Traffic model for micro-/pico-cellular packet-switching wireless networks

Abstract

Traffic modeling of an integrated voice/data/video wireless networks has its own unique characteristics. The traffic issues of circuit switching and packet switching networks are different. In circuit switching networks when a mobile user is in the calling mode, he is using the channel during the whole period of the call, while in packet switching networks, at any given time a calling host might be active or inactive. Thus in circuit switching networks the number of calling hosts directly specifies the number of available channels. In packet switching networks, the number of available channels depends on the calling hosts and their activity pattern. Thus the number of calling calls in a packet switching network is not the same as channel utilization. In a cellular system, especially when cells are small, the traffic of a cell is related to the traffic of its adjacent cells. In the case of small cells, when a host leaves a cell, the probability of returning to the same cell after two hand-offs is negligible. This fact should be considered in modeling a cellular network to get correct results. The capacity limitation and call hand-off are defined based on the availability of channels and the quality of service. The capacity limitation is defined based on channel usage pattern of calling hosts. Decreasing the cell size results in more hand-offs and also more capacity. When the cell size is small we need a precise traffic model which is based on traffic pattern and call hand-off to define the network capacity.