TETRA Optimisation System, Luxembourg

In 2014, The Grand Duchy of Luxembourg embarked with the planning and rollout of a new TETRA Public Safety radio network called RENITA to replace the existing analogue systems. Following a competitive tender a contract was awarded to a partnership of ConnectCom and POST Luxembourg and the ‘RENITA’ project was created.        icca
SHORTLIST

A New Approach to TETRA Test and Measurement Solutions 


Although small by most national standards (Luxembourg has a population of 500,000 with approximately 12,000 P.S users) the new system would still need to deliver high levels of availability, reliability and service as expected of its Public Safety status. To help ensure this was a reality the contract put a lot of emphasis around measurement and verification of service across the network. In practice this meant a method was needed that could comprehensively measure, manage and report more than 25 voice, data and network KPI’s each month across the whole network continuously for the15 year contract duration.

 Due to the range, complexity and volume of test data to be captured, processed and reported the Quality of Experience (QoE) system as it was called would need to be as automated, reliable and efficient as possible. With so many tests running every day from so many locations across the network, the task of efficiently processing and managing all that data was going to be a key challenge.

 To meet this challenge Syntech Systems Ltd was selected as a sub-contractor to deliver the QoE system. The approach was to adapt two existing products, IFPM (In-Field Performance Measurement) & Tetra Active. These products were proven solutions used in several other TETRA radio networks in Europe including Norway Nødnett, Netherlands C2000 and UK Airwave. The difference this time was that they would need to be combined and enhanced to provide a much more comprehensive and automated QoE system to fulfil the RENITA requirements.

"We wanted a solution that would allow us to continually monitor our network so we
could find problems early on. The greatest benefit is we can see any problems quickly,
find patterns and plan for capacity during busy times.
 It’s different because it enables us
to see all areas of our network quickly, easily and in great detail. The solution means
we can run one system to do several jobs rather than several tools to do one job."

Claude Dupont – Director, S.à rl ConnectCom

 

TETRA Architecture to allow for Continuous Testing 


To confidently report the true condition of a network such as RENITA requires a balance between the need to test continuously over a wide area vs the cost, complexity and practicality of doing so. It was of course impossible to measure every event in the network but a statistical valid representation would provide confidence in the likely service being delivered to users.

The principle of the RENITA QoE system was to automatically schedule a series of structured, end-to-end tests using all TETRA voice and data services between several static locations located across the network and one or more drive-test vehicles. To provide confidence about the validity of the data being collected; and hence it’s correlation with the behaviour and performance of the whole network, a relatively large data sample size and broad distribution of locations was needed. In practice this meant the deployment of 6 static, 1 fixed and two drive-test vehicles. These were set to continuously test throughout the country each day of each month. The data collected was used to produce the KPI and service level reports. Results would also demonstrate that service was being delivered and any issues or anomalies within the network could be quickly identified.

In parallel with undertaking the end-to-end tests a number of QoE remote ‘probes’ would also be deployed in customer vehicles across the country. These probes would stream back further information about the network, its configuration and the service being experienced at that location. Combining these data with that from the scheduled QoE tests provides even more visibility and evidence about the level of service also being experienced by the users.
      


Innovation & Benefits of Syntech's TETRA Quality of Experience System 


The RENITA QoE system works on several different levels with the aim to minimise user resources and provide a panoramic and highly accurate view of network availability and performance.

Achieving a reliable level of process automation was a key objective to minimise the resources, effort and skill required to continuously operate the QoE solution over such a long contract period.

The approach taken was to first undertake a thorough review of the work and data flow from testing, data collection & transportation, to cross-referencing, analysing and reporting. Each step had to involve as little user intervention as possible and deliver a clean set of results from which to report i.e. free from all ‘process or execution’ related errors

To de-skill the process as much as possible any manual steps were automated. This approach meant a move away from the more traditional and time-consuming methods commonly used to capture and process network drive-test data.

By getting the automated process right the goal a more reliable, robust and cost-effective method of reporting from multiple data sets was achieved. Crucially it also meant that stakeholders would have reports available much more quickly and regularly than would otherwise have been possible. In effect, more effort could be focused on interpreting the results and acting on them and less on the mundane collection and management of the considerable volumes of test data being generate each day.

Regarding the KPI themselves the QoE needed to be both broad and flexible in its ability to set up the required test scenarios and capture the resultant data. Processing and linking all the raw event data recorded at different devices and locations needed to be developed. For example, Group calls were set up between one device and several others spread around the network and voice samples were exchanged between them. The KPI for Call Success Ratio (CSR) was a measure of a successful call set-up and confirmation that all parties involved in the call also receiving a voice sample of sufficient quality. In other words, multiple events recorded at different locations and devices needed to be co-ordinated, related, processed and combined to calculate each KPI.

 Continuous network monitoring across a broad area is key to the success of any QoE solution. The TETRA Active system uses this principle and combines with the RENITA QoE to provide a very comprehensive and detailed view of the network through its continuous logging and reporting of results. Any service affecting events or anomalies are detected and highlighted so that poor service areas, network glitches or total outages can be reported and investigated quickly and efficiently. Because data is captured with no interruptions or breaks the results reflect a complete and consistent analysis of the network.


RENITA TETRA Optimisation System in Action 


The RENITA QoE solution went live in May 2015 and has since racked up many thousands of tests over its 6 months of use.  The time and effort from testing to producing meaningful results and reports is measured in hours not days. The quality of the collected data is delivering the consistency and quality expected meaning all stakeholders have confidence in the results. The data available for analysis is constantly being added to day by day and over time will provide valuable information about patterns, trends and variations of performance.

Looking beyond RENITA, the principles implemented are equally applicable to any wireless network or technology. For example, simply changing the end-point terminal and any metric specific to that technology would deliver similar efficiencies & benefits. With the impending change in the UK from Airwave (TETRA) to ESN (LTE) and the likely focus on comparison of service & coverage between them this type of approach may offer a solution of how to continuously assess network performance. 

Finally, what sets Syntech’s QoE solution apart and makes it different and innovative from what has been done before is how it has streamlined and simplified the whole process and in turn made it more manageable. This in turn means more data is collected with less effort and greater accuracy which gives the customer what he wants – confidence that the Public Safety network delivers.


For more information on our TETRA Quality of Experience Testing Solutions please call us on +44 (0)1483 443800. 



 

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Syntech Systems
Mission Hall

53a Woking Road
Guildford
Surrey
United Kingdom
GU1 1QD

Tel: +(44) 1483 443800
Email: info@syntechsystems.com

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