Comcast has now formally requested permission from the Federal Communications Commission (FCC) to conduct both indoor and outdoor tests in the 3.5GHz band for both fixed and mobile applications. That, of course, also includes testing applications of the 3650MHz – 3700MHz bands for use with smartphones. Specifically, Comcast says it plans the tests to gain a better understanding of "propagation characteristics for model verification, data throughput, performance, inter-cell interference, and advanced SAS functionality" in the bands. Those will include uses of both pre-commercial and market-ready equipment. According to a redacted copy of the application which is available via the source link below, testing is set to be conducted in the company's home city of Philadelphia. In fact, the exact coordinates are for a location several blocks away from Comcast headquarters and testing will happen within a 7km – around 4.3-miles – radius from that location.
For those who may not be aware, the portion of the 3.5GHz spectrum in question is actually a part of the Citizens Broadband Radio Service (CBRS) band. Unfortunately, the redactions included on the publicly available documents don't provide much more by way of details about the tests. It is explained that at least one of the tests will utilize a transmitter comprised of rooftop-mounted base stations associated with current or prior carrier cell sites. Moreover, Comcast has indicated that it will comply with all restrictions associated with the use of CBRS bands. That means its equipment will not interfere with other services currently using the band, as per protections afforded to non-commercial users. That will, Comcast notes in its application, include the company maintaining manual control over the tests and all testing equipment so that it can switch channels on the fly if it needs to.
Comcast's interest in the CBRS band is, perhaps, unsurprising since the company is a member of the CBRS Alliance. Verizon, another member of the conglomerate, and others have also expressed interest in conducting tests in those bands. The FCC has actually already been moving toward opening the band for commercialization. However, it isn't known yet whether Comcast wants to implement its own networking technologies using the spectrum. The company could also pay other carriers for use of their networks and these tests may just be to determine the commercial viability of that option.