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MOBILEMAN Résumé de rapport

Project ID: IST-2001-38113
Financé au titre de: FP5-IST
Pays: Italy

Enhanced 802.11 MAC: design, implementation and validation

We developed a complete study of 802.11 use in multi hop ad hoc networks based on extensive experimental measurements and simulations. These studies produced an in depth understanding of 802.11 behaviour in ad hoc mode that was exploited to develop an accurate channel model. These results constitute the basis for the design, implementation and validation of an enhanced 802.11 MAC card that provides significant performance gains with respect to the standard 802.11 cards. The enhanced card has been designed to interoperate with legacy standard cards. More precisely, we achieved the results listed below, and expensively documented in Deliverables D12, D13 and D16.

-Extensive measurements to characterize the behaviour of IEEE 802.11 ad hoc networks from which we extracted a model to characterize it.

-Design of an enhanced MAC protocol (AOB) for ad hoc networks. The new MAC protocol is compatible with the IEEE 802.11 and provides a better channel utilization and fairness.

- Extension of the AOB mechanism, with a credit-based mechanism, to effectively operate in a heterogeneous environment where enhanced and legacy 802.11 cards co-exist.

The credit mechanism provides a formal basis to the activities of TG 802.11n that is working toward higher throughput for 802.11 networks. Indeed, AOB extended with the credit mechanism provides an optimised and efficient solution to the multiple transmissions approach currently under study in TGn.

The credit mechanism provides an efficient solution to fix 802.11 unfairness in multi-hop scenarios.
- Hardware implementation of the enhanced MAC card implementing both the AOB mechanism and its credit-based extension.

- Experimental validation of the AOB mechanism on a 4-node testbed.

- Implementation in the NS-2 tool of the simulation model of the enhanced MAC card.

- Validation of the AOB mechanism via simulation on large-scale networks.

Informations connexes


Marco CONTI, (Research director)
Tél.: +39-0503153062
Fax: +39-0503153273