Cross-Layer Performance Analysis of Downlink Multi-Flow Carrier Aggregation in Heterogeneous Networks

Abstract

Multi-flow carrier aggregation (CA) is an emerging technique that is implemented to improve the capacity of cellular networks. In this paper, we study the cross-layer performance of user equipments (UEs) in heterogeneous networks under multi-flow CA. We develop a queuing analytical model for measuring packet-level performance parameters, e.g., packet loss probability and queuing delay. Our developed model accounts for the time-varying channels, the channel scheduling algorithm, partial channel quality information feedback, and the number of component carriers deployed at each tier. Our model also takes into consideration stochastic packet arrivals, the packet scheduling algorithm, and out-of-sequence packet delivery. The developed model can be used to tune the various system and operating parameters in order to offload traffic from the macrocells to the small cells while maintaining the quality of service requirements of UEs. The accuracy of the analytical model developed in this paper is validated through computer simulations.