CalAmp Wireless Networks NRU Users Manual

CONFIDENTIAL AND PROPRIETARY

NRU Network Repeater Unit

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.

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 Alt­Deactivate.

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:

certified for 13 Second Systems and FCC certified as a
mobile transmitter for 8 second Systems.

The NRU is not base station certified. It is ETSI

200 Lowder Brook Drive

Westwood, MA 02090 USA

Voice: 1-781-326-4700

Fax: [phone]

www.lojack.com

LoJack Corporation

CONFIDENTIAL AND PROPRIETARY

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.

 Uplink message receiving and repeating

capability

 Easy to maintain/upgrade system, reduces or

eliminates site visits

 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)

Current 0.5 A nominal (receive)

1.5 A nominal (transmit)

2.0 A (Peak)

Connections Built-in GPS

DC Power 2.5 mm Male Locking Jack Internal GPS Receiver Trimble Lassen iQ

FSK RX Sensitivity -129 dBm +/- 2 dB for

3 successful consecutive

message reception

Transmit Power

+31 dBm +/- 1 dB

(at Antenna Connector)

VHF Antenna Female SMA connector Certifications

Serial/Multi-Purpose I/O (2)

Ethernet

GPS Antenna (optional)

Environment
Temperature Range
(operating)
Temperature Range
(storage)
Relative Humidity 0-90% Non-Condensing
Environmental Rating N/A

Female RJ45 connector

Female RJ45 connector

Female SMA connector

o

C to +60 o C

-20

o

C to +105 o C

-40

ROHS Compliance The NRU is ROHS compliant.

FCC Part 15 Class “B”

CENELEC (CE) EN

55022:1998 Class B

Standards from CENELEC

EN 55024:1998

The information and specifications contained in this document are subject to change without notice.

200 Lowder Brook Drive

Westwood, MA 02090 USA

Voice: 1-781-326-4700

9080-0026-00 Rev B – NRU Fax: [phone]
Revised Sep 2010 www.lojack.com

LoJack Corporation