A COMPONENT PERSPECTIVE ON ENERGY EFFICIENCY OF OPTICAL NETWORKS

摘要

Power consumption is a growing concern in the telecommunications industry. Both data centers and switching offices have growing power needs that effect carriers' operating expenses. The cost of this power is directly tied to both the utility cost of power, and to the space requirements defined by the power density of the individual devices Primary electrical costs are the cost associated with powering the network equipment. Secondary electrical costs include the cost of conditioning the environment surrounding the equipment (Heating, Ventilation, Air Conditioning, HVAC) as well as the cost of backing up the utility when AC electrical power fails (UPS). These secondary electrical costs come to 40-60% of the total power use and electrical cost of network equipment . The interplay of primary and secondary electrical cost is directly related to the capital expenditures associated with upgrading and building central office space. This associated CAPEX is sufficiently high to force operators to pack increasing amounts of equipment into the same square feet of space. A measure of this trend toward higher power densities in COs is the distortion of Network Equipment Building Standards (NEBS) since the deregulation of the service-provider industry. While NEBS sets limits for dissipated power density of approximately 2 kW in a 7 ft. equipment rack, most networking equipment exceeds some NEBS limits and there are examples of the NEBS limits being exceeded by an order of magnitude. However, the NEBS guidelines are still widely used to qualify equipment for collocation and as a measure of interoperability. Since power density is still of critical importance, the total module power consumption is directly linked to the cost associated with space. Reducing the power density of each device can result in significant space savings, since more devices could now fit in the same footprint, Industry-wide efforts to reduce form factors, lower the power requirements of electronic components and migrate to uncooled optical components are all part of an effort to save power and also, therefore, central office space.