• LTE-U fight continues with disputed testing results
• FCC brought in to much anger
• But if spectrum sharing works so well, why not increase public spectrum pool?

The fight over LTE-U (LTE over the public spectrum used for WiFi) is getting more vociferous in the US and, as seems to be the pattern now, has taken on a politically ‘partisan’ flavour. The US cable industry along with the existing WiFi advocates are effectively on the pro-regulation, Democrat, side of the fence, telcos on the other, as the arguments over LTE-U deployment and whether the technology can be made to ‘fair share’ with WiFi play out.  And, also importantly, once the proof is in, how telcos can be trusted not to abuse by attempting to shoulder out WiFi.

Back in late July a group of Democratic senators wrote to FCC Chairman Tom Wheeler, urging him to deploy some oversight of the LTE technologies being deployed in unlicensed spectrum. The FCC needed to provide some adult supervision to the process of the industry developing “an effective sharing solution”, they urged. In early August, seemingly in response, the FCC asked the telcos for more information on how LTE was going to work - especially on how Carrier Sense Adaptive Transmission (CSAT), the chosen LTE-U contention technique wouldn’t shoulder out WiFi.

Both sides have been filing and counter-filing technical arguments resulting from their own testing of the LTE-U technologies. That’s most recently lead to T-Mobile filing a document that states that claims by LTE-U opponents about the impact on WiFi were based on testing "with parameters set at extremes that do not represent realistic deployments or do not reflect actual LTE-U specifications."

Predictably perhaps, US telcos are officially most outraged at the attempt to involve the FCC -  a move they see as a cynical attempt to hamstring them in their quest to find more and better ways to increase the bandwidth available for their customers.

The telco lobbying body, the CTIA, points out that if, as its protagonists claim, unlicensed spectrum works because of ‘permissionless innovation’ then the telcos should be allowed to innovate in it as well. ‘Public’ spectrum is public, after all - meaning open to everyone.

That’s not quite how many on the WiFi side of the house see things. What they fear is the ability to re-run what in medieval England was called the ‘tragedy of the commons’ - that’s where a common resource (say public grazing land) subject to unfettered use by individuals with ‘rights’, is so overused that everyone loses - except those rich enough to fall back on other resources when the grass runs out.  

That, essentially, is the dynamic WiFi operators fear is going to kick in if LTE-U is allowed. They claim that even if LTE-U were to be configured as a ‘good neighbour’ it would give licensed carriers the ability to - admittedly fairly - share public spectrum so that packet delay for all users (WiFi and LTE-U) would become more prevalent, but that licensed carriers could unleash their private spectrum to make up the quality deficit for their own users when required, putting them at a structural advantage.

But, the telcos might argue in turn, this is exactly the model that is going to be deployed against them via the so-called WiFi first operators, such as Google, where the intention appears to be to use as much free public spectrum as possible as part of a service, falling back to managed (paid for) spectrum purchased on an MVNO basis, only when required.

If it is determined that LTE-U can be fairly used to share public spectrum then perhaps the argument should quickly shift to obtaining some sort of quid pro quo. Rather than trying to foil the telcos, perhaps WiFi advocates and the cable companies should argue that telco entry argues for opening up more of all the available spectrum to shared use since, by carriers’ own admission when pushing for LTE-U, sharing can work without compromising quality and can lead to far better utilisation of available spectrum. In the past the assertion that it couldn’t was often the argument deployed to support licensed spectrum allocation.

After all, the grazed common can be made far less tragic if you substantially increase its size.