Smart homes technology will soon be affecting many aspects of our lives. Mike Perry, principal consultant at BRE, explains what it is and where it’s leading. In a subsequent article he will examine how the technology is being rolled out.

Until the mid-1990s there were dedicated hi-fi systems, often comprising separate record turntable, tape deck, CD player and tuner. Now that we have internet protocol (IP) technologies and MP3 players, things have got simpler. The modern approach is to deliver all audio content through a single channel, offering all four functions via one output source.

This revolution in the delivery of music and audio content is extending into other home entertainment and amenity systems. Voice over IP (VoIP) is the digital replacement for traditional phones, and recently IPTV the digital delivery of TV content has been introduced. The signals for these different output systems come through a single, digital communications channel.

This integration of services into a single, digital channel is the underlying principle of “smart homes” technology, which uses one modern communications backbone to provide intelligent information services in the home.

Installation costs for a basic internal communications hub and cabling loom these days are typically about £1000 for new build and major refurbishment projects. At this level of cost it may be difficult for the developer or builder to justify not including the basic installation of a communications infrastructure.

Many engineers may not be aware of the basic technological elements required for smart homes. Here is a quick tour of the three basic technological components that smart homes require – plus some practical examples of service delivery using digital communications.

Tier 1: communications infrastructure

Information delivered to smart homes is transmitted through one of three types of transmission media:

  • cable – at the moment, most commonly Cat5e cable
  • fibre optic – usually the medium to carry data to the external wall of the property
  • wireless – offering convenience and flexibility, but not necessarily a universal solution.

The best medium for transmission of internet or community intranet information to the external wall of the property is fibre optic (glass cable). Most often the fibre optic will be owned by the internet service provider.

Fibre optic has a very wide bandwidth (information-carrying capacity) and is likely to be the most commonly used transmission medium for broadband applications in the future. However, at present fibre optic is not universally installed throughout the UK. Developments to increase the bandwidth of the existing copper technology for phone signals have enabled copper cables to deliver broadband services, but a limit is being reached as demand for services grows.

The external, high bandwidth cable terminates in a communications hub inside the property. This hub links the external cable to the internal communications infrastructure usually, at present, Cat5e cable.

The internal communications loom runs throughout the house, enabling voice and data connections in each room through “RJ45 face plates”.

Tier 2: sensors and devices

These are the technologies that allow signals to be generated for transmission, and are the first stage of environmental interaction. They are a broad class, and will include items such as:

  • temperature sensors for use in monitoring ambient temperature to support effective management of the house boiler
  • door sensors for use in access control as part of the day-to-day activities in the property, and as part of the house security system
  • fall and alarm devices to support independent living for the elderly in their home setting.

Signals from sensors & devices are sent to applications, where software located in a computer or other electronic device has been programmed to provide the “smart response”, or to link with users or back-up services.

Tier 3: applications

The application may simply be the display of information to the user, but often will also allow interaction or feedback. In the case of automated systems the signals will be received by “intelligent software”, containing algorithms to provide an automated response.

It is the applications that close the communications loop, and enable active responses. In the case of environmental control, for example, by:

  • allowing lights to be switched intelligently according to the need and occupancy;
  • enabling an independent lifestyle the transmission of an alarm signal to a support centre will activate a system to check if there is a need to alert the medical services.

Source

Building Sustainable Design