JPL's Wireless Communication Reference Website

Chapter: Data Networks

Performance of Packet Data Networks

It cannot be assumed that such cellular structures optimized for non-blocking voice circuits are also optimal for a mobile network of virtual circuits between users who are prepared to accept delays of their data packets. When computer users are prepared to gamble against the risk of mutual conflicts in order to reap the benefit of lower average delay, they can also adopt a more tolerant attitude to the additional random vagaries of the mobile radio channel. Moreover, such users prepared to accept occasional mutual conflicts between their accesses may find it counterproductive to invoke the strict power control assumed in mobile telephone systems: If access powers are very unequal among competing signals, there is a better chance that at least one competitor wins the contest for the receiver (capture), than in the event of perfectly balanced signals, which will all annihilate each other in a collision. Research has shown that this effect causes mobile packet-data random-access networks to have a higher throughput than predicted by conventional models used for wireline networks.

Figure: One of the objectives in a cellular data network is to minimize the waiting time in the packet buffer of base station.

It appears that for many data networks with bursty traffic, the optimum reuse pattern is to use the same channel in all cells. This has been verified by calculations for the uplink and the downlink.

JPL's Wireless Communication Reference Website 1993, 1995.