Wireless N2L5-7S1-01 Point-to-point communication transmitter User Manual Unknown
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manual operation description
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| Document ID | 6082 |
| Application ID | lj1ZjjYZxMh6d0CCXD+1WQ== |
| Document Description | manual operation description |
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| Permanent Confidential | No |
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| Document Type | User Manual |
| Display Format | Adobe Acrobat PDF - pdf |
| Filesize | 86.01kB (1075162 bits) |
| Date Submitted | 1998-08-25 00:00:00 |
| Date Available | 1998-10-22 00:00:00 |
| Creation Date | 0000-00-00 00:00:00 |
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| Document Lastmod | 0000-00-00 00:00:00 |
| Document Title | Unknown |
| Document Author: | Unknown |
IJJIHELESSJHE.
DSi/E1 N2-Link
Installation and Operations Manual
Part Number XXXXXXXX
Version 01
May 1998
Wireless, Inc.
19 Davis DI’lVS
Belmont. CA 94002-3001
"24an Installation and Opal-nth»! Manual
Notice
Information in this document is subject to change without notice. No part of this document may
be reproduced or transmitted in any form or by any means, electronic or mechanical, lor any
purpose, without the express written permrsslon of Wireless, Inc.
© Copyright 1998, Wireless. Inc. All rights reserved.
N2-Link and ACCESS Series are trademarks of Wireless, Inc.
[I
Figure 2.1
Figure 2.2
Figure 2.3
Figure 2.4
Figure 3.1
Figure 3.2
Figure 3.3
Figure 4.1
Figure 01
Figure 0.2
Figure 0.3
Table 1.1
Table 31
Table 3.2
Table 4.1
Table 0.1
Table 0.2
Table F.1
Table F.2
Table F.3
Table F.4
Table F.5
M2-Llnk Installation and Operatlon Manual
Figures
Typical Deployment of a N2-Link in a Point-to-Point Configuration .......
Terminal Unit Interfaces ...............
Outdoor Unit .............
N2-Link Block Diagram
N2-Link Rack Mount ...........
N2-Link Ground Attachment
Antenna Mount Assembly ..................
Pole Mount Assembly ......................
FCC U-Nll Bands
Installation Checklist...“..‘.........
Approximation Table
Contents List .................
Nut Torque Recommendations
Fresnel Zone Radius on 10-rmle Path“.
Path Calculations
Antenna Specifications
Fresnel Zone Clearance Requirements - Two-mile Path
Fresnel Zone Clearance Requirements - Twenty-mile Path
1,0
2.0
3.0
Nz-Unk Installallon and Operation Manual
Table of Contents
General Overview ......
1.1 N2 ACCESS Series Product Family.
1.2 Introduction to the Nz-Link ...........
13 Regulatory Information .................
N2—Link Product Profile .
2.1 General Overview.
2.2 Specifications .............. t
2.3 User Interfaces ...............
2.4 Alarms and Indicators (Interface Panel) .
2.5 Alarms, Indicators and Displays (Outdoor Unit)
2.6 Theory of Operation
Equipment Installation and Commissioning .................
31 System Planning, Analysis and Implementation .
n n I—.b-Ilat:h—\
Nz-Link Installation and Operation Manual
Welcome!
Welcome to the Wireless, Inc N2 ACCESS Series product family This manual is designed to
introduce you to the DSl/El N2-Link, and to provide you with information necessary to plan,
install, operate and maintain a DSi/Ei N2-Link wireless communication system.
The N2-Link is intended for professional installation only. This manual, however, is also
@ designed for personnel who plan, operate and administrate the N2-Link communication
system. Please review the entire manual before powering up or deploying any N2-Link.
Updates to this manual will be posted on the Wireless. Inc Customer Service Website at
hflp://www.wire-less-inc,com/CusfSalv. Registered Wireless customers can access Wireless’
on-Iine inlormation and support service, available 24 hours a day, 7 days a week Our on-Iine
serwce provides users with a wealth of up—to-date information, with documents being added or
updated each month.
Radiation Warnings
Microwave Radio Radiation Warning
Under normal operating conditions, N2-Link radio equipment complies withtheglimlts for human
exposure to radio frequency (RF) fields adopted by the Federal Communications Commission
(FCC). All Wireless, inc. microwave radio equipment Is designed so thal under normal working
conditions, microwave radiation directly from the radio is negligible when compared with the
permissible Iimitoicontinuous daily exposure recommended in the United States by ANSI/lEEE
C95.1-1991 (R1997). Safety Levels with Respect to Human Exposure to Radio Frequency
Electromagnetic Fields, 3 kHz to 300 GHz
Microwave signal levels that give rise to hazardous radiation levels can exist within transmitter
power amplifiers, associated RF multiplexers, and antenna systems.
Never look into the open end of a Waveguide as eyes are particularly vulnerable to radiation
Do not disconnect RF coaxial connectors, open microwave units, or break down any
microwave screening while the radio equipment is operating,
Microwave Antenna Radiation Warning
Designed for point-to-point operation, an N2-Link microwave radio system will use directional
antennas to transmit and receive microwave signals. These directional antennas are usually
circular or rectangular in shape, are generally located outdoors, and are usually mounted on a
lower or mast.
Referencing OET Bulletin 65 (Edition 97-01, August 1997) from the Federal Communication
Commission's Office of Engineering & Technology, limits for maximum permissible exposure
(MPE) to microwave signals have been adopted by the FCC for both OccupationaVControIIed
environments and General Population/Uncontrolled environments. These limits are 5.0 mW/
cm2 and 1.0 mW/cm“, respectively, with averaging times of six-minutes and thirty-minutes.
respectively.
N2-Llnk Installation and Operation Manual
The closer you are to the front center-point of a microwave antenna. the greater the power
density of its transmitted microwave signal. Unless you are very close, however, microwave
exposure levels will fall far below the MPE limits. To determine how close to a microwave
antenna you can be and still remain below the MPE limits noted above, “worst case" predictions
of the field strength and power density levels in the vicinity 01 an ACCESS Link microwave
antenna can be made lrom the following calculations. The equation is generally accurate in the
far-field of an antenna, and will overpredict power density in the near-field (i.e close to the
antenna).
S = PG/ATIRZ
where: S = power density (in mW/cm’)
P = power input to the antenna (mW)
G = power gain of the antenna in the direction of interest relative to an isotropic
radiator
Ft ; distance to the center of radiation of the antenna (cm)
Note that G, the power gain factor, is usually expressed in logarithmic terms (i.e, dB), and must
be convened using the following equation:
G = 10 alarm
For example, a logarithmic power gain of 27 dB is equal to a numeric gain of 251.19.
Assuming (1) maximum output power from the N2-Link (+35 dBm [2238 mW]), (2) no signal
loss in the cable connectingthe N2-Linkto the antenna, and (3) the use ofa 27 dBi gain parabolic
antenna, the 5.0 mW/cm2 and 1.0 mW/cm2 MPE power density limits woulrl he reached at
distances of approximately 422 cm and 9.44 cm. respectively.
Wireless, lnc. fully supports the FCC’s adopted MPE limits, and recommends that personnel
maintain approprlate dlstances from the front ofall dlrectional microwave antennas. Should you
have questions about N2-Link microwave signal radiation, please contact the Wireless, lnc.
Customer Service Department.
Notice Regarding Operation pursuant to no part 15 Rules
This equipment has been tested and found to comply with the limits for a Class A digital device
pursuant to part 15 of the FCC Flutes. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
enVlronmenl. This equipment generates, uses and can radiate radio frequency energy and. if
not installed and used in accordance with the instruction manual. may cause harmful
interference to radio communications. Operation of this equrpmenr in a residential area is likely
to cause harmful interference in which case the user will be required to correct the interference
at his own expense.
"2-1.an installation and Operation Manual
1.0 General Overview
1.1
1.2
N2 ACCESS Series Product Family
All N2-Link radios are members of the N2 ACCESS Series radio product family. The N2
ACCESS Series is designed to provide an economical wireless solution for local access
ielecommunicalion requirements.
The N2 ACCESS Series radio product family consists of several product offerings, to include
both the N2 ACCESS Link and ACCESS MicroLink product lines. This manual addresses in
detail, the operation of the N2-Link. For detailed information on other N2 ACCESS Link radios
or other members of the ACCESS Series. please refer [U the appropriate Operation Manual(s).
Introduction to the N2-Link
The N2—Link series of radios are designed for operation in two of the Unlicensed National
Infrastructures at frequencies of 5,250 - 5,350 MHz or 5,725 - 5,825 MHz, '
Each N2-Link is comprised 012 main units, adesktop or rack mountable indoorterminal unit and
a pole mounted RF/antenna unit. Each link is powered by means of 3 AC wall transformer
(optional DC powering available) located With the indoor terminal unit. The system has a data
transmission capacity of lxDSi or El (1 54412048 Mb/s)4 The TU offers complete front~access
for all interfaces, displays and controls. Referto the N2»Link data sheets for information relating
to product offerings and specifications.
1.3
Nz-Llnk lnstnllallon and Operation Manual
Regulatory Information
In January 1997, the FCC made available 300 MHz
of spectrum for Unlicensed National
lnlorrnation infrastructure (U-Nl I) devices. The FCC believes that the creation of the U-Nli band
will stimulate the development of new unlicensed digital products which will provide efficient and
less expensive solutions for local access applications.
The U-NII band is divided into three sub bands ai5.15 - 5.25. 5.2
The first band is strictly allocated tor indoor use and is consistent
5 - 5.35 and 5.725 - 5.825 GHz.
with the European High
Performance Local Area Network (HIPERLAN). The second and third bands are intended for
high speed digital local access products for “campus" and “short haul' microwave applications.
Table 1.1 - FCC U-Nll Bands
m—
—m
Frequency
Power (Max)
intended Use
5.725 to 5.825 GHZ
Band 3
4 watts EIRP
Approx 6 miles
WLIEJMI
Nz-Llnk Installation and Operation Manual
2.0 N2-Link Product Profile
2.1
General Overview
The N2-Link series of microwave radio products provides digital capacities for DSX, ITU-T and
data rates for snort'haul applications up to 15 km in the US. and up to 10/20 km. The radio
terminal operates in the newly allocated Unlicensed National Information infrastructure (U-Nli)
spectrum with a revolutionary Split Modulation system architecture that provides full duplex
operation in the 5.3/5.7 GHz frequency bands.
The N2-Link series provides the unique advantage of a very robust digital transmission scheme
which combines a high degree of error identification and correction.
Split Modulation uses two separate 100 MHz bands within the U-Nli trequency spectrum. Within
these bands, the N2-Link series operates in one of many independent channels providing for
frequency re-use and network flexibility, ideal for dense network applications.
Synthesized FlF channel selection is field configurable, as are the power output options for the
selection of antenna Sizes.
Complying with all aspects of FCC Rules Subpart (15,401 715407), the transmission charac—
teristics of the N2-Link series are ideally suited to meet the peak power spectral density
reqmrements of the U-NII 5.250 - 5.350 and 5.725 - 54825 GHz bands.
Link refers to the 5.3/5.7 GHz DSi/Ei N2—Link radior
@ Note: From this point on in this Operations Manual, unless spectfied otherwise, the term N2-
The N2-Link as been designed forcompletefront access to all interfaces, controls and displays.
Information in this manual will familiarize you with all of these items. Figure 2.1 illustrates two(2)
N2-Link terminals in a point-to-point configuration.
N2-Llnk Installation and Overatlon Manual
Thls Page Left Blank Intentionally
Antenna
1 Meter
ODU- Antenna
Interconnect
cable
Outdoor Unvt
AGO Test Point
Twin axial cable
(650 tt‘ max length)
g/O
N2 Ten'ninal Unit
Optional DC Input —————
RJABC 1XDS1/E1 Data IIO
(Can he ordered as 759 unbalanced intertace)
AC
Power Suppry
Antenna
0 Q
1 Meter
ODU» Antenna
Interconnect
cable
mmw
Outdoor Unit
AGO Test Point
Twin axial cable
(650 Vt max length)
. . 1 2
Tarmmal Unlt
u...-
424 o 2°32: 0
Optional DC Input - - ‘ - + DDDO
RJ4SC 1XDS1/E1 Data I/O
(Can be ordered as 759 unbalanced intedace)
AC / =
Power Supply
\____’_____,—_____1
Figure 2. 1 - Typical Deployment of a N2-Link in a Point-to-Paim Configuration
wuNw-sm
2.2
2.2. 1
2.2.2
Specifications
General
Frequency Band
Regulations
Frequency Flange
Frequency agility
Low Band
High Band
Channel Pairs
Capacrty options
Error Correction
Modulation
Digital Interface
Type
Line Hate
Line Code
Interface
Physical Connection
NZ-Link Installation and Operation Manual
Full-duplex operatlon in both 5.2 and 5.7 GHz
Complies with FCC Ruling 15.407, U-NII
5,250 » 5,350 MHz and 5,725 - 5,825 MHZ
Tunable in 2.5 MHz steps
5.260810 5.34016 GHz
5.73568 to 5.81504 GHz
5 x 10 MHZ (3 MHz max overlap)
52008573568 GHZ
5271041574592 GHz
5.28128/5.75616 GHZ
5.29152/57664 GHz
5.30176/577664 GHz
5312001578688 GHz
5.32224/579712 GHz
5,33248/580736 GHZ
1xDSS1 and 1xE1
4 x oversampling (bit interleaved)
BPSK ‘
DS1 - Bellcore TR-NWT-00499
E1 , ITU-T
D31 - 1.544 Mb/s
E1 - 2.048
D81 - AMI or 8828 (field selectable)
E1 - HDBa
081 - 100 Ohm balanced
E1 - 75 Ohm unbalanced (optional 120 ohm balanced). On 75
Ohm systems, the Tx and Rx shields are DC coupled to ground,
The Rx shield can be optionally AC coupled toground by the user
at the Interface Panel.
DS1 - RJ-4SC
E1 - BNC (optional FlJ-4EC)
NzUnk installation and Oporation Manual
2.2.3 Transmitter
2. 2.4
Frequency Bands
Output Power
Maximum EIRP
Power Spectral Density
Requirements for BW
(20 MHZ
Inband Emissions
Out of Band Emissions
Frequency Tolerance
Receiver
Type
Sensitivity, BER 10 5-6
Unfaded BEFi
Maximum Rx Input
Co»channel interference
Adjacent Channel
Interference ($10 MHz)
Semi-Adjacent Channel
Interference ($20 MHz)
Low Band - 5,250 to 5.350 GHZ
High Band - 5.725 to 5.825 GHZ
Low Band - —8.5 or -2.5 dBm or +75 dBm
High Band - -2.5 dBm or +35 dBm
Low Band - +245 dBm
High Band - +30.5 dBm
Low Band - 12,5 mW/MHz
High Band - 50 mW/MHZ
Low Band - 34 dB attenuation
High Band - 40 dB attenuation
Low Band - 44 dB attenuation
High Band - 50 dB attenuation
is ppm
Coherent Detection
DSi - 89 dBm
E1 - 89 dBm
1x10 E-12 or better
Error-Free ~ 30 dBm
Without Rx Damage - 0 dBm
+15 dB
+5 dB
-12 dB
2.2.5 Antennas
"24.an Installation and Opal-anon Manual
General Specillcallons and Pertormance
input R648 Female connector
Regulatory Compliance FCC Part 15
Frequency Range 5.2 - 5.9 GHz
E-plane Polarization fl deg.
2 fl. Single Polarization
Galn (mid-band) 27 dBi
Beamwidth, 3 dB 6.0 degrees
Cross Pol Disc. 28 dB
From/Back Ratio 36 dB
VSWR 1.35:'l (RU/16.5 dB
4 ft. Single Polarization
Gain (mid-band) 33 dBi '
Beamwidth. 3 dB 3.0 degrees
Cross Pol Disc. 28 dB
FronUBack Ratio 42 dB
VSWR
2 fl Dual Polarization
1.35:1 (RU/16.5 dB
Gain (mid-band) 26.5 dBi
Beamwidth. 3 dB 6.0 degrees
Cross Pol Disc. 28 dB
From/Back Ratio 36 dB
VSWFl 1.3521 (RU/16.5 dB
Isolation 35 dB min
4 fl Dual Polarization
Gain (mid-band) 32.5 dBi
Beamwidth. 3 dB 3.0 degrees
Cross Pol Disc. 28 dB
FronUBack Ratio 42 dB
VSWR 1.35:1 (RU/1&5 dB
Isolation 35 dB rnin
Mechanical/Environmental
Wind Loading ElA/T lA-1QSC and EIA/TlA-222E
Operational 112 krthr (70 mph) 25 mm (1")
Survival 201 km/hr (125 mph) 25 mm H")
rim-Link installation and Operation Manual
2.2.6 Diagnostics
Interiace Panel Front
Panel Indicators
Interface Panel Alarm
Relays A Form C
ODU Alarm indicators
(for MFG and Maintenance)
ODU Performance
Monitoring
2.2.7 Power Requirements
Power (normally On) - Green LED
Local Alarm (normally Off) - Red LED
Link Alarm (normally Off) - Red LED
Connector Type - DB-9 Female
Local Alarm - (Non-energized in the power-up state)
Link Alarm - (Energized in the power-up state)
Normal Operation - Green LED (and no red LEDs)
Link Alarm - Fied LED
Local Alarm - Red LED
Loss of Signal (LOS) - Red LED
Page Indicator - Red LED
RSSI - Red LED
RSSI - A voltage provided through a BNC connector on the
outside of the ODU. The RSSI port is used (or antenna alignment
during installation and for periodic measurement of Receiver!
Path performance The FlSSI voltage is related to BEFl from -30
dBm to -90 dBm. with an accuracy oi 15 dB
Remote Loopback - Accessed from the ODU
Local Loopback - Accessed irom the ODU
Primary AC power supply, with AC to DC conversion
AC
DC
Power Consumption
Power Input Connector
110 -240 VAC
12 to 15 VDC
Maximum 8 Watts
Coaxial DC connector, “snap and lock"
2.2.8 Environmental Specifications
Interface Panel
Outdoor Unit
Temperature Flange -30 to +55°C
Altitude - 4,500 meters max
Humidity - 95%. non-condensing
Temperature Range -30 to +55°C
Altitude - 4.500 meters max
Humidity - Outdoor. all-weather enclosure
10
N2-Llnk lnstallaflon and Operatlon Manual
2.2.9 Mechanical
Interface Panel Dimensions (HxWxD) » 43 x 200 x 152 mm
Weight - 1.2 kg
Outdoor Unit Dimensions (HxWxD) - 356 x 203 x 76 mm
Weight - 3.5 kg
Interface to Outdoor
Unii Connection 2 cables max
Maximum separation 650 it.
081! E1 Tx/Rx
12 - 15 VDC
2.2.10 Safety
EN 60950
11
Nz-Llnk lnslallatlan and Opomtlon Manual
Figure 2.2 - Terminal Unlt Interfaces
Alanns
Oplional DC
Connector
Hess! Chasm Ground
NZ-Link'“
wimp-1 um. ”um..." ___ m
r. g Q @*
“T. cw-n ©
Powsr Input
Digital Inpu'luutpur Cable 1 came 2
Power On
Link Alarm
Local Alarm
Optional Data IIO:
menu wmr
|XDS1IE1 1209
mmuuwvvwwv
1x51 755}
WLlD- | 1 7m
13
(RN)
N/A
(Green)
BREE!
(Rodi
“mu-m
14
N2-Llnk Installation and Operation Manual
2.4 Alarms and lndicators (lnterlaco Panel)
The N2—Link Interface Panel is equipped with diagnostic tools In the form of LED indicators. The
lollowing describes the functions 01 these items as shown in Figure 22.
2.4. 1 Power LED
The Power LED:
- Green - The N2-Link has proper DC power applied, and the unit is On,
. ClearIOff - The N2-Link is Off and has no DC power
2.4.2 Local Alarm LED
The Local Alarm LED is a single-color (red) device:
supplied.
. Red - The Nz-Link is registering one or more monitored alarm functions: summary radio
alarm, loss of local data input, bipolar violations (BPV)
power supply failure.
detected on local incoming data, or
- Clear/OH - The N2-Link is not registering any alarm condition.
2.4.3 Link Alarm LED
The Link Alarm LED is a singlecolor (red) device:
- Red - A loss oi data signal from the lar terminal has occurred
15
NZ-Link Installation and Operation Manual
2.5 Alarms, Indicators and Displays {Outdoor Unit)
The N2-Link outdoor RF unit is provided with several LED indicators that supply operational
status. Figure 2.3 shows the location of each indicator.
2.5.1 ODU Alarm lndlcators
- Normal Operation (Green LED) -
- Page 0 (Red LED) - When lit (red), indicates that page 0 of the EEPROM has loaded to the
FPGA indicating that a reset or start condition has occurred.
- Link Alarm (Red LED) - Indicates that the data signal from the far end terminal is not
present.
- Local Alarm (Red LED) - An alarm condition is present at the local terminal.
- Loss of Signal (LOS) Alarm (Red LED) - The signal from the far end terminal has dropped
below threshold.
- DRSSI Alarm (Red LED) -
2.5.2 ODU Performance Monitoring
RSSI - A voltage provided through a BNC connector on the outside ofthe ODU. The RSSI port
is used for antenna alignment during installation and for periodic measurement of
Receiver/Path performance. The RSSI voltage is related to Rx BER from 20 dBm to -90
dBm, with an accuracy ol 15 da
Remote Loopback - Accessed from the ODU
Local Loopback - Accessed from the ODU
ODU Alarm Indicators
ODU Performance monitoring
is
N2-Link Installation and Operation Manual
2.6 Theory of Operation
2.6. 1 N2-Link Transmitter
This description should be used in conjunction with the system block diagram Figure 2.4.
At the terminal unit (TU), at THE data signal is input through the FlJ-4EC connector in the
case of a balanced impedance interface or BNC type connectors for unbalanced inter-
faces.
A 15 VDC voltage is input to the TU by means of the supplied AC power supply This will
supply the voltage necessary to operate the TU and the Outdoor Unit (ODU).
The T1/El data signal and the 15 VDC supply voltage are connectedto the ODU by means
of a twin-axial type cable. The supply voltage drives three DC regulators within the ODU.
One regulator provides —5 VDC, the second 1 1 VDC and the third being a dual output type
supplies +5 and +5.8 volts. The data signals are transformer decoupled from the DC
voltage and connected to the Data level converter. The AMI/BBZS or HDBS formatted data
is convened to TTL level.
The FPGA coder interleaves and scrambles the TTL data from the coder. The FPGA is
programmed to output the data at 4 times the input rate (6 176 MHz for the T1 rate ms 192
for E1 rates) This provides a data rate which is optimal with respect to the FCC rules for
spectral power densities defined for this frequency allocation.
The data is passed through a 7th order low pass filter to reduce unwanted high frequency
signal Images prior to modulation A double balanced mixer is used to modulate the data
signal on to a CW signal provided by the synthesizer at the desired output frequency. The
output of the mixer contains the BPSK modulated Signal at the desired frequency.
A high pass filter eliminates spurious noise, rejects harmonic images and insures that the
proper bandwidth is maintained prior to being amplified.
The RF output section consists of three main components: a RF driver amplifier, a logic
controlled switch attenuator and a RF power amplifier. The driver amplifier provides the first
stage of RF amplification, the switch attenuator serves a dual purpose. The first is to
provide a customer selectable 6 dB attenuator to reduce output power when needed.
Secondly, this circuit acts as an RF impedance matching network between the driver and
power amplifier gain stages. The power amplifier provides the amplification required prior
to being output through a diplexing filter and ultimately to the antenna
17
Figure 2.4 - N2-Llnk Block Diagram
N2-Unk Installation and Operation Manual
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M2-Llnk Installation and Operation Manual
2.6.2 Nz-Llnlr Receiver
The description should be used in conjunction with the system block diagram (Figure 2.4).
0 At the antenna, the received BPSK modulated signal from the opposite terminal is passed
through a diplexing filter which is used to isolate the incoming signal from the transmitter
output and to bandpass filter the received signal thereby reducing the chance of unwanted
signal products from entering the receiver. A low noise amplifier (LNA) detects and
amplifies the signal bandpass filter on the output of the LNA provides band limiting of the
received spectrum to reject unwanted signal products. The first downconverter combines
3 CW signal at the receiver frequency from the synthesizer and the incoming signal by
means of a mixerto produce the first IF product at 474.880 MHz. A 75 MHz bandpass filter
limits the possibility of unwanted out of band products from entering the 2nd IF. The first
IF is amplified by a MMIC device and is downconverted by mixer a 389.76 MHz slgnal from
the synthesizer with the 474.880 MHz 1st IF signal. The result is a 85.12 MHz 2nd IF
product which is bandpass filtered and led to an RSSI IF processing It; which derives an
AGC voltage used to determine signal strength.
' A BPSK demodulator places the 85.12 MHz 2nd IF and 85.12 MHz crystal source out of
phase The resultant product is a DC level I and Q signal ofwhich only the I signal is input
to the Bit Synchronizer to re-clock the data. The re-clocked data is decoded and output at
‘l’l’L level to the T1/E1 level converterwhich outputs the data in AMI, 8828 or HDBS format
as needed. The data is interconnected to the TU and output on the front‘panel by means
of RJ-480 or BNC connector depending on the data format being used.
2.6.3 Synthesizer
The FPGA provides four 22-bit streams in a serial format loaded to the synthesizer. This data
prnvides all of the possible frequencies at which the system can operate. Depending upon the
dip switch settings selected, the actual frequency being used is selected. When the resetbutton
is pressed, the FPGA will reload this data to the synthesizer. The PROM contains all of the
possible frequency combinations.
19
Nz-Llnk Installation and Operallnn Manual
2D
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