Federated Wireless and Alphabet’s Access team reached a major milestone in demonstrating interoperability between their Spectrum Access System (SAS), going a long way toward validating sharing in the 3.5 GHz band, also known as the Citizens Broadband Radio Service (CBRS) band.
To be sure, such a feat was required by the FCC, but to show it actually can be done moves the whole 3.5 GHz band ecosystem forward. The FCC in April put the final rules in place for the 3.5 GHz band, which is seen as an unproven experiment by some and a vast opportunity by others.
To accomplish the interop demo, engineers from Federated Wireless and Access, who have been working together over the past weeks and months, staged a conference call Dec. 1 between Federated Wireless’ offices in Boston and the Access team in Mountain View, California, so that they could observe the demo, which used Amazon Web Services (AWS) on Federated Wireless’ side and Google Cloud for Access. The two cloud systems worked together over the air to conduct SAS interoperability—which in the old days before software-defined tech would have required them to physically sit next to one another in a lab.
Creation of the standards and protocols for CBRS has been ongoing through the Wireless Innovation Forum (WinnForum), whose members include Federated Wireless, Google, Ericsson, Nokia, Ruckus Wireless and others. Earlier this month, WinForum announced the public availability of its signaling protocols and procedures related to the 3.5 GHz CBRS band—first-of-their-kind standards to address the new FCC rules for 3.5 GHz.
Demonstrating interoperability of the Federated Wireless and Access SASs, which were independently developed, was a necessary step toward launching a commercial shared spectrum service while validating the SAS-to-SAS interface protocol defined by the WinnForum, according to the companies. It’s a major accomplishment that they wanted to get done before the end of the year.
In terms of plans for rolling out SAS-based services, “it’s right on plan,” Iyad Tarazi, CEO of Federated Wireless, told FIerceWirelessTech. “We’ve always said we expect commercial availability of these services to be in the first half of next year,” he added. “We’re still on track for that.”
The CBRS rules open 150 MHz of spectrum (3550-3700 MHz) for commercial use and establish a three-tiered system for users that includes an Incumbent Access tier, Priority Access tier and General Authorized Access tier. The three tiers are to be coordinated through a dynamic SAS, which uses sensors to determine when and where spectrum is available.
Given the vast amount of 3.5 GHz spectrum out there and how much of it is currently unused, the expectation is there will be a lot of desire to work with the spectrum before the licensed part comes into play, which is likely in the 2018 timeframe so that stakeholders can see how the usage looks before putting a price on it at auction, according to Tarazi.
Commercial products based on 3.5 GHz, like access points and different radio systems, are expected to be available in the first half of next year, but it’s unclear when support for 3.5 GHz will come in end-user devices.
Six companies announced the launch of the CBRS Alliance in August to develop, market and promote LTE-based solutions using the shared spectrum of the 3.5 GHz band. The companies—Access Technologies (Alphabet), Federated Wireless, Intel, Nokia, Qualcomm and Ruckus Wireless (now part of Brocade)—said they believe that access to spectrum in the 3.5 GHz frequency band will be critical to meet expanding wireless data demands. In October, they were joined by AT&T, Ericsson, CableLabs, Accelleran, Airspan Networks, American Tower, Baicells, ExteNet Systems, Nsight, Ranzure Networks, Rise Broadband and ZTE USA to drive the technology.