Realty Check: Smaller and greener: The base stations of the future

Editor’s Note: Welcome to our weekly Reality Check column. We’ve gathered a group of visionaries and veterans in the mobile industry to give their insights into the marketplace.
At the Mobile World Congress in Barcelona last month, smart phones and tablets weren’t the only feats of miniaturization on display. Mobile base stations are also getting smaller and sleeker. Crucially, with oil prices again on an upward march, these slim-line base stations also use less power.
Paradoxically, the rollout of high-performance mobile broadband networks is paving the way for more compact and power-efficient base stations, which will lower energy consumption and reduce both operating costs and greenhouse gas emissions. That might sound counterintuitive, but here’s why it’s not.
As mobile operators deploy HSPA+ and LTE technology in the radio link that connects an individual device to a base station, they are also employing fibre-optic cables, typically capable of carrying between 10Gbps and 40Gbps, to connect the base station to the core network.
Although the primary purpose of these fibre links is to ensure that mobile traffic won’t hit a bottleneck as it passes through the base station, they also offer mobile operators a significant side-benefit. With a fibre-optic backhaul connection, operators no longer need to deploy as much equipment on-site at the base station, enabling them to create what is becoming known as a simplified RAN (radio access network). In a simplified RAN, centralised computers, typically serving 10 base stations, carry out many of the functions that are traditionally handled by equipment located next to each base station’s mast. That means the base station itself can be pared back to just the mast, bearing the antenna, and the related radio equipment.
Fibre-optic backhaul links make this kind of miniaturisation feasible because, unlike a traditional copper-based connection, fibre is fast enough and responsive enough to allow remote computers to handle real-time functions, such as the synchronisation of network clocks, which are essential for smooth handovers of connections between base stations. Pushing more of the intelligence deeper into the network in this way has a number of benefits.
First, the base stations consume less power. For example, Alcatel-Lucent reckons its lightRadio architecture, which is a form of simplified RAN, can reduce a mobile network’s energy consumption by up to 50%, which would lead to a major cut in both operating costs and greenhouse gas emissions (Alcatel-Lucent’s Bell Labs research unit estimates that base stations globally emit roughly 18,000,000 metric tons of CO2 per year). As energy can amount to between 10% and 20% of a mobile operator’s total operating costs, a reduction in energy consumption of 40%, for example, would have a significant bottom line impact.
Second, operators won’t need to spend so much money maintaining their radio networks. Rather than sending engineers out to individual base stations, they will be able to perform most of their network maintenance in the centralised facilities. An operator also needs less contingency and safety equipment. Rather than having contingency equipment installed at each base station, a single reserve set of equipment at the centralised facility can, for example, back-up 10 base stations. On a related note, a simplified RAN will be easier, cheaper and quicker to upgrade, as the operator will have to replace equipment in a much smaller number of locations.
Third, compact base stations are less intrusive and easier to deploy, enabling mobile operators to improve overall network coverage and capacity.
So, how quickly might simplified RANs be deployed by mobile operators? China Mobile, and LG-U+ in South Korea are among the many mobile operators evaluating the technology, while all the major equipment vendors, including Alcatel-Lucent, Ericsson, Huawei, Nokia Siemens Networks and ZTE, were promoting the concept and related products at the Mobile World Congress in Barcelona in February. All this activity suggests simplified RANs will be deployed in the next couple of years.
Of course, the speed at which smaller, greener base stations spread will be heavily dependent on how quickly fibre backhaul links are deployed. The amount of fibre in the ground today varies dramatically from operator to operator, but it is clearly growing with the increasing coverage of HSPA and LTE. Wireless Intelligence said in February that HSPA connections had doubled in the previous year, passing 400 million globally. Moreover, by the end of 2011, there will be 4.2 million LTE connections in 24 countries, according to Wireless Intelligence, rising to almost 300 million connections in 55 countries by 2015.
As well as enabling the industry to develop entirely new devices and services, the rollout of mobile broadband connectivity is fuelling new thinking and innovation in the networks market. For both economic and ecological reasons, the adoption of high-performance mobile broadband networks needs to be accompanied by a new power paradigm. With mobile operators under intense pressure to both cut costs and expand capacity, small and more energy-efficient base stations could ultimately prove to be as important as the smart phone or the tablet computer to the future vitality of the mobile industry.