Communal TV aerial systems
Posted on 28th April at 10:10 AM
A communal TV system provides television signals to a number of users from a single set of aerials and/or dishes. This can be used with all types of properties, from small numbers of detached houses where for example planning constraints restrict the use of roof mounted aerials, to tower blocks and even entire estates of several thousand households.
The benefits of a properly designed and installed communal TV aerial system include:
- reliable service of high quality signals for all users;
- added value to the building infrastructure;
- reduction or elimination of the need for individual aerial and satellite installations; and
- minimisation of disputes, both with and between tenants.
It is likely that most communal TV systems will need upgrading to receive digital transmissions. Indoor reception through a set top aerial may be possible for some residents but will only be satisfactory in areas of high signal strength. Indoor reception is dependent on factors such as the distance from the transmitter, the height above ground level, and the loss of signal as it passes through the building. At best, reception using the indoor aerials currently available is likely to be haphazard and may not provide residents with satisfactory signals.
For a technical explanation of why communal aerial systems may need replacing the DTI have produced this report.
There are several different systems that can be used to provide communal TV reception.
A modern Master Antenna TV (MATV) can carry analogue and digital television signals through an aerial, both free-to-view and subscription, FM radio and DAB (Digital Audio Broadcasting) but it cannot carry satellite signals. Some older MATV systems in use today are over 30 years old. Many of these are unsuitable for carrying digital television signals and will require require modification or replacement.
A typical MATV system, as found in a block of 12 flats, is shown in the diagram below:
An Integrated Recetpion System (IRS) is in effect a MATV system that carry satellite signals as well as signals through an aerial. It provides the greatest choice for users but has a higher initial cost than a MATV system.
A diagram of a typical IRS is shown below:
Both systems can be enhanced to carry a range of other services, such as video from security cameras and door entry systems, and online services such as email, internet access and connection to e-government services. Pilot projects involving data services have been carried out by Glasgow Housing Association and in the London Borough of Newham.
Other communal TV systems consist of the following.
Cable TV services
Cable TV services are provided through underground cable by ASDL – Asymmetrical Digital Subscriber Line to an individual property or a group of properties. Cable TV services are available across 45% of the UK and the main provider of cable TV services in the UK is Virgin Media (previously NTL: telewest). Cable TV providers can offer ‘triple and quad play’ bundles of services - TV, broadband, fixed/mobile telephone services over the fibre optic cables.
Internet Protocol Television (IPTV)
This is a means of delivering television services over a local area broadband network using web protocols. In a typical IPTV system the signal is processed by an IPTV head end and the IPTV signal is distributed to users through a minimum category 5 cable network. Typically, viewers receive TV services on a TV adapted with an IP set-top box or a PC or a laptop.
For the residential sector the main providers are BT vision and Tiscali TV. There are therefore ongoing costs, which could either be paid by residents though subscription to the IPTV service, or built into service charges. Although there are no commercial service applications currently available, IPTV can be used for TV service distribution within a hotel, hospital, office block, for example.
Multi Distribution Box
A Multi Distribution box could help ease the digital switchover process for multi dwelling properties, care homes, bed-and-breakfasts and small hotels as it receives digital channels and converts them into analogue television channels. A Multi Distribution box will allow people to continue to watch the main channels BBC1, BBC2, ITV, Channel Four and Five on their existing TVs without the need for any extra set top box, remote control or extra cabling.
The principle of this system is the Multi Distribution box receives the digital signal, converts them back to analogue and distributes them around the building on the existing cabling. The Multi Distribution box is installed centrally for 6 services - for example, if BBCI, BBC2, TV, Channel 4 and Five are required, and 1 extra service such as BBC News 24 or the History Channel.
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