High Throughput Low Delay Wireless Multicast via Multi-Channel Moving Window Codes

TL;DR

This paper introduces Multi-Channel Moving Window Codes (MC-MWC), a novel scheme that significantly improves throughput and reduces delay in wireless multicast by exploiting multi-channel resources with low feedback overhead.

Contribution

The paper presents MC-MWC, a new multi-channel coding scheme that achieves order-optimal throughput, linear delay reduction with channels, and constant feedback overhead in wireless multicast.

Findings

MC-MWC achieves order-optimal throughput in many-user, many-channel regimes.

Delay decreases linearly with the number of channels using MC-MWC.

Feedback overhead remains constant regardless of network size.

Abstract

A fundamental challenge in wireless multicast has been how to simultaneously achieve high-throughput and low-delay for reliably serving a large number of users. In this paper, we show how to harness substantial throughput and delay gains by exploiting multi-channel resources. We develop a new scheme called Multi-Channel Moving Window Codes (MC-MWC) for multi-channel multi-session wireless multicast. The salient features of MC-MWC are three-fold. (i) High throughput: we show that MC-MWC achieves order-optimal throughput in the many-user many-channel asymptotic regime. Moreover, the number of channels required by a conventional channel-allocation based scheme is shown to be doubly-exponentially larger than that required by MC-MWC. (ii) Low delay: using large deviations theory, we show that the delay of MC-MWC decreases linearly with the number of channels, while the delay reduction of conventional schemes is no more than a finite constant. (iii) Low feedback overhead: the feedback overhead of MC-MWC is a constant that is independent of both the number of receivers in each session and the number of sessions in the network. Finally, our trace-driven simulation and numerical results validate the analytical results and show that the implementation complexity of MC-MWC is low.