CalAmp Wireless Networks NRU Network Repeater Unit User Manual
LoJack Corporation Network Repeater Unit Users Manual
Users Manual
LoJack Corporation
200 Lowder Brook Drive
Westwood, MA 02090 USA
Voice: 1-781-326-4700
Fax: 1-781-251-9117
www.lojack.com
CONFIDENTIAL AND PROPRIETARY
NRU Network Repeater Unit
The LoJack Network Repeater Unit (NRU) is a
low cost network device that can be used in a
LoJack Stolen Vehicle Recovery Network. The
NRU was designed to replace the obsolete
Tracker Repeater Unit (TRU), and the Packet
Decoder used for repeating. The NRU is now
available for 13 and 8 second networks.
An NRU can repeat downlink transmission
bursts it receives from either a Remote
Transmitter Unit (RTU), another NRU, or from
the network. It relays back any reply code
transmission it receives from an activated
Vehicle Locator Unit (VLU) as an uplink
message to a tower connected to the central
system. An NRU can also repeat uplink
transmissions from any nearby VLU or
repeaters. If connected via IP/broadband, the
NRU can forward to a central system any reply
code or uplink messages it hears.
Finally, the NRU can be used as a mobile
Installation Test Unit (ITU) for performing on-site
installation verification and routine inspection of
VLUs. When configured for ITU use, the NRU
can send properly timed and indexed test
command to the new VLU7 unit. This allows the
user to perform post-installation testing of the
VLU7 without the need to access the VLU7
ground wires. This powerful feature works both
inside and outside network coverage areas.
Product Description
The NRU is a self-contained unit in an indoor-
rated housing with mounting tabs, and includes
a built-in GPS receiver. The unit has a dedicated
serial interface, connectors for power and
antenna as well as relay contacts to drive an
external power amplifier.
The NRU fully supports VLU7 timing and
indexing requirements for downlink
transmissions for basic messages such as
Activation, Deactivation, Speed up, and
extended downlink messages such as Alt-
Deactivate.
The NRU can be used in conjunction with a
GSM modem. The NRU will not repeat
transmissions from a mobile transmitter with
pseudo dotting 15 in 13 second networks. It will
respond to either configuration or report request
messages from a mobile transmitter or from the
network.
NOTE: The NRU is not base station certified. It is ETSI
certified for 13 Second Systems and FCC certified as a
mobile transmitter for 8 second Systems.
Product Highlights
• Network device that
o Repeats downlink and uplink
messages.
o Enables post installation
testing of VLU7 while in or
out of the network area.
• Available in two models
1. Full function – provides
complete NRU feature set.
2. ITU only - Supports only VLU
installation testing. No
network repeating features.
CONFIDENTIAL AND PROPRIETARY
LoJack Corporation
200 Lowder Brook Drive
Westwood, MA 02090 USA
Voice: 1-781-326-4700
9080-0026-00 Rev B – NRU Fax: 1-781-251-9117
Revised Sep 2010 www.lojack.com
Product Features User Benefits
NRU design based on the VLU-7 transceiver Ability to supports all VLU-7 channel frequencies
Improved timing accuracy over the obsolete TRU Better timing accuracy decreases network
congestion, improves communication with VLUs.
Includes indexing for VLU7. Communicates with
all VLU7 models including self powered VLU.
Ensures maximum life expectancy of VLU7-SP.
Enables post installation testing of VLU7-SP
without the need for full service mode
Supports firmware updates both locally and
remotely using the Ethernet connection.
Easy to maintain/upgrade system, reduces or
eliminates site visits
Uplink message receiving and repeating
capability
Ability to offer expanded services such as
LoJack Early Warning
Technical Specifications
Physical RF Performance (VHF)
Dimensions Single Frequency Options 160MHz to 174MHz
Height 174.53 mm (6.87 in ) Center Frequency ± 9.0 ppm (-20°C to +55°C)
Width 99.4 mm (3.91 in ) Accuracy
Depth 41.6 mm (1.64 in ) Channel Spacing 25 KHz
Weight (Wideband)
Operational 0.9 kg Channel Spacing 12.5 KHz
Shipping 0.45 kg (Narrowband)
Antenna Impedance 50 Ohms
Power Requirements MSK RX Sensitivity -117 dBm +/- 2 dB for
50% message reception rate
Input Voltage +13.8 VDC nominal
(+9 VDC…+18 VDC)
FSK RX Sensitivity -129 dBm +/- 2 dB for
3 successful consecutive
message reception
Current 0.5 A nominal (receive)
1.5 A nominal (transmit)
2.0 A (Peak)
Transmit Power
+31 dBm +/- 1 dB
(at Antenna Connector)
Connections Built-in GPS
DC Power 2.5 mm Male Locking Jack
Internal GPS Receiver Trimble Lassen iQ
VHF Antenna Female SMA connector
Certifications FCC Part 15 Class “B”
Serial/Multi-Purpose I/O (2)
Female RJ45 connector
CENELEC (CE) EN
55022:1998 Class B
Ethernet
Female RJ45 connector
Standards from CENELEC
EN 55024:1998
GPS Antenna (optional) Female SMA connector
ROHS Compliance The NRU is ROHS compliant.
Environment
Temperature Range
(operating) -20 o C to +60 o C
Temperature Range
(storage) -40 o C to +105 o C
Relative Humidity 0-90% Non-Condensing
Environmental Rating N/A
The information and specifications contained in this document are subject to change without notice.