Low-Power Sleep Mode and Out-Of-Band Wake-Up for Indoor Access Points

The expected massive adoption of indoor access points requires specific solutions to meet requirements for eco-sustainability regarding consumed power and radio interferences. Since access points are unused the main part of the day, application of a sleep mode mechanism is a promising approach. However, its implementation represents a radical change in mobile networking paradigm and requires innovative mechanisms to wake up the access points and thus rapidly restore the connectivity. Our approach uses an auxiliary low-power radio to carry out-of-band control information to maintain connectivity and wake up the access points when necessary. The paper details the software and hardware architecture as well as the prototyping results on Wi-Fi technology.

I. INTRODUCTION

Within the past decade, global recognition of the need to protect the environment for future generations has emerged as a central issue that is now shaping behaviors in every industry. This study follows the trend to reduce the telecommunication networks footprint over energy consumption issues. Recent European directives [1] required to include eco-designed off-mode or standby-mode in the household and office equipment. By the end of 2012, the equipment will have to automatically switch to off/stand-by mode after a short period of inactivity. Furthermore, the energy consumption limits of those low-power modes are set to be challenging.