Yesterday, the Wi-Fi Alliance issued a final version of the coexistence test plan between LTE-U and Wi-Fi and today, both T-Mobile US and Verizon Wireless have announced that they are reviewing the details of this plan with a view to deploying the technology to bolster their own licensed networks. LTE-U is the term used for utilizing unlicensed spectrum for operating an LTE network, but it uses the same frequencies that current 802.11 Wi-Fi networks use such as 5GHz. This has caused some uncomfortable discussions between carriers and hardware vendors because the fear has been that LTE operating in the same spectrum as Wi-Fi could cause disruption for both types of signal and result in a poor customer experience. The test plan should ensure a common baseline for vendors to test Wi-Fi products' functionality when LTE-U networking is being used. Currently, neither T-Mobile US nor Verizon Wireless have stated when they are going to be ready to deploy a commercial LTE-U system but both have expressed positive language about the test being complete.
T-Mobile US' vice president of government affairs, Steve Sharkey, explained that the carrier believed there still to be "significant work to be done" but that the company was reviewing the Wi-Fi Alliance LTE-U coexistence document. Verizon's spokesperson explained that America's largest carrier was pleased that the process had come to an end and that the company were looking "forward to reviewing the final details of their coexistence test plan." Verizon also explained that they were pleased the Wi-Fi Alliance were not incorporating or texting other unlicensed technologies such as LAA, adding "It is important that unlicensed spectrum remain an open platform for innovation." Verizon (and Qualcomm) had previously criticized draft versions of the document stating that it was unfair and biased against LTE-U.
There has been some compromise in producing the final document, as one might expect from technologies that are essentially competing for the same spectrum. The test plan detailed in the document was still being worked on earlier in the week. Keith Robinson, the vice president of marketing for the Wi-Fi Alliance, explained that key Wi-Fi and LTE stakeholders were still building a fair and equitable multi-vendor benchmarking system, but that in the end "nobody gets everything they want." However, Keith also explained that the industry was only going to make progress through compromising and all involved parties had invested a great deal of time and effort to reach this point. He also added that it had taken just one year to reach the final document in an industry where it usually takes twice this long. He also alluded that the industry had been able to produce the document without the US' telecom regulator, the FCC, stepping in, which is something the industry does not want. Ultimately, LTE-U is an interesting technology as it will allow the carriers to boost their network capacity whilst at the same time keeping control of customer's data access, offered in areas that already have LTE coverage. That LTE-U needs to co-exist with Wi-Fi radios is important as it means established Wi-Fi networks will not be disrupted and so impact on those customers without LTE-U enabled devices.