HomeMobile EuropeGreen telecoms networks - A waste of energy?

    Green telecoms networks – A waste of energy?


    Operators and vendors are stepping up their commitments to reduce energy consumption,  reports Keith Dyer

    As the world's political leaders prepare for negotiation at the UN climate conference in Copenhagen in December, readers might be surprised to find that there is a danger that there will be no role for, and discussion of, the role of the ICT industry.

    At a major meeting held in Barcelona in November, which will produce the draft text to be considered at the UN's COP 15 Copenhagen Climate Change Conference in December, the ITU were present and lobbying for the role of ICT in addressing climate change to be taken into account.

    The ITU argues that ICT can have a significant impact, and will help commit policy makers around the world to seek technical solutions to reducing GHG emissions.

    A recent study, GeSI Smart 2020 : Enabling the low carbon economy in the information age, estimated that more effective use of ICTs could help reduce total global emissions by 15% by 2020, representing carbon savings five times higher than the estimated emissions for the whole ICT sector in 2020. The Global e-Sustainability Initiative (GeSI), of which ITU is a part, estimates that these reductions could deliver energy efficiency savings to global businesses of over EUR 500 billion.

    It may be, of course, that the ICT industry has been seen as part of the problem, rather than part of the solution. Huge data centres demand their own power plants to support their operation, and the controlled temperatures they need. Mobile radio networks, too, cover the globe, with every cell site needing power, as well as heating or cooling.

    Indeed, the networks of mobile and fixed line communications service providers are of particular concern, as Rohit Kumar, Head of Energy Solutions at Nokia Siemens Networks, points out in a white paper recently released by the company. "Typically a CSP's infrastructure accounts for about 80% of the energy they consume, and even up to 30% of operational costs, with higher costs in emerging markets," he says. "There is a great opportunity – and pressure from costs and social responsibility – to cut energy consumption."

    Marc Benowitz, Director Reliability and Eco-Environmental Engineering, Alcatel-Lucent, says, "The communications industry is responsible for about 2 percent of the world's carbon emissions, and we are working on reducing that. We recognise the important role the communications industry plays in addressing environmental challenges. However, we will make a much bigger impact by developing innovative communications applications that will enable other industries reduce their impact."

    The ITU, too, has produced a list of ways in which the industry is moving to put its own house in order. This includes the development of what it terms a ‘green revolution', with new developments in areas such as smart grids, sustainable networks, energy-efficient data centres, teleworking, intelligent cars, smart buildings and energy-efficient workspaces.

    It also points to strategies like the universal charger, which has just been standardised by ITU, and will, it says, deliver an estimated 50% reduction in standby energy consumption, eliminate 51,000 tonnes of redundant chargers, and cut GHG emissions by 13.6 million tonnes annually. The ITU also claims that next-generation networks will reduce power consumption by as much as 40% for large network switching centres.

    The GSMA has also moved to add the mobile industry's commitment to the cause. It has set up a project called "Green Power for Mobile", that has set the goal of helping the mobile industry use renewable energy sources, such as solar, wind, or sustainable biofuels, to power 118,000 new and existing off-grid base stations in developing countries by 2012. Achieving that target would, the GSMA says, save up to 2.5 billion litres of diesel per annum and cut annual carbon emissions by up to 6.8 million tonnes.

    And the matter is pressing not just in environmental terms, but in business terms as well. Juniper Research reports that mobile base station electricity costs could rise by about 55% over the next five years unless operators cut their reliance on non-renewable energy resources and address network inefficiencies. In fact, Juniper warns that unless operators in Africa and Asia shift to renewable energy sources they will find their margins increasingly squeezed as they expand, such that their networks may no longer be financially viable in a few years time.

    David Taverner, Programme Manager of the Green Power for Mobile project, says that although off-grid solutions are the focus for the developing world and emerging markets, there is still progress that can be made in mature markets such as Europe.

    One area Taverner highlights is in the area of back-up power. He says we are seeing the emergence of fuel cell technologies as a viable alternative for back-up power when grid connections at base stations fail. Although there have traditionally been concerns over the stability of fuel cells, Taverner says recent developments have been positive.

    "Fuel cells are lightweight and the technology has advanced recently. Operators are trialling them and have seen some excellent results," Taverner says.

    Apart from the actual power supply another key, and much larger area, is the operating efficiency of the network equipment itself.

    "The radio access network, the base stations themselves, consume the vast proportion of the energy across an operator's footprint," Taverner says, "typically about 2/3 of the total energy consumer.

    Widespread deployment of energy efficient base station solutions such as passive cooling (air conditioners), remote radio heads (reduction of losses of power through cable transmission) and night-time shutdown software can all help, Taverner says.

    Alcatel-Lucent's Benowitz says that the vendors can play a key role here.

    "For example, at the Base Station level we leverage both hardware and software engineering to provide more coverage and traffic handling capability with less energy consumption – using hardware integration and power amplifiers technology, but also dynamic software to dynamically adapt the power consumption to the actual traffic carried by the site. This dynamic power capability is much more than simple nighttime shutdown – and in fact – we are applying this technique to legacy equipment also, which in itself adds environmental (and economic) benefits.

    "Then, at the Base Station site level, what is at stake is really avoiding thermal or feeder losses: that's where passive cooling and remote radio heads come into play-. removing the need for any air conditioning system with direct-air cooling solutions, as well as removing the feeder losses with remote radio heads solutions. Finally, some schemes/features can be leveraged also at network level to decrease the overall power consumption of the network, by methods such as the topological optimisation of cell sizes, local switching to decrease useless backhaul and processing for local calls." 

    One operator that is emphasising the power reduction of a new investment is T-Mobile Austria, which is deploying 2,500 of Nokia Siemens Networks' Flexi base stations, estimating they will cut the carbon footprint by as much as 2,500 tons of CO2 a year, as they work without air conditioning and also take less energy to transport and install.

    Indeed, a key way of increasing power efficiency, Benowitz says, is simply to move to next generation systems.

    "On the most recent W-CDMA networks, a typical Node B leverages HSPA+ to provide up to 56 Mbps per sector on a 20 Mhz band. With LTE, a Node B consuming the same level of electricity power will be able to provide up to 173 Mbps per sector: the amount of electricity required to provide a given traffic capacity over a given geographical coverage is divided by more than three," he reasons.
    All of these developments can have tangible effects, he says.

    "We have demonstrated up to 30% power consumption decrease thanks to our features. In GSM/EDGE, for instance, our Dynamic Power Save (DPS) feature enables us to turn on and off power amplifiers at time slots level (which is 0,5 ms) depending on telecom traffic need. This very high reactivity enables savings not just at night but also during the day, and ensures zero impact to the quality of service. This power-saving enhancement can be installed on all of the 500,000 GSM/EDGE Alcatel-Lucent base stations deployed since 1999.  On the Remote Radio Head (RRH) front, our solutions enable typical savings in the 25% range. The power consumption of our GSM/EDGE transceiver modules has decreased by 80% in 13 years for the same performances. And by deploying no A/C in base stations we can enable the BTS to operate at full capacity in ambient temperatures of up to 55%C. Removing the need for installation in heavy shelters with air conditioning saves up to 30% CAPEX and 40% OPEX.

    Finally, there is the issue of energy control. The head of NSN's Services unit Ashish Chowdhary  pointed out in a recent launch of NSN's energy services portfolio, that while all the measures discussed so far while these can be very effective and more ‘green' -savings may not be realised without careful planning and provisioning of the network as a whole  – including factors such as the topology and mobile technology used – and central monitoring and maintenance.

    "It is a myth that operators can optimise OPEX of their networks on a site-by-site basis without taking a full view of the OPEX spent on the entire network," he says. That's why NSN (and its not alone) is placing emphasis on efficiency consulting services to optimise networks from an energy point of view, and has implemented its Green Energy Control, which allows operators to manage power sources – from solar power to battery condition to the temperature of shelters. Apart from being able to adjust energy settings round the clock, this allows staff to plan fewer and better targeted site visits.

    Power points

    – Based on key CSP benchmarks across the globe in developed markets, an average of 10% of network operational cost is energy. In emerging markets it
    can be from around 15% to 30%.

    – As mobile networks expand in developing markets, an estimated 75,000 mobile base stations are built each year that need their own power source as they are not connected to an electricity grid.

    – The number of base stations powered by renewable sources will reach 320,000 sites at the end of 2014, according to IMS Research, which also notes that power to keep the latest mobile devices going is increasing by 15%
    a year.

    – Juniper Research estimates that by transforming base stations with equipment that takes less power and migrating from diesel to renewable energy to power off-grid generators, electricity costs will peak in 2011 and then drop to 10% below current levels by 2014.

    – ABI Research has produced a vendor matrix that ranks the top ‘green' mobile operators in North America. No operator leads in all criteria.

    – The International Telecommunications Union (ITU) is lobbying for the role of ICT to be recognized at Copenhagen. The ITU is also developing standards for assessing the environmental impact of ITC.