The Small Cell Forum is preparing a new technical release that will tackle deployment of small cells in rural and remote areas, and it is also initiating a work stream aimed at introducing virtualization into the small cell arena, said the group's top executives.
At the Small Cells World Summit earlier this month in London, the forum announced its fourth educational release, which built upon a previous release aimed at helping operators deploy urban small cells. The group also began work on Release 5 in the series, which will be unveiled at the 2015 Mobile World Congress trade show in February.
"The rural and remote release is Release 5 that we are currently working on. If you think of rural, it's really similar to enterprise, but with a smaller RAN (radio access network) and smaller core. So applications for rural and remote provide coverage for both isolated locations and remote communities and can be used indoors and outdoors," forum CEO Sue Monahan told FierceWirelessTech.
"While most probably think of cow fields and deep valleys when you think of rural or remote small cells, the reality is that they're really a good fit in many different deployment scenarios," she said. Those can include special events, disaster recovery, military installations as well as verticals such as oil and gas, maritime, aviation and automotive.
Gordon Mansfield, who chairs the forum, said serving remote villages that currently have no broadband access is yet another scenario. In this instance, satellite backhaul or whatever other means are available would be used to bring the village broadband services, which would then be distributed via small cells.
Mansfield noted many of the rural and remote use cases for small cells already exist, but use 2G GSM technology, so they do not offer broadband capabilities. He said combining today's 3G and LTE small cell architecture with virtualized core functions could enable localized switching at remote locations and introduce new applications.
For example, the use of virtualized core applications could enable an events director on a cruise ship to send an updated list of ship events to passengers' smartphones without the need for a connection back to the mainland. Similarly, localized switching could enable communications within a remote village without a link to any outside networks. This would lower the cost of service for those types of locations, he observed.
In addition to its work on Release 5, the Small Cell Forum is also in the very early stages of kicking off a work stream to look at virtualization in small cells, a massive topic Monahan described as "a monster." She said this initiative could eventually evolve into the forum's educational Release 6 and possibly Release 7.
Mansfield indicated the forum is looking at some tenets of centralized RAN and cloud RAN (CRAN) for guidance. CRAN is today used only in places, such as dense Asian cities, that have lots of dark fiber that can deliver high-bandwidth and low latency.
But there may be ways to revise the distributed base-station architecture for use in other markets. This would involve breaking down the MAC and PHY layers to push out latency-sensitive call-processing functions. "Maybe you can push the very latency-sensitive elements out to the edge, where coordination is necessary but there's not so much sensitivity to latency. Maybe you can centralize or virtualize that," Mansfield said.
The forum's existing Femto Application Platform Interface (FAPI) could be used as a foundation for this construct. "Taking some of those same principles that we've already done in femtocells and seeing if we can do the same for virtualization, that's a key aspect," Mansfield noted.
The forum sees its planned virtualization work as stepping stone on the way toward the vision of 5G that is emerging in the wireless industry.
"To be clear, this is not 5G that were talking about, but you can't forget about some of the concepts people are talking about for 5G if you want to start changing the architecture to move toward that. 5G is going to be all about small cells and in fact, it's likely going to be all about virtualized small cells," Mansfield said.
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