Abstract

In this project, we propose to study the next generation ad hoc networks integrated in heterogeneous systems, and in particular, address two challenging problems in the Medium Access Control (MAC) sub-layer and the Network Layer, respectively. Recent researches have shown that the MAC protocol defined in IEEE 802.11 Standard does not work well in a multi-hop network running TCP/IP and interacting with other networks. In this research, we propose a MAC protocol with Separate Signaling Channel (MAC-SSC) to reduce the collision of the signaling frames and the bandwidth wasted during the back-off time. The basic idea of MAC-SSC is to reserve a small fraction of the total bandwidth for signaling, and pipeline the contention of data channel for the next data frame with the transmission of the current data frame. Moreover, we study the scalability problem of ad hoc networks due to the limited capacity of the wireless link and the absence of backbone infrastructure, and develop an analytical model to determine the upper bound and the recommended network size for a given network profile. We also propose a novel clustering scheme, and deploy the Support Points (SPs) running protocol similar to Multi-Protocol Label Switching (MPLS) to facilitate intra-cluster and inter-cluster routing.