―AT+QPOWD=1‖ and the PWRKEY pin. For more details, please refer to the Section 3.4.2.4. Sleep Mode, the module can still receive paging message and SMS from the system normally. GSM IDLE Software is active. The module has registered to the GSM network, and the module is ready to send and receive GSM data. GSM TALK GSM connection is ongoing. In this mode, the power consumption is decided by the configuration of Power Control Level (PCL), dynamic DTX control and the working RF band. GPRS IDLE The module is not registered to GPRS network. The module is not reachable through GPRS channel. GPRS STANDBY The module is registered to GPRS network, but no GPRS PDP context is active. The SGSN knows the Routing Area where the module is located at. GPRS READY The PDP context is active, but no data transfer is ongoing. The module is ready to receive or send GPRS data. The SGSN knows the cell where the module is located at. GPRS DATA There is GPRS data in transfer. In this mode, power consumption is decided by the PCL, working RF band and GPRS multi-slot configuration. POWER DOWN Normal shutdown by sending the ―AT+QPOWD=1‖ command, using the PWRKEY or the EMERG_OFF1) pin. The power management ASIC disconnects the power supply from the base band part of the module, and only the power supply for the RTC is remained. Software is not active. The UART interfaces are not accessible. Operating voltage (connected to VBAT) remains applied. Minimum Functionality Mode (without Removing Power Supply) ―AT+CFUN‖ command can set the module to a minimum functionality mode without removing the power supply. In this case, the RF part of the module will not work or the SIM card will not be accessible, or both RF part and SIM card will be disabled, but the UART port is still accessible. The power consumption in this case is very low. NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 25 / 85 3.3. Power Supply 3.3.1. Power Features of Module The power supply is one of the key issues in designing GSM terminals. Because of the 577us radio burst in GSM every 4.615ms, power supply must be able to deliver high current peaks in a burst period. During these peaks, drops on the supply voltage must not exceed minimum working voltage of module. For M35 module, the max current consumption could reach to 1.6A during a transmit burst. It will cause a large voltage drop on the VBAT. In order to ensure stable operation of the module, it is recommended that the max voltage drop during the transmit burst does not exceed 400mV. Vdrop4.615ms577usIBATVBATBurst:1.6A Figure 3: Voltage Ripple during Transmitting 3.3.2. Decrease Supply Voltage Drop The power supply range of the module is 3.3V to 4.6V. Make sure that the input voltage will never drop below 3.3V even in a transmitting burst. If the power voltage drops below 3.3V, the module could turn off automatically. For better power performance, it is recommended to place a 100uF tantalum capacitor with low ESR (ESR=0.7Ω) and ceramic capacitor 100nF, 33pF and 10pF near the VBAT pin. The reference circuit is illustrated in Figure 4. The VBAT route should be wide enough to ensure that there is not too much voltage drop during transmit burst. The width of trace should be no less than 2mm and the principle of the VBAT route is the longer route, the wider trace.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 26 / 85 VBATC2C1+C3 C4GND100uF 100nF 10pF060333pF0603 Figure 4: Reference Circuit for the VBAT Input 3.3.3. Reference Design for Power Supply The power design for the module is very important, since the performance of power supply for the module largely depends on the power source. The power supply is capable of providing the sufficient current up to 2A at least. If the voltage drop between the input and output is not too high, it is suggested to use a LDO as module’s power supply. If there is a big voltage difference between the input source and the desired output (VBAT), a switcher power converter is recommended to be used as a power supply. Figure 5 shows a reference design for +5V input power source. The designed output for the power supply is 4.0V and the maximum load current is 3A. In addition, in order to get a stable output voltage, a zener diode is placed close to the pins of VBAT. As to the zener diode, it is suggested to use a zener diode of which reverse zener voltage is 5.1V and dissipation power is more than 1 Watt. DC_INC1 C2MIC29302WU U1IN OUTENGNDADJ2 4135VBAT 100nFC3470uFC4100nFR2D1124K56KR3470uF 5.1VR4470RMCU_POWER_ON/OFF47K4.7KR5R6R151K Figure 5: Reference Circuit for Power Supply
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 27 / 85 It is suggested to control the module’s main power supply (VBAT) via LDO enable pin to restart the module when the module has become abnormal. Power switch circuit like P-channel MOSFET switch circuit can also be used to control VBAT. 3.3.4. Monitor Power Supply The command ―AT+CBC‖ can be used to monitor the supply voltage of the module. The unit of the displayed voltage is mV. For details, please refer to the document [1]. 3.4. Power On and Down Scenarios 3.4.1. Power On The module can be turned on by driving the pin PWRKEY to a low level voltage. An open collector driver circuit is suggested to control the PWRKEY. A simple reference circuit is illustrated as below. Turn on pulsePWRKEY4.7K47K Figure 6: Turn On the Module with an Open-collector Driver 1. M35 module is set to autobauding mode (AT+IPR=0) by default. In the autobauding mode, URC ―RDY‖ is not reported to the host controller after module is powered on. When the module is powered on after a delay of 4 or 5 seconds, it can receive AT command. Host controller should first send an ―AT‖ or ―at‖ string in order that the module can detect baud rate of host controller, it should continue to send the next ‖AT‖ string until receiving ―OK‖ string from the module. Then enter ―AT+IPR=x;&W‖ to set a fixed baud rate for the module and save the configuration to flash memory of the module. After NOTE NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 28 / 85 these configurations, the URC ―RDY‖ would be received from the UART Port of the module every time when the module is powered on. For more details, refer to the section ―AT+IPR‖ in document [1]. 2. AT command response indicates module is turned on successfully, or else the module fails to be turned on. The other way to control the PWRKEY is through a button directly. A TVS component is indispensable to be placed nearby the button for ESD protection. For the best performance, the TVS component must be placed nearby the button. When pressing the key, electrostatic strike may generate from finger. A reference circuit is shown in the following figure. PWRKEYS1Close to S1TVS Figure 7: Turn On the Module with a Button The turn-on timing is illustrated as the following figure. VDD_EXT(OUTPUT)VIL<0.1*VBATVIH > 0.6*VBATVBATPWRKEY(INPUT)EMERG_OFF(INPUT)54msSTATUS(OUTPUT)800ms>1sOFF BOOTINGMODULE STATUS RUNNINGT1 Figure 8: Turn-on Timing
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 29 / 85 1. Make sure that VBAT is stable before pulling down PWRKEY pin. The time of T1 is recommended as 100ms. 2. EMERG_OFF should be floated when it is unused. 3. For more details about the application of STATUS pin, please refer to the Chapter 3.13. 3.4.2. Power Down The following procedures can be used to turn off the module:  Normal power down procedure: Turn off module using the PWRKEY pin.  Normal power down procedure: Turn off module using command ―AT+QPOWD=1‖.  Over-voltage or under-voltage automatic shutdown: Take effect when over-voltage or under-voltage is detected.  Emergent power down procedure: Turn off module using the EMERG_OFF pin. 3.4.2.1. Power Down Module Using the PWRKEY Pin It is a safe way to turn off the module by driving the PWRKEY to a low level voltage for a certain time. The power down scenario is illustrated in Figure 9. VBATPWRKEY(INPUT)STATUS(OUTPUT)EMERG_OFF(INPUT)Logout net about 2s to 12s0.7s<Pulldown<1s Figure 9: Turn-off Timing The power down procedure causes the module to log off from the network and allows the firmware to save important data before completely disconnecting the power supply. NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 30 / 85 Before the completion of the power down procedure, the module sends out the result code shown below: NORMAL POWER DOWN 1. This result code does not appear when autobauding is active and DTE and DCE are not correctly synchronized after start-up. The module is recommended to set a fixed baud rate. 2. As logout network time is related to the local mobile network, it is recommended to delay about 12 seconds before disconnecting the power supply or restarting the module. 3. For more details about the application of STATUS pin, please refer to the Chapter 3.13. After that moment, no further AT commands can be executed. Then the module enters the power down mode, only the RTC is still active. 3.4.2.2. Power Down Module Using AT Command It is also a safe way to turn off the module via AT command ―AT+QPOWD=1‖. This command will let the module to log off from the network and allow the firmware to save important data before completely disconnecting the power supply. Before the completion of the power down procedure, the module sends the result code as shown below: NORMAL POWER DOWN After that moment, no further AT commands can be executed. And then the module enters the power down mode, only the RTC is still active. Please refer to the document [1] for details about the AT command ―AT+QPOWD‖. 3.4.2.3. Over-voltage or Under-voltage Automatic Shutdown The module will constantly monitor the voltage applied on the VBAT, if the voltage is ≤3.5V, the following URC will be presented: UNDER_VOLTAGE WARNING If the voltage is ≥4.5V, the following URC will be presented: OVER_VOLTAGE WARNING NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 31 / 85 The normal input voltage range is from 3.3V to 4.6V. If the voltage is >4.6V or <3.3V, the module would automatically shut down itself. If the voltage is <3.3V, the following URC will be presented: UNDER_VOLTAGE POWER DOWN If the voltage is >4.6V, the following URC will be presented: OVER_VOLTAGE POWER DOWN After that moment, no further AT commands can be executed. The module logs off from network and enters power down mode, and only RTC is still active. 1. These result codes do not appear when autobauding is active and DTE and DCE are not correctly synchronized after start-up. The module is recommended to set to a fixed baud rate. 2. Over-voltage warning and shutdown function is disabled by default. 3.4.2.4. Emergency Shutdown Using EMERG_OFF Pin The module can be shut down by driving the pin EMERG_OFF to a low level voltage over 40ms and then releasing it. The EMERG_OFF line can be driven by an open-drain/collector driver or a button. The circuit is illustrated as the following figures. Emergency shutdown pulseEMERG_OFF4.7K47K Figure 10: An Open-collector Driver for EMERG_OFF NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 32 / 85 S2EMERG_OFFTVS2Close to S2 Figure 11: Reference Circuit for EMERG_OFF by Using Button Be cautious to use the pin EMERG_OFF. It should only be used under emergent situation. For instance, if the module is unresponsive or abnormal, the pin EMERG_OFF could be used to shut down the system. Although turning off the module by EMERG_OFF is fully tested and nothing wrong detected, this operation is still a big risk as it could cause destroying of the code or data area of the flash memory in the module. Therefore, it is recommended that PWRKEY or AT command should always be the preferential way to turn off the system. 3.4.3. Restart The module can be restarted by driving the PWRKEY to a low level voltage for a certain time, which is similar to the way of turning on module. In order to make the internal LDOs discharge completely after turning off the module, it is recommended to delay about 500ms before restarting the module. The restart timing is illustrated as the following figure. PWRKEY(INPUT)STATUS(OUTPUT)Delay >500msTurn off RestartPull down the PWRKEY to turn on the module Figure 12: Timing of Restarting System
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 33 / 85 The module can also be restarted by the PWRKEY after emergency shutdown. EMERG_OFF(INPUT)STATUS(OUTPUT)Delay >500msPulldown >40msPWRKEY(INPUT) Figure 13: Timing of Restarting System after Emergency Shutdown For more details about the application of STATUS pin, please refer to the Chapter 3.13. 3.5. Power Saving Based on system requirements, there are several actions to drive the module to enter low current consumption status. For example, ―AT+CFUN‖ can be used to set module into minimum functionality mode and DTR hardware interface signal can be used to lead system to SLEEP mode. 3.5.1. Minimum Functionality Mode Minimum functionality mode reduces the functionality of the module to a minimum level. The consumption of the current can be minimized when the slow clocking mode is activated at the same time. The mode is set with the ―AT+CFUN‖ command which provides the choice of the functionality levels <fun>=0, 1, 4.  0: minimum functionality.  1: full functionality (default).  4: disable both transmitting and receiving of RF part. NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 34 / 85 If the module is set to minimum functionality by ―AT+CFUN=0‖, the RF function and SIM card function would be disabled. In this case, the UART port is still accessible, but all AT commands related with RF function or SIM card function will be not available. If the module has been set by the command with ―AT+CFUN=4‖, the RF function will be disabled, but the UART port is still active. In this case, all AT commands related with RF function will be not available. After the module is set by ―AT+CFUN=0‖ or ―AT+CFUN=4‖, it can return to full functionality by ―AT+CFUN=1‖. For detailed information about ―AT+CFUN‖, please refer to the document [1]. 3.5.2. SLEEP Mode The SLEEP mode is disabled by default. You can enable it by ―AT+QSCLK=1‖. On the other hand, the default setting is ―AT+QSCLK=0‖ and in this mode, the module cannot enter SLEEP mode. When the module is set by the command with ―AT+QSCLK=1‖, you can control the module to enter or exit from the SLEEP mode through pin DTR. When DTR is set to high level, and there is no on-air or hardware interrupt such as GPIO interrupt or data on UART port, the module will enter SLEEP mode automatically. In this mode, the module can still receive voice, SMS or GPRS paging from network, but the UART port does not work. 3.5.3. Wake Up Module from SLEEP Mode When the module is in the SLEEP mode, the following methods can wake up the module.  If the DTR Pin is set low, it would wake up the module from the SLEEP mode. The UART port will be active within 20ms after DTR is changed to low level.  Receiving a voice or data call from network will wake up the module.  Receiving an SMS from network will wake up the module. DTR pin should be held at low level during communication between the module and DTE. NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 35 / 85 3.5.4. Summary of State Transition Table 6: Summary of State Transition 3.6. RTC Backup The RTC (Real Time Clock) function is supported. The RTC is designed to work with an internal power supply. There are three kinds of designs for RTC backup power:  Use VBAT as the RTC power source. When the module is turned off and the main power supply (VBAT) is remained, the real time clock is still active as the RTC core is supplied by VBAT. In this case, the VRTC pin can be kept floating.  Use VRTC as the RTC power source. If the main power supply (VBAT) is removed after the module is turned off, a backup supply such as a coin-cell battery (rechargeable or non-chargeable) or a super-cap can be used to supply the VRTC pin to keep the real time clock active.  Use VBAT and VRTC as the RTC power source. As only powering the VRTC pin to keep the RTC will lead an error about 5 minutes a day, it is recommended to power VBAT and VRTC pin at the same time when RTC function is needed. The recommended supply for RTC core circuits are shown as below. Current Mode Next Mode Power Down Normal Mode Sleep Mode Power Down Use PWRKEY Normal Mode AT+QPOWD, use PWRKEY pin, or use EMERG_OFF pin Use AT command ―AT+QSCLK=1‖ and pull DTR up SLEEP Mode Use PWRKEY pin, or use EMERG_OFF pin Pull DTR down or incoming voice call or SMS or data call
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 36 / 85 Non-chargeable Backup BatteryModuleRTC CoreVBATPower SupplyLDO/DCDC LDOVRTC 1.5K Figure 14: VRTC Is Supplied by a Non-chargeable Battery Rechargeable Backup BatteryModuleRTC CoreVBATPower SupplyLDO/DCDC LDOVRTC 1.5K Figure 15: VRTC Is Supplied by a Rechargeable Battery ModuleRTC CoreVBATPower SupplyLDO/DCDC LDOVRTC 1.5KLarge Capacitance Capacitor Figure 16: VRTC Is Supplied by a Capacitor
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 37 / 85 For the choice of a rechargeable or non-chargeable coin-cell battery, please visit http://www.sii.co.jp/en/. If the module is only powered by VRTC , the real time will have an error about 5 minutes a day. If you want to keep an accurate real time, please use VBAT to supply the RTC core. 3.7. Serial Interfaces The module provides two serial ports: UART Port and Debug Port. The module is designed as a DCE (Data Communication Equipment), following the traditional DCE-DTE (Data Terminal Equipment) connection. Autobauding function supports baud rate from 4800bps to 115200bps. The UART Port:  TXD: Send data to RXD of DTE.  RXD: Receive data from TXD of DTE.  RTS: Request to send.  CTS: Clear to send.  DTR: DTE is ready and inform DCE (this pin can wake up the module).  RI: Ring indicator (when the call, SMS, data of the module are coming, the module will output signal to inform DTE).  DCD: Data carrier detection (the validity of this pin demonstrates the communication link is set up). Hardware flow control is disabled by default. When hardware flow control is required, RTS and CTS should be connected to the host. AT command ―AT+IFC=2,2‖ is used to enable hardware flow control. AT command ―AT+IFC=0,0‖ is used to disable the hardware flow control. For more details, please refer to the document [1]. The Debug Port:  DBG_TXD: Send data to the COM port of computer.  DBG_RXD: Receive data from the COM port of computer. NOTE NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 38 / 85 The logic levels are described in the following table. Table 7: Logic Levels of the UART Interfaces Table 8: Pin Definition of the UART Interfaces 1. 1) DTR pin can be used as SIM1_PRESENCE pin via ―AT+QSIMDET‖ command. 2. 2) When using the SIM2 interface, DCD pin can be used as SIM2_RST pin. For more details, please refer to the document [6]. 3. 3) When using the PCM interface, RI pin can be used as PCM_CLK. Parameter Min. Max. Unit VIL 0 0.25×VDD_EXT V VIH 0.75×VDD_EXT VDD_EXT +0.2 V VOL 0 0.15×VDD_EXT V VOH 0.85×VDD_EXT VDD_EXT V Interfaces Pin No. Pin Name Description Alternate Function Debug Port 14 DBG_RXD Receive data 15 DBG_TXD Transmit data UART Port 20 1)DTR Data terminal ready SIM1_PRESENCE 21 RXD Receive data 22 TXD Transmit data 23 CTS Clear to send 24 RTS Request to send 25 2)DCD Data carrier detection SIM2_RST 26 3)RI Ring indication PCM_CLK NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 39 / 85 3.7.1. UART Port 3.7.1.1. The Features of UART Port  Seven lines on UART interface.  Contain data lines TXD and RXD, hardware flow control lines RTS and CTS, other control lines DTR, DCD and RI.  Used for AT command, GPRS data, etc. Multiplexing function is supported on the UART Port. So far only the basic mode of multiplexing is available.  Support the communication baud rates as the following: 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600 and 115200.  The default setting is autobauding mode. Support the following baud rates for Autobauding function: 4800, 9600, 19200, 38400, 57600 and 115200.  The module disables hardware flow control by default. AT command ―AT+IFC=2,2‖ is used to enable hardware flow control. After setting a fixed baud rate or autobauding, please send ―AT‖ string at that rate. The UART port is ready when it responds ―OK‖. Autobauding allows the module to detect the baud rate by receiving the string ―AT‖ or ―at‖ from the host or PC automatically, which gives module flexibility without considering which baud rate is used by the host controller. Autobauding is enabled by default. To take advantage of the autobauding mode, special attention should be paid according to the following requirements: 1. Synchronization between DTE and DCE: When DCE (the module) powers on with the autobauding enabled, it is recommended to wait 4 to 5 seconds before sending the first AT character. After receiving the ―OK‖ response, DTE and DCE are correctly synchronized. If the host controller needs URC in the mode of autobauding, it must be synchronized firstly. Otherwise the URC will be discarded. 2. Restrictions on autobauding operation:  The UART port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting).  Only the strings ―AT‖ or ―at‖ can be detected (neither ―At‖ nor ―aT‖).  The Unsolicited Result Codes like ―RDY‖, ―+CFUN: 1‖ and ―+CPIN: READY‖ will not be indicated when the module is turned on with autobauding enabled and not be synchronized.  Any other Unsolicited Result Codes will be sent at the previous baud rate before the module detects the new baud rate by receiving the first ―AT‖ or ―at‖ string. The DTE may receive unknown characters after switching to new baud rate.  It is not recommended to switch to autobauding from a fixed baud rate.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 40 / 85  If autobauding is active it is not recommended to switch to multiplex mode. To assure reliable communication and avoid any problems caused by undetermined baud rate between DCE and DTE, it is strongly recommended to configure a fixed baud rate and save it instead of using autobauding after start-up. For more details, please refer to the Section ―AT+IPR‖ in document [1]. 3.7.1.2. The Connection of UART The connection between module and host using UART Port is very flexible. Three connection styles are illustrated as below. Reference design for Full-Function UART connection is shown as below when it is applied in modulation-demodulation. TXDRXDRTSCTSDTRDCDRITXDRXDRTSCTSDTRDCDRINGModule (DCE)Serial portUART portGND GNDPC (DTE) Figure 17: Reference Design for Full-Function UART NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 41 / 85 Three-line connection is shown as below. TXDRXDGNDUART portRTS 0RTXDRXDGNDModule (DCE) Host (DTE)Controller Figure 18: Reference Design for UART Port UART Port with hardware flow control is shown as below. This connection will enhance the reliability of the mass data communication. RTSCTSRTSCTSGNDRXDTXD TXDRXDGNDModule (DCE) Host (DTE) Controller Figure 19: Reference Design for UART Port with Hardware Flow Control
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 42 / 85 3.7.1.3. Firmware Upgrade The TXD, RXD can be used to upgrade firmware. The PWRKEY pin must be pulled down before firmware upgrade. The reference circuit is shown as below: IO Connector TXDRXDGNDPWRKEY Module (DCE) UART portTXDRXDGNDPWRKEY Figure 20: Reference Design for Firmware Upgrade The firmware of module might need to be upgraded due to certain reasons. It is recommended to reserve these pins in the host board for firmware upgrade. 3.7.2. Debug Port As to Debug Port, there are two working modes, Standard Mode and Advanced Mode, which can be switched through using AT command‖ AT+QEAUART‖. For more details, please refer to the document [7]. In Standard Mode, it can be used to execute software debug and it can also connect to a peripheral device. Furthermore, its default baud rate is 115200bps. In Advanced Mode, it can only be used to execute software debug, capture the system’s log with Cather Log tool and output the log. In this mode, its baud rate is 460800bps. NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 43 / 85 The reference design for Debug Port is shown as below. PeripheralTXDRXDGND Module DBG_TXDDBG_RXD GND Figure 21: Reference Design for Debug Port 3.7.3. UART Application The reference design of 3.3V level match is shown as below. If the host is a 3V system, please change the 5.6K resistor to 10K. Peripheral/TXD/RXD1KTXDRXDRTSCTSDTRRI/RTS/CTSGPIOEINTGPIO DCDModule1K1KVoltage level:3.3V5.6K5.6K5.6K1K1K1K1KGND GND Figure 22: Level Match Design for 3.3V System It is highly recommended to add the resistor divider circuit on the UART signal lines when the host’s level is 3V or 3.3V. For the higher voltage level system, a level shifter IC could be used between the host and the module. For more details about UART circuit design, please refer to document [8]. NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 44 / 85 The following circuit shows a reference design for the communication between module and PC. Since the electrical level of module is 2.8V, so a RS-232 level shifter must be used. Note that you should assure the IO voltage of level shifter which connects to module is 2.8V. TXDRXDRTSCTSDTRRIDCDModuleGNDC1+C1-C2+C2-V+VCCGNDV-3.3VT1INT2INT3INT4INR1INR2INR3INR1OUTR2OUTR3OUTT1OUTT2OUTT5OUTT3OUTT4OUTT5INGNDGND/R1OUT123456789GNDTo PC Serial PortGND1K1K1K1K1K5.6K5.6K1K1K5.6KRS-232 Level Shifter Figure 23: Sketch Map for RS-232 Interface Match Please visit vendor web site to select the suitable RS-232 level shifter IC, such as: http://www.exar.com/ and http://www.maximintegrated.com. 3.8. Audio Interfaces The module provides two analogy input channels and two analogy output channels. Table 9: Pin Definition of Audio Interface Interfaces Name Pin NO. Description AIN1/AOUT1 MIC1P 4 Channel 1 Microphone positive input MIC1N 5 Channel 1 Microphone negative input SPK1P 7 Channel 1 Audio positive output SPK1N 6 Channel 1 Audio negative output AIN2/AOUT2 AGND 1 Form a pseudo-differential pair with SPK2P
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 45 / 85 AIN1 and AIN2 can be used for input of microphone and line. An electret microphone is usually used. AIN1 and AIN2 are both differential input channels. AOUT1 is used for output of the receiver. This channel is typically used for a receiver built into a handset. AOUT1 channel is a differential channel. If it is used as a speaker, an amplifier should be employed. AOUT2 is used for loudspeaker output as it embedded an amplifier of class AB whose maximum drive power is 870mW. AOUT2 is a differential channel. AOUT2 also can be used for output of earphone, which can be used as a single-ended channel. LOUDSPKP and AGND can establish a pseudo differential mode. All of these two audio channels support voice and ringtone output, and so on, and can be switched by ―AT+QAUDCH‖ command. For more details, please refer to the document [1]. Use AT command ―AT+QAUDCH‖ to select audio channel:  0--AIN1/AOUT1, the default value is 0.  1--AIN2/AOUT2, this channel is always used for earphone.  2--AIN2/AOUT2, this channel is always used for loudspeaker. For each channel, you can use AT+QMIC to adjust the input gain level of microphone. You can also use ―AT+CLVL‖ to adjust the output gain level of receiver and speaker. ―AT+QSIDET‖ is used to set the side-tone gain level. For more details, please refer to the document [1]. Table 10: AOUT2 Output Characteristics MIC2P 2 Channel 2 Microphone positive input MIC2N 3 Channel 2 Microphone negative input LOUDSPKP 9 Channel 2 Audio positive output LOUDSPKN 8 Channel 2 Audio negative output Item Condition Min. Type Max. Unit RMS Power 8ohm load VBAT=4.2v THD+N=1% 870 mW 8ohm load VBAT=3.3v THD+N=1% 530 mW
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 46 / 85 3.8.1. Decrease TDD Noise and Other Noise The 33pF capacitor is applied for filtering out 900MHz RF interference when the module is transmitting at EGSM900MHz. Without placing this capacitor, TDD noise could be heard. Moreover, the 10pF capacitor here is for filtering out 1800MHz RF interference. However, the resonant frequency point of a capacitor largely depends on the material and production technique. Therefore, you would have to discuss with its capacitor vendor to choose the most suitable capacitor for filtering out GSM850MHz, EGSM900MHz, DCS1800MHz and PCS1900MHz separately. The severity degree of the RF interference in the voice channel during GSM transmitting period largely depends on the application design. In some cases, EGSM900 TDD noise is more severe; while in other cases, DCS1800 TDD noise is more obvious. Therefore, you can have a choice based on test results. Sometimes, even no RF filtering capacitor is required. The capacitor which is used for filtering out RF noise should be close to audio interface. Audio alignment should be as short as possible. In order to decrease radio or other signal interference, the position of RF antenna should be kept away from audio interface and audio alignment. Power alignment and audio alignment should not be parallel, and power alignment should be far away from audio alignment. The differential audio traces have to be placed according to the differential signal layout rule. 3.8.2. Microphone Interfaces Design AIN1 and AIN2 channels come with internal bias supply for external electret microphone. A reference circuit is shown in the following figure. MICPDifferential layoutModule 10pF 33pF33pF33pFGNDGNDElectret MicrophoneGNDGND10pF10pFGNDGNDESDESDClose to ModuleMICNGNDGNDClose to Microphone06030603060306030603060333pF060333pF060333pF060310pF060310pF060310pF0603 Figure 24: Reference Design for AIN1&AIN2
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 47 / 85 3.8.3. Receiver Interface Design SPK1PSPK1NDifferential layoutModule10pF 0603Close to speakerGNDESD 33pF 060333pF 0603GND10pF 0603 ESD 10pF 060333pF 0603 Figure 25: Reference Interface Design of AOUT1 3.8.4. Earphone Interface Design 1243Amphenol9001-8905-050MIC2P22uF68R33pFGND GNDAGNDClose to SocketAGND33pF10pFGND GNDGNDGNDAGNDModule4.7uFLOUDSPKPClose to ModuleGNDGND33pF33pFDifferential layout33pFMIC2N0R060306030603 060306030603060310pF ESDESD10pF10pF10pF060306030603 Figure 26: Earphone Interface Design
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 48 / 85 3.8.5. Loud Speaker Interface Design LOUDSPKN0R0RLOUDSPKP8 ohmModuleGND GNDGNDClose to Speaker10pF 33pF33pF10pF10pF 33pFGND GNDGNDDifferential layout060306030603060306030603 ESDESD Figure 27: Loud Speaker Interface Design 3.8.6. Audio Characteristics Table 11: Typical Electret Microphone Characteristics Table 12: Typical Speaker Characteristics Parameter Min. Typ. Max. Unit Working Voltage 1.2 1.5 2.0 V Working Current 200 500 uA External Microphone Load Resistance 2.2 k Ohm Parameter Min. Typ. Max. Unit AOUT1 Output Single-ended Load resistance 32 Ohm Ref level 0 2.4 Vpp Differential Load resistance 32 Ohm
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 49 / 85 3.9. PCM Interface Pulse-code modulation (PCM) is a converter that changes the consecutive analog audio signal to discrete digital signal. The whole procedure of Pulse-code modulation contains sampling, quantizing and encoding. M35 supports PCM interface. It is used for digital audio transmission between the module and the device. This interface is composed of PCM_CLK, PCM_SYNC, PCM_IN and PCM_OUT signal lines. The module disables PCM interface by default. AT command ―AT+QPCMON‖ is used to configure PCM interface. Table 13: Pin Definition of PCM Interface 1) When using the PCM interface, STATUS pin can be used as PCM_SYNC pin, RI pin can be used as PCM_CLK pin. Ref level 0 4.8 Vpp AOUT2 Output Differential Load resistance 8 Load Resistance Reference level 0 2×VBAT Vpp Single-ended Load resistance 8 Load Resistance Reference level 0 VBAT Vpp Pin NO. Pin Name Description 1)Alternate Function 12 PCM_SYNC PCM frame synchronization output STATUS 26 PCM_CLK PCM clock output RI 41 PCM_OUT PCM data output 42 PCM_IN PCM data input NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 50 / 85 3.9.1. Configuration M35 module supports 13-bit line code PCM format. The sample rate is 8 KHz, and the clock source is 256 KHz, and the module can only act as master mode. The PCM interface supports both long and short synchronization simultaneously. Furthermore, it only supports MSB first. For detailed information, please refer to the table below. Table 14: Configuration 3.9.2. Timing The sample rate of the PCM interface is 8 KHz and the clock source is 256 KHz, so every frame contains 32 bits data, since M35 supports 16 bits line code PCM format, the left 16 bits are invalid. The following diagram shows the timing of different combinations. The synchronization length in long synchronization format can be programmed by firmware from one bit to eight bits. In the Sign extension mode, the high three bits of 16 bits are sign extension, and in the Zero padding mode, the low three bits of 16 bits are zero padding. Under zero padding mode, you can configure the PCM input and output volume by executing ―AT+QPCMVOL‖ command. For more details, please refer to Chapter 3.9.4. PCM Line Interface Format Linear Data Length Linear: 13 bits Sample Rate 8KHz PCM Clock/Synchronization Source PCM master mode: clock and synchronization is generated by module PCM Synchronization Rate 8KHz PCM Clock Rate PCM master mode: 256 KHz (line) PCM Synchronization Format Long/short synchronization PCM Data Ordering MSB first Zero Padding Yes Sign Extension Yes
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 51 / 85 12 11 10 9 8 7 6 5 4 3 2 1 012 11 10 9 8 7 6 5 4 3 2 1 0PCM_CLKPCM_SYNCPCM_OUTPCM_INMSBMSBSign extensionSign extension Figure 28: Long Synchronization & Sign Extension Diagram 12 11 10 9 8 7 6 5 4 3 2 1 012 11 10 9 8 7 6 5 4 3 2 1 0PCM_CLKPCM_SYNCPCM_OUTPCM_INMSBMSBZero paddingZero padding Figure 29: Long Synchronization & Zero Padding Diagram PCM_CLKPCM_SYNCPCM_OUTPCM_IN12 11 10 9 8 7 6 5 4 3 2 1 012 11 10 9 8 7 6 5 4 3 2 1 0MSBMSBSign extensionSign extension Figure 30: Short Synchronization & Sign Extension Diagram
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 52 / 85 PCM_CLKPCM_SYNCPCM_OUTPCM_IN12 11 10 9 8 7 6 5 4 3 2 1 012 11 10 9 8 7 6 5 4 3 2 1 0MSBMSBZero paddingZero padding Figure 31: Short Synchronization & Zero Padding Diagram 3.9.3. Reference Design M35 can only work as a master, providing synchronization and clock source. The reference design is shown as below. PCM_SYNCPCM_CLKPCM_OUTPCM_INPCM_SYNCPCM_CLKPCM_INPCM_OUTModule(Master)Peripheral(Slave) Figure 32: Reference Design for PCM 3.9.4. AT Command There are two AT commands about the configuration of PCM, listed as below. ―AT+QPCMON‖ can configure operating mode of PCM. AT+QPCMON=mode, Sync_Type, Sync_Length, SignExtension, MSBFirst.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 53 / 85 Table 15: QPCMON Command Description ―AT+QPCMVOL‖ can configure the volume of input and output. AT+QPCMVOL=vol_pcm_in, vol_pcm_out Table 16: QPCMVOL Command Description 3.10. SIM Card Interfaces The module contains two smart interfaces to allow module access to the two SIM cards. These two SIM interfaces share the same ground and only SIM1 interface has card inserted detection. Only one SIM card can work at a time. For more details, please refer to the document [6]. 3.10.1. SIM Card Application The SIM interfaces supports the functionality of the GSM Phase 1 specification and also supports the functionality of the new GSM Phase 2+ specification for FAST 64 kbps SIM card, which is intended for use with a SIM application Tool-kit. Parameter Scope Description Mode 0~2 0: Close PCM 1: Open PCM 2: Open PCM when audio talk is set up Sync_Type 0~1 0: Short synchronization 1: Long synchronization Sync_Length 1~8 Programmed from one bit to eight bit SignExtension 0~1 0: Zero padding 1: Sign extension MSBFirst 0~1 0: MSB first 1: Not support Parameter Scope Description vol_pcm_in 0~32767 Set the input volume vol_pcm_out 0~32767 Set the output volume The voice may be distorted when this value exceeds 16384.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 54 / 85 The SIM interfaces are powered by an internal regulator in the module. Both 1.8V and 3.0V SIM Cards are supported. Table 17: Pin Definition of the SIM Interfaces 1) If several interfaces share the same I/O pin, to avoid conflict between these alternate functions, only one peripheral should be enabled at a time. Pin NO. Name Description 1)Alternate Function 27 SIM1_VDD Supply power for SIM1 card. Automatic detection of SIM1 card voltage. 3.0V±5% and 1.8V±5%. Maximum supply current is around 10mA. 30 SIM1_CLK SIM1 card clock. 29 SIM1_DATA SIM1 card data I/O. 28 SIM1_RST SIM1 card reset. 20 SIM1_PRESENCE SIM1 card detection. DTR 31 SIM_GND SIM card ground. 18 SIM2_VDD Supply power for SIM2 card. Automatic detection of SIM2 card voltage. 3.0V±5% and 1.8V±5%. Maximum supply current is around 10mA. 17 SIM2_CLK SIM2 card clock. 16 SIM2_DATA SIM2 card data I/O. 25 SIM2_RST SIM2 card reset. DCD NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 55 / 85 The following figure is the reference design for SIM1 interface. VDD_EXTModuleSIM1_VDDSIM_GNDSIM1_RSTSIM1_CLKSIM1_DATASIM1_PRESENCE22R22R22R10K100nF SIM_HolderGNDGNDTVS33pF33pF 33pF33pFVCCRSTCLK IOVPPGNDGND Figure 33: Reference Circuit for SIM1 Interface with 8-pin SIM Card Holder If SIM1 card detection function is not used, keep SIM1_PRESENCE pin open. The reference circuit for a 6-pin SIM card socket is illustrated as the following figure. ModuleSIM1_VDDSIM_GNDSIM1_RSTSIM1_CLKSIM1_DATASIM1_PRESENCE22R22R22R100nF SIM_HolderGNDTVS33pF33pF 33pFVCCRSTCLK IOVPPGNDGND33pF Figure 34: Reference Circuit for SIM1 Interface with the 6-pin SIM Card Holder
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 56 / 85 The following figure is the reference design for SIM2 interface with the 6-pin SIM card holder. ModuleSIM2_VDDSIM_GNDSIM2_RSTSIM2_CLKSIM2_DATA 22R22R22R100nF SIM_HolderGNDTVS33pF33pF 33pFVCCRSTCLK IOVPPGNDGND33pF Figure 35: Reference Circuit for SIM2 Interface with the 6-pin SIM Card Holder For more information of SIM card holder, you can visit http://www.amphenol.com and http://www.molex.com. In order to enhance the reliability and availability of the SIM card in application. Please follow the below criteria in the SIM circuit design.  Keep layout of SIM card as close as possible to the module. Assure the possibility of the length of the trace is less than 200mm.  Keep SIM card signal away from RF and VBAT alignment.  Assure the ground between module and SIM cassette short and wide. Keep the width of ground no less than 0.5mm to maintain the same electric potential. The decouple capacitor of SIM_VDD is less than 1uF and must be near to SIM cassette.  To avoid cross talk between SIM_DATA and SIM_CLK. Keep them away with each other and shield them with surrounded ground  In order to offer good ESD protection, it is recommended to add a TVS diode array. For more information of TVS diode, you can visit http://www.onsemi.com/. The most important rule is to place your ESD protection device close to the SIM card socket and make sure the net being protected will go through the ESD device first and then lead to module. The 22Ω resistors should be connected in series between the module and the SIM card so as to suppress the EMI spurious transmission and enhance the ESD protection. Please to be noted that the SIM peripheral circuit should be close to the SIM card socket.  Place the RF bypass capacitors (33pF) close to the SIM card on all signals line for improving EMI.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 57 / 85 3.11. Behaviors of The RI When using PCM interface, RI pin can be used as PCM_CLK. Table 18: Behaviors of the RI If URC of SMS is disabled, the RI will not change. If the module is used as a caller, the RI would maintain high except the URC or SMS is received. On the other hand, when it is used as a receiver, the timing of the RI is shown as below. RIIdle RingOff-hook by“ATA”On-hook by “ATH”HIGHLOW Figure 36: RI Behavior of Voice Calling as a Receiver State RI Response Standby HIGH Voice Calling Change to LOW, then: 1. Change to HIGH when call is established. 2. Use ATH to hang up the call, RI changes to HIGH. 3. Calling part hangs up, RI changes to HIGH first, and changes to LOW for 120ms indicating ―NO CARRIER‖ as an URC, then changes to HIGH again. 4. Change to HIGH when SMS is received. SMS When a new SMS comes, the RI changes to LOW and holds low level for about 120ms, then changes to HIGH. URC Certain URCs can trigger 120ms low level on RI. For more details, please refer to the document [1]. NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 58 / 85 RIIdle Calling On-hookTalkingHIGHLOWIdle Figure 37: RI Behavior as a Caller RIIdle or Talking URC or SMS received HIGHLOW120ms Figure 38: RI Behavior of URC or SMS Received 3.12. Network Status Indication The NETLIGHT signal can be used to drive a network status indicator LED. The working state of this pin is listed in the following table. Table 19: Working State of the NETLIGHT State Module Function Off The module is not running. 64ms On/800ms Off The module is not synchronized with network. 64ms On/2000ms Off The module is synchronized with network. 64ms On/600ms Off The GPRS data transmission after dialing the PPP connection.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 59 / 85 A reference circuit is shown as below. ModuleNETLIGHT 4.7K47K300RVBAT Figure 39: Reference Design for NETLIGHT 3.13. Operating Status Indication The STATUS pin will output a high level after the module being turned on. but it is not recommended connecting this pin to a MCU’s GPIO to judge whether the module is turn-on or not. The following LED indicator circuit for STATUS pin can be used to indicate the state after the module has been turned on. Table 20: Pin Definition of the STATUS 1) When using PCM interface, STATUS pin can be used as PCM_SYNC. Name Pin Description 1)Alternate Function STATUS 12 Indicate module operating status PCM_SYNC NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 60 / 85 ModuleSTATUS 4.7K47K300RVBAT Figure 40: Reference Design for STATUS
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 61 / 85 4 Antenna Interface The Pin 39 is the RF antenna pad. The RF interface has an impedance of 50Ω. Table 21: Pin Definition of the RF_ANT 4.1. RF Reference Design The reference design for RF is shown as below. ModuleRF_ANT0RNM NM Figure 41: Reference Design for RF M35 provides an RF antenna pad for antenna connection. The RF trace in host PCB connected to the module RF antenna pad should be coplanar waveguide line or microstrip line, whose characteristic impedance should be close to 50Ω. M35 comes with grounding pads which are next to the antenna pad in Name Pin Description GND 37 Ground GND 38 Ground RF_ANT 39 RF antenna pad GND 40 Ground
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 62 / 85 order to give a better grounding. Besides, a π-type match circuit is suggested to be used to adjust the RF performance. 4.2. RF Output Power Table 22: The Module Conducted RF Output Power In GPRS 4 slots TX mode, the max output power is reduced by 2.5dB. This design conforms to the GSM specification as described in section 13.16 of 3GPP TS 51.010-1. 4.3. RF Receiving Sensitivity Table 23: The Module Conducted RF Receiving Sensitivity Frequency Max. Min. GSM850 33dBm±2dB 5dBm±5dB EGSM900 33dBm±2dB 5dBm±5dB DCS1800 30dBm±2dB 0dBm±5dB PCS1900 30dBm±2dB 0dBm±5dB Frequency Receive Sensitivity GSM850 < -109dBm EGSM900 < -109dBm DCS1800 < -109dBm PCS1900 < -109dBm NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 63 / 85 4.4. Operating Frequencies Table 24: The Module Operating Frequencies 4.5. Antenna Requirement The following table shows the requirement on GSM antenna. Table 25: Antenna Cable Requirements Type Requirements GSM850/EGSM900 Cable insertion loss <1dB DCS1800/PCS1900 Cable insertion loss <1.5dB Table 26: Antenna Requirements Type Requirements Frequency Range GSM850/EGSM900/DCS1800/PCS1900MHz. VSWR ≤ 2 Gain (dBi) 1 Max Input Power (W) 50 Input Impedance (Ω) 50 Polarization Type Vertical Frequency Receive Transmit ARFCH GSM850 869~894MHz 824~849MHz 128~251 EGSM900 925~960MHz 880~915MHz 0~124, 975~1023 DCS1800 1805~1880MHz 1710~1785MHz 512~885 PCS1900 1930~1990MHz 1850~1910MHz 512~810
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 64 / 85 4.6. RF Cable Soldering Soldering the RF cable to RF pad of module correctly will reduce the loss on the path of RF, please refer to the following example of RF soldering. Figure 42: RF Soldering Sample
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 65 / 85 5 Electrical, Reliability and Radio Characteristics 5.1. Absolute Maximum Ratings Absolute maximum ratings for power supply and voltage on digital and analog pins of module are listed in the following table: Table 27: Absolute Maximum Ratings 5.2. Operating Temperature The operating temperature is listed in the following table: Table 28: Operating Temperature Parameter Min. Max. Unit VBAT -0.3 +4.73 V Peak Current of Power Supply 0 2 A RMS Current of Power Supply (during one TDMA- frame) 0 0.7 A Voltage at Digital Pins -0.3 3.08 V Voltage at Analog Pins -0.3 3.08 V Voltage at Digital/analog Pins in Power Down Mode -0.25 0.25 V Parameter Min. Typ. Max. Unit Normal Temperature -35 +25 +80 ℃
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 66 / 85 1) When the module works within this temperature range, the deviation from the GSM specification may occur. For example, the frequency error or the phase error will be increased. 5.3. Power Supply Ratings Table 29: The Module Power Supply Ratings Restricted Operation1) -40 ~ -35 +80 ~ +85 ℃ Storage Temperature -45 +90 ℃ Parameter Description Conditions Min. Typ. Max. Unit VBAT Supply voltage Voltage must stay within the min/max values, including voltage drop, ripple, and spikes. 3.3 4.0 4.6 V Voltage drop during transmitting burst Maximum power control level on GSM850 and EGSM900. 400 mV IVBAT Average supply current Power down mode SLEEP mode @DRX=5 150 1.3 uA mA Minimum functionality mode AT+CFUN=0 IDLE mode SLEEP mode AT+CFUN=4 IDLE mode SLEEP mode 13 0.98 13 1.0 mA mA mA mA TALK mode GSM850/EGSM9001) DCS1800/PCS19002) 223/219 153/151 mA mA DATA mode, GPRS (3Rx,2Tx) GSM850/EGSM9001) DCS1800/PCS19002) 363/393 268/257 mA mA DATA mode, GPRS(2 Rx,3Tx) GSM850/EGSM9001) DCS1800/PCS19002) 506/546 366/349 mA mA NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 67 / 85 1. 1) Power control level PCL 5. 2. 2) Power control level PCL 0. 3. Under the EGSM900 spectrum，the power of 1Rx and 4Tx has been reduced. 5.4. Current Consumption The values of current consumption are shown as below. Table 30: The Module Current Consumption DATA mode, GPRS (4Rx,1Tx) GSM850/EGSM9001) DCS1800/PCS19002) 217/234 172/170 mA mA DATA mode, GPRS (1Rx,4Tx) GSM850/EGSM9001) DCS1800/PCS19002) 458/485 462/439 mA mA Peak supply current (during transmission slot) Maximum power control level on GSM850 and EGSM900. 1.6 2 A Condition Current Consumption Voice Call GSM850 @power level #5 <300mA, Typical 223mA @power level #12, Typical 83mA @power level #19, Typical 62mA EGSM900 @power level #5 <300mA, Typical 219mA @power level #12, Typical 83mA @power level #19, Typical 63mA DCS1800 @power level #0 <250mA, Typical 153mA @power level #7, Typical 73mA @power level #15, Typical 60mA PCS1900 @power level #0 <250mA, Typical 151mA @power level #7, Typical 76mA @power level #15, Typical 61mA GPRS Data NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 68 / 85 GPRS Class 10 is the default setting. The module can be configured from GPRS Class 1 to Class 10. Setting to lower GPRS class would make it easier to design the power supply for the module. 5.5. Electro-static Discharge Although the GSM engine is generally protected against Electro-static Discharge (ESD), ESD protection precautions should still be emphasized. Proper ESD handling and packaging procedures must be applied throughout the processing, handling and operation of any applications using the module. The measured ESD values of module are shown as the following table: DATA Mode, GPRS ( 3 Rx, 2Tx ) CLASS 10 GSM850 @power level #5 <550mA, Typical 363mA @power level #12, Typical 131mA @power level #19, Typical 91mA EGSM900 @power level #5 <550mA, Typical 393mA @power level #12, Typical 132mA @power level #19, Typical 92mA DCS1800 @power level #0 <450mA, Typical 268mA @power level #7, Typical 112mA @power level #15, Typical 88mA PCS1900 @power level #0 <450mA, Typical 257mA @power level #7, Typical 119mA @power level #15, Typical 89mA DATA Mode, GPRS ( 4 Rx,1Tx ) CLASS 10 GSM850 @power level #5 <350mA, Typical 216mA @power level #12, Typical 103mA @power level #19, Typical 83mA EGSM900 @power level #5 <350mA, Typical 233mA @power level #12, Typical 104mA @power level #19, Typical 84mA DCS1800 @power level #0 <300mA, Typical 171mA @power level #7, Typical 96mA @power level #15, Typical 82mA PCS1900 @power level #0 <300mA, Typical 169mA @power level #7, Typical 98mA @power level #15, Typical 83mA NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 69 / 85 Table 31: The ESD Endurance (Temperature: 25ºC , Humidity: 45%) Tested Point Contact Discharge Air Discharge VBAT,GND ±5KV ±10KV RF_ANT ±5KV ±10KV TXD, RXD ±2KV ±4KV Others ±0.5KV ±1KV
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 70 / 85 6 Mechanical Dimensions This chapter describes the mechanical dimensions of the module. 6.1. Mechanical Dimensions of Module Figure 43: M35 Module Top and Side Dimensions (Unit: mm)
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 71 / 85 1 Figure 44: M35 Module Bottom Dimensions (Unit: mm)
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 72 / 85 6.2. Recommended Footprint frame lineBBAAframe lineSilksreen Silksreen Figure 45: Recommended Footprint (Unit: mm) The module should keep about 3mm away from other components in the host PCB. NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 73 / 85 6.3. Top View of the Module Figure 46: Top View of the Module 6.4. Bottom View of the Module Figure 47: Bottom View of the Module
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 74 / 85 7 Storage and Manufacturing 7.1. Storage M35 module is distributed in a vacuum-sealed bag. The restriction for storage is shown as below. Shelf life in the vacuum-sealed bag: 12 months at environments of <40ºC temperature and <90%RH. After the vacuum-sealed bag is opened, devices that need to be mounted directly must be:  Mounted within 72 hours at the factory environment of ≤30ºC temperature and <60% RH.  Stored at <10% RH. Devices require baking before mounting, if any circumstance below occurs.  When the ambient temperature is 23ºC ±5 ºC , humidity indication card shows the humidity is >10% before opening the vacuum-sealed bag.  If ambient temperature is <30ºC and the humidity is <60%, the devices have not been mounted during 72hours.  Stored at >10% RH. If baking is required, devices should be baked for 48 hours at 125ºC ±5 ºC . As plastic container cannot be subjected to high temperature, devices must be removed prior to high temperature (125ºC ) bake. If shorter bake times are desired, refer to the IPC/JEDECJ-STD-033 for bake procedure. 7.2. Soldering NOTE
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 75 / 85 The squeegee should push the paste on the surface of the stencil that makes the paste fill the stencil openings and penetrate to the PCB. The force on the squeegee should be adjusted so as to produce a clean stencil surface on a single pass. To ensure the module soldering quality, the thickness of stencil at the hole of the module pads should be 0.2 mm for M35. For more details, please refer to document [5]. It is suggested that peak reflow temperature is from 235ºC to 245ºC (for SnAg3.0Cu0.5 alloy). Absolute max reflow temperature is 260ºC. To avoid damage to the module when it was repeatedly heated, it is suggested that the module should be mounted after the first panel has been reflowed. The following picture is the actual diagram which we have operated. Time(s)50 100 150 200 250 30050100150200250 160℃ 200℃217070s~120s40s~60sBetween 1~3℃/SPreheat Heating Cooling℃sLiquids Temperature Figure 48: Ramp-Soak-Spike Reflow Profile 7.3. Packaging The modules are stored inside a vacuum-sealed bag which is ESD protected. It should not be opened until the devices are ready to be soldered onto the application. 7.3.1. Tape and Reel Packaging The reel is 330mm in diameter and each reel contains 250 modules.
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 76 / 85 Figure 49: Tape and Reel Specification
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 77 / 85 PS6DETAIL:A DETAIL:A Figure 50: Dimensions of Reel Table 32: Reel Packing Model Name MOQ for MP Minimum Package: 250pcs Minimum Package×4=1000pcs M35 250pcs Size: 370 × 350 × 56mm3 N.W: 0.63kg G.W: 1.47kg Size: 380 × 250 × 365mm3 N.W: 2.5kg G.W: 6.4kg
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 78 / 85 8 Appendix A Reference Table 33: Related Documents SN Document Name Remark [1] Quectel_M35_AT_Commands_Manual AT commands manual [2] ITU-T Draft new recommendation V.25ter Serial asynchronous automatic dialing and control [3] GSM_UART_Application_Note UART port application note [4] GSM_EVB_User_Guide GSM EVB user guide [5] Module_Secondary_SMT_User_Guide Module secondary SMT user guide [6] M35_Dual_SIM_Application_Notes_V3.0 M35 Dual SIM Application Notes [7] GSM_Multi_UART_Application_Note M35 Multi UART Application Notes [8] Quectel_GSM_Module_Digital_IO_Application_Note GSM module digital IO application note [9] GSM 07.07 Digital cellular telecommunications (Phase 2+); AT command set for GSM Mobile Equipment (ME) [10] GSM 07.10 Support GSM 07.10 multiplexing protocol [11] GSM 07.05 Digital cellular telecommunications (Phase 2+); Use of Data Terminal Equipment – Data Circuit terminating Equipment (DTE – DCE) interface for Short Message Service (SMS) and Cell Broadcast Service (CBS) [12] GSM 11.14 Digital cellular telecommunications (Phase 2+); Specification of the SIM Application Toolkit for the Subscriber Identity module – Mobile Equipment (SIM – ME) interface [13] GSM 11.11 Digital cellular telecommunications (Phase 2+); Specification of the Subscriber Identity module – Mobile Equipment (SIM – ME) interface
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 79 / 85 Table 34: Terms and Abbreviations [14] GSM 03.38 Digital cellular telecommunications (Phase 2+); Alphabets and language-specific information [15] GSM 11.10 Digital cellular telecommunications (Phase 2); Mobile Station (MS) conformance specification; Part 1: Conformance specification Abbreviation Description ADC Analog-to-Digital Converter AMR Adaptive Multi-Rate ARP Antenna Reference Point ASIC Application Specific Integrated Circuit BER Bit Error Rate BOM Bill of Material BTS Base Transceiver Station CHAP Challenge Handshake Authentication Protocol CS Coding Scheme CSD Circuit Switched Data CTS Clear To Send DAC Digital-to-Analog Converter DRX Discontinuous Reception DSP Digital Signal Processor DCE Data Communications Equipment (typically module) DTE Data Terminal Equipment (typically computer, external controller) DTR Data Terminal Ready DTX Discontinuous Transmission
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 80 / 85 EFR Enhanced Full Rate EGSM Enhanced GSM EMC Electromagnetic Compatibility ESD Electrostatic Discharge ETS European Telecommunication Standard FCC Federal Communications Commission (U.S.) FDMA Frequency Division Multiple Access FR Full Rate GMSK Gaussian Minimum Shift Keying GPRS General Packet Radio Service GSM Global System for Mobile Communications G.W Gross Weight HR Half Rate I/O Input/Output IC Integrated Circuit IMEI International Mobile Equipment Identity Imax Maximum Load Current Inorm Normal Current kbps Kilo Bits Per Second LED Light Emitting Diode Li-Ion Lithium-Ion MO Mobile Originated MOQ Minimum Order Quantity MP Manufacture Product MS Mobile Station (GSM engine)
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 81 / 85 MT Mobile Terminated N.W Net Weight PAP Password Authentication Protocol PBCCH Packet Switched Broadcast Control Channel PCB Printed Circuit Board PDU Protocol Data Unit PPP Point-to-Point Protocol RF Radio Frequency RMS Root Mean Square (value) RTC Real Time Clock RX Receive Direction SIM Subscriber Identification Module SMS Short Message Service TDMA Time Division Multiple Access TE Terminal Equipment TX Transmitting Direction UART Universal Asynchronous Receiver & Transmitter URC Unsolicited Result Code USSD Unstructured Supplementary Service Data VSWR Voltage Standing Wave Ratio Vmax Maximum Voltage Value Vnorm Normal Voltage Value Vmin Minimum Voltage Value VIHmax Maximum Input High Level Voltage Value VIHmin Minimum Input High Level Voltage Value
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 82 / 85 VILmax Maximum Input Low Level Voltage Value VILmin Minimum Input Low Level Voltage Value VImax Absolute Maximum Input Voltage Value VImin Absolute Minimum Input Voltage Value VOHmax Maximum Output High Level Voltage Value VOHmin Minimum Output High Level Voltage Value VOLmax Maximum Output Low Level Voltage Value VOLmin Minimum Output Low Level Voltage Value Phonebook Abbreviations LD SIM Last Dialing phonebook (list of numbers most recently dialed) MC Mobile Equipment list of unanswered MT Calls (missed calls) ON SIM (or ME) Own Numbers (MSISDNs) list RC Mobile Equipment list of Received Calls SM SIM phonebook
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 83 / 85 9 Appendix B GPRS Coding Scheme Four coding schemes are used in GPRS protocol. The differences between them are shown in the following table. Table 35: Description of Different Coding Schemes Radio block structure of CS-1, CS-2 and CS-3 is shown as the figure below. Figure 51: Radio Block Structure of CS-1, CS-2 and CS-3 Scheme Code Rate USF Pre-coded USF Radio Block excl.USF and BCS BCS Tail Coded Bits Punctured Bits Data Rate Kb/s CS-1 1/2 3 3 181 40 4 456 0 9.05 CS-2 2/3 3 6 268 16 4 588 132 13.4 CS-3 3/4 3 6 312 16 4 676 220 15.6 CS-4 1 3 12 428 16 - 456 - 21.4 Rate 1/2 convolutional coding Puncturing 456 bits USF BCS Radio Block
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 84 / 85 Radio block structure of CS-4 is shown as the following figure. Figure 52: Radio Block Structure of CS-4 Block Code No coding 456 bits USF BCS Radio Block
GSM/GPRS Module Series M35 User Manual M35_User_Manual Confidential / Released 85 / 85 10 Appendix C GPRS Multi-slot Class Twenty-nine classes of GPRS multi-slot modes are defined for MS in GPRS specification. Multi-slot classes are product dependant, and determine the maximum achievable data rates in both the uplink and downlink directions. Written as 3+1 or 2+2, the first number indicates the amount of downlink timeslots, while the second number indicates the amount of uplink timeslots. The active slots determine the total number of slots the GPRS device can use simultaneously for both uplink and downlink communications. The description of different multi-slot classes is shown in the following table. Table 36: GPRS Multi-slot Classes Multislot Class Downlink Slots Uplink Slots Active Slots 1 1 1 2 2 2 1 3 3 2 2 3 4 3 1 4 5 2 2 4 6 3 2 4 8 4 1 5 9 3 2 5 10 4 2 5

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