Impact of Routing Metrics on Path Capacity in Multirate and Multihop Wireless Ad Hoc Networks

Abstract

Finding a path with enough throughput in multihop wireless ad hoc networks is a critical task of QoS Routing. Previous studies on routing algorithms focused on networks with a single channel rate. The capability of supporting multiple channel rates, which is common in wireless systems, has not been carefully studied in routing algorithms. In this paper, we first carry out a comprehensive study on the impacts of multiple rates, interference and packet loss rate on the maximum end-to-end throughput or path capacity. A linear programming problem is formulated to determine the path capacity of any given path. This problem is also extended to a joint routing and link scheduling optimization problem to find a path with the largest path capacity. We show that interference clique transmission time is inversely proportional to the upper bound of the path capacity, and hence we propose to use it as a new routing metric. Moreover, we evaluate the capability of various routing metrics such as hop count, expected transmission times, end-to-end transmission delay or medium time, link rate, bandwidth distance product, and interference clique transmission time to discover a high throughput path. The results show that different routing metrics lead to paths with significantly different path capacity, and the interference clique transmission time tends to discover paths with higher throughput than other metrics.

Spectrum clouds: A session based spectrum trading system for multi-hop cognitive radio networks

“…Depending on different modulation schemes, the achievable data rate is actually determined by the SNR at the receiver and receiver sensitivity [24], [26]. However, in most of existing literature [17], [18], [20], the achievable data rate is approximated by (2), even though this data rate can never be achieved in practical.…”

“…In the rest of this section, we first extend the conflict graph [24], [26] to characterize the interference relationship among CR links in spectrum clouds. Then, based on the extended conflict graph, we mathematically describe link scheduling and flow routing constraints and formulate the spectrum trading into the revenue maximization problem of the SSP under multiple constraints.…”

“…In the widely used protocol model [17], [18], [20], [22]- [24], the interference range is typically 2 or 3 times of the transmission range, i.e., R I RT = 2 or 3. These two ranges may vary with frequency.…”

Coolest Path: Spectrum Mobility Aware Routing Metrics in Cognitive Ad Hoc Networks

“…Various routing metrics have been proposed in wireless networks, targeted at load-balancing [12]- [14] or characterizing channel interference [15]- [17]. Extensions of ETX [17] considering varying link reliability are introduced in [18].…”

Fair Profit Allocation in the Spectrum Auction Using the Shapley Value

“…Even though interference is a local effect, the spatial reuse of frequency makes the problem of finding the optimal spectrum allocation NP-complete [15], [16], which fails all the optimal allocation based conventional auction mechanisms [17].…”