CBRS proponents quietly fret over NTIA’s ongoing 3.5 GHz tech testing

A number of executives in the 3.5 GHz CBRS space are quietly worrying that the NTIA is taking too long to test elements being used in the technology. The NTIA, for its part, argues that it’s going as fast as it can.

The situation boils down to the fact that CBRS players are chomping at the bit to launch commercial 3.5 GHz services. Although no executive wanted to speak about the topic publicly, several expressed concerns privately that the momentum behind 3.5 GHz services could be held up by a lengthy government testing process.

And it appears that the NTIA is aware of those concerns. Keith Gremban, director of the NTIA’s Institute for Telecommunication Sciences (ITS), wrote in a post on the agency’s website that “we are working efficiently and judiciously to make sharing in the 3.5 GHz band a reality as soon as possible.” The ITS is the NTIA organization conducting the CBRS tests.

At issue are the Environmental Sensing Capability (ESC) sensors and the Spectrum Access Systems (SAS) necessary for communications in the CBRS band. As the NTIA noted, the ESC sensors are designed to alert the associated SASs when federal radar systems are operating in the 3.5 GHz band, so that the SAS can take immediate action to manage CBRS devices to prevent interference.

It’s no surprise that the NTIA’s ITS is involved in the issue. The NTIA is essentially a steward of spectrum for government users and is therefore playing a key role in the CBRS space because the 3.5 GHz band is being shared between commercial users and the military, mainly the U.S. Navy. The spectrum sharing scenario for CBRS is a first-of-its-kind in the world.

“ITS has released a study guide for Spectrum Access System testing via GitHub. The guide consists of samples of tests that will be conducted on Spectrum Access Systems. The tests will include a wide variety of scenarios and situations to test the systems’ ability to manage CBRS devices,” NTIA’s Gremban wrote. “ITS is also advancing its testing of ESC sensors and expects to complete the laboratory phase of testing ahead of schedule.”

In response to questions from FierceWireless on the topic, a variety of CBRS proponents acknowledged the importance of the NTIA’s ongoing tests.

“The collaboration between industry and numerous federal agencies and departments to operationalize the CBRS band has achieved unprecedented levels of coordination and cooperative development,” the CBRS Alliance said in a statement on the topic last month. “This is quite encouraging as we look to a future where federal/commercial sharing may be increasingly important. NTIA, FCC, the DoD and other government stakeholders have all been very active and supportive as we move closer to initial commercial deployments and to full commercial service in CBRS, which we expect soon.”

The WInnForum similarly offered conciliatory comments on the topic: “WInnForum is pleased to have collaborated closely with ITS during both development and evaluation of the test code,” the association's steering group said in a statement last month. “WInnForum is working with our government partners to ensure that certification is progressing as quickly as possible while making sure that all incumbents are properly protected.”

But the NTIA, in statements last month, made it clear that it is not at fault for any delays. “ESC testing is ahead of schedule, and certification testing for ESC Operators is expected to be completed by the end of the year,” the agency said in a statement. “Test code for the SAS certification system, first provided by industry on May 29, has had to be repeatedly updated to correct problems in the code provided for testing. ITS is working with several conditionally approved SAS Administrators to ensure that the code is capable of being appropriately tested for compliance. Given the complex code and systems involved, SAS testing is proceeding as expected.”

The FCC, for its part, voted last month to move forward with rules governing the CBRS 3.5 GHz spectrum—that action essentially removed another obstacle to widespread 3.5 GHz deployments. And companies ranging from AT&T to Verizon to Charter have expressed interest in using the spectrum.

Now all eyes are on the NTIA.