Public-safety LTE networks operating in the 700 MHz band should use a single public land-mobile network identification (PLMN-ID) throughout the nation to make interoperability easier and to reduce costs, according to several key public-safety organizations.

The Association of Public-Safety Communications Officials (APCO), the Public Safety Alliance (PSA) and the Public Safety Spectrum Trust (PSST) are among the public-safety organizations that recently expressed support for public-safety LTE networks to use a common PLMN-ID throughout the United States.

“It’s simpler for management purposes and oversight of the network,” PSST Chairman Harlin McEwen said. “Secondly, it’s cheaper.”

Indeed, APCO noted in its statement of support for a single PLMN-ID that such an approach would eliminate the need for “costly roaming infrastructure” and would simplify roaming by public-safety users to and from commercial networks.

Commercial carriers such as AT&T and Verizon have long used a single PLMN-ID to identify devices on their national networks, and both carriers have expressed support for public safety to use a single PLMN-ID throughout the U.S. when it leverages commercial LTE technology for the first time.

Some have expressed fear that using a single PLMN-ID would result in a single vendor’s equipment being used throughout the country, but this is not the case, said Morgan Wright, vice president of Alcatel-Lucent’s global public-safety segment. In the commercial arena, multiple vendors supply equipment that support nationwide networks deployed by carriers such as Verizon, he said.

In addition, having a single PLMN-ID would not impact a local public-safety agency’s ability to control use of its network, Wright said.

“Having that single national ID does not take away — at all — from their ability to manage their own local resources,” he said.

With 700 MHz waiver entities like the state of Texas and the city of Charlotte, N.C., seeking to deploy LTE networks in the spring, a decision on the PLMN-ID approach is needed soon, McEwen said. He expressed concern that having multiple PLMN-IDs would make roaming between public-safety networks more difficult and force entities to spend time unnecessarily negotiating individual roaming agreements between each other.

Under the proposal backed by the public-safety organizations, the PSST would apply for the PLMN-ID and the public-safety entities that lease 700 MHz broadband spectrum from the PSST would be given PLMN-ID numbers that would be assigned to devices on their networks.

Of course, Congress is considering multiple pieces of legislation that would establish a new governance organization to replace the PSST as the national licensee for public safety’s 700 MHz spectrum. McEwen said the PSST would not oppose shifting the PLMN-ID authority and the spectrum license to the new governing body.

“Once the new legislation gets passed — hopefully, it will get passed — it sets up a new governance structure, and we would defer to that,” McEwen said. “We would bow out of the process.”