ºÚ¶´ÉçÇø

Delivering television over a building’s local area network (LAN) is the latest example of the revolution in intelligent building controls – using technology based on internet protocol (IP) to combine systems such as telephones, data, controls, access control and fire alarms.

Ethernet networks are now standard in new buildings, and high-speed networks can be retrofitted to existing ones. This produces a cost-effective, high-bandwidth internet conduit which provides technological advancements and gives opportunities for integrated systems, more recently of TV and visual display equipment.

New-build, high-quality commercial developments are increasingly requiring TV and radio at every desk and throughout the buildings, providing news as it happens as well as corporate information and entertainment in breakout/ social areas. Developments in technology mean this can be delivered more cost-effectively than by comparable conventional distribution systems.

Technological development

IP networks have radically changed TV systems in buildings. Until recently TV was distributed via an expensive and often cumbersome coaxial cable system. This was difficult to manage and upgrade as well as being unreliable, and could only transmit high-quality pictures over limited distances. It often suffered interference because of poor cable quality or mains electrical supply, causing ghosting and dead zones on transmitted images. It was also, more often than not, installed outside the traditional contractual procurement routes, which exacerbated the problems.

The development of a TV to IP gateway interface has enabled terrestrial and satellite services to be plugged directly into a LAN, allowing live broadcast TV and radio to be distributed across a building or campus network. This is a significant development and follows the trend of electronic devices such as telephones, CCTV and building management systems, card readers, and so on, connecting to and communicating via the network.

This so-called network IPTV, whereby all TV, including satellite and analogue feeds, can be streamed directly onto an ethernet network and distributed to any point around the building, does not have any of the problems of the traditional system. As a result, media, financial, leisure and retail companies are increasingly looking to replace their troublesome and fragile coaxial systems.

Benefits of providing TV over LAN

• The system promotes a rapid rollout of new TV, video and broadband services across the whole business.

• Costs are significantly reduced through not having to buy separate TV units or provide a separate satellite/aerial signal distribution system within the building.

• The equipment deployed can utilise the existing network infrastructure, so there is no need for additional cabling to deliver TV at PC terminals. In addition, any PC can be converted easily into a TV with PVR (personal video recorders).

• The system provides access to live news, entertainment and information channels to any PC or TV/AV equipment/device attached to the local IP network.

• Digital terrestrial (DVB-T) and digital satellite (DVB-S) services can be plugged directly into the LAN to distribute real-time

TV and radio across the whole building or campus network.

• Replacement of analogue Cat5 TV distribution is straightforward.

• Picture and sound quality is superior.

• Compatibility with inherent customer systems.

• Interruption of critical networks can be avoided by utilising a separate video LAN.

Application

A network IPTV is increasingly seen as a pre- requisite for a variety of end-users for which the provision of TV to desktop is an important and sometimes vital working tool.

Many large trading organisations and banking institutions, for example, rely on access to real-time financial news. Without dedicated and reliable access to such information, many would not be able to compete. In terms of corporate TV, an IP system makes it easy to deliver information to staff as well as entertainment in breakout areas.

In the academic world, teaching can be enhanced by making channels available to every PC or display across a campus, providing students with TV and radio channels profiled to suit their interests, home countries and education needs.

Implementing digital TV headends for hotels, leisure and event arenas allows local and foreign language channels and radio into hotel guest rooms, common parts and conference areas. Delivering television to patients’ bedsides in hospitals and other care facilities helps to improve the healthcare environment.

IPTV is completely scalable, allowing the system to grow as a company expands. It is easy to manage, reliable and relatively simple to maintain, and more robust than the traditional alternative. The advantages in cable and equipment reduction, coupled with vastly superior reception qualities, also simplify procurement and installation procedures.

Specialist companies are able to deliver a total solutions package for the delivery of an organisation’s media requirements, including management input and strategic advice, together with all the necessary hardware and software, such as headends, gateways and satellites.

Cost analysis and comparison

The table (see attached) shows the typical comparative costs of a coaxial distribution system and an equivalent IP system.

The costs are expressed in terms of the supply to 50 PCs to give a representative comparison, since while the IP system theoretically can provide TV signals to every desktop, this would rarely be provided via traditional coaxial cabling as the cost would be prohibitive. Instead, coaxial would normally be fed selectively to certain areas on a floor.

The principal differences in the cost for the different sizes of building are a result of the greater vertical distances over which the cable has to be run (assuming that the building height increases with area) and the need for additional amplifiers on the coaxial system to maintain the signal strength in larger buildings.

The cost savings are achieved through not having to run dedicated cabling networks with the IP system, as well as the savings attributed to hardware, satellite receivers and modulators, and so on.

Comparisons of the conventional and IPTV systems should also take into account space savings within communications cabinets, M&E risers and roof plant areas.