Case No. IP-2016-000202

6.I will describe the technical background by reference to cable TV. The TV signal travels from an origin called the ‘head end’ to a final distribution point which, in the UK, is typically in a street cabinet. The distance from the head end to the cabinet may be several kilometres, over which the signal will attenuate to a degree that depends on the distance travelled and the qualities of the trunk cable. TV subscribers, relatively close by the cabinet, receive the signal via cables which cause further attenuation of the signal. 7.The strength of the signal delivered to a subscriber’s set-top box must fall within a required range to ensure that it is accurately processed. The signal will arrive at the distribution point at a strength higher than required. ‘Directional couplers’ are used to reduce it. A directional coupler taps off a proportion of the signal so that its strength when ultimately fed to the set-top box lies within the required range. The necessary proportion to be tapped off will vary. Directional couplers come in different grades to meet the differing requirements. 8.Directional couplers usually feed ‘splitters’. These divide the signal into two equal parts. They can be used in series so that the signal is divided into four, eight, or a larger number of parts as appropriate to deliver the signal via output ports to multiple subscribers. 9.Directional couplers and splitters are mounted on a support. The support and mounted components are collectively referred to as a ‘tap unit’. A cable TV street cabinet will contain a number of tap units. 10.Typically, a group of eight subscribers located at approximately the same distance from the tap unit will receive a signal via one directional coupler, with splitters having eight output ports, or ‘signal outputs’. Another group of subscribers at a different distance from the tap unit will receive their signal via another directional coupler selected to tap off a different proportion of the signal, and so on.