Quality of service and channel-aware packet bundling for capacity improvement in cellular networks
Abstract
We study the problem of multiple packet bundling to improve spectral efficiency
in cellular networks. The packet size of real-time data, such as VoIP, is often very small.
However, the common use of time division multiplexing limits the number of VoIP users
supported, because a packet has to wait until it receives a time slot, and if only one small
VoIP packet is placed in a time slot, capacity is wasted. Packet bundling can alleviate
such a problem by sharing a time slot among multiple users. A recent revision of cdma2000 1xEV-DO introduced the concept of the multi-user
packet (MUP) in the downlink to overcome limitations on the number of time slots. However, the efficacy of packet bundling is not well understood, particularly in the presence of time varying channels. We propose a novel QoS and channel-aware packet bundling algorithm that takes advantage of adaptive modulation and coding. We show that optimal algorithms are NP complete
and recommend heuristic approaches. We also show that channel utilization can
be significantly increased by slightly delaying some real-time packets within their QoS requirements while bundling those packets with like channel conditions. We validate our
study through extensive OPNET simulations with a complete EV-DO implementation.
Table of Contents
Introduction -- Related work -- Background on wireless systems -- Multiple packet bundling -- Evaluation -- Conclusions
Degree
Ph.D.