Green Cellular Network Deployment
John Cunliffe, CTO, Ericsson Ltd, describes the way new technology is helping cellular networks to become more green.
Firstly let's put things into context: ICT represents around 2% of total carbon emissions. Mobile networks consume about 0.2% and fixed networks 0.4%, the remaining 1.4% being IT.
At Ericsson we think about our own operations and are dedicated to making reductions, however, we can do far more for the environment by reducing the consumption of our products and innovating to develop products which others can use to reduce / avoid carbon. We calculate that through the innovative use of ICT it will be possible to reduce overall carbon consumption by 15%.
Incidentally, most of us can apply this leveraging principle to our daily work activities too, i.e. if we can do something through our professional roles which makes a carbon saving, it might be far bigger than anything we can save at home as it could have global scale and impact.
It has been shown that manufacturing our equipment only consumes 34% of emissions whereas 67% of emissions take place during its operation.
In addition to this, power consumption of our 3G radio basestations has dropped from the 1st to 2nd generation.
The diagram below demonstrates how continuous development of Ericsson basestation technology has saved power and carbon. Note also the log y axis. The blue curve shows a staggering increase in data performance over the period.
An example of how technology can be leveraged to save carbon is to compare the amount of carbon needed to run a mobile phone with that to run a car. The numbers say it all: one hour of car usage equates to one years worth of mobile phone usage. So if you can use your mobile phone to avoid one hour travelling to a meeting then the payback is immense.
Avoiding carbon burning travel
When people speak of saving travel through the use of technology, they often jump to the notion that video conferencing is the answer, whilst I'll come back to it, we should pause to remember the regular, self administered voice conference. These conference calls are saving a massive amount of travel, yet we take them very much for granted. Just think of the saving we could leverage if we increased our usage by say 10-20%.
Collaboration tools which allow us to share presentations are now increasingly used and will certainly contribute to squeezing that extra 10-20% of voice conferences.
Back to video conferencing: Video conferencing has been around since the 1980s but running at 384kbps and with little or no compression. I sense there was a period when we had become rather disappointed that the quality hadn't improved and people diverted their usage to the self administered voice conference. High quality video conferencing changes our view again by making the experience far more real.
Saving carbon, electricity or money?
Well rather obviously, saving carbon, electricity and money go together pretty virtuously. Save electricity, you save carbon and you will also save money. With the introduction of the Carbon Reduction Commitment by the UK government in April 2010 reducing carbon helps avoid paying for carbon credits but also saves the embarrassment of being at the southern end of the public league table or heading south. This is especially so if your company is trying to develop a green reputation.
By 2020 the UK government plans to role out 44m smart meters to meter both electricity and gas usage. The goals being to reduce carbon usage to meet national and European targets and also to reduce load on the nation's aging power stations. Furthermore these devices will support dynamic tariff changes to encourage changes in user behaviour and they will provide instant feedback to consumers, support remote meter reading and remote device management. By remote device management I'm including the notion at to avoid peak demands on power generation and distribution, the electricity companies e.g., will be able to switch of your refrigerator for say 15 minutes. Whilst this will have no damaging effect it could help reduce the need to build and operate more capacity. The concepts also include support for domestic micro generation.
Connectivity for Smart Meters is currently a huge debate. Whilst most of the trials have been based on 2 and 3G cellular networks we envisage a number of technologies will be used to provide national coverage.
With the rise of ubiquitous broadband and the decreasing cost of connectivity and countless opportunities to connect like smart meters, vehicles and appliances we anticipate 50bn connected devices by 2020. This level of connectivity will create massive opportunities to avoid travel and hence reduce carbon emissions.
Energy Efficient Radio Access Networks
Many of our customers have set goals to cut CO2 emissions. This means there is a lot of potential for Ericsson to help them with more energy efficient products and energy optimisation services. One such opportunity is through the delivery of energy efficiency in the Radio Access Networks.
In access networks where the volume of equipment is, Ericsson has been innovating to reduce power. The Tower Tube base station is hollow; the electronics are located just beneath the antennas at the top of the tower, massively reducing feeder cable transmission losses. Locating a base station radio unit closer to its antennas can cut energy wastage and reduce consumption by two-thirds.
We avoid the need for air conditioning by leveraging the "chimney effect" of the tower to use the natural air flow. We also locate the batteries underground at a constant temperature. Finally wind turbines can be fitted to the top of the tower to generate electricity.
Electricity generation for many basestations comes form local diesel generators. These generators are conventionally dimensioned to support peak loads. By adding batteries we can use much smaller generators which work at a more constant and efficient load, then using the batteries to cope with peak demand. This saves some 50%.
Additionally we can help our customers to reduce the consumption and cost of power in their Radio Access Networks in several ways. Such solutions range from enhancements in AC/DC power conversion and site cooling through to high efficiency fuel cells for battery backup. With intelligent power system management, for example, base station equipment can go into stand-by mode during quieter periods. This means that energy consumption can be reduced by 10-20 per cent.
But it's not just about efficient products and components: energy optimised network design is another key opportunity to be greener. A well-designed network can reduce the number of radio sites required by 30-50 per cent.
Focus and hard work to reduce energy consumption and use of raw materials has led to consistent improvements in the energy efficiency of mobile networks. At the same time, the technical performance has increased dramatically, so that the networks of today contribute much more value to users and to society as a whole.
And finally, I have a lot of confidence for a sustainable future.
John Cunliffe is Chief Technology Officer at Ericsson Ltd. Here, his role incorporates a wide range of responsibilities including, working with customers, research, government and regulatory affairs and UK R&D activities. He has a broad understanding of the telecoms industry from both technology and business perspectives.
John is a Chartered Engineer, a Fellow of the Institute of Engineering and Technology (IET) and a board member at Intellect.