Combining satellite and PMR cuts costs and complexity

Bringing satellite and PMR networks together has been possible for a decade or more but the cost has been prohibitive, the quality poor and the systems complex to set up. Thanks to advances in satellite and PMR base station technology, those barriers have now gone away, Eric Devalo of Cassidian, tells George Malim

Combining satellite and PMR cuts costs and complexity

The concept is straightforward and well-established. Picture a scene involving a disaster at a remote location where cellular coverage is poor and fixed connections are unavailable. Communications are needed to enable workers at the location to communicate with each other and back to the headquarters network and systems. 

It’s logical, therefore, that the emergency service brings a base station with it – perhaps attached to a mobile command vehicle. That base station can then establish coverage – typically PMR – in the local area and a satellite connection back to base.

‘It’s not something really new, the combination has been there for quite some time but it has changed in the last 18 months,’ explains Eric Davalo, Head of Portfolio and Technology Authority for Cassidian Security Solutions. ‘We’ve brought Tetrapol and TETRA PMR products to market. In TETRA, pico base stations have significant power, but are very small, so it’s extremely easy to put them in a truck or vehicle.’

Portable base stations

Communications capability simply becomes another check list item on emergency vehicles alongside specialist equipment. ‘On the tactical side, most of the users have a solution that is put on a truck so it can be taken to big crisis sites and disaster areas,’ he adds. 

‘Emergency services want a tactical solution that is completely integrated and that can connect via VSAT (very small aperture [satellite] terminal) back to their network and create coverage areas in remote locations.’

Fire brigades, for example, have outdoor repeaters combined with VSAT and they can put one, two, three or four in the field, which automatically switch on. ‘They can also have GPS location information to send back,’ points out Davalo. ‘It’s easy and simple to do.’

When there’s an event and additional resources are required, emergency services can deploy this kind of packaged solution using a mobile terminal to connect back to the command and control centre. 

‘If you have a fire in Spain or Greece, for example, fire services go with packaged, integrated solutions so they can have local and remote communications,’ says Davalo. ‘New types of base station make it much easier to deploy because they are small and well packaged.’

Cost considerations

However, satellite is known to be both costly and patchy in terms of coverage and latency. Davalo claims the cost is falling and points out that satellite charges need to be compared against their alternatives. Satellite may look expensive compared to a fixed line voice telephone call but, compared to installing cellular base stations or fibre links nationwide, the cost pales into insignificance.

‘The main usage of combined satellite at PMR is one with fixed PMR and a base station,’ says Davalo. ‘In some countries with low-density populations it is very expensive to connect back the base station from rural areas to the city and satellite is used to connect back as a purely economic solution. Satellite is mostly cheaper [than alternatives]. We see it particularly in Brazil, Mexico and Russia which are very large countries.’

Even if the cost can make sense in large geographies with limited populations, surely the coverage and latency of satellite present problems.

Latency issues

‘For coverage you don’t really have an issue,’ says Davalo. ‘You need [access to] the right satellite of course, but coverage is large. When it comes to latency, we’ve done a lot of tests and it’s not a performance affecting issue when you’re on the same network if you go through two satellites. There is no operational affect on voice quality.’

This type of combined solution doesn’t deliver true mobility today. It is more of a portable solution in which fixed satellite technology can be moved rapidly to the site of an emergency. The concept of enabling a mobile base station is being explored, but is currently too costly for all except the most sensitive defence users.

‘If you wanted to be really mobile – that is, working while the base station is moving – dynamic satellite antennas are available but the cost is very, very high,’ says Davalo. ‘You have it in some cases in some defence solutions, but very seldom because it is so expensive. Most of the time you move the package to fixed locations.’

That portable, fixed-location approach brings value to a series of blue light applications. ‘For blue light services today it is mainly a solution in case of big disasters when you have to have a back up base station,’ he explains. ‘Also, in remote areas it makes sense for services to have this type of solution. It depends on the country, and the density of the population.’ 

‘We have also found that people are changing their way of working,’ adds Davalo. ‘For instance, if there is a G20 meeting or a sports event you need additional blue light forces to support the event. More and more emergency services want to keep the existing network for their normal day-to-day people and have the special units bring their own solution to connect back to the network.’

Perhaps the key development that has made the combination of satellite and PMR attractive to blue light organisations is the advances that have been made in removing complexity from the set up process. 

Simple set up

‘Simplicity [of set up] is absolutely mandatory,’ confirms Davolo. ‘Ten years ago people had different pieces to set up and it was complex so people didn’t use it. First, with the small repeaters you have the same device, so then people started to use it because they started to see the benefit. Full automation makes it extremely simple to use.’

The coming together of improved satellite coverage, compression technologies to eliminate latency and the automation of set up have combined to make solutions of this type attractive to emergency services. It was a change that Cassidian had not foreseen.

‘We did not anticipate the move of emergency services using this, but the combination of PMR and satellite – with compression of the traffic – means the cost decreases,’ explains Davalo. 

‘The significant improvement in satellite communications [quality] means we will now see this type of solution more and more. In the future we see it combine with the use of renewable energy such as solar panels which will extend how long you can run the system. We already provide an integrated solution,’ says Davalo.

Written by Wireless magazine
Wireless magazine

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