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TP-UrbanX - A New Transport Protocol for Cognitive Multi-Radio Mesh Networks


Abstract—Wireless Multi-Radio Mesh Networks (WMNs) that operate in license-free spectrum portions in dense urban areas face heavy interference from e.g. residential access points. We address this challenge by designing Urban-X- a new architecture for Multi-Radio Cognitive Mesh Networks based on principles from Dynamic Spectrum Access Networks. Based on spectrum sensing, it estimates traffic load of existing users outside the mesh in each channel and utilizes less occupied channels op- portunistically. In this environment, there are several challenges that must be addressed by a transport layer protocol. Among others, spectrum sensing and mobility can lead to variation in delay and available bandwidth. Also external traffic may lead to high packet loss making it difficult for standard TCP to operate efficiently. In this study, we propose a new transport protocol TP-UrbanX for cognitive wireless multi-radio mesh networks which exploits reinforcement based learning techniques to learn an optimal sending rate and adapt this rate given the dynamics of the environment such as spectrum sensing. Information available from backpressure scheduling is used to adapt to congestion state information. TP-UrbanX is evaluated using an enhancement of the popular ns-2 simulator, which allowed us to model different external user conditions and traffic loads as well as spectrum sensing and mobility. The results demonstrate the feasibility of our approach and show enhanced throughput by 25% rather than TCP New Reno.


Information & Date

WOWMOM'11, Lucca, Italy, June. 2011


Wooseong Kim
Andreas J. Kassler
Marco Di Felice
Mario Gerla