Inter-session Network Coding for Transmitting Multiple Layered Streams over Single-hop Wireless Networks

TL;DR

This paper explores inter-session network coding for transmitting multiple layered video streams over single-hop wireless networks, demonstrating that mixing packets across streams enhances performance, especially with more streams and higher error rates.

Contribution

It introduces a novel inter-session network coding scheme combining RLNC and UEP, with analytical modeling showing performance improvements over intra-session coding.

Findings

Inter-session NC improves user performance trade-offs.

Throughput gain increases with number of streams and error rate.

Performance degrades in highly heterogeneous networks.

Abstract

This paper studies the problem of transmitting multiple independent layered video streams over single-hop wireless networks using network coding (NC). We combine feedback-free random linear NC (RLNC) with unequal error protection (UEP) and our goal is to investigate the benefits of coding across streams, i.e. inter session NC. To this end, we present a transmission scheme that in addition to mixing packets of different layers of each stream (intra-session NC), mixes packets of different streams as well. Then, we propose the analytical formulation of the layer decoding probabilities for each user and utilize it to define a theoretical performance metric. Assessing this performance metric under various scenarios, it is observed that inter-session NC improves the trade-off among the performances of users. Furthermore, the analytical results show that the throughput gain of inter-session NC over intra-session NC increases with the number of independent streams and also by increasing packet error rate, but degrades as network becomes more heterogeneous.