Robustness of heuristic strategies with slow mobility in spatial TDMA multihop ad hoc networks

Multi-hop wireless networks (MWNs) are a promising technology for releasing the vision of pervasive communications, e.g., providing communications in remote areas without telecommunication infrastructure. In MWNs, the channel resource is efficiently managed by proper spatial reuse. One of the Medium Access Control (MAC) protocols with such characteristic is Spatial TDMA (STDMA). In addition, STDMA is a ldquoconflict-freerdquo MAC protocol, which enables high spectral utilization, by scheduling transmissions on the channel. In this paper, we study heuristic algorithms for link-oriented STDMA, where the schedule specifies when particular radio links will be activated, and its sensibility to nodespsila mobility. We analyze algorithms that exploit capabilities of the physical layer such as power control or discrete variable data rate. We consider the limited-mobility management in STDMA networks; that is we try to find out the ldquorangesrdquo where our heuristics will avoid the re-scheduling of the whole STDMA frame. We found that a substantial throughput degradation due to slow mobility in STDMA can be compensated, and this can be obtained by means of traffic adaptivity, variable power or rate control, and spatial reuse. Our results show that power or rate-controlled STDMA are robust in handling this situation.