Femtocells could be vital to LTE deployments

Femtocells are just starting to hit the wireless market, but considerable momentum is building for the technology to play a key role when carriers start to deploy LTE networks.
More than 18 wireless providers said they are planning to deploy LTE technology within the next two years. Verizon Wireless has said that it will test the technology this year and is hopeful to offer commercial LTE by next year. Plans by the carriers to roll out LTE coincide with 3G femtocells being introduced to the market and LTE femtocells are being developed.
“The femtocell will play a key role in LTE network rollout plans,” said Todd Mersch, senior product line manager for Continuous Computing, a San Diego-based company that uses telecom platforms and Trillium software that enables network equipment providers to deploy carrier-class LTE and femtocell applications.
The 3G femtocell market is starting to take shape. Sprint Nextel Corp. and Verizon Wireless offer femtocell products to customers to boost wireless coverage in homes where location or structures may interfere with wireless signals. AT&T Mobility is expected to offer a similar product, dubbed 3G MicroCell, later this year, and T-Mobile USA Inc. offers an in-home Wi-Fi router that allows customers to place calls using its broadband network with select devices.
Included from the start
Mass commercial deployments for femtocells are forecast this year. When standards were being established for 3G technologies, femtocells were not included in the initial work but updates have been added to the standard to address the technology.
The industry is taking a smarter approach in the standards process for LTE. The femtocell is part of the process in developing the standard, which is expected to be completed next month, and manufacturers are developing LTE femtocells.
It makes sense that femtocells are being included in LTE because the 4G technology is expected to deliver higher speeds through a broadband connection. The femtocells on the market today route network calls through a customer’s broadband Internet connection with the use of a small base station.
Vish Nandlall, Nortel Network Corp. CTO of carrier networks, said what makes femtocells attractive is they can be deployed in residential and public settings with base stations that are small in scale compared to current traditional towers.
“The femtocell will be a necessary part of broadband deployment,” Nandlall said.
Nortel is one of numerous infrastructure vendors participating in LTE trials spearheaded by Verizon Wireless and Vodafone Group plc.
Mersch said there are a number of reasons why femtocells are seriously being considered by carriers for LTE. The technology provides an avenue for incremental network rollout of LTE services that matches investment with revenue.
Cost advantage
The femtocell will also allow operators to provide coverage where it is needed most and where data service is likely to be used – homes and public hotspots that include airports and coffee shops. The femtocell is also expected to cost significantly less than other base stations.
“For these reasons, operators are actively considering how best to exploit femtocells for LTE,” Mersch said.
Airvana Inc., which has highly leveraged its future on the femtocell market, has not only been developing femtocells for 3G networks, CDMA and GSM/UMTS carriers, but is also focusing on the LTE femtocell.
“We certainly expect femtocells to become an important aspect of LTE, especially in network deployment,” said Vedat Eyuboglu, CTO and co-founder of Airvana.
Eyuboglu said operators are considering aligning femtocells deployments with LTE macrocell deployments.
“It remains to be seen if that actually will be the case,” he said.
When 3G and LTE intersect, Eyuboglu said femtocell base stations will be multimode in that they will be able to support both 3G and LTE technologies. The first users of LTE will be laptops, enabled PC cards and some smartphones with multimode capabilities.
“It will be awhile before you will see LTE handsets wide spread,” he said. “Obviously that will take time.”
Eyuboglu agrees that femtocells could be used to create hotspots as wireless providers build out their networks.
“Hot zones could be created in downtown areas by placing femtocells on the sides of buildings to cover streets,” he said.
Challenges
There are regulatory issues that still need to be dealt with regarding the use of femtocells. Carriers must ensure that individual femtocell base stations don’t interfere with other signals. Wireless providers also have to be able control every portion of their network by being able to disable a signal. How uplinks and backhaul will be handled are also issues.
Eyuboglu said femtocells in the near future will be sold to the public directly from the wireless providers. In time, the base stations could be available in stores.
“Over time, it is possible there will be more and more retail possibilities,” he said.
It will also take some time to integrate femtocells in LTE deployments.
“We are on the cusp of 3G femtocell deployments today with the technology maturing now,” Mersch said. “Moving it to a next generation solution will take time. Challenges aside, the benefits of femtocells are too substantial to be overlooked and we’ve seen early interest from mobile operators with LTE network plans for LTE femtocells.”