TECHNOLOGY TRENDS

LightRadio: How Alcatel-Lucent aims to transform energy usage

Alcatel-Lucent in February caused a stir when it announced LightRadio, a range of products that mark a radical departure in how cellular networks can be implemented. The company claims the technology can reduce energy consumption of mobile networks by up to 50% over current radio access network equipment: its Bell Labs research arm estimates that base stations globally emit 18 million metric tons of CO2 per year. LightRadio comprises a wideband active array antenna that integrates the amplifier and antenna elements, combining 2G, 3G, and LTE technologies into a single system. Another element of the technology is a baseband system-on-chip that can move processing power to the antenna or the cloud.

The active antenna supports beam-forming and multiple-input multiple-output (MIMO) technology which boost cell capacity, says Alcatel-Lucent. Combining the amplifier antenna with the chip technology also enables compact base station and antenna designs. LightRadio will also support cloud-like architectures. By carrying the signal over a fibre- optic link, the baseband processing of some 25 or 30 cell sites can be centralised in one facility up to 40 kilometres away. This removes the need for traditional air-conditioned huts housing the base station and amplifier.

“The system-on-chip in the cloud is going to give us the ability to do all sorts of new things,” says Tod Sizer, head of Alcatel-Lucent Bell Labs’ wireless research domain. The pooled base stations can be used for interference management between cells. And the architecture can be used in new ways to benefit energy consumption. “One we

are going to see in the coming years is coordination on the basis of energy usage,” says Sizer, citing how, for example, all users could be moved to the 3G network with the LTE network turned off to save power based on time-of-day and subscriber requirements. HP is working with Alcatel-Lucent to apply virtualisation techniques to integrate three generations of radio controllers onto one platform based on software running on general- purpose processor cards.

dozen data centres in France and Poland to two, filling both with more energy- efficient equipment. Such an initiative will improve the power usage effective- ness (PUE), an important data centre efficiency measure, halving the energy consumption associated with France Telecom’s data centres’ cooling system. Philippe Tuzzolino, environment direc-

tor for France Telecom/Orange, says energy consumption is rising in its core network and data centres due to the increasing traffic and data usage, but that it can be reduced at sites using such tech- niques as server virtualisation, free-air cooling, and increasing the operating temperature of equipment. “We employ natural ventilation to reduce the energy costs of cooling,” says Tuzzolino. Moreover, such developments are

impacting operators’ central offices. “As you look at the evolution of cloud-based services, virtualisation and applications, you are going to see a blurring of data centres and central offices as they inter- operate to provide a service,” says Brian Trosper, vice president at Verizon’s global real estate operations. “The PUE measure started in the data centre, but it is rele-

March 2011 www.totaltele.com

vant in the future central office.” Such energy efficiency developments

have significant consequences for system vendors: Operators are justifying spend on new technologies and platforms based on the opex power savings. “There is a business case based on total cost of ownership for migrating to newer plat- forms,” says Blom at KPN. By upgrading its network to all-IP, as

well as deploying more energy efficient wireline and wireless equipment, KPN says it has almost halted growth in its energy demands despite strong traffic growth, and by 2012 it expects that demand to start reducing. The operator’s target by 2020 is to reduce energy consumption by 20% compared to its network demands of 2005. France Telecom/Orange and Deutsche

Telekom both have set a target of reduc- ing CO2 emissions by 20% by 2020 from 2006 levels; Belgacom has said it plans to upgrade its mobile infrastructure with 20% more energy-efficient equipment over the next two years, and is seeking a 25% network energy efficiency improve- ment by 2020. And BT arguably has an even more ambitious aim (see box p.14).

France Telecom forecasts that its data

centre and site energy saving measures will only work until 2013, with power consumption rising again thereafter. “We also have to invest in capex for a big swap of equipment—in mobile and DSLAMs [access equipment],” says Tuzzolino. Despite such stated aims, Don

McCullough, vice president of marketing for IT and broadband at Ericsson, quali- fies the impact of power efficiency on operators’ equipment spend. While cost reduction is now a prominent issue with operators, it has yet to “take over” purchasing, he says: “It’s a new factor, but it is not an overriding factor.” Nevertheless, equipment makers must

have compelling power efficiency prod- ucts with a demonstrable roadmap. “We select platforms not only on their current energy efficiencies but [also on] what the expected [efficiencies] will be in the coming years,” says Blom at KPN. In 2009 Verizon informed its suppliers

of new energy requirements. “If you intend to put a new piece of gear in our environ- ment—and it is a logical successor to a previous one—we expect it to be at least 20% more energy efficient,” says Kimm. Meanwhile, France Telecom says it is

working with 19 operators that include Vodafone, Telefonica, BT, Deutsche Telekom, China Telecom and Verizon, as well as organisations such as the ITU and ETSI, to define standards for DSLAMs and base stations to aid operators in meeting their energy targets. Networking equipment consumes more

power the deeper it is within the network, but it is at the edge where unit volumes are far greater that power consumption is rising fastest. Broadband lines and digital home equipment volumes are rising fast, for example, while wireless base stations and handsets are growing exponentially. Point Topic says fixed broadband subscribers reached 508.8 million in the third quarter of last year, up from 454.5 million year-on-year; and Gartner says worldwide mobile device sales to end users totalled 1.6 billion units last year, a 31.8% increase from 2009. Based on analysis of its operator custom- ers’ networks, Huawei

estimates

that 13