INTRODUCTIONCurrently, the internet

INTRODUCTION
Currently, the internet is widely used and much networked equipment such as set top boxes and PCs utilize 24/7 networking services. For example, remote management such as automatic firmware update and content download can be performed without the user’s attention. However, this equipment constantly consumes electric power, with most of the energy consumption occurring when no one is present and the equipment is in an idle state, continuously receiving network service [1]. The technique of adding a subsystem to provide proxying for a host system to continue network service has been studied (Figure 1). By introducing proxying, for example, maintaining its presence on a network, it is possible to reduce power consumption, even though the system is in a sleep state. The goal of proxying is to enable full network connectivity even while the host system is asleep, while hiding this from the rest of the network [2]. The power state transition of the host system also causes a state transition between the host system and the subsystem. Just before the host system is about enter a sleep state, the network configuration of the host system is copied to the subsystem; then, the network control switches to the subsystem. After that, the subsystem behaves as the host system and provides network services. When the host reverts to an active state, it resumes control of the network and services once again [5]