Energy Efficient Optical-Wireless Residential Access/In-House Networks

Both ecological and economical forces drive the recent energy efficiency efforts for communication networks. The growth of the number of users and the ever-increasing bit rates raise concerns about the society's ability to reduce its energy consumption significantly in the near future. Access networks play a key role in this arena due to the sheer number of users and terminals and low sharing of the infrastructure as compared with other network segments. However, there is no universal framework so far for breaking down and analyzing the energy consumption map within access network. This paper introduces a comprehensive approach to the problem of energy consumption in the fiber-to-the-home (FTTH) access networks integrated with the in-house fiber/copper/wireless networks. The Customer Premises Equipment for Low-Power and Low-Cost Architectures (CUPELLA) project in our research group at Stanford investigates energy efficient access technologies using a structured methodology based on fundamental equipment building blocks both at the micro level and on the macro level when they are integrated into larger systems. Our study looks into both static and dynamic scenarios to exploit temporal and spatial features of the whole access network usage with the goal of substantially reducing the access energy consumption. Our preliminary results indicate that substantial energy saving is in fact possible. For example, with selective sleep mode and switching-mode customer premises equipment (CPE), more than 30% of energy could be saved as compared to broadcast-and-select architecture that does not apply sleep modes.