The Application Of Network Coding In Virtual Backbone

Virtual Backbone has been shown to facilitate efficient communications in wirelessnetworks. Network coding has great potential to improve network performance in wirelessnetworks. In this work, we mainly consider the application of network coding on the back-bone of wireless networks. To specify, we will discuss the throughput gain and energy gainof applying network coding on backbone separately.While considering the throughput improvement of network coding over backbonebased routing, we find the “reciprocity” relationship between them. On one hand, the infras-tructure can be seen as a “coding enhancer” that increases coding opportunities by allowinginformation flows to intersect more easily, thus leading to a higher network coding gain.On the other hand, network coding improves the throughput of infrastructure based rout-ing by transmitting several packets with one coded packet. Theoretical analysis shows thatthe throughput gain by using network coding over infrastructure is upper bounded by2K/K+1,where K is the maximum number of encoded packets. A novel scheme NCIR, the NetworkCoding over Infrastructure based Routing mechanism is proposed. We implement the NCIRalgorithm in NS-2and experimental results show that NCIR achieves a high throughputgain.Enerry efficient broadcast is indispensable for many applications in wireless networks.It has been proved that network coding has great potential to improve performance interms of energy consumption in wireless ad hoc networks. However, the power of networkcoding depends on the availability of coding opportunities, which in turns depend on howrouting paths are established. It is thus beneficial to establish paths in such a way thatmore coding opportunities are created. By combining network coding and virtual backbone(usually constructed by Connected Dominating Set), we explore energy minimal broadcastprotocols in wireless networks. The rationale behind this combination is that CDS providesbetter chances for data flows to intersect, which means more coding opportunities. Wedesign a scheme, named NCDS, that uses Network Coding over Connected Dominating Set, to reduce energy consumption. Analysis and experimental results show that NCDSoutperforms broadcast algorithms that use CDS or network coding alone.