Opportunistic relay selection for wireless network coding

Abstract

Owing to its potential of enhancing the network performance and to the large number of applications it can be suited for, wireless network coding is attracting a lot of interest from both the academic and the industrial communities. A common assumption in most of the literature is the presence of a single intermediate relay node where the network coding operation takes place. However, in an actual wireless system, a multitude of relaying nodes would exist, thus potentially further improving the performance; but with this the issue of relay selection arises. In this paper we study the performance of network coding in presence of opportunistic relay selection. We conjecture that relay selection schemes should be aware of, and account for, the network coding operation in case of its presence. Based on system level simulation results, it is demonstrated that such an awareness provides considerable capacity gains as compared to its traditional opportunistic counterparts, in addition to increased fairness among the encoded sources.

Advances in wireless network coding for IMT-Advanced & beyond

“…This is because the data of both sources to be encoded together should be available at the network coding node. In [21] an opportunistic relay selection algorithm for MARC with network coding based scenario was proposed and studied. The opportunistic algorithm tries to maximize the sum capacity of the cooperating pair of users by selecting the appropriate relay node.…”

“…However, it is clear that the opportunistic relay selection algorithm can be made more general and efficient by selecting the appropriate relay node and the pair of users that should cooperate via that relay node. In fact, it was observed in [21] that applying a joint user grouping and opportunistic relay selection algorithm can achieve this purpose.…”

User pairing in cooperative wireless network coding with network performance optimization

“…With network coding, the intermediate nodes are allowed to linearly combine packets from multiple sources and then forward the linearly combined packets for better throughput and resource utilization. The application of network coding in wireless networks has been studied in a variety of settings, including the cases of two sources transmitting to a common destination [6][7][8][9][10][11][12][13], multi-cast networks [14,15], ad-hoc networks [16], and two-way relay channels [17][18][19][20].…”

“…Owing to its importance, this problem has received significant interest from the wireless communication research community [21]. The problem of relay selection for transmission to a common destination, such as a base station (BS) in a cellular environment, is considered for instance in [6,7]. However, the relays are assumed to be dedicated; the relaying nodes participate in cooperation but transmit nothing for themselves when relaying.…”

Physical layer network coding based on dual relay selection in two-way relay channel

“…Unlike traditional transition schemes, NC allows the immediate nodes (the relay nodes) to combine several input packets into one or several output packets and then broadcast the coded packet to different recipients simultaneously instead of transmitting each packet separately, thus can reduce the time slots from four to three. Due to the broadcast nature of wireless channel, an interesting number of works have subsequently tackled the problem in a wireless environment [4]- [7]. However, the broadcast nature will result in interference which causes throughput degradation on wireless networks and its negative effect for multi-hop ad-hoc networks is particularly significant.…”