1. Determining detailed regulations for the enforcement of the energy-saving laws in the case of router systems in Japan Yutaka Matsushita Tokyo University of Technology

2. Fig.1 Global CO2 Exhaust Levels (millions of tons

3. Fig.2 Japanese CO2 Emission Levels (In hundreds of millions ot tons) 1990 100million 2003 growth( ) Manufacturing 5.6 5.62 0.5 Transportation 2.1 2.5 19.5 Offices 1.5 2.0 36.9 Homes 1.3 1.7 28.9 Total 10.5 11.3 8 Japan must reduce its CO2 emission to levels 6% lower than those of 1990 As of 2005, Japanese CO2 emission levels are already 8% greater than those of 1990 In total, Japan must reduce its CO2 emission to levels 14% lower than those of 1990 by 2010

4. Overviews of energy-saving laws in Japan Only special facilities such as manufacturers and energy suppliers have been obliged to reduce energy consumption 18 special appliances and devises such as cars, air-conditioners, TV sets, computers, and others The committees are responsible to select the most efficient energy device in each class and such devices will be called top-runners

5. The special appliances /devices to which top-runner scheme will be applied will be selected if the following three conditions are met. Appliances/devices used in large quantities in Japan Appliances/devices consuming large energy Appliances/devices with room for energy consumption improvement

6. Revised Energy-Saving Laws (April 2003) All kinds of office buildings, department- stores, hotels, schools, hospitals, and other buildings have been added to the list of facilities that are obligated to reduce energy consumption. microwave ovens, electric rice-cookers and router systems have been newly added to the top- runner scheme list.

7. 21Designated Appliances or devices Cars, Trucks, Air-conditioners, Illuminators/lights, Televisions, Copiers, Computers, Hard disk systems Video-recorders, Refrigerators, Cold storage, Gas/Oil stoves, Lavatory seat warmers Vending machines, Gas-cookers, Gas/Oil water warmers Microwave ovens, Rice-cookers, Router systems

8. Classification scheme for appliances/devices Each appliances or devices can be classified by both basic physical characteristics and built–in functions Examples of the basic index physical characteristics) Television ; screen size Cars car weight Refrigerator capacity Examples of built-in functions involved in broadband routers Modem Wireless LAN VOIP There are many cases in which it is not appropriate to decide the target value for the class of some appliances/devices

9. Target Values and target Functions for Television There are many cases in which it is not appropriate to decide the target value for the class of some appliances/devices The level of power consumption usually increases in proportion with the screen size If a class of TV sets is composed of those having screen sizes between 15 and 21inches, the target value based on the top-runner scheme will be that of a 15 inch TV sets, because creating a 21 inch television with the same energy consumption as a 15 inch is difficult.

10. Fig.3 Target Function and Target Value (TV sets) Energy consumption 15 16 1718192021 Target value Television (inches) Target Function Screen size (basic index) X

11. Fig.4 Multiple target functions defined for basic index Power consumption Basic index A class Another class No.1 target function No.2 target function b1

13. Router systems claasification using top-runner scheme Router systems are mainly classified into two categories, routers and L2 switches. Furthermore, routers can be classified according to the number of ports into high-end, midrange and low-end. An IP network is composed of carrier IP networks provided by carriers and ISPs, and the access networks in between office buildings or homes and carrier IP networks High-end router systems are usually used in carrier IP networks or IP data centers. Midrange router systems are used in the border between carrier IP networks and access networks.

14. Low-end Routers classification Low-end router systems are used in SOHOs and firm- networks. Broadband routers for ADSL telephone lines and optical fiber access lines are used mainly in homes.

15. Compound Router systems Compound router systems with multiple functions are becoming popular. they are classified by the functions involved, namely, PoE, Wireless LAN, ADSL modems, VOIP functions and others.

16. Present conditions Our committee members are now investigating the correlation between throughput and power consumption of router systems used in Japan Top-runners in each class and the final classification results will be finalized in May 2006. Manufacturers and selling agents will not be able to sell routers with less efficient energy consumption than the top-runner in the class after an appropriate term.