Optimizing Idle State Configuration to Improve Power Saving for M2M Communication over LTE Networks

M2M communication has gained popularity because of its endless possibilities, and when it is conducted over more advance networks like the 3GPP LTE/LTE-A which deliver higher throughput and can handle more active devices with a cell the possibilities even become greater. LTE networks were mainly designed for H2H communication meaning that we cannot just use M2M communication over it without any changes. M2M devices are usually sensors or actuators meaning that they have a limited power source. LTE networks have a power saving mechanism known as Discontinuous Reception (DRX). M2M devices spend most of their time in the idle state therefore more optimization needs to be carried out in the idle state. In this paper, an analysis of the available power saving mechanisms like reducing the RRC Inactivity timer and extending the DRX paging cycle is carried out. Then a DRX configuration switching mechanism is proposed, implemented and analyzed so as to save battery power but also ensure that delay (latency) is controlled at the same time for delay sensitive traffic. The results show that the switching mechanism actually helps to reduce the delay significantly as well as save power at the same time but if the sole purpose is to save battery power only then reducing the RRC Inactivity timer is the best approach.