A Semi-Analytical Macroscopic MAC Layer Model for LTE Uplink

This paper proposes a semi-analytical medium access control (MAC) layer model for the macroscopic analysis of long term evolution (LTE) uplink. The model takes into consideration the expected number of retransmissions arising from channel disturbances and the number of allocated resources so that to satisfy a required packet delay budget. The former is computed in terms of the mean bit error probability while the latter is calculated through a high order Markov chain incorporating cell traffic load conditions. The proposed model can be used as a macroscopic planning decision tool that poses the working limits of MAC schedulers for different packet delay budget requirements, in terms of the mean number of allocated resources, MAC packet length and maximum retransmission attempts according to the channel conditions. In this context, based on measured data, we investigate the impact of the MAC packet size on the total uplink delay budget of a single user aiming to set-up the basis for future multi-user analysis.