000151661 001__ 151661
000151661 005__ 20190316234853.0
000151661 037__ $$aREP_WORK
000151661 245__ $$aUnderstanding and Tackling the Root Causes of Instability in Wireless Mesh Networks: (extended version)
000151661 269__ $$a2010
000151661 260__ $$c2010
000151661 300__ $$a19
000151661 336__ $$aReports
000151661 500__ $$aA journal paper version of this work is under submission in the IEEE/ACM Transactions on Networking
000151661 520__ $$aWe investigate, both theoretically and experimentally, the stability of CSMA-based wireless mesh networks, where a network is said to be stable if and only if the queue of each relay node remains (almost surely) finite. We identify two key factors that impact stability: the network size and the so-called "stealing effect", a consequence of the hidden node problem and non-zero transmission delays. We consider the case of a greedy source and prove, by using Foster's theorem, that 3-hop networks are stable, but only if the stealing effect is accounted for. We also prove that 4-hop networks are, on the contrary, always unstable (even with the stealing effect) and show by simulations that instability extends to more complex linear and non-linear topologies. To tackle this instability problem, we propose and evaluate a novel, distributed flow-control mechanism, called EZ-flow. EZ-flow is fully compatible with the IEEE 802.11 standard (i.e., it does not modify headers in packets), can be implemented using off-the-shelf hardware, and does not entail any communication overhead. EZ-flow operates by adapting the minimum congestion window parameter at each relay node, based on an estimation of the buffer occupancy at its successor node in the mesh. We show how such an estimation can be conducted passively by taking advantage of the broadcast nature of the wireless channel. Real experiments, run on a 9-node testbed deployed over 4 different buildings, show that EZ-flow effectively smoothes traffic and improves delay, throughput, and fairness performance.
000151661 700__ $$0242765$$aAziz, Adel$$g149125
000151661 700__ $$aStarobinski, David
000151661 700__ $$0240373$$aThiran, Patrick$$g103925
000151661 8564_ $$s1372321$$uhttps://infoscience.epfl.ch/record/151661/files/aaziz-ToN10_extended_1.pdf$$zn/a
000151661 909C0 $$0252614$$pLCA$$xUS00024
000151661 909C0 $$0252454$$pLCA3$$xU10431
000151661 909CO $$ooai:infoscience.tind.io:151661$$pIC$$preport$$qGLOBAL_SET
000151661 917Z8 $$x149125
000151661 917Z8 $$x149125
000151661 917Z8 $$x103925
000151661 937__ $$aEPFL-REPORT-151661
000151661 973__ $$aEPFL$$sPUBLISHED
000151661 980__ $$aREPORT