Distributing Data Rate Using Cooperative Channel Assignment for Multi-Rate Wireless Mesh Networks

Abstract

Wireless Mesh Networks (WMNs) have emerged to provide cost-effective broadband Internet accesses. Today's IEEE 802.11 PHY and MAC specifications support multi-channel and multi-rate capabilities. Designing an efficient channel assignment protocol utilizing available channels and data rates is a hot issue to leverage the network capacity. In multi-rate networks, low-rate links severely decrease the capacity of high-rate links, known as performance anomaly. In this paper, we design a Cooperative Channel Assignment (CoCA) protocol to address the performance anomaly in WMNs. For the channel assignment of family architecture, CoCA utilizes the Estimated Delivery Time (EDT) metric and the balancing algorithm. With the EDT metric, CoCA separates different rate links via multiple channels. By using the balancing algorithm, CoCA also increases throughput fairness. Our simulation results show that CoCA outperforms the existing well-known channel assignment protocols for WMNs. Index Terms-Channel Assignment, Multi-Channel, MultiRate, Wireless Mesh NetworksSystem Model. Although IEEE 802.11b or 802.11a can be used for our protocol, we consider IEEE 802.11a-based MCMR WMNs, since IEEE 802.11a provides higher data rates and more channels. For simplicity, we make following assumptions.

Exploiting channel and interface heterogeneity for rate separating channel assignment in IEEE 802.11 wireless multimedia sensor networks

“…[20][21][22][23][24][25][26][27] These protocols do not modify the commodity 802.11 devices, since they just utilize and assign channels to available NICs. Instead, they assume multiple NICs per node.…”

“…9,10,12,[20][21][22][23][24][25][26][27] Motivation 1: Channel and interface heterogeneity Using our IEEE 802.11a WMSN test bed, we observe the channel and interface heterogeneity to motivate our work on designing a rate separating channel assignment protocol. First, we discuss the channel heterogeneity by measuring the RSS values of a single link per second for each IEEE 802.11a channel in a round-robin fashion.…”

“…Figure 2 To mitigate rate anomaly, we can assign channels differently by separating high-rate links from low-rate links. When channels and NICs are assumed to be homogeneous according to existing rate separating protocols, [20][21][22][23][24][25][26][27] we can consider one possible solution as shown in case 2 (Figure 2(c)), where the data rate of links is equivalent regardless of the used channels and Figure 3 shows the aggregate throughput of two multihop flows in the three cases of Figure 2. The results in Figure 3 are averaged from five repeated experiments on our test bed and depicted with the 95% confidence interval.…”

“…[14][15][16][17][18][19] For multichannel networks, there have been several rate separation works that separate high-rate links from low-rate links by exploiting multiple channels and interfaces without 802.11 extensions. [20][21][22][23][24][25][26][27] Our research objective in this article is to develop a novel channel assignment protocol, called heterogeneity-aware mesh (HMesh), to exploit ''channel and interface heterogeneity'' for ''rate separation'' in IEEE 802.11 multiradio multirate WMSNs. In HMesh, each node is equipped with multiple NICs and forms a tree architecture rooted at a sink node to deal with the traffic distribution of WMSNs.…”

“…15,[20][21][22][23][24][25][26][27] That is, the link data rates can be different depending on the operating channels and interface pairs. Hence, an intelligent channel assignment protocol should consider the channel and interface heterogeneity in IEEE 802.11 WMSNs.…”