Firm plans now have been laid for linking the national TETRA networks of Norway and Sweden. ‘Jeppe’ Jepsen, of the TCCA, was present at a recent workshop meeting

Finally Nødnett in Norway and Rakel in Sweden are to be connected together via the TETRA Inter-System Interface (ISI).

During August, in Strömstad on the border between Sweden and Norway, representatives from Norwegian and Swedish public safety organizations and the suppliers of the two nations’ TETRA networks met for two days. That marked the kick-off for cross-border communication between the two countries. The functionality will be implemented across the two networks in 2015.

The workshop was hosted by DNK and MSB, the national operator organizations responsible for the two networks. During the sessions, participants from the Norwegian and the Swedish police, fire/rescue and health services were briefed about the planned work and the communication capabilities within ISI.

Expectation

This will be the first time two fully independent secure national networks will be connected – and many have been waiting a long time to see this come to fruition. Norway and Sweden share a border 1630 km long and this capability has been a requirement in both nations’ user communities.

The complexity is huge. Just imagine the flexibility there is in implementing a TETRA system: think about how each system has been optimized for each country’s needs; and now we will connect them.

To help in understanding that complexity, a little analogy has been developed. Imagine that both systems are private houses designed to meet the owner’s needs and preferences. The houses don’t look quite the same; they don’t have quite the same facilities. And when you visit, you behave differently than at home – you adhere to the rules of the house, and you must make do with the existing facilities. The same will be the case with cross-border operation.

Collaboration

Co-operation between the Norwegian and Swedish forces occurs frequently today. The long border and the similarities in culture and languages make a good starting point. As a consequence we heard realistic use cases as a basis for discussions in a number of workshops. This proved very useful as a means to raise the users’ needs and wishes and to give the developers a better understanding of the operational procedures. It also became clear that there are quite a few differences between the two countries in terms of operational procedures and the use of TETRA functionality. 

The fact that users will be able to receive service from the neighbouring system when they cross the border – and participate in group calls across the border – was seen as very valuable. It will mean, for example, that group members in Kristiansand and Tromsø in Norway can communicate with group members in Malmø and Kiruna in Sweden. It will also allow organizations to join forces with their colleagues on the other side of the border.

Specification

The four organizations involved in the project – DNK and MSB plus their network suppliers Motorola Solutions and Cassidian – have now completed the Common Functional Specification for this cross-border link.

The implementation will need to be of a high grade because both systems are highly secure and certified to national security standards. It must allow terminals that have moved to the other country to be authenticated by the home system, in a secure manner.

In addition to group call capability, the ISI will support individual calls, telephony calls, and status and SDS messages.

Preparation

With all these possibilities opening up, many questions arose at the workshop. It surfaced that status messaging means different things in the two countries and that operational procedures are different.

Organizations using the two networks now have a big task in front of them. The new capabilities need to be carefully incorporated by all the organizations. User groups will now enter a phase where:

• formal agreements for collaboration will be agreed at agency level;

• they can develop processes for working together;

• communication protocols are defined;

• fleetmap structures across borders are defined;

• training and exercises are conducted.

Issues such as assigning radio terminals to talkgroups dynamically across the border, group affiliation while in the neighbouring network, and telephony over the ISI gateway will need to be investigated further. But some limitations will have to be accepted at an early stage. 

Compared to today’s capabilities, the planned ISI implementation will be a major step forward for cross-border communication. The agreement to go ahead with this development also opens up potential for implementing similar solutions between other countries which operate TETRA networks.