Network Coding Performance for Reliable Multicast

Abstract

The capacity gain of network coding has been extensively studied in wired and wireless networks. Recently, it has been shown that network coding improves network reliability by reducing the number of packet retransmissions in lossy networks. However, the extent of the reliability benefit of network coding is not known. This paper quantifies the reliability gain of network coding for reliable multicasting in a wireless network where network coding is the most promising. We define the expected number of transmissions per packet as the performance metric for reliability and derive analytical expressions characterizing the performance of network coding. For a tree-based multicast, we derive expressions for the expected number of transmissions at the source of the multicast and inside the multicast tree. We also analyze the performance of error control mechanisms based on rateless codes and automatic repeat request (ARQ). We then use the analytical expressions to study the impact of multicast group size on the performance of different error control schemes. Our numerical results show that network coding significantly reduces the number of retransmissions in lossy networks compared to end-to-end ARQ scheme, however, rateless coding and link-by-link ARQ are able to achieve performance results comparable to that of network coding. Interestingly, link-by-link ARQ can outperform rateless coding depending on the network size and loss probability. We conjecture that network coding achieves a logarithmic reliability gain with respect to multicast group size compared to a simple ARQ scheme.

Performance of HARQ with Reduced Size Retransmissions Using Network Coding Principles

“…III outperforms the LTE reducing ReTx scheme. In the CC case the gain starts at the ν = 2 retransmission, due to the altern structure of the puncturing matrix in (6). In the IR case, the main difference is starting with retransmission ν = 4 due to the limited definition of 4 different RV in LTE [1].…”

“…There, the authors have applied the NC principle across packets of different users. Corresponding throughput improvements by using this NC-HARQ principle has been demonstrated in [6] and [7]. In contrast, another approach to use NC principle was published in [8] and [9].…”

Adaptive Random Linear Network Coding with Controlled Forwarding for wireless broadcast

“…In [39], the delay performance of network coding for a tree-based single source multicast problem is studied and compared analytically with various Automatic Repeat reQuest (ARQ) and Forward Error Correcting (FEC) techniques in terms of effective number of retransmissions per packet. For network coding, this paper assumes reliable and instantaneous feedback to acknowledge correct decoding of all data packets.…”

Joint identity-message coding

“…Recently, techniques inspired from coding and network coding have been successfully used to harness the broadcasting capabilities of the wireless medium [14], [15], [16], [17], [18], implement intelligent in-network storage [19], and provide resilience in lossy environments [20]. These coding techniques are not suitable for identity-aware sensor networks, as they are developed with a focus on data dissemination (as opposed to joint identity/message delivery).…”