Joint Optimal Channel Assignment and Congestion Control for Multi-channel Wireless Mesh Networks

Abstract

Abstract-The aggregate capacity of wireless mesh networks can be increased by the use of multiple channels. Stationary wireless routers are equipped with multiple network interface cards (NICs). Each NIC is assigned with a distinct frequency channel. In this paper, we formulate the Joint Optimal Channel Assignment and Congestion Control (JOCAC) as a decentralized utility maximization problem with constraints that arise from the interference of the neighboring transmissions. Unlike other previous work, the JOCAC algorithm is able to assign not only the non-overlapping (orthogonal) channels, but also the partiallyoverlapping channels within the IEEE 802.11 frequency bands. Using 802.11b with 3 non-overlapping channels, simulation results show that our algorithm provides a higher aggregated goodput than the recently proposed load-aware algorithm by 20%. The goodput is further increased by 40% when all the 11 partially-overlapping channels are being used.

Congestion-aware channel assignment for multi-channel wireless mesh networks

“…We would also have M lk ¼ 0 for any l 2 L and each k 2 L n flg. In fact, the capacity model in (8) is a special case of the capacity model in (22). Similar to (9), we can replace c l ðxÞ in problem (CACA) with (22) and obtain the complete formulation of our congestionaware channel assignment model.…”

“…Various congestion measures can be considered. For example, following the steps in [22], we can show that the network utility maximization (NUM) problem [25][26][27][28] in the presence of elastic traffic sources can be reduced to solving problem (CACA) if k l denotes the congestion price on link l. In this case, the congestion prices depend on the transport-layer protocol is being used. For example, the congestion prices are queueing delay and packet loss probability for TCP Vegas [29] and TCP Reno [30], respectively.…”

“…Kodialam and Nandagopal [13] also proposed an algorithm that maximizes the network throughput subject to the minimum rate requirements for each flow. It has been also recently shown in two independent works in [21,22] that using partially-overlapped frequency channels can further improve network performance. Last but not least, the study of channel assignment when smart directed antennas are used is presented in [23].…”

Joint logical topology design, interface assignment, channel allocation, and routing for multi-channel wireless mesh networks

“…A joint routing and NIC assignment scheme is proposed in [21]. In [22], we formulate the joint channel assignment and congestion control as a utility maximization problem. The model is extended to incorporate network interface assignment and media access control in [23].…”

“…Load balancing is shown to be a proper objective for joint topology control and routing algorithms in optical networks [28]. Congestion aware capacity planning is also proposed for cross-layer congestion control designs in wireless ad-hoc [29] and mesh networks [22]. Maximizing δ min can also be justified in terms of providing fairness among the existing logical links.…”