Internet of smoke-detecting things

While the past few years have seen rapid developments in smoke-alarm device technologies their potential could not be fulfilled because standards had not kept apace – until now, writes Ulrich Rabe.

VdS has harmonised standard EN specifications in line with modern technology with new standard VdS 3438-3. It aims to provide industry with practical, standard-compliant support for making full use of the opportunities offered by the Internet of Things shaping this future market.

The current EN standard considers smoke-alarm devices as independent units rather than as network components.

More and more countries are making it a legal requirement for private homes to install smoke alarm devices with the primary aim of protecting human life, something that many studies have shown leads to significantly positive results.

A side-effect of these requirements has been – and will be – the creation of an enormous market for smoke alarm devices. Another important aspect is differentiation, for example through integration in smart-home systems or connection with other devices, which is crucial for gaining market share in a sector where the typical optical signalling principle has been in existence since 1976. According to various studies, this industry will see a double-digit growth in the next years worldwide.

Within the European Union, smokealarm devices are categorised as construction products and are therefore covered by the construction products regulation. According to this directive, an independent body has to test the products and confirm compliance with the requirements of the harmonised standard EN14604. The fact that this standard dates back to 2005 is clearly a challenge for developers. As we all know, the last 13 years have seen a rapid development in the networking of devices and in the creation of new applications. Keep in mind that the first smartphone was sold two years after the standard was published, changing user behaviour significantly.

The current EN14604 standard explicitly allows the interconnection of smoke-alarm devices but remains vague on all further function possibilities. Up to now, all additional functions have been viewed with suspicion and only accepted if they have no repercussions on the smoke-alarm device, specifically not impairing correct functioning. Only crosslinked smoke alarm devices are allowed to – or have to – transmit alarm and fault signals to each other.

Today's smoke-alarm devices can be cross-linked within a network that can transmit fault and alarm signals to all participants. This ensures that within an opportune time, in case of fire, all those affected and possibly in mortal danger are alerted, even when the fire breaks out in infrequently accessed areas such as an attic or basement. While this is not a legal requirement in the EU, users often opt for this function.

It is also currently possible to monitor smoke alarm devices via an application that allows, for example, checking battery status or transmitting an alarm signal to a mobile terminal. In this context, smoke alarm devices are also integrated into a network with other building technology components, which avoids having to equip each network participant with an individual application. However, current guidelines and standards do not include any requirements or tests methods for these applications.

The obvious next step is to enable

smoke-alarm devices to emit alarm signals from other network participants. If intruder protection is integrated into the building management system, the smoke alarm could be triggered to acoustically signal a burglary. Furthermore, many countries are discussing the use of smoke-alarm devices for civil protection. In the event of disasters, an additional chip could enable the smoke-alarm device to emit a different alarm, a function that may even be improved with voice output.

As voice control technology has become more and more sophisticated, the application of such modules in smoke-alarm devices is a foreseeable next step. Unlike other building technology components, smoke-alarm devices already have a sound-emitting component, which is essential for a voice control-based dialogue. It is therefore more cost-efficient to use a smoke-alarm device than to retrofit other components – a fact that should also boost this market. However, connection to the internet involves, as we all know, the risk of external interference.

How do these developments impact guidelines? The detection and warning of fire, the primary and mandatory function, is a matter of life and death. All other possibilities and components are secondary. Compared to any other part of smart-home systems, smoke-alarm devices always have the highest safety relevance.

As described above, the existing standard is not of much help if we want to strengthen smoke-alarm device abilities beyond their core function. In its current version, the EN standard regards them as independent functional units and none of the above-described developments are taken into consideration. However, it is clear that smoke-alarm devices now often take on the function of a network component.

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Ulrich Rabe is head of customer service for fire detection systems at VdS and is the lead author of new guidelines VdS 3438-3. The guidelines for the EN-compliant integration of smoke-alarm devicesin smart building systems are freely available at vds-shop.de/en.

As a component in a network, the device receives a wealth of additional information, such as fault or alarm signals from other network participants, which needs to be processed. Not all information can be processed simultaneously, but must be arranged in a sequence. For smoke-alarm devices, the detection and warning of fire always has the highest priority, so this also applies to the processing of information.

Smoke-alarm devices must be able to differentiate between incidents and ensure fire alarms always take precedence over other information. Those life-saving alarms must never be displaced by other signals and a current burglar alarm signal must be overruled by a fire warning, alerting everyone present, including burglars, of this mortal danger.

Fire alarms must always be clearly distinguishable from all other acoustic signals because an alarm signal that is mistaken could, in a worst-case scenario, induce people to go into the danger zone instead of evacuating it.

Furthermore, smoke-alarm devices must continue to function independently. This means that even if the whole network collapses, is hacked, flooded by malware, or falls to a power surge, the smoke alarm devices must remain operational.

In some fire detection and alarm systems, as per EN54-13, the detector is only responsible for providing data, and not for its evaluation with regard to the existence of fire, which is realised via control and indicating equipment. This, however, is not allowed for smoke-alarm devices that are integrated within smart-home systems. As smart-home systems are not required to have a redundant power supply, a power failure could lead to a complete breakdown of the entire network. In such a scenario, only smoke-alarm devices that have their own independent and verifiable power supply can remain operational. Another consideration is the lack of exclusive transmission paths in smart-home systems, which mean it is not possible to guarantee that information can always be received.

Smoke alarm devices are increasingly used as components in a network – but what kind of network? Clearly not a fire detection and alarm system in accordance with EN54-13, because, as shown above, some decisive characteristics are lacking, such as an exclusive transmission path. In fact, it is a building network that can be accessed from anywhere in the world via the Internet. This also means that the potential for sabotage vaii hacking or malware has to be addressed. While a disabled burglar alarms system primarily puts material assets at risk, the consequences of a disabled smoke-alarm device can be fatal.

It is therefore vital that standards and guidelines keep up with rapid technological change. However, already today there is a wide gap between the theoretical world of the guidelines and fast-moving actual practice. We will all need guidelines in line with technical possibilities to guarantee that the smoke-alarm device that consumers purchase for fire protection still fulfils this function and can be relied on. VdS has addressed this important task and has published part three of its guidelines 3438, specifically dealing with the integration of smoke-alarms devices in home-protection management systems. These new guidelines not only look at networked smoke-alarm devices as providers of information, but also take into account the possibility of using the devices' alarm transmitter for intrusion protection.

The precise requirements, as already outlined, are that the detection and signalling of fires always has the highest priority; that the fire alarm must always be clearly distinguishable from all other signals; and that smoke-alarm devices must continue to function independently under any circumstances.

The basic product requirements as stipulated in EN14604 or the corresponding VdS guidelines 3131, remain unaffected. What VdS is doing, in accordance with its innovation focus, is supporting manufacturers by combining the opportunities of modern technical development with the demands of maximum safety – at all times in accordance with the relevant EU standard.

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