Cable company Charter Communications appears to be in the early stages of charting out the contours of a mobile network in cities across the country, including Dallas, New York and Orlando.
Charter spent roughly $500 million on 3.5GHz CBRS spectrum licenses in an FCC auction last year, and last month the company asked for FCC approval to test transmissions in the band in roughly a dozen different cities where it won licenses.
"As a recent CBRS Auction 105 winning bidder, in approaching its RF network design Charter requires propagation data detailing the characteristics of CBRS signal propagation in varied topology and clutter environments," the company wrote in its FCC application. "As is standard industry practice, Charter intends to collect such data through Continuous Wave (CW) drive testing in varied locations characteristic of potential future deployment areas. In doing so, a calibrated non-modulated transmitter emits a precise signal, both in frequency and transmit power, while a measurement team 'drive tests,' collecting received power level data at dispersed geographic points throughout the covered area of the transmitter using a similarly specialized calibrated recording receiver."
Charter said it would conduct the tests by installing a CBRS transmitter from Berkeley Varitronics atop one of its bucket trucks. Technicians will then drive the bucket truck around to see where they can find signals.
Charter explained that such testing is standard in designing a mobile network, as it allows technicians to figure out where transmitters need to be installed to provide suitable coverage of a geographic area. After all, things like trees and buildings can affect how wireless signals cover a given topography.
However, Charter explained that transmissions in the CBRS band pose unique challenges to network planners because the band is shared among licensed, unlicensed and government users. That sharing is managed through a Spectrum Access System (SAS); Charter uses one provided by Federated Wireless.
"Charter is conducting this testing in cooperation with Federated Wireless, and will manually employ Federated's SAS database for frequency and power coordination," the company wrote.
Charter's mobile network ambitions have been slowly crystalizing. Light Reading reported in 2019 that the company is planning to use eSIM technology to push customers' mobile traffic from Verizon's LTE network and onto Charter-owned cell towers, where they're available, in order to reduce the amount of money Charter pays to Verizon for wholesale access to Verizon's LTE network.
Charter's CEO, Tom Rutledge, said in January that the company could use its CBRS spectrum to eventually offload up to one third of its MVNO traffic onto its own network over the course of the next four or five years. Rutledge added though that Charter's deployment of CBRS would be "opportunistic," focused on dense, high-traffic areas where the cable operator can get the most bang for the buck.
Charter already estimates that 80% of all its Spectrum Mobile MVNO mobile traffic is delivered across its Wi-Fi network.
Rutledge's comments come just a few months after Verizon inked an "expanded and extended" MVNO agreement with Comcast and Charter. Verizon announced that new deal in the wake of AT&T's overt courting of its cable MVNO deals. Terms of that new deal have not been disclosed.
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