Effective forward-channel capacity of non-dedicated CDPD networks

Cellular digital packet data (CDPD) is a mobile packet data technology developed to operate on the spectrum assigned to a telephone cellular network. Since it operates on non-dedicated RF channels, it is subject to channel hopping and its performance is affected by the traffic profile of the underlying telephone system. We develop formulas expressing the normalized forward channel capacity in terms of telephone traffic conditions and channel hopping parameters. We show that forward capacity is very near to maximum for telephone network utilization less than one, while it degrades rapidly thereafter. Moreover, we develop an expression for the average hopping rate and we demonstrate the sensitivity of capacity with the number of RF channels.