Specifications

Sierra Wireless, Inc. CDPD Primer
2130006 Rev 1.0 Page iii
Contents
1. About this Guide............................................................................1
1.1. Introduction ........................................................................................................... 1
1.2. Document Structure .............................................................................................. 1
1.2.1. Format.................................................................................................... 1
1.2.2. Organization .......................................................................................... 1
1.3. References .............................................................................................................. 1
1.3.1. Terminology and Acronyms .................................................................. 1
2. Telephones and Wireless Data Transmission .............................2
2.1. Telecommunications and the Telephone ............................................................. 2
2.1.1. Wireline Telephones.............................................................................. 2
2.1.2. Wireless Telephones.............................................................................. 2
2.2. The Advanced Mobile Phone System (AMPS).................................................... 2
2.2.1. Why Cellular?........................................................................................ 3
2.2.2. Analog FM Using Different Channels to Send and Receive ................. 3
2.2.3. A-side and B-side Carriers..................................................................... 3
2.2.4. Cell Sites Coordinated by the MTSO .................................................... 4
2.2.5. Assigning and De-Assigning Frequencies ............................................. 4
2.2.6. Reusing Frequencies.............................................................................. 5
2.2.7. Cell Handoff .......................................................................................... 6
2.3. Cellular Data Transmission.................................................................................. 6
2.3.1. Circuit-Switched vs. Packet-Switched Data .......................................... 6
3. Background: Introduction to CDPD..............................................8
3.1. Cellular Digital Packet Data (CDPD) .................................................................. 8
3.1.1. Packet-Switched Data Shared With Voice Calls ................................... 8
3.1.2. Channel Hopping................................................................................... 9
3.1.3. Dedicated CDPD Channels.................................................................. 10
3.1.4. Base Station Broadcast Parameters...................................................... 11
3.1.5. CDPD Services Provided Over the Airlink ......................................... 11
3.1.6. A Buffer Between the Internet and the Modem................................... 11