The gray zone problem in IEEE 802.11b based ad hoc networks

ABSTRACT

Our experiments with IEEE 802.11b based wireless ad hoc networks show that neighbor sensing with broadcast messages introduces "communication gray zones": in such zones data messages cannot be exchanged although the HELLO messages indicate neighbor reachability. This leads to a systematic mismatch between the route state and the real world connectivity, resulting in disruptive behavior. Concentrating on AODV we explore this issue and present three different techniques to overcome the gray zone problem.

REFERENCES

• 1: AODV-UU webpage http://www.docs.uu.se/scanet/aodv/
• 2: APE testbed project webpage http://apetestbed.sourceforge.net
• 3: H. Lundgren, D. Lundberg, J. Nielsen, E. Nordström, C. Tschudin: A Large-scale Testbed for Reproducible Ad hoc Protocol Evaluations. Proc. IEEE Wireless Communications and Networking Conference 2002 (WCNC'02), March 2002.
• 4: The Network Simulator - ns-2 webpage http://www.isi.edu/nsnam/ns/
• 5: C. Perkins, E. Royer, S. Das: Ad hoc On-demand Distance Vector (AODV) Routing, Internet Draft, draft-ietfmanet-aodv-10.txt, work in progress, January 2002.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Wireless communication

Additional Classification:
  C. Computer Systems Organization
  C.4 PERFORMANCE OF SYSTEMS
      Subjects: Reliability, availability, and serviceability

General Terms:
Experimentation, Measurement, Performance