A Wireless Flit-Based OpNET Model

Recent evaluation of ad hoc networks has shown that current techniques do not scale well with either network size or desired throughput. We argue that the greatest opportunity for improvement is in the integration and coupling of different network layers. To this end, we are building a “relay network” design in which end-to-end path resources are pre-allocated to avoid the cost of channel acquisition and contention at every hop. The routing, congestion control, and MAC functions are coupled – contention informs the routing and packet admission decisions, and demand determines link capacity allocation. We propose using spatial frequency division multiple access (SFDMA) to reduce interference and propose a forwarding layer using label-switching to allow a combination of SFDMA as well as statistical multiplexing. Normally, SFDMA methods are difficult to allocate due to a paucity of channels; we provision our network using Orthogonal Frequency Division Multiple Access (OFDMA) channels, avoiding re-synchronization delays on each packet. One option for such networks is to use wireless flits rather than full packets for store-and-forward communication. This report describes an OpNET model that implements both those wireless flits and the traditional store-and-forward SFDMA networks.