Performance analysis of adjustable discontinuous reception (DRX) mechanism in LTE network

Abstract

Long Term Evolution (LTE) is being widely deployed to support real-time applications, such as voice over IP and video games. These power consuming applications require low latency guarantee since a long latency can severely impact user satisfaction. Thus, providing low latency as well as extending user equipment's (UE) battery lifetime is two of the main goals in LTE. The Discontinuous Reception (DRX) mechanism, which is widely adopted in LTE to conserve the mobile phone's battery resources, results in higher latency due to its sleep period. In this paper, we first present the analytical model of DRX mechanism, then propose an adjustable DRX mechanism which can tune the DRX sleep period dynamically. We consider the percentage of time that UE spends in sleep state and wake-up delay as two main performance metrics. Our study concludes that by choosing α = 1 and β = 2 in adjustable DRX mechanism, the wake-up delay decreases by approximately 66.7% for the case that DRX short sleep period equals to 200ms. The smaller value of α and β are suggested for delay sensitive applications. While larger values of α and β are more suitable for applications such as background traffic and social networking.