On the impact of far-away interference on evaluations of wireless multihop networks

It is common practice in wireless multihop network evaluations to ignore interfering signals below a certain signal strength threshold. This paper investigates the thesis that this produces highly inaccurate evaluations in many cases. We start by defining a bounded version of the physical interference model, in which interference generated by transmitters located beyond a certain distance s from a receiver is ignored. We then derive a lower bound on neglected interference and show that it is approximately two orders of magnitude greater than the noise floor for typical parameter values and a surprisingly small number of nodes. We next evaluate the effect of neglected interference through extensive simulations done with a widely-used packet-level simulator (GTNetS), considering 802.11 MAC with both CBR and TCP traffic in networks of varying size and topology. The results of these simulations show very large evaluation errors when neglecting far-away interference: errors in evaluating aggregate throughput when using the default interference model reached up to 210% with 100 nodes, and errors in individual flow throughput were far greater.

[1]  Panganamala Ramana Kumar,et al.  RHEINISCH-WESTFÄLISCHE TECHNISCHE HOCHSCHULE AACHEN , 2001 .

[2]  George F. Riley,et al.  The Georgia Tech Network Simulator , 2003, MoMeTools '03.

[3]  David A. Maltz,et al.  Dynamic Source Routing in Ad Hoc Wireless Networks , 1994, Mobidata.

[4]  Ness B. Shroff,et al.  On the Complexity of Scheduling in Wireless Networks , 2006, MobiCom '06.

[5]  Samir Ranjan Das,et al.  A measurement study of interference modeling and scheduling in low-power wireless networks , 2008, SenSys '08.

[6]  André Schiper,et al.  On the accuracy of MANET simulators , 2002, POMC '02.

[7]  Roger Wattenhofer,et al.  The Complexity of Connectivity in Wireless Networks , 2006, Proceedings IEEE INFOCOM 2006. 25TH IEEE International Conference on Computer Communications.

[8]  Yin Zhang,et al.  A general model of wireless interference , 2007, MobiCom '07.

[9]  Dimitrios Koutsonikolas,et al.  Characterizing multi-way interference in wireless mesh networks , 2006, WINTECH.

[10]  Roger Wattenhofer,et al.  Topology control meets SINR: the scheduling complexity of arbitrary topologies , 2006, MobiHoc '06.

[11]  Jason Liu,et al.  Experimental evaluation of wireless simulation assumptions , 2004, MSWiM '04.

[12]  Roger Wattenhofer,et al.  Complexity in geometric SINR , 2007, MobiHoc '07.

[13]  Mineo Takai,et al.  Effects of wireless physical layer modeling in mobile ad hoc networks , 2001, MobiHoc '01.

[14]  Rudolf H. Riedi,et al.  On the Broadcast Capacity of Multihop Wireless Networks: Interplay of Power, Density and Interference , 2007, 2007 4th Annual IEEE Communications Society Conference on Sensor, Mesh and Ad Hoc Communications and Networks.

[15]  Elyes Ben Hamida,et al.  Scalable versus Accurate Physical Layer Modeling in Wireless Network Simulations , 2008, 2008 22nd Workshop on Principles of Advanced and Distributed Simulation.

[17]  Qi Chen,et al.  Overhaul of ieee 802.11 modeling and simulation in ns-2 , 2007, MSWiM '07.

[18]  Catherine Rosenberg,et al.  What is the right model for wireless channel interference? , 2006, IEEE Transactions on Wireless Communications.

[19]  Ness B. Shroff,et al.  On the Complexity of Scheduling in Wireless Networks , 2010, EURASIP J. Wirel. Commun. Netw..

[20]  Deborah Estrin,et al.  Effects of Detail in Wireless Network Simulation , 2001 .

[21]  J. Broch,et al.  Dynamic source routing in ad hoc wireless networks , 1998 .

[22]  Paolo Santi,et al.  Computationally efficient scheduling with the physical interference model for throughput improvement in wireless mesh networks , 2006, MobiCom '06.

[23]  Mario Gerla,et al.  GloMoSim: a library for parallel simulation of large-scale wireless networks , 1998 .