A Reliability-oriented Transmission Servicein Wireless Sensor Networks
Yunhuai Liu, Yanmin Zhu and Lionel NiComputer Science and Engineering
Hong Kong University of Science and Technology{yunhuai, zhuym, ni}[email protected]
Speaker: Peixin Wang
• Motivation• Related Work and challenges• Existing routing techniques and their drawbacks• In-middle Recovery and Proliferation Routing
design• Analysis of Proliferation Routing • Performance Evaluation• Conclusion
Motivation
• Reliable transmission service is in dire need for many applications in wireless sensor networks (WSNs). However ,Most existing routing protocols seriously suffer from low end-to-end success rates in real deployments which may lead to great loss.
Related Work and challenges
Two categories: Packet-loss avoidance ,Packet-loss recovery• Packet-loss avoidance: select more productive
forwarding nodes ( no guarantee of the service quality ) or by multi-path transmissions ( no recovery mechanisms )
• Packet-loss recovery: recover the packet loss when it happens. Existing recovery can be classified as end-to-end recovery (big latency and large energy cost)and per-hop recovery(no guaranteed service quality).
Related Work and challenges
• The first challenge is the long transmission paths in large-scale WSNs.
• The second challenge is the self-congestion phenomena due to the radio interference and collisions.
• The third challenge is the bad link propagation problem due to the unreliable links.
Existing routing techniques and their drawbacks
• Flooding-like routing(Impact of network density and environment)
Packet-loss avoidance approaches by multi-path in essential share a common idea of restricted flooding in a particular region. They have a similar behavior in the context of the one dimensional network.
Drawbacks :the radio interference and packet congestions with the increasing nodes
Existing routing techniques and their drawbacks
(Impact of routing metrics)• MCFN-like routing: a representative of hop-count
based routing algorithms using single path to transmit• GPSR-like routing: also employs single data path. But
geographic information is used instead of the hop count.
Drawbacks: Experimental results (not shown in the paper) show that MCFN-like routing presents poor success rate no matter how many intermediate nodes are deployed.
In-middle Recovery and Proliferation Routing design
• The basic idea of In-middle Recovery is that packet-loss is detected and recovered in a several-hop manner rather than per-hop or end-to-end.(fill the gap between the traditional per-hop recovery and end-to-end recovery mechanisms)
Advantages :1.Packet-loss due to congestions will not be further degraded by the per-hop recovery. 2.A level of end-to-end transmission service quality can be guaranteed when transmissions are monitored and recovered in a larger scale than per-hop. 3.In-middle recovery is able to offer a great potential of compatibility and flexibility.
In-middle Recovery and Proliferation Routing design
The core idea of proliferation routing is randomized dispersity of packet copies combined with a reproduction procedure.Three components:• Capability-based path finder to find more productive data
paths for seeds;• Seed splitter to disperse the seeds over the network so
that congestions and radio interferences can be reduced;• Seed reproduction to compensate packet-loss during
transmissions.
In-middle Recovery and Proliferation Routing design
• Capability-based path finderThe idea is that every node maintains a capability value that reflects the estimated transmission success rate from the node to the sink by a single path. Beacon messages are exchanged between neighboring nodes to calculate the link quality. This process repeats and propagates until every node obtains its capability.
In-middle Recovery and Proliferation Routing design
Multiple seeds with seeds splitter• The major difference: the trails of seeds are
designed to be disjoint• The travel of a seed has two phases: the randomized
dispersity phase and the deterministic phase.• The advantages :1.congestions and radio interferences can be mitigated2. high dynamic wireless links are alleviated3. hot-spot problem can be avoided
In-middle Recovery and Proliferation Routing design
• Seed reproductionBesides the original data source, intermediate forwarding nodes are also allowed to reproduce seeds.
In-middle Recovery and Proliferation Routing design
Analysis of Proliferation Routing
• Three key parameters: reproduction coefficient ,, random walk steps w, seed lifetime r.
• Reproduction coefficient
• Random walk steps w
• Seed lifetime r
Performance Evaluation
Experimental results :set the control parameters =3, w=4 and r=8 as suggested in the last section, no reproduction due to the space limitation
• Simulation results
Conclusion
• This paper proposed a novel in-middle recovery mechanism by designing and implementing proliferation routing scheme.
• Carefully designed system parameters grant designers more freedom to provide a guaranteed level of end-to-end transmission service quality
• Analysis and experiment results show that the success rate can be maintained to up 80% with a moderate communication overhead.