This week we have been invited to an event by Qualcomm which is entitled “Setting the Record Straight on LTE-U with WiFi Coexistence,” which will be presented by Signals Research Group, a company who regularly wins contracts almost exclusively from Qualcomm and Ericsson research budgets, and with no WiFi expert in sight. We plan to listen and ask questions carefully before unveiling it as what it seems to be, a plot to ruin WiFi.
The charm offensive has been ongoing and insistent – “Cellular knows best how to avoid interference with WiFi,” and “No! We will not copy WiFi techniques,” but will invent our own.
This week also Verizon and T-Mobile in the US came out firing at the WiFi Alliance certification proposal to the FCC, to let it run a compliance program to certify that LTE-LAA devices use fair spectrum sharing. Interestingly they asked why should a rival technology determined their right to use license free spectrum – and of course they are right, the FCC will have to either do that itself or appoint someone, with known sympathies, who can do it on its behalf. Perhaps Signals Research Group would offer?
In a way the WiFi Alliance is being a tad arrogant protecting its rights by testing rival technologies, but so far, if we believe CableLabs, the back off approaches suggested by the LTE community are exceptionally corrosive to the performance of WiFi and the FCC can easily determine whether or not the conditions of such a test were rigged, or if the insistence that its coexistence between the LTE community and WiFi is done fairly.
We do not think this is a PR battle, not in any way, it’s a technical battle. But there are some grounds for compromise.
We don’t think that co-existence really matters outdoors. WiFi cannot really claim that it is the dominant technology outdoors, and in congested cellular base stations, LAA (Licensed Assisted Access) could help MNOs. The outdoor power limits for WiFi are far higher, distances served are further, with less obstructions and the likelihood of colliding with local WiFi services are minimal. The FCC could even amend the regulations around outdoor somewhat, because less than 1% (much less) of all WiFi hotspots are outdoors and not that many more reach outdoors at a usable signal strength.
So why is it that Ericsson continually talks about installing LAA indoors where WiFi really does reign and has something to be worried about?
Here cellular simply has deliberately underpowered and underinvested in in-home femto cells, and it would be fairly easy for operators to sell femto cells so cheaply that they were irresistible for in-home installation. After all if the problem is that only 3 out of 10 homes have a good enough signal, then the operators have little to worry about, such as interference with the macro base station, by putting another cell in the home.
The price of such a cell, would be largely in line with the price of an Access Point and it can be backhauled by the home broadband line. But it gains the operator so little because simple VoWiFi software on the handset gets the operator to the same point and it’s much cheaper.
It is the failure of Ericsson to ever try to explain its strategy and the economics around it that make its motives so suspicious. Hence the fact that no-one believes the cellular community when it says there is no interference issue.
The latest issue began earlier this month when the WiFi Alliance announced its Co-Existence Evaluation Program. It said it could develop a “comprehensive coexistence test plan” that would assess the level of fair sharing between LTE-U and WiFi technologies.
If such a test plan did exist, and it showed co-existence to be unworkable using the current LAA back off process, it would stop the movement in its tracks.
Qualcomm and Ericsson could learn a lot about such an exercise, like how to actually build a co-existence configuration. Instead they send out invites to “white is black” conferences that try to turn this into a PR battle, when it is a factual, engineering one.
Verizon and T-Mobile have both said they intend to launch commercial LTE services into unlicensed spectrum starting next year. Again this is a PR exercise. They want to pile pressure onto the FCC to give them the go-ahead, as if it is the FCC’s fault if they miss that deadline. When asked why they want to install this indoors, the answer is invariably that this is for enterprise environments, not the home – clearly untrue, they want to charge for LTE services in the home, replacing WiFi, driving their revenues.
Enterprises would switch off the LTE LAA the moment that it affected WiFi, and ask for their money back. Homes would be unable to test it as accurately as an enterprise, and equally unable to tune the two technologies to work side by side. And besides, Ericsson has not come up with an Enterprise product for LTE LAA we know of as yet.
The entire discussion appears duplicitous and secretive, and the claims, such as LTE LAA improving WiFi, and having better spectral efficiency are never checked, and are demonstrably wrong. And if this managed to get past the FCC, it would be held up in Europe and some parts of the rest of the world, so that the solution would be a single country hodge-podge.