Fire Alarms for Deaf People and Hearing Impaired
What is the difference between unlicensed, light licenced and your technically assigned licence?
An unlicensed system is restricted to very low power (usually 0.5 watt) and offers absolutely no protection from interference from either legitimate or illegitimate sources. Ofcom keeps no records of the number or locations of unlicensed fire alarm systems, the frequencies are effectively unregulated and are advised against in BS5839-1:2013. Common unlicensed usage includes DECT phone systems, baby monitors, wireless routers and domestic alert call systems.
A simple light licence offers some protection from illegitimate interference. Take an on-site paging licence as an example; it’s limited to a maximum of only 2 watt power output. Illegal broadcasts that interfere with your broadcasts and are reported to Ofcom will be investigated. However a basic paging licence offers no protection from legitimate interference. There is no overview from Ofcom on the licence application and they don’t administer licenses based on potential interference, they simply allocate licenses. It is the responsibility of the site manager and supplier to ensure they don’t interfere with any other system. As such, if you have an on-site paging licence and another licensed system interferes with yours, there is nothing you can do.
What is particularly worrisome is that there are no ‘grandfather’s rights’ on light licenses. This is the notion that your system has been licensed longer and therefore the ‘newer’ system should change their frequency. This is simply not the case. If a light licensed system causes interference, even on a new system install right next door, then Ofcom may demand that the offender change their frequency. Regardless of length of deployment.
A technically assigned licence used by both DeafWatch (radio-based fire alarm for deaf people) and RefugeWatch (wireless refuge communication system for managing the safe evacuation of disabled and vulnerable individuals) has direct oversight by Ofcom and ensures the elimination of legitimate interference and the investigation of illegitimate interference. Ofcom take your transmission strength and antenna location and effectively sterilise your desired area. Any future licence applications will take this exclusive usage area into consideration and deny a licence accordingly. Only a technically assigned licence can ensure broadcast security now and into the future. Additionally, licences with overview of Ofcom usually have much higher power ratings available. In the case of the distress fire alarm frequency, we are permitted to broadcast anything up to 25 watts effective radiated power.
Why can’t I use mobile phone text messaging?
It seems like a convenient and reasonably reliable way of letting deaf people know about the fire alarm. A user could log in to a ‘service’ and receive a text message when the fire alarm at the building is activated. It’s a great idea, right?
Well, sadly, no. The problems are manifold. Firstly, there’s the problem of coverage. The performance of one service provider might be quite good in a building, but another may be dreadful. Many suppliers operate on different technologies, spanning 2G, 3G and now 4G technologies. These work on higher and higher bandwidths and have remarkably different performance inside and around buildings. In a nutshell, the more data you put in a frequency, the less penetration it may be capable of. This means that a building manager for a department store, supermarket or hospital will have no idea whether the deaf user who has ‘registered’ within their building will actually get the text message if the fire alarm goes off. Additionally, over time, you’ll have no idea what your coverage is.
Next up, mobile phones themselves have changed dramatically in the last 5 years. With the introduction of the smart phone, the space available for the antenna within these units is smaller and smaller. My first mobile phone had an extendable antenna, and that was only 11 years ago! Nowadays, companies are placing ‘reception’ at the bottom of a long list of features. This combined with spiralling bandwidths, means that coverage will get more noticeably choppy.
Building construction is getting more varied. In the 80’s and 90’s, building construction lent itself to steel frame and breeze block buildings. Now department stores are much more likely to be built from ‘flat-pack’ concrete (high density with steel reinforcement) or solid materials. Even the lowly supermarket is invariably ‘precast’ from steel exo-skeleton with a lattice work of metal supports. This acts as a ‘Faraday cage’, meaning that signal from outside the building is bad at best. Combined with the issues highlighted above – it gets impossible to predict coverage now, let alone into the future.
Finally there are the legal requirements. BS5839-1(2013) specifies that the fire alarm message for deaf people should be received within 5 seconds and repeated every ten seconds to ensure the user is aware. This isn’t an objective of the text system and would be difficult to implement. The process for delivering a text message is also via an IT system (which is specifically excluded in the standard) and operates in a similar manner to emails. Few guarantees are given over a delivery time, if you’re out of range the server will just store your message for when you eventually come on line. What if you never do?
The standard also requires that the means of delivering the message is equivalent in security (i.e. cabled, battery backed, monitored) to your own fire alarm. I don’t think your mobile phone provider signed up to that one? The standard also makes specific reference to the requirement to ‘differentiate’ between a fire alarm message and a standard message; otherwise a priority message could be ignored at the worst of times.
It is worth also noting that during the terrorist attacks in London of 2005, there was large scale civilian panic because mobile phone services were restricted. This both prioritises security usage and may stop any devices being detonated remotely.
There are two parts to the fire protection of deaf people. The first is to consider the practicality of a mobile solution, on balance with the varying coverage of different providers, different frequencies, the changes in phones and the variety of building constructions; I would be deeply concerned about having a lot of confidence in the system. The second part is the legal protection of the provider, if the system doesn’t alert the deaf person in time, I would like to be very sure that I have fulfilled the legal requirements and standard highlighted by the government. As that is what will protect my company from prosecution. My concern is that this solution doesn’t even consider these requirements.
Finally, the last benchmark. The system is better than nothing, isn’t it? My concern is that for the user it may provide a sensation of security which isn’t justifiable. This may make them more confident, but with the caveat that they may take risks that they usually wouldn’t. The system also is a physical acknowledgement of an identified risk for the building operator, but concerns about compliance would put the operator in a weak position if the worst case scenario was to occur.
So all in all, no, text messaging isn’t a viable option.
What restrictions should I consider when covering multiple buildings?
If you are broadcasting from a single point, you must ensure that every connection from building to building is connected via fire retardant cabling. Many multiple building sites use a basic paging system to alert security personnel or the estates manager to a fire alarm across the site. The cabling for fire alarms between buildings may be network cable or even telephone cable. As this alert is for “information only” it has no overarching legal requirements on it and few standards. After all, if the system fails, it doesn’t matter as the building will still be evacuated.
However, once you attach a DeafWatch – deaf fire alarm or equivalent system to the end of that process, your paging system then counts as part of the fire alarm. The DeafWatch signal is the only fire alarm for the deaf person concerned. Therefore it is imperative that all connections from the activation point, between buildings and through subsidiary fire alarm panels, back to the main panel and through to the DeafWatch transmitter are cabled securely in fire retardant or equivalent secure cabling.
Are the laws and standards for the DeafWatch – Fire Alarms for Deaf people and an audible fire alarm system equivalent?
When purchasing a fire alarms for hearing people, the standards and requirements that define the system and protect the organisation purchasing are stringent and detailed. Most of these requirements fall under the aegis of BS5839:01 (2002) and subsequent amendments. Simply put, to say a wired fire alarm for hearing people is BS5839 compliant implies a certain level of safety, self checking, reporting and multiple redundancies. To say a paging based fire alarm for deaf people is BS5839 compliant means none of these things.
In the past, the recommendations in BS5839 for paging based solutions were not equivalent. Some suppliers, like Wireless Alert Solutions Limited, adopted the principle that both audible and DeafWatch type fire alarms should be equitable in safety and function. They should be fail-safe, self testing and report faults quickly and effectively.
The standard and demands have since improved and become more detailed. BS5839-1(A2:2008) introduced standards for wireless fire alarm systems for deaf people and many of these and the wiring standards were made part of the requirements for Section 18, concerning a DeafWatch type system. BS5839-1(2013) cemented this relationship.
For our company, it had little impact as we had already adopted a stringent approach on our fire alarms for deaf people. Unfortunately this still does not guarantee that the alarm system you are looking at does comply. The safest way for the customer to confirm what they are getting is to request a full technical breakdown of the fire alarm system. That way you know what you are buying at what price, and can identify whether the system is good value for money.
Is a radio based fire alarm for deaf people always the best solution?
Not always, we would recommend the best solution for your particular environment. A simple small open plan office with one set of toilets and a coffee area could perhaps make do with a visual alarm and buddy system. We would however recommend the combination of a technical deaf alarm system and a man managed solution. This gives you a fall back to ensure that if one option fails (for whatever reason) you have a backup alarm system for any deaf or hard of hearing people in your organisation.
Our approach is that whatever fire alarm system best suits, it should be cost effective and appropriate. And as mentioned in previous sections, our focus is on complex, difficult environments. Our experience is that few fire alarm systems for the deaf can compete with DeafWatch for safety, security of signal, and low cost.
Is it best to cover a site with a transmitter in every building, or can I cover multiple buildings at once?
Some providers suggest that the best approach to coverage is to install in each building separately. They argue that this will ensure that users in one building are not disturbed by fire alarms that aren’t relevant. There is no requirement to do this in the British Standards, and if your site has securely connected fire alarm systems (see below for details) then there is no reason not to cover multiple buildings with a single transmitter.
This is always the most cost effective way of managing your fire alarm system for deaf and hard of hearing people. It will effectively exploit your existing fire alarm infrastructure and potentially save thousands of pounds. The inconvenience for users during the day is minimal. As radio broadcasts cannot be “sculptured” around a building, certain overspill will occur (usually via windows) and even with a building by building coverage approach, users will receive fire alarm messages for buildings that they aren’t in.
Some systems are lower powered (as detailed above), or may have restrictions to their licence (an on-site licence is inhibited against broadcasting across roads for example) and therefore are unable to cover multiple buildings from a single point. Be aware of why a supplier may be suggesting this approach.
For most deaf and hard of hearing users, they are well aware that hearing people can hear fire alarms from different buildings, and are happy that while information is delivered to them for alternative buildings, they actually receive more precise information than an audible fire alarm could achieve.
The exception that proves the rule however is the operation of DeafWatch type system in accommodation. It is one thing to receive a discreet warning of a fire alarm across a site or campus. It is quite another to be woken up at 2 am because the student unions fire alarm has gone off. This can be overcome by either going to the expense of a separate transmitter, or with DeafWatch, a simple addition of a line of code.