Delay Performance Analysis of LTE in Various Traffic Patterns and Radio Propagation Environments

Most real-time multimedia services like VoIP (voice over IP), TV conference and real-time gaming require low end-to-end delay. In the near future, it is expected that more delay sensitive applications such as cloud computing or telepresence will appear. LTE (long term evolution) is able to provide real-time services in mobile environments. LTE is designed to have an end-to-end delay of less than 5ms. The delay performance in LTE may, however, be degraded by the radio propagation environment or traffic pattern. For example, if the quality of radio signal is poor, more retransmission is required between eNB (evolved NodeB) and UE (user equipment) which degrades the delay performance. If packet size is large, the packets may be segmented which also degrades the delay performance. Thus it is very difficult to predict the delay performance of LTE system prior to its installation. This paper analyzes how the delay performance in the layer 2 (L2) process of LTE is affected depending on the traffic pattern and radio propagation environment. We conduct numerical simulations that consider the L2 processes. The numerical simulation correctly estimates the delay pattern even in a realistic fading environment.