Analytical evaluation of multicast packet delivery and user-clustering schemes in high-speed cellular networks

Abstract

Transmission on data-oriented radio interfaces of cellular networks has been primarily designed for unicast applications. Nevertheless, unicast may not optimize the resource usage when the same content has to be transmitted to several users in the same cell. In this context, multicast seems to be an efficient means to convey data. In this paper, we develop an analytical model that allows the computation of the mean bitrate for both multicast and multiple-unicast transmission schemes. Furthermore, we propose a multicast transmission scheme called the equal-bitrate (EB) algorithm that allocates bandwidth to mobiles according to their instantaneous channel quality. We compare it to adaptations of the well-known max-signal-to-noise ratio and round robin to multicast. We propose to group users into clusters. The clustering method combines multicast and unicast transmission schemes according to the user's average channel conditions. We use the analytical model to evaluate the proposed solutions. We compare the resulting performance against pure multicast and multiple-unicast approaches. We show that the EB algorithm offers a good trade-off between throughput and fairness. Also, we show that mixed clustering achieves good performance compared to conventional clustering methods.

Rate guarantees for multicast scheduling in high speed cellular networks

“…More precisely, it considers a cluster for UEs with low average SNRs and a second one for "good" UEs. However, we have shown in previous studies [11]- [7] that grouping users having a bad channel quality cuts down the system throughput. In this framework, we introduced a new clustering algorithm, namely mixed clustering.…”

“…Mixed clustering is considered with a threshold of 3.7 dB for the SNR to differentiate unicast users from multicast ones. This value has been discussed in [7]. The highest overall satisfaction is obtained for Min GBR with its clustersize aware version.…”

“…MAC-hs layer is implemented with HSDPA fast scheduling and Hybrid-ARQ (HARQ). The radio parameters are chosen like in [7]- [11]. Opnet radio pipeline is based on the point to multi-point transmission mode.…”

Max-Min Throughput-Optimal Multicast Link Adaptation for Non-Identically Distributed Link Qualities

“…The maximum of Rtot in each section is: (6) λ u can be interpreted as a per UE priority weight and is therefore renamed to w u in the following, because by increasing w u it can be achieved that Ra s equals the supported rate of UE u.…”