An Improved Route Repair Approach of Wireless Sensor Networks

1. An Improved Route Repair Approach of Wireless Sensor Networks Yuhua Liu and Haiyan zhu yhliu@mail.ccnu.edu.cn Department of Computer Science, Central China Normal UniversityWuhan 430079, China 2006.06

2. Outline • 1 Introduction • 2 Several efficient route repair protocols • 3 The route repair approach based on sink sequence number (RRASS) • 4 Performance compare of several route protocols • 5 Conclusion

3. 1 Introduction • For the limitations in communication bandwidth, battery power, computing ability, memory and the characteristics of large scale, complex dynamic topology, the traditional route protocol of Ad Hoc can’t meet the demand of WSN exactly any more. • As the route maintenance of some route protocols are not perfect, the essential route repair is very important when route goes wrong.

4. 2 Several efficient route repair protocols • The route of WSN is designed to reduce energy depletion as possible as we can. So the route algorithm must be more efficient but not too complex. • Existing route protocols • AODV • QL • ERUP

5. 2 Several efficient route repair protocols • AODV (Ad Hoc On-demand Distance Vector Protocol ) • The route table of AODV established on demand, which is better than DSR (Dynamic Source Route) protocol on enhancing the using rate of bandwidth more efficiently, and also reduce the overhead which brought by each packet must bring path information. • AODV uses sequence numbers maintained at destinations to determine freshness of routing information and to prevent loops. • AODV tries to minimize route recovery traffic, but it sacrifices the optimization of new routes.

6. 2 Several efficient route repair protocols • QL (Query Localization) • a COUNTER set in each query packet. • The nodes along the old route rebroadcast each received query packet without increasing the COUNTER value; the nodes not along the old route rebroadcast each received query packet and increase the COUNTER value by one. When the COUNTER in one query packet reaches a limit, this packet couldn’t be rebroadcast any more. • It makes the update route with most parts overlapping with the old route, and it can find new route without much energy overhead.

7. 2 Several efficient route repair protocols • ERUP (Efficient Route Update Protocol) • The route repair process is divided into two steps: • Firstly, the node on the old route broadcast a Route Discovery Region Packet (RDR) at home to mark a region to show that this region need to route repair, then broadcast Route Request (RRQ) packet in this region; • Secondly, RRQ packets are send out by sources or the farther nodes of failure nodes to search the new route to the sinks.

8. 3 The route repair approach based on sink sequence number (RRASS) • AODV, QL and ERUP solve the route repair problem with different extents, but each of them has the shortage of itself. So, in this paper, an improved route repair approach based on them is presented. • The idea of RRASS • It is a route repair approach based on sink sequence number and existing route path information. • ERUP circle a region firstly, and then carries through route repair in this region, but RRASS only use sink sequence number to carry through route repair.

9. 3 The route repair approach based on sink sequence number (RRASS) • The implement of RRASS • Network initialization Initialize the route from source to sink using AODV protocol.As fig.1 and fig.2. Fig.1. Network initialization Fig.2. Establish route from Src to Sink

10. 3 The route repair approach based on sink sequence number (RRASS) • The judgment of node failure • The implement of route repair Fig.4. The request of route from node B and the result of repair Fig.3. Node A failure

11. 3 The route repair approach based on sink sequence number (RRASS) • The implement of route repair (cont’) when the route repair from node A can not find a new route, the route repair process implement from node C (as fig.4) which is the prior node of node A.

12. 4 Performance compare of several route protocols

13. 4 Performance compare of several route protocols • RRASS compare to some algorithm: • 1) It not only utilizes the direction information of old route path, but also utilizes the sequence number of the node to sink which is better than ERUP. ERUP circles a route discovery region in advance and then implement route repair, but RRASS doesn’t need the procedure.

14. 4 Performance compare of several route protocols • 2) RRASS considers that not all nodes join the data transmission in WSN, and let inactive node dormancy to reduce energy overhead, but other protocols don’t consider this condition such as ERUP. • 3) RRASS also consider that one node may on several paths in WSN, so the node may under high strength working state, and can not manage the data transmission of some paths in time.

15. 5 Conclusion • In this paper we propose a sink sequence number route repair approach (RRASS) based on analyzing some existed route repair protocols of WSN, and introduce the implementing process. • Route repair algorithms solve some sink mobile and node failure problem in a certain extent, but the energy of WSN application is not used in optimal mode.

16. Thank You ! 06-20-2006