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}l@cse.ust.hk

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.