Impact of spatio-temporal power sharing policies on cellular greening

Abstract

In this thesis, we analyze short-time scale BS (Base Station) power saving controlling transmission power and scheduling users of each BS on multi-cell cellular networks. Although the transmission power of a typical macro BS is lower (10W-20W) than total BS power consumption (500W-2000W), the transmission power also exerts influence linearly on the power consumption of power amplifiers and cooling systems and battery backup and power supply loss in the BS. Even with a transmission power reduction, users can expect high performance when they are in the interference-limited region and appropriate power control and user scheduling algorithms are adopted. Through simple simulations under EQ (equal power allocation) and IM (interference management) cases, we verify that more than 76% throughput can be obtained for edge and center users only with a 1/5 of transmission power. Furthermore, we propose four BS power sharing policies which are novel greening policies exploiting temporal and spatial degree of freedom with fixed fairness criterion (proportional fair) and present power allocation and user scheduling algorithms to meet asymptotically near optimal solutions of given framework. Through extensive simulation, we verify that the impact of proposed power sharing policies on BS power saving. Besides, we show more outstanding greening performance of IM and spatio-temporal power sharing with network-level average power constraint than IM and no spatio-temporal power sharing through the simulations under the part of the Manchester city, UK (United Kingdom) irregular BS deployment and power consumption scenarios. Furthermore, we verify greening performance of our frameworks on the small cell (such as micro and femto cell) which is an inevitable trend in the next generation cellular network to maximally exploit the spectral resources. A promising conclusion in drawn that higher GAT and greening efficiency are achieved with smaller cell sizes when applying IM and spatio-t...