Nokia NSN - Tetra Performance Testing

"The transition to a new digital public safety network is a huge, but necessary for a safer society. The aim of the Government is that the authorities should work to improve the people's safety. With Nodnett, the emergency and public safety services will have access to a reliable radio network with good voice quality and good coverage, which cannot be intercepted."
Grete Faramo, Norwegian Minister of Justice and The Police

NSN / Nødnett

Nokia Siemens Networks (NSN) was the turn-key supplier of Nødnett, the multi-agency digital radio (TETRA) communication system for emergency and public safety services in Norway. Nødnett, owned by the Directorate for Emergency Communication (DNK), a subordinate of the Ministry for Justice, is the largest IT-project in Norwegian history.

Test & Acceptance Regime/Rollout

The Norwegian parliament, the Storting, approved a first area of rollout (Phase 0) which included the Oslo region. The contractual Test and Acceptance regime stipulated that an in-depth evaluation of Phase 0 would take place before proposals for nationwide roll-out were presented to Storting for approval. As part of this evaluation Syntech Systems was contracted by NSN to undertake in-field performance testing of Nødnett in the Oslo region.

Objective

The objective of the in-field performance testing was to verify that the voice and data performance of the Nødnett infrastructure conformed to the requirements of DNK. This was done by undertaking a series of performance tests between two base stations (each in a different zone of the Oslo region), and between the base stations and a control room. The test locations were equipped with either a fixed-end IFPM tool (at the control room) or static mobile IFPM equipment affiliated to the base station under test (using the ‘air interface’).

Challenges

A major challenge facing Syntech was the large volume of tests that were required to be executed and analysed in a limited period of time. Call types were to be tested for three different models of TETRA terminal with calls being set-up between base stations and from each base station to control room. In addition, voice tests (where appropriate) were to be conducted (i) with air interface encryption and (ii) with air interface + end-to-end encryption. In total, 220 tests were to be scripted and executed over a 3 month period with the final report (T06) being delivered to NSN 3 weeks after the end of testing.

Requirements
Syntech Systems undertook to deliver the following project tasks:

Define the test methodology, the test system and the acceptance criteria for Nødnett performance testing (T03 document). The T03 would have to be approved by NSN and DNK before performance testing could begin.
Provide In-Field Performance Measurement (IFPM) equipment and associated software to measure the voice and data performance of the Nødnett network.
Provide test scripts to replicate the various voice and data services provided by the network.
Perform in-field performance testing and collect results.
Analyse results.
Produce final report (T06 document) to be approved by NSN and DNK.

Performance Testing

Performance testing was carried out by a 2 and 3 person field team supported by a project manager and analyst at Syntech’s headquarters in the United Kingdom (Guildford). The field team followed a detailed schedule of testing so that potential delays could be highlighted to the project manager and corrective measures implemented as and when required. The IFPM software was enhanced to allow the use of “Multi-Scripting” whereby tests could be scheduled to run outside of normal working hours.

The Outcome

The report provided a summary of the results of each test, showing results of the KPIs such as maximum, minimum and average values measured. The report included the number of tests that meet or exceed the target limits outlined in DNK's requirements specification. The reasons for any unexpected results were explained, for example describing in detail what the analysis revealed about the state of a call at the time a particular measurement was made. The T06 Final Report was fully approved by DNK and NSN.

Uøtya Island Tragedy

The importance of testing and verfication was highlighted on July 22nd 2011 when a car bomb explosion in Oslo was followed by shootings on Uøtya Island. The Nødnett network held up and performed well during these tragic events. The project manager for Nødnett stated that, “The downtown area with the bomb blast was fully covered by TETRA and used by all services, and that worked very well. We had good feedback from agencies after the bomb blast incident.” Uøtya Island, however, was not inside the Phase 0 coverage area and there were issues around how to handle incidents with analogue system cells. The nationwide roll-out of Nødnett will overcome these issues and make Norway a safer society.

To download the IFPM Brochure please click here