US cable operator Comcast revealed plans to launch pre-commercial field trials in the 3.5GHz band next month, covering both fixed and mobile applications.
In a partially redacted filing with the Federal Communications Commission (FCC), Comcast requested permission to test three different types of prototype radio transmitters operating between 3650MHz and 3700MHz, including rooftop-mounted base stations located at current and former cell sites. Trials will take place in a portion of Philadelphia, Pennsylvania.
Using three kinds of mobile test devices and commercially available handsets – including an “LG V30 or equivalent” and a Mi-Fi device – the operator said it will evaluate propagation characteristics, data throughput performance, inter-cell interference and functionality with a shared spectrum management structure known as the Spectrum Access System (SAS).
Since the 3.5GHz band is designated as the shared Citizens Broadband Radio Service (CBRS), the SAS was adopted to coordinate access across incumbent, priority licensed and general licensed users.
Comcast said the goal of the tests is to better understand the “full potential” of CBRS technology. The company did not directly say whether the 3.5GHz band might be used to supplement coverage for its fledgling MVNO wireless service, Xfinity Mobile.
The operator’s decision to push ahead with testing at 3.5GHz comes despite regulatory uncertainty around the future of licensing parameters in the band. In October 2017, the FCC opened a proceeding to revisit the rules for priority access licences, proposing longer licence terms and larger coverage areas, among other changes.
However, the review has not deterred operators. Shortly after 3GPP’s approval of 5G non-standalone specifications in December 2017, all four tier-1 US mobile operators announced interoperability testing in the 3.5GHz and 28GHz bands. In January, cable operator Charter also revealed it is testing fixed-wireless 5G at 3.5GHz.
In a recent interview with Mobile World Live, Nokia North America CTO Mike Murphy confirmed CBRS tests are underway at nearly all tier-1 and tier-2 wireless operators and cable providers, and revealed at least one US broadband provider is preparing to launch 5G on 3.5GHz spectrum.