Entry Granted

The advantages of such an entry system are obvious as the inhabitants gain control over who enters the premises with the convenience of not having to set foot outside the building.

Bearing this in mind, the larger the building, the more necessary a door entry system becomes. But, for the installer, does a large door entry system involve highly complex equipment and installation, or is it just more of the same?

The answer is yes ... and no!

When you get a building that has over 30 apartments (most large door entry systems are in residential buildings after all) or a multi-block site with a concierge, you have to seriously start thinking about using a different door entry system from what you might be used to installing, although often using the same accessories or 'hardware'.

Because of the size of the installation, there is likely to be a number of different entrances/exits and even a porter or concierge, so you may well have to incorporate different features into the system than is normally required.

You need to take a step back and look at the overall picture, taking into account other systems installed in the building, be it security, telecommunications, building management services, etc and work out whether the door entry system is best integrated with these or left as a stand alone system.

In other words, the larger the system, the more possibilities there are and the more thought that will need to go into the system design.

Key to success
The key to a large door entry system (no pun intended) is to make it a digital one.

There has been a lot of talk about digital technology in the security industry, but what do we mean by this and what benefits does it have to offer?

Analogue signals, which are the traditional means of communicating information, consist of levels represented by a directly proportional voltage and are one continuous 'wave' of information. Whilst they remain perfectly adequate and cost-effective for small to medium sized door entry systems, they are restricted in the amount of information that can be held on their bandwidth, hence a separate call wire is required from each button to each monitor/handset.

Digital signals, on the other hand, are based on a bit stream of information, coded in to an 'on / off' binary signal. This technology is not only fast and provides excellent quality signals, but is highly flexible and able to carry a vast amount of information.

These latter two aspects are important for large door entry systems as it means a substantial number of apartments in different blocks can all be easily catered for on the one system. This is because using digital entry panels alleviates the need for a separate calling wire from each apartment to the entry panel, as all communications signals are encoded and are carried on a single wire, ensuring the installation is straightforward. The signals are then decoded at each apartments' handset.

Digital panel more attractive
Digital technology is also important for the entry panels in another, more aesthetic way. An analogue entry panel has a separate push button for every apartment. When you get to over 30 apartments, each with their own button, the panel looks too big and unattractive. A digital panel, on the other hand, is ideal for large installations as it can accommodate vast numbers of calls.

Users simply punch the flat number in to a keypad instead of directly onto the specific button. Alternatively, by installing a name directory within the digital panel, users have the option of scrolling to find the name either individually or alphabetically on an LCD display.

Many large, luxury residential developments use a concierge or porter. Where that porter cannot readily see all the entrances, the door entry system can be connected to a digital 'porter' switchboard. Such a set-up enables visitors to call a flat directly or, when in intercept mode, all calls made from an entry panel to a flat are diverted to the porter. Of course, any of the flats can call the porter and vice versa.

However, apart from the entry panel and switchboard, the equipment for a large door entry system, including the handsets and monitors, remains the same as that used with analogue, so should be familiar to installers. Even the fact that it is digital – a technology that often scares many – does not mean that installation is any more difficult, as a single cable is all that is used.

Integrating with other systems
The most interesting aspect of designing a substantial door entry system for a large site, and one that has only become a reality more recently, is that the technology now employed enables us to integrate it with other relevant systems.

The most obvious systems to integrate it with are other security ones, including access control, CCTV, panic alarms and intruder detection.

Access control, in the form of keypads or proxi-mity systems, are easily installed into the entry panels of a door entry system providing added security and convenience for residents and services.

For instance, visitors at the main door press either the flat number to speak directly with the flat or use the porter/concierge button to speak to him/her. They can then be 'vetted' and admitted by the respondent pushing a door release button.

Residents, on the other hand, simply use the access control system to gain instant access.

Of course, one of the other major benefits in such an instance is that the access control system can be set up so that trades people can enter certain doors at certain times only, once again making it a highly convenient and secure system. Access control systems have their own control unit, reader and either keypad or, in the case of proximity systems, cards or 'tags' each of which are encoded with the users identification, pemitted time of entry and points of entry. With a keypad, when the user enters the correct code, the electronic door release or electro magnetic lock is released, thus opening the door.

The proximity access control systems perform the same function, but use a different technology.

The proximity reader emits a constant field of RF energy via an antenna. The tag also has an antenna which picks up the RF energy and responds by transmitting back its unique code. Once valid tags are presented within the pre specified range (from 5cm up to 2 metres), their code is compared to the data in a look-up table in a database either at the reader location, a separate access control unit or at a central computer.

   Prox systems taking over
Keypads are the more traditional choice of access control, but proximity systems are quickly taking over as they are more secure and durable, as there are no moving parts.

Where proximity systems really come into their own is when their use is widened to incorporate not only pedestrian but vehicular traffic. With larger installations, electronic vehicle access control becomes a cost-effective and often necessary addition to the security of a premises. If you have a gate at the entrance to an apartment block's car park, for example, you will need a means of opening and closing it. You could use a guard but this is expensive. The most appropriate solution would be to use a proximity access control system integrated with the door entry system.

Long range vehicle proximity access control systems are also becoming widely available and can be just as easily integrated with a door entry system, using the same tags.

Other security systems, such as panic alarms and intruder detection, are also easily combined into the same system as extra alarm signals are taken from each of the flats and brought to the concierge switchboard. This allows the concierge to monitor the system and take appropriate action in the event of an alarm, such as checking the premises for any suspicious activity and/or contacting the police or on-site security guards.

Integrating with CCTV
As video entry systems already have many of the relevant components in place, it becomes both easy and cost-effective to integrate it with a CCTV system. We are seeing more and more residential areas being fitted with cameras to monitor external areas such as car parks and walkways, plus some internal areas including receptions and main corridors. Combining the two systems is very straightforward as the same monitors can be used.

But as we said earlier, integrating a door entry system doesn't have to stop at other security systems. Using a digital switchboard, we are also able to run the fire detection system through the door entry system. This is set up in a similar way to the intruder detection system, with extra signals being run from each alarm to the porter's switchboard along the same cabling as the other systems, enabling the porter to quickly and easily check to see if an alarm is false or requires further action. The time saving element is vital if there really is a fire. It is also highly beneficial in detecting false alarms, decreasing the number of 'unnecessary' calls outs by the fire brigade.

More recently, with the introduction of digital technology and dramatically improved door entry equipment facilities and audio quality, we are able to combine these systems with telecommunica-tions. An obvious step, combining the two, makes for a versatile, cost-effective and space saving design, plus it reduces the amount of cabling required. Equipment such as BPT's Exedra and Integra handsets can be used as an integrated telephone and video/audio door entry system. The equipment is being continually developed and will soon come with a wide range of additional features such as video memory and answering facilities.

The Westminster Square residential development in the heart of London has used many of these systems. Consisting of 141 apartments, Midnight Security and Communications has designed and installed a fully integrated system monitored 24 hours per day at the concierge desk in the reception area.

The system features an extensive BPT video entry system incorporating monitors for every apartment, a brass digital entry panel at the main entrance and brass sub panels on the entrances to each block. In addition, there are over 20 colour and monochrome CCTV cameras located around the exterior of the building and at the entrances to the underground car park, intruder alarms and smoke detectors in each apartment, proximity access control on all communal entrances and a pager system which can be used to contact the porter day or night.

The reasoning behind such a design is simple – it's cost effective to integrate a building's elect-ronic systems as much of the same cabling and equipment can be used, plus it's far more efficient as much of the systems' monitoring can be done through one switchboard by one person. With these key benefits it's easy to understand why more and more systems are being integrated.