LTE  |  2019-09-27

LTE Devices for Public Safety Communications Have Room for Improvement

Source: The Critical Communications Review | Gert Jan Wolf editor

Testing in Spirent’s performance center found noisy environments can thwart first responder communication nearly 50 percent of the time.

Spirent Communications plc, a leading provider of test, assurance, and analytics solutions for next-generation devices and networks, announced in a new whitepaper critical findings from its LTE Device Speech Intelligibility Benchmark Analysis. The findings in the report show that phrase misunderstandings can occur in mission-critical communications scenarios up to almost 50 percent of the time, even when using devices that are marketed specifically for use by the public safety community.

As public safety networks transition to PS-LTE (Public Safety LTE), more handsets are entering the market. Spirent conducted testing of a representative sample of these handsets in its Maryland-based Performance Center - a world-class testing facility that specializes in evaluating the communications performance of voice, video and data devices. As part of the test process, the company evaluated speech intelligibility in four commercially-available devices. Testing emulated use within a quiet environment, followed by six emulated first-responder noise environments including a nightclub, emergency siren and a fire-rescue situation utilizing a saw.

Spirent’s whitepaper, “Speech Intelligibility Evaluation Highlights Differences Between LTE Public Safety Devices”, offers a look into anonymized results of the benchmark testing, which revealed:

  • The top-performing device outperformed the others tested by at least a six-to-one margin in certain emulated environments;
  • No device proved perfect – intelligibility failure rates ranged from 1% to 49%, depending on the environment;
  • Great performance in one environment did not necessarily correlate with similar performance in other emulations; and
  • In some cases, consumer-grade devices outperformed devices purpose-built for PS-LTE use.

“Our testing looked at certain devices through the lens of how well they were able to transmit the essentials of speech while suppressing most background noise, because that’s where the largest performance gaps emerge in public safety applications,” said Vice-President of Product Marketing at Spirent, Saul Einbinder. “The significant performance discrepancies we uncovered indicate that device makers must further re-evaluate designs and components to assure performance on the mission-critical LTE networks being rolled out around the world.”