Some Relief for WiFi?

Wi-FiThe FCC is currently considering a proposal by Globalstar to open up a fourth and private WiFi channel. It looks like the vote is going to be close with Commissioners Rosenworcel and Pai saying they oppose the idea.

Globalstar, based in Covington, Louisiana, is a provider of satellite-based telephone systems, but has been dwarfed in that part of the industry by the much larger Iridium. Globalstar was awarded a swath of spectrum in the high 2.4 GHz bandwidth to use for its satellite phones. The Globalstar bandwidth sits next to the part of the WiFi spectrum used for Bluetooth – but there is such a small amount of satellite phone usage that interference has never been an issue.

Globalstar made a proposal to make their spectrum available for WiFi, but with the twist that the want their slice of spectrum to be private and licensed by them. This differs from the rest of the WiFi spectrum that is free and open for anybody to use. Globalstar argues that allowing some large users, such as AT&T, to use their spectrum will take a lot of the pressure off of existing WiFi.

There are places today where WiFi interference is noticeable, and it is likely to get worse. Cisco projects that the amount of data carried by WiFi will triple in the next three years – a growth rate 50% greater than data usage overall. There is expected to be a lot of demand put onto WiFi from the Internet of Things. And the cellular companies have a proposal called LTE-U that would let them dip into the WiFi spectrum for cellular data.

But as might be imagined there is a lot of opposition to the Globalstar plan. One of the major objections is that this would be a private use of the spectrum while the rest of the WiFi is available to everybody. Globalstar could license this to a handful of companies and give them an advantage over other WiFi users by giving them access to a largely empty swath of spectrum that wouldn’t have many users. Having a few companies willing to pay the price for Globalstar’s spectrum flies against the whole concept of making WiFi available to everybody.

But the primary concern about the idea is that it will cause interference with existing WiFi. Today the normal WiFi antennas used to send and receive data are not very expensive, and they routinely broadcast signals outside of the range of the narrow WiFi channels. This creates a condition called adjacent channel interference where WiFi interferes with adjacent bands of spectrum. The FCC has handled this by creating buffers around each WiFi channel that allows for the bleed-over signals.

The Globalstar spectrum sits in one of those adjacent buffer zones and critics say that heavy use of the Globalstar spectrum would directly then interfere with existing WiFi that already bleeds into the Globalstar spectrum. In general it’s never been a good idea to place two heavily used slices of spectrum next to each other without buffers, and the proposal would jam Globalstar spectrum next to existing WiFi. On the other side of the Globalstar spectrum is the part of WiFi reserved for Bluetooth, and again use of the spectrum would eliminate any buffer.

The opponents to the idea have been very vocal. They don’t think the FCC should allow for the risk that Globalstar will create a clear channel for a few carriers while interfering with everybody else trying to use WiFI. The industry as a whole says this is an overall losing idea.

The issue has been in front of the FCC for a few years and looks like it will come to a vote soon. Chairman Wheeler is for the Globalstar plan with two other Commissioners already against it. It will be up to the final two commissioners to decide if this is a go or not.


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