Adding small cells to mobile networks made up of full-sized base stations should help to fuel more voice and data calls, but outdoors, linking those dispersed cells to wired networks presents its own problems.
Connecting a high-capacity data line to a cell mounted on a lamp post or a telephone pole isn't as easy as wiring up a cell tower. Power, security and wiring are all harder to arrange, vendors and analysts say. The problems are unique to outdoor small cells, versus indoor ones that tend to have easy access to wiring.
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Several vendors will try to help carriers meet those challenges at Mobile World Congress later this month. Their product announcements may help to speed a small-cell boom that has been promoted as the next generation of mobile networks since before last year's show.
"How quickly you will see massive deployment of the small cells is, I still think, an open issue," Ovum analyst Ron Kline said. The difficulty of providing backhaul from those cells is a big part of the uncertainty, he said.
It's just one of several challenges facing carriers that would follow the small-cell star to a future of mobile abundance, analysts said. Others are finding room to mount the cells, getting local approval for the new street clutter, and preventing interference with the larger "macro" cells on towers and rooftops. But backhaul is such a serious problem that it's forcing mobile operators to change how they plan networks, according to Ed Gubbins of Current Analysis. They used to find backhaul after putting up cells where they were most needed, but now they have to plan both together. Some carriers are even looking for backhaul sites first, he said.
Much of what the vendors will be pitching at MWC is wireless backhaul, which is available in several forms over different frequency bands. All these technologies can deliver enough speed to carry traffic to and from a small cell, and they can be deployed at cell sites where wired connections can't be set up or would be too expensive. Most small cells are indoors today, but as carriers deploy them outdoors, 75 percent of those cells will use wireless backhaul, according to Infonetics Research.
To deploy wireless backhaul, service providers still need space and power for the equipment and approval from the local planning authorities. But when it comes to the connections themselves, no fiber or copper needs to be strung out to the site. All that's required is a clear line of sight to another radio that is plugged into a wired network, or a non-line-of-sight wireless path that can find its way around whatever obstacles may be in the way.
In Barcelona, wireless backhaul vendor DragonWave plans to show off a set of products that it will introduce on Tuesday ahead of the show. The company has long experience in the field and is now introducing smaller devices for operation in both high and low frequencies.
DragonWave's Avenue Link Lite is a new design for a radio that uses bands under 6GHz. The company already has gear for those bands that's designed for specialized networks such as public safety, said Alan Solheim, vice president of corporate development.