Wireless mesh networks

This project is mainly focused on the investigation of multi-channel assignment scheme for multi-hop wireless mesh networks.

· Hybrid Temporal-Spatial Multi-Channel Assignment with Single Radio per Node (GLOBECOM09)


(a) a spatial channel assignment scheme for gateway node and its neighbors	(b) a temporal channel assignment scheme for gateway node and its neighbors

Figure 1 Temporal-spatial channel assignment scheme

To maximize the network throughput, we propose a synchronization-free, Hybrid Temporal Spatial Multi-channel Assignment (HTSMA) scheme (Fig. 1) in a random heterogeneous network requiring only a single radio interface per host. In this scheme, the gateway is allowed to use all the available channels sequentially in a round-robin fashion. This temporal channel assignment approach ensures that all the neighboring hosts that communicate with the gateway directly shall have a fair access to the gateway. The channel assignment for the remaining wireless hosts is based on the geographical location and channel availability (a spatial approach) to avoid the interference within the communication region of each sender host in its transmission time period. Compared with another multichannel scheme MMAC, extensive simulation results demonstrate that our proposed scheme can improve the network throughput substantially with the acceptable collision ratio.

· Multi-Radio Multi-Channel Assignment (AHN2012, ICCSIT10)
The HTSMA scheme is extended to the general case where each node is equipped with various numbers of radios. The proposed scheme does not require global time synchronization for coordinating communications or a dedicated channel for exchanging the control messages, which indicates it can be simply upgraded in the firmware without any hardware/software change. On the other hand, this scheme assigns the distinct channels to the communication nodes in a flow (toward the gateway), which is efficient for flows with a large number of hops, because channel conditions may vary in different parts of the flow. With its simplicity and flexibility, it is very suitable to be applied for large-scale WMNs. Simulation results confirm that this scheme can improve both the aggregate and saturation network throughput substantially with the acceptable collision ratio.