Cellular Digital Packet Data: channel availability

Cellular Digital Packet Data (CDPD) systems borrow idle radio channels from Advanced Mobile Phone Standard (AMPS) cellular networks to send short bursts of packet data traffic. Due to trunking inefficiencies inherent to AMPS systems, a relatively large amount of spare AMPS air link capacity can be found for CDPD. In addition, the periods that time AMPS channels are idle are fairly long. Due to fluctuations in the number of AMPS radios in a sector that are busy serving voice calls, there will be periods of time when there is not an ample number of idle AMPS channels to satisfy the demands of CDPD. Resource contention between CDPD and AMPS affects the amount of data that can be carried on the CDPD air link and the performance of link and higher layer protocols. We present a series of analytical results which serve as the basis for cell site capacity engineering rules for CDPD systems