This thesis contributes to the domain of medium access control for ad hoc networks. These networks are by definition created for the occasion, or for a specific purpose, and usually have to operate without any existing fixed infrastructure. In this context, the MAC layer appears to be a performance bottleneck, especially at high input loads. It can be demonstrated that the off-the-shelf solutions like the standard IEEE 802.11 present lack of performance related to throughput and fairness in multi-hop networks. A new slotted protocol, called Collision-free Receiver Oriented MAC (CROMA), provides an elegant solution to overcome the above mentioned drawbacks especially in heavily loaded wireless multi-hop ad hoc networks. The receiver oriented nature of CROMA is a determining factor both for the fairness and for an improved throughput (with respect to IEEE 802.11) in multiple targeted environments. Cross-layer mechanisms useful for further capacity increase and enhancement of CROMA exist. This has been demonstrated through theoretical analysis and simulations in the following three cases: (i) A simplified version of CROMA and an associated scheduling policy can take advantage of node mobility for throughput improvement. (ii) Multi-user diversity considerably improves the CROMA reservation scheme based on slotted ALOHA. (iii) Multi-user detection can offer additional improvement for reservation too.
Distributed MAC protocols for heavily loaded ad hoc networks
Thesis
Type:
Thèse
Date:
2004-06-25
Department:
Systèmes de Communication
Eurecom Ref:
1422
Copyright:
© ENST Paris. Personal use of this material is permitted. The definitive version of this paper was published in Thesis and is available at :
See also:
PERMALINK : https://www.eurecom.fr/publication/1422