TETRA IN THE USA - EWA ASKS FCC FOR TETRA CLARIFICATION
..an entity moving from analog 25 kHz channels to TETRA — a narrowband-compliant digital technology — also should be subject to frequency coordination..
Enterprises choosing opting to utilize TETRA technology should be required to complete the frequency-coordination process to ensure they operate on airwaves that will not generate harmful interference to a TETRA network or neighboring systems, according to a recent filing from the Enterprise Wireless Alliance (EWA).
TETRA is a land-mobile-radio system that is popular in Europe but has had very limited deployment in the United States. An FCC ruling clears TETRA’s usage by non-public-safety enterprises, but a recent agency order states that “frequency coordination is not required for TETRA modification applications if the only proposed change to the station’s technical parameters is the emission bandwidth.”
LMR networks subject to the FCC’s narrowbanding mandate do not require frequency coordination if the system transition involves a move from analog 25 kHz channels to analog 12.5 kHz channels, according to EWA President and CEO Mark Crosby. LMR systems that migrate from analog 25 kHz to digital 12.5 kHz channels require frequency coordination. With this in mind, an entity moving from analog 25 kHz channels to TETRA — a narrowband-compliant digital technology — also should be subject to frequency coordination, he said.
“It’s a change in emission designator from analog to digital,” Crosby said. “Even in the bands below, if you go from 25 to 12.5 and go from analog to digital, that requires coordination.”
Furthermore, the frequency-coordination process can help ensure that the TETRA system will operate on the exclusive channels the technology requires, Crosby said. An entity trying to operate a TETRA system on shared channels would experience poor performance and likely would interfere with adjacent systems, he said.
“It’s not just the emission designator that you’re looking at, because TETRA requires exclusive channels — it doesn’t operate in a shared environment,” Crosby said. “You can’t place a centralized trunked system that doesn’t have a monitoring capability [like TETRA] in the middle of a shared band. It will wreck havoc, and it would destroy the investment that the licensee put into TETRA.”
Source: www.urgentcomm.com
