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Communications Voice and Data Communications Most commercial installations comprise a Public Network Interface (PNI) which is where the building infrastructure connects to the external public network, a Main Cross Connect (MCC) which is the main cabling distribution point, vertical cabling which connects the MCC to Intermediate Cross Connect (ICC) points which are generally distributed on a floor by floor basis which can provide more localised distribution and the horizontal cabling which is the final cabling from the ICC to the final outlet sockets. Since various telecommunications vendors are available, for large installations the PNI may need to allow connection to different vendors, each of which may require a secure area containing their equipment. For conventional telephone installations this would simply require the standard telephone cabling connection sized to suit the number of exchange lines required. The vertical cabling usually consist of optical fibre backbone cabling for data system applications and copper cabling backbone for the telephone applications. If higher levels of reliability and/or redundancy are required then dual backbone cabling systems may be required which are physically separated to provide most security. With the realisation from the industry that staff are often relocated and this results in a high churn rate, particularly for commercial premises, the method of installing the communications cabling has progressed to a “structured cabling system”. This is basically where the horizontal cabling from the ICC is usually identical for both voice and data applications to provide maximum flexibility and ease of cable management. With the type of outlets and cabling identical for any applications means that it very rarely needs to be physically modified to suit changed user requirements. If the application is changed from voice to data or visa versa then the horizontal cabling needs only to be re-patched at the ICC to accomplish the change. This results in minimising time, cost and disruption to operations resulting from churn. The capacity/speed required for particular data/information technology applications needs to be determined to select the appropriate category of cabling infrastructure system. The category of communications networks is defined in AS 3080. Typical categories utilised at present is as follows:
It should be noted that the category of cabling infrastructure should be seen as a continuous system from the ICC through to the final outlet, including all cross connects and patch leads to ensure a complete system. Communications Space Requirements The following spaces should be provided for the standard communications installations:
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