AirLink CDPD

Cellular Digital Packet Data 
About the Technology

CDPD is particularly well-suited to mobile professionals because it offers a high-speed, high-capacity, low-cost system with the greatest possible coverage. Additionally, data is encrypted for greater security.

CDPD became a networking standard in the early 1990s, when a consortium of cellular carriers across the United States came together for the purpose of creating a method for sending data over cellular telephone channels. They wanted to provide a cost-effective, reliable and flexible solution to providing two-way wireless data communications service for mobile professionals.

Here's how it works: During transmission across cellular telephone channels, there are moments when the channel is idle. In fact, industry research indicates that over 30 percent of air time, even during heavy traffic, is unused. CDPD technology is able to detect and use these otherwise wasted moments by packaging data in small packets and sending it in short "bursts" during the idle time. As a result, the cellular channel operates more efficiently, and voice and data transmissions are unaffected. CDPD is based on the same communications protocol as the Internet, so mobile users have access to the broadest range of information.  

AirLink CDPD Raven

The  Raven is a rugged, full duplex Cellular Digital Packet Data (CDPD) modem that provides wireless transport capabilities for fixed and mobile applications. The Raven is an efficient and secure wireless packet data technology that is ideal for un-tethered applications. CDPD is more cost effective than circuit-switched cellular data for small volumes of data. It provides instantaneous response for transaction processing because there are no dialing delays. Additionally, built-in encryption maintains the security of the application data over the air.

The CDPD Raven is ideally suited for all fixed and mobile Industrial and Commercial Applications, including Telemetry, SCADA, Public Safety, Dispatch, Field Service, Financial Transaction Processing, and Security. The Raven’s embedded TCP/IP stack enables virtually any type of remote device to access the CDPD network.

The Raven is currently installed with many different types of Remote Terminal Units (RTUs) which perform remote metering and monitoring functions in the oil, gas, and water industries. The CDPD Raven can be a low-cost replacement for existing landline, private radio and circuit-switched cellular installations.

The Raven is certified by numerous Public Safety application providers and is installed with many Police Departments throughout the US.

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  • 19.2 kbps raw data transfer rate
  • Full duplex transceiver
  • 600 mW transmit power
  • Integrated TCP/IP protocol stack
  • Proven technology
  • Compact size
  • Rugged aluminum case
  • LEDs show status of CDPD operation
  • Mounting brackets

Application Interfaces

Standard interfaces include:

  • AT command serial character streams (uses embedded TCP/IP stack)
  • Host TCP/IP stack communicates with Raven using SLIP
  • Windows 95/98/NT Dial-Up Networking communicates with Raven using PPP

    (Modem configuration file included)

In addition, several protocol conversions (Modbus, Opto22, BSAP) have been implemented to allow hosts to communicate with RTUs over CDPD without modifying the host or remote software.

Custom Application Development

AirLink can customize the software in the Raven to include all or part of your application processing. In some cases, the entire application can reside inside the Raven. No additional processor is required.

Wireless ACE

Windows 95/98/NT 
modem configuration utility

  • Configure AirLink Modems locally or remotely without using AT commands
  • Monitor the operating status of an AirLink Modem locally or remotely
  • Secure communications with password protection
  • Reduce troubleshooting time and support costs

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Physical Characteristics NovAtel Wireless CDPD Modem NRM6812
Weight: < 2 lb. Integrated TCP/IP Full Duplex
Size: 6.8" x 3.3" x 2" Transmit Power 600 mW
Status LEDs: Power Transmit 824-849 MHz
  Channel Acquired Receive 869-894 MHz
  Link Status RF Protocol CDPD 1.0, 1.1
  Network Registration Airlink Data Rate 19.2 Kbps
  RSSI Serial Protocols AT Commands
  Transmit   SLIP
  Receive   PPP
Block Errors
RF Antenna Connector Power Requirements
50 Ohm TNC Input Voltage 9 VDC to 30 VDC
Input Current .10 to .54 Amps
Serial Interface Typical Receive .14 Amps @ 12 VDC
RS-232 DB-9F   Typical Transmit .34 Amps @ 12 VDC
300-19,200 bps
Environmental Warranty
Operating Temperature Range
-30° C to 70° C
With transmissions limited to a 10% duty cycle above 60° C
Humidity: 5% - 95% Non-condensing
Software 1 year updates & feature enhancements
Hardware 1 year parts and labor
Extended warranties available

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