The SAS interoperability test between Alphabet’s Access team and Federated Wireless bolsters plans to free up the 3.5 GHz band for eventual 5G support.
The telecommunication industry’s access to 3.5 GHz spectrum garnered momentum as Google parent company Alphabet and Federated Wireless said they had demonstrated interoperability between their respective spectrum access systems.
The companies said the demonstration included operational interoperability for their SAS platforms that validated the SAS-to-SAS interface protocol defined by the Wireless Innovation Forum. The demo is said to have shown an exchange of information between Federated Wireless’ CINQ XP platform and the SAS developed by Alphabet’s Access team required to protect interference-free operation by commercial and federal incumbent users in the 3.5 GHz band, also known as the citizens broadband radio service band.
The validation is a requirement for a multi-SAS administered citizen broadband radio service, which Federated noted could support higher data rate LTE access for mobile devices.
“One of the fundamental challenges of the CBRS ecosystem was to demonstrate that the complex algorithms could be implemented by independent SAS suppliers,” said Preston Marshall, engineering director at Alphabet’s Access division, connected with the trial. “This test not only shows the maturity of the implementations, but the viability of multiple suppliers and the benefits that consumers will obtain from different implementation options.”
Federated Wireless recently announced it had set up a test bed in Norfolk, Virginia, to demonstrate and verify its Environmental Sensing Capability, which it claims can unlock the value of shared spectrum in major metropolitan areas. The company said the ESC platform is designed to increase available spectrum in coastal areas while providing “prioritized, interference-free use by incumbent federal users.”
“When the ESC sensor detects a federal transmission, it will activate a protection zone and inform the SAS to dynamically reallocate users in the area to other parts of the band,” the company noted.
RCR Wireless News recently spoke with Kurt Schaubach, CTO at Federated Wireless, to discuss the impact spectrum sharing has had on the mobile telecom space and how planned spectrum sharing initiatives are set to be critical as the industry moves into the 5G environment.
The Federal Communications Commission has been working for several years on freeing up access to spectrum in the 3.5 GHz for shared use. That work initially focused on up to 100 megahertz of spectrum, before being increased to 150 megahertz.
The 3.5 GHz band is now in the hands of the Department of Defense for use in certain radar installations, as well as by non-federal fixed satellite service earth stations for receive-only, space-to-earth operations and feeder links. The FCC’s goal was to find a way for shared access to the spectrum without causing interference with existing users.
Initial plans included a focus on small cell deployments in support of LTE services, which aligned with the limited propagation characteristics of the spectrum band. The current plan includes three tiers of spectrum usage comprised of federal and non-federal incumbents, priority access licensees and general authorized access users. Access would be under a flexible model taking advantage of technology to reduce interference between users.
More recently, focus on the band has switched to it being considered one of the “low-band” options in support of 5G services expected to have a high reliance on spectrum bands above the 25 GHz level. While the 3.5 GHz band would be considered high band for current network deployments, Marshall cited the somewhat limited propagation characteristics of the 3.5 GHz band as an advantage, noting the spectrum sets up well as a floor-by-floor option for enterprises and venues.
“Imagine if every floor of an office building had access to 150 megahertz of spectrum,” Marshall said at the recent 5G North America event.
While traditional wireless carriers have expressed interest in the 3.5 GHz spectrum, Marshall said he thinks the killer application for the band is a neutral host concept, noting the benefits of having robust spectrum support using common backhaul and common management of devices not tied to a single network provider. This nontraditional model could also play into the evolving usage model of wireless services, with Marshall explaining most growth is happening indoors, which could be difficult for established mobile operators to tackle using standard deployment models.
Bored? Why not follow me on Twitter.
