Work on Mission-Critical Voice over LTE Under Way, but Indefinite Timeline
September 28, 2011
By Lindsay A. Gross
In April, public-safety professionals named Long Term Evolution (LTE) the global standard
of broadband communications. Several government agencies and associations are working to make sure the standard, developed for the commercial wireless market, evolves to meet the specific needs of public safety.
The Department of Homeland Security (DHS) committed to support the public-safety community in identifying the requirements necessary for LTE to meet public safety’s needs, especially in a crisis, said Dr. David Boyd, director of interoperable communications, DHS Science and Technology Directorate.
“LTE is the technology of choice for broadband; we know that. However, right now the technology is running ahead of the standards process,” Boyd said. “We, and the public-safety community, need to make sure that we involve industry in the standards process so they understand how public-safety needs differ from commercial needs, and the National Public Safety Telecommunications Council (NPSTC) is leading the way.”
In early September, NPSTC released mission-critical voice communications requirements
for public safety as technology to provide voice over broadband gains more steam. The requirements aren’t necessarily a road map for those who desire to build mission-critical voice networks over LTE, but as a basis of understanding for future standards, NPSTC officials said.
The key elements for the definition of mission-critical voice include direct or talk around, push to talk (PTT), full-duplex voice systems, group call, talker identification, emergency alerting and audio quality
“It is important to understand that for a network to fully support public-safety, mission-critical voice communications each and every one of these elements must address part of the overall voice communications services supported by the network,” NPSTC officials said. “A network cannot be a mission-critical network without all these elements.”
Some of the standards necessary for LTE will be on the network end, but some standards will be on the device end, Boyd said. “The ordinary user doesn’t need a BlackBerry that can withstand incredibly high temperatures as a firefighter does,” he said. There is some level of broadband capability available now, and public safety is using it, just not for mission-critical applications, Boyd said.
Earlier this year, octoScope and Covia Labs each received about $100,000 contracts from the DHS S&T Small Business Innovation Research (SBIR) program to research and develop handset and infrastructure components for the nationwide 700 MHz public-safety LTE network.
octoScope, in collaboration with Telcordia Technologies, will develop the mission-critical voice service architecture for a nationwide broadband public-safety LTE network. The octoScope architecture will incorporate an LTE handset with mission-critical voice capabilities and an ability to automatically switch to different operating modes that allow continuous voice support with or without the infrastructure.
Separately, Covia will engage the public-safety community to understand its requirements for mission-critical interoperable voice communications. Covia will then develop a plan and deliver software that leverages LTE, existing communications systems and Covia Labs’ Connector interoperability platform to address these requirements. The contract has an optional $50,000 phase.
The federal Public Safety Communications Research (PSCR) program is also researching public safety’s needs for LTE. Earlier this month, the National Institute of Standards and Technology (NIST), which funds PSCR, released a notice and request for comment
seeking input on various possible features of a new nationwide interoperable public-safety broadband network.
Andrew Seybold, CEO and principal analyst of Andrew Seybold, said that if LTE broadband can meet both voice and data requirements of the first responder community, a single device could be deployed that would provide not only data/video interoperability, but voice interoperability as well. “This could be an ideal situation and one that is worth pursuing,” Seybold said. “However, existing narrowband spectrum should not be allocated for other users until such time as LTE broadband can and does meet all the requirements for public-safety mission-critical voice, as well as data and video services.
“LTE for data and video should be deployed as quickly as possible, and workaround solutions for interoperable voice should continue to be implemented on a local, area, regional and statewide basis,” Seybold said.
Boyd believes that mission-critical voice for LTE will definitely happen; it’s just a matter of how fast. He said 700 MHz public-safety broadband waiver jurisdictions that have already started building broadband networks for data could eventually add voice once a standard is set. “DHS plans to help those waiver cities figure out how to incorporate mission-critical voice into their current broadband projects,” Boyd said.