Mobile carriers detail plans for adding unlicensed spectrum to their portfolios

by Steve Blum • , , ,

Kind of like parking one of these in a yacht harbor. But it’s OK. They’ll be careful.

With the rate of growth – let alone growth itself – in mobile data usage continuing to boom, with no end in sight, mobile carriers are searching for new spectrum. First choice is licensed, exclusive frequencies of course, but there’s no reason for them not to grab for their second choice too, which is unlicensed spectrum.

The Federal Communications Commission has been taking comments on the possibility of mobile carriers operating alongside WiFi in the unlicensed bands. FierceWirelessTech has a good roundup of the comments so far, written by Monica Alleven.

As you might expect, the people on the carrier side of the business think it’s a great idea for carrier-class LTE-based services to jump in alongside WiFi, particularly in the 5 GHz bands. Those on the WiFi side of the divide, including Google and Broadcom, think there needs to be formal coordination between the two camps before any sharing schemes move further…

The Wi-Fi Alliance is not at all convinced that [unlicensed LTE technologies] are going to play fair with Wi-Fi. According to the alliance, there is insufficient information about how [unlicensed LTE technologies] will coexist with Wi-Fi and other users of unlicensed spectrum. While efforts are underway to foster collaboration between the affected parties, it urges the commission to continue monitoring developments to ensure there is sufficient dialogue and consideration on how unlicensed spectrum will be shared fairly…

[Unlicensed LTE] is a proprietary system developed privately by a few companies, and it employs carrier sensing adaptive transmission (CSAT) technology that is not under consideration by [the LTE standard group]. “This lack of industry standard implementation of CSAT means that its impact on other users of shared spectrum will be variable and unpredictable.”

I don’t doubt that whether or not it’s coordinated, there is a lot of effort going into trying to minimise the damage mobile carriers do to unlicensed users, including wireless Internet service providers. But even if optimally designed, adding countless access points professionally engineered for maximum effectiveness to unlicensed bands will significantly raise the RF noise floor and make it more difficult for independent operators to provide wide area service. The impact on hotspots and home routers might be minimal, but don’t assume the same will be true for WISPs.