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White Paper Addresses Testing for Emergency Services Mobile Networks

A white paper on validation and regression testing for emergency services mobile networks is available from GL Communications.

“Emergency services mobile networks include land mobile radio systems and often interface with the public switched telephone network (PSTN),” said Robert Bichefsky, director of engineering at GL Communications “These networks are used by police officers, firefighters and other first responders and must reliably transmit audio between endpoint devices.

“In responding to emergency situations, clear communication between personnel is mandatory,” Bichefsky said. “Poor voice quality and long latency can lead to miscommunication resulting in catastrophic consequences such as loss of life and damage to critical infrastructure. Clear voice quality is needed not just outdoors but in vehicles, aircraft, buildings, and underground as well.

“Objectively measuring end-to-end voice quality in a wide range of scenarios spanning different locations can be challenging but is essential,” Bichefsky said. “In this whitepaper, we have proposed a systematic way to test voice quality over emergency services mobile networks. The resulting testing will identify gaps in coverage, potential sources of interference, and other obstructions. This will allow the users to identify and eliminate vulnerabilities in their emergency services mobile networks and better protect their citizens.”

Solutions mentioned in the white paper include a VQuad probe which is is a self-contained unit for voice, video, and data testing. It contains many physical interfaces for connecting to telecommunications endpoints such as radios, landline telephones and cellular phones, according to GL Communications.

The company said the VQuad probe includes a high-density dual universal telephony adapter (Dual UTA HD), which provides interfaces such as Bluetooth, 2-wire analog, 4-wire analog, RJ-11 and push-to-talk for mobile radios. In addition, the VQuad probe includes an embedded single board computer running Windows 10 64-bit operating system, GL Communications said.

Another solution, the vMobile device, is a hand-held portable device that can connect to a single mobile radio and perform the same operations as the VQuad probe, the white paper said. According to the company, the solution is ultra-portable with a self-contained battery for ease of operation during walking tests. Using the onboard Wi-Fi, the vMobile device can tether to a mobile phone for Wi-Fi connectivity while connecting to the vMobile central console for remote operation, GL Communications said. It said that the vMobile device also can be controlled directly from any mobile phone using the installed vMobile console app for running vMobile service autonomously using scripts. In addition, GL Communications said, the vMobile device and VQuad probe can work independently or together as part of a single end-to-end call.

Yet another solution, the indoor tracking system (ITS), works with the VQuad probe and vMobile device and with GL voice-quality testing (VQT) software applications to track voice quality while walking within a building or in an underground location where GPS is not available, the white paper said. ITS allows the user to upload floor plans as a JPG prior to conducting the test, configure test points on the JPG and traverse the space while indicating on the GUI as they pass each pre-defined point while automatically performing voice quality measurements during the walk test, GL Communications said.

As a result, according to the company, the ITS can plot the voice quality test results directly on the floor plan and show the path the user took during the test. This plot allows the user to accurately identify locations within a building or underground where voice quality is degraded, the company said.

Meanwhile, VQT software supports the next-generation voice-quality testing standard for fixed, mobile and IP-based networks using POLQA (ITU-T P.863) or PESQ (ITU-T P.862) with the ability to correlate the PESQ results to DAQ, GL Communications said.

The company said that VQT software analyzes the degraded (received) files and compares them with the reference (sent) files using ITU standard POLQA and PESQ algorithms.

Another solution, a web-based client for voice and data quality testing called WebViewer, uses a web browser to display and access, in real time, results and events associated with the VQuad and VQT testing, GL Colmmunications said. Using the WebViewer, the company said, one can query and filter results, generate custom reports, schedule reports to be generated and emailed, plot results within Google Maps and obtain network status of all deployed devices, including VQuad probes and vMobile devices.