Transmission Rate Sampling and Selection for Reliable Wireless Multicast

Abstract

The multicast communication concept offers a scalable and efficient method for many classes of applications; however, its potential remains largely unexploited when it comes to link-layer multicasting in wireless local area networks. The fundamental lacking feature for this is a transmission rate control mechanism that offers higher transmission performance and lower channel utilization, while ensuring the reliability of wireless multicast transmissions. This is much harder to achieve in a scalable manner for multicast when compared with unicast transmissions, which employs explicit acknowledgment mechanisms for rate control. This article introduces EWRiM, a reliable multicast transmission rate control protocol for IEEE 802.11 networks. It adapts the transmission rate sampling concept to multicast through an aggregated receiver feedback scheme and combines it with a sliding window forward error correction (FEC) mechanism for ensuring reliability at the link layer. An inherent novelty of EWRiM is the close interaction of its FEC and transmission rate selection components to address the performance-reliability tradeoff in multicast communications. The performance of EWRiM was tested in three scenarios with intrinsically different traffic patterns; namely, music streaming scenario, large data frame delivery scenario, and an IoT scenario with frequent distribution of small data packets. Evaluation results demonstrate that the proposed approach adapts well to all of these realistic multicast traffic scenarios and provides significant improvements over the legacy multicast- and unicast-based transmissions.

Joint Link Rate Selection and Adaptive Forward Error Correction for High-Rate Wireless Multicast

“…In contrast, the FEC layer in our approach works supplementary on the packet level for recovering lost frames. This builds on our preceding work, which presented the basic mechanisms of a multicast link rate control protocol based on aggregated receiver feedback [2]. The current work provides significant extensions and improvements on several aspects.…”

“…With reference to its origin (Enhanced Rate Control for Wireless Reliable Multicast (EWRiM) [2]) and highlighting its more dynamic and adaptive behavior, we refer to the protocol presented in this paper as DEWRiM, which also helps distinguish it from the original version in the rest of the text.…”

“…1. As described more in detailed in [2], those other link rates are selected in our current implementation randomly out of the commonly supported ones.…”

“…In addition to the periodic polling by the sender, the receiver can initiate a Multicast Statistics Proactive Report (MSP) message when it detects a high loss, which will also be applied to the statistic calculation. More details about the information collection and statistic calculation is given in [2].…”

“…The proactive reporting mechanism can be triggered by any receiver node on detecting a high packet loss at the FEC decoder and has already been described in [2]. That basic mechanism is used here with two modifications.…”