In wireless sensor networks (WSN), nodes have very limited power due to
hardware constraints. Packet losses and retransmissions resulting from congestion
cost precious energy and shorten the lifetime of sensor nodes. This problem motivates
the need for congestion control mechanisms in WSN.
In this thesis, an observation of multiple non-empty queues in sensor networks
is first reported. Other aspects affected by congestion like queue length, delay and
packet loss are also studied. The simulation results show that the number of occupied
queues along a path can be used to detect congestion.
Based on the above result, a congestion control scheme for the transport layer
is proposed in this thesis. It is composed of three parts: (i) congestion detection
by tracking the number of non-empty queues; (ii) On-demand midway non-binary
explicit congestion notification (CN) feedback; and (iii) Adaptive rate control based
on additive increase and multiplicative decrease (AIMD).
This scheme has been implemented in ns2. Extensive simulations have been
conducted to evaluate it. Results show that it works well in mitigating and avoiding
congestion and achieves good performance in terms of energy dissipation, latency and
transmission effciency.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/2331 |
| Date | 29 August 2005 |
| Creators | Xiong, Yunli |
| Contributors | Miller, Scott L. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 298931 bytes, electronic, application/pdf, born digital |
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