Group calls and video

More about group communications came from Philippe Devos, who chairs the CCBG’s System Architecture working group. “In July we posted our first contribution into 3GPP SA1 in order to support the group communication work item and the proximity service”, he said.

But he added: “This is a complex topic and we are unable in one hour and 30 minutes to discuss this group communication in a plenary session of SA1. And so that is why they have decided to assign two days to only discuss group communication and the borderlines between the application and the 3GPP communication layers.”

Meanwhile, the SA working group has other problems to consider, such as how to manage new services which will be important in critical communications, such as video. “There are so many ways to share video”, Mr Devos observed. “You can post a video, you can have video streaming, you can have push-to-video – but at the control level, this type of communication service needs be defined and all the parameters, quality and so on, need to be defined.”

Some level of automation would be necessary to enable dispatchers to handle these increasingly complex services. But more generally, a management layer would be required to integrate TETRA with public and private broadband services during a possibly lengthy period of migration. “For a long time we will have Tetra networks and we will use data, but we need priority, QoS, for all these applications and we will also probably use possibly Wi-Fi and other access points”, continued Mr Devos. “We need to find a solution that manages different types of access systems. This is obviously directly linked to a layer on top that will manage communications above and across different boundaries.

“We have to manage this TETRA migration, coexistence, whatever, to add capability for a long, long time. And this is driving this type of architecture.”

Finally, Mr Devos urged the TETRA community to present a common view in negotiations with 3GPP, with no divergence of aims between ETSI TC TETRA and the TCCA. “It would be a disaster if we come into 3GPP and we have different views”, he said.

Tony Gray, CCBG chairman, strongly agreed. “If we are seen to have the slightest, paper-thin gap between us, that will be exploited by the nay-sayers in 3GPP. So we absolutely have to be going there with a totally harmonized viewpoint.”

Involving the user

Lastly came a report from the Business Case working group. Jason Johur, of Motorola spoke of a large volume of work now in progress in conducting interviews with users, analysing operational scenarios, and collating the results to build a picture of users’ future requirements. Covering business users, the utilities and transport as well as the emergency services, it will establish a business case for broadband to justify the demand for spectrum. The group hopes to publish a completed document by the end of the first quarter of 2013.

Also leading the work on the business case is Robin Davis. “It’s about this value proposition and it has to be credible”, he said. “So there is going to be quite a big review period. I think that we want to try and draft things as soon as we can, so we can at least get that out there to maybe some core working groups to actually make sure that when this goes out into the public domain, or users use it to convince people about either money or spectrum or both, that it’s robust, it’s fit for purpose. If we put some ideas and thoughts together and just send them out and it’s not quite right, and it’s challengeable, we won’t get very far.

After these presentations, Hans Borgonjen commented: “Some people have the feeling that there is not enough user involvement in the activities we are doing.”

Tony Gray answered: “I think we definitely minute the fact that we are seeking support, advice, ideas, anything that might help to do exactly that, to try to build more of a groundswell of user involvement.” But he acknowledged: “We are absolutely not of great interest to the average end user, and we are certainly not of great interest to the very senior officers. I think it is those senior individuals that we have to be able to motivate to go and demand. So from your end-user, bored-out-of-your-skull-and-struggling perspective, please help us to think about how we can roll those people in.

“We can debate this ad infinitum. But I think the best thing is to go away, put your thinking caps on and come back through whatever mechanism you want to use to try to start to put ideas together.”

Next meeting of the CCBG has been fixed for January 30, at a venue to be announced. For information about the CCBG, and contacts, visit http://www.tandcca.com/assoc/page/18100