Forth Estuary Experimental Data NETwork

Emergency Communications


RAYNET-UK, The Radio Amateurs’ Emergency Network is the UK’s national voluntary communications service provided for the community by licensed radio amateurs.

RAYNET-UK was formed in 1953 following the severe East coast flooding, to provide a way of organising the valuable resource that Amateur Radio is able to provide to the community.

Since then, it has grown into a very active organisation with around 2000 members, providing communication assistance on many hundreds of events each year. Amateur Radio operators have access to a wide range of radio bands, operating modes and equipment which allows RAYNET to offer a unique range of emergency communication services to our user services. Coupled with our members endless resourcefulness, RAYNET is regarded as a professional support organisation by both the statutory and volunteer emergency service organisations.

Public Telecommunications

We are all used to being able to make and receive telephone calls and send texts from almost anywhere and at any time of the day. But what happens in times of urgent need when major incidents affect many hundreds of thousands of people in an area simultaneously ? The answer is well documented.  Public telephone networks, comprising both fixed services and mobile services can collapse under the massive weight of extra calls generated by the public. 

If one of the aggravating factors of this collapse is damage wrought to public  infrastructure itself, such outages can become lengthy. We should not take the ability to communicate lightly – how do we fix the telephone network (or anything else come to think of it) if even the engineers cannot speak to each other ?

Emergency services and the public utility companies have, of course, thought of these things and various schemes are in place to mitigate against this problem but none are perfect and no-one knows in advance exactly how the next incident will affect us.

The use of RAYNET-UK is written into the Emergency Plan of many local authorities and RAYNET-UK often work together with them in joint exercises to help evaluate the level and kind of assistance that a voluntary group of skilled and flexible communicators and engineers can bring. Thankfully the instances of urgent need are rare, but occasionally real incidents do occur and RAYNET-UK have risen to the challenge many times over the 60 years since its inception.

Should Emergency Response communicators use Public Telecommunications facilities ?

This is a complex question. In essence the answer is probably along the lines of “An effective emergency communications platform should be as diverse as possible in the nature of its methods. Major incident scenarios should be anticipated in advance and where possible the agencies involved in responding to an incident should have ready made plans prepared and they should carry out regular exercises and practice”

A key facility that RAYNET-UK brings to its user services is flexibility and simplicity – the two go together.  Simplex two way radio on HF/VHF/UHF and rapidly commissioned repeater stations, either automatic or manned, are a staple of the RAYNET-UK response and rightly so.

MESH networking carried out the FEEDNET way is more complex to organise but it has so much to offer that it seems a worthy tool  to have in support of many incidents. The Instant Messaging, Email, Voice over IP, File, photo and video transfer capability are excellent means of communication that we should not turn our backs on.

By employing a preplanned and fixed backhaul network with rapidly drafted in mobiles to cover incident areas RAYNET could provide a useful level of response, but a bottleneck is always going to be how our communications are handled to the outside world. The fragility of a single connection is obvious.

If FEEDNET is connected to internet services in a number of geographically remote points its utility can be vastly improved.  Despite all that has been said about public telecommunications failure in times of emergencies, we should remember two points.

First is that most emergencies are contained within a particular geographic area. This may be a square mile around a football stadium or city centre, it may be a town or an entire  county. Whatever the size, if an emergency response team can ensure that a link into the public services is established at a point geographically remote from the area in question then the worst effects of communications collapse can be avoided.

Secondly, it has been demonstrated time and time again that the telephone services are more susceptible to overloading than the internet services and that the PSTN takes much longer to recover.  In technical terms, circuit switched networks (the PSTN) degrade rapidly while packet switched networks (the Internet) degrade gracefully. Virtually all telephone communications were wiped out in New York city in the wake of the Twin Towers terrorist attack yet the internet services in Manhattan returned to sustainable levels within an hour. This pattern has been observed during many other incidents over the last ten years.

A final consideration in the debate over the use of public services by emergency communications responders is that we should bear in mind that the kind of major incident that affects a relatively small metropolitan area is always going to be more prevalent than that affecting a national infrastructure so it makes sense to have at least some capability for connection to public services at a point remote to the incident site, and for reasons outlined above, the Internet and its capability for a wide range of communication methods would seem ideal for this purpose.

FEEDNET and the public communications infrastructure

To this end, FEEDNET is connected to the internet and traffic can be switched into the Internet at a number of points to increase resilience. Despite this FEEDNET always needs to maintain an architecture capable of being used without public interconnection and so various features will always be kept within the FEEDNET network such as time servers , required to keep VoIP systems synchronized. But to maintain a connection which allows public exchange of email from an affected area, or telephone links to the outside world can always be a useful tool for emergency communication responders.