Green Ethernet

Much discussion is being carried out on green communications. Some people support the idea as it can help to control the power consumption by communication systems. However, some people think it is a politic strategy by some companies. Their arguments are: If we look at the power consumption distribution at home, the communication facilities like modem consume a very small amount of energy compared to a refrig and a TV. For example, a modem consumes 5w power, while a refrig consumes several KW power. Thus, the effort on energy saving should be taken for a refig rather than a modem.

Green communications may not be critical for the access network. Rather, we may need to focus on power saving for the backbone networks. For example, the high power consumption of router could make it more and more difficult to disseminate heats of the router with the increase of routing capacity. Thus, the power consumption could be an eventual limiter for a router to further upgrade capacity. In addition, data centers such as Google and facebook data centers are another important sector that we can spend effort on saving power consumption as they are really power-hungry beasts.

With the success of the first two workshops of green communications, the third workshop of green Communications (GreenComm) will be hold in Miami, Florida, USA, 10 December 2010, together with the well-known annual IEEE communications conference, IEEE Global Communications Conference (IEEE GLOBECOM 2010). The last two workshops were hold together with ICC 2009 and Globecom 2009, respectively.

The major topics that this year’s workshop will focus on the following directions:
Energy-efficient protocols and protocol extensions
- Energy-efficient transmission technologies
- Cross-layer optimizations
Energy-efficient technology for network equipment
- Energy-efficient switch and base station architectures
- Low-power sleep mode
- Exploitation of passive network elements
Energy-efficient communications management
- Architectures and frameworks
- Hierarchical and distributed techniques
- Remote power management for terminals
- Context-based power management
Measurement and profiling of energy consumption
- Instrumentation for energy consumption measurement
- Operator experiences
Energy-efficiency in specific networks
- Mobile and wireless/wired access networks
- Broadband access networks
- Management of home and office networks

The call-for-paper link is here, and the paper submission deadline is Friday, 02 July 2010.

IP over WDM network is a popular network layered architecture for today’s transport network. Using WDM layer’s capacity and IP layer’s intelligence, the combination of the two layers are considered as a cost-effective scheme from the aspects of both network efficiency and operational simplicity. For IP over WDM networks, their power consumption has started to become an interesting research topic.

Recently, a paper “Energy-Minimized Design for IP over WDM Networks” was published in an IEEE/OSA new journal “IEEE/OSA Journal of Optical Communications and Networking, vol. 1, no. 1, June 2009, pp. 176-186.” Viewing the major power consumption by IP routers, the paper targets to minimize the required number IP router ports subject to all the IP traffic is fully supported. The research results indicate that in an IP over WDM network more than 90% power is essentially consumed by the IP routers, and the components in the WDM layer such as transponders and EDFAs actually consume very little energy. Interestingly, the paper also finds that a power-efficient IP over WDM network is likely to be a cost-effective design viewing that the IP router ports are also the most expensive among all the network components.

Due to the major power consumption from IP router, following the above work recently there are also some studies considering sleeping of IP router ports or tuning down the power consumption of IP router port when the data traffic on the port is low. Theoretically these technologies are possible. They are however highly dependent on the standardization of IP routing protocols. Currently, no mature IP technologies can support router port sleeping (though recently Cisco proposed to shut down a router when the internet traffic is low) and different power consumption at different data rates.

“Green” is a hot “word” in this year’s OFC/NFOEC. Everybody is considering to save energy in the communications areas from the lowest component level to the highest network architecture and protocols.  One of related panel session is Green Optical Networks: From Access to Core, organized by Hans-Martin Foisel from Deutsche Telekom, Germany. “In this workshop different views of carriers, vendors, R&D, standardisation bodies and initiatives on this new telecommunication challenge will be presented, covering:

• New network design and architectures – allocation of functions
• Evaluation of different technologies – from routers to optical network elements
• New approaches to in-house networks
• Content and processing power allocation – from customer end devices to carrier networks”

The second panel session is “OMD, Is All-Optical Processing Green?” organized by Javier Marti¹, Keith Williams². “The workshop addresses relevant key notes and further discussion on how AOP compares to all electrical processing and to hybrid opto-electronic processing in terms of power consumption efficiency. Figures of merit have to be defined to establish a fair comparison. Key visions on AOP’s opportunities in both ultra-high speed network node equipments (routing, demultiplexing, etc) and high-performance computing will also be addressed.”