A throughput/delay comparison: narrowband versus broadband wireless LAN´s

A communication system in which some large number of portable notebook computers access a centrally-located base station by means of a shared, high-speed, radio-based LAN is considered. The delay and throughput performances of two alternative approaches are compared: one high-speed channel shared by all portable remotes versus several moderate-speed channels, each shared by a subset of portable units. In both cases, access to the intended services is impeded by contention for the medium and queueing for some shared server (processor or database). Both systems are modeled as closed-queueing networks, and expressions for system throughput and average request delay are obtained. Numerical results show that over a wide range of parameters, the system containing one high-speed channel outperforms the system containing several parallel medium-speed channels by less than 10%