Case No. IP-2016-000202

has a filing date of 21 November 2001 and no priority date. 4.Technetix accept that if claim 1 is invalid over the cited prior art, none of the other claims are valid. I need only consider claim 1. 5.Adam Gamsa appeared for Technetix, Mark Chacksfield and Thomas Jones for Teleste. Technical Background 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. The witnesses 11.Christopher Bailey gave expert evidence for Technetix. He is an engineer of 25 years standing, currently Head of Market & Applications Engineering at PPC Broadband Inc., a company in the broadband and communications industry. Mr Bailey was crossexamined and gave clear, straightforward evidence. 12.Teleste filed an expert report from John Bartlett, a consultant in the cable TV industry. Following his cross-examination of Mr Bailey, Mr Chacksfield told me that he would not call Mr Bartlett. Mr Bartlett’s report fell away save for any passages which were approved by Mr Bailey and thereby became part of Mr Bailey’s evidence. The skilled person 13. It was common ground that the skilled person was an electronics engineer working in the broadband or cable industry. He or she would have a degree in electronics and experience of cable network design. The common general knowledge 14.Mr Bailey said that US-style tap units with a removeable face plate, protected in a box from the weather and RF (radio frequency) interference were known to the skilled person. It is not clear to me whether when giving this answer in cross-examination Mr Bailey meant that such units were common general knowledge to the skilled person in the UK. I will assume that he did. 15.I will discuss other disputes about the common general knowledge below in the context in which they arose. The Patent 16.The background section of the specification identifies two known types of tap unit. The first has directional couplers in series, each of them passing a portion of the signal to a signal splitter. The splitters have different loss characteristics so that a range of levels of signal output are available to suit the varying needs of customers located at varying distances from the tap unit. If a signal output fails and no alternative unused output is available, the entire tap unit needs to be replaced. 17.The second known type has a base unit with a number of plug-in modules. Each module consists of a directional coupler and an 8-way splitter, the modules having varying output levels. This is an improvement over the first type in that if a module fails, it can be changed without having to replace the entire tap unit. But it still requires an engineer to maintain a large number of expensive modules in stock. 18.A tap unit according to the invention has at least one removable directional coupler in the signal path between the input of the signal from the network and a group of signal outputs. The engineer can select a directional coupler to suit the output level required. To effect repairs or changes to the tap unit the engineer need only carry in stock a range of directional couplers, which are relatively small and inexpensive. 19.The arrangement of the invention was sometimes described in the evidence as a ‘plug and play functionality’, i.e. allowing the selection of the appropriate directional coupler and plugging it into a receptor in the base unit to achieve the required signal output level. This can be done without disturbing other components, in particular the group of signal outputs. Claim 1 20.Claim 1 was divided into convenient integers: (1) A cable tap unit comprising (2) a base unit with an input for a signal from a cable network, (3) at least one group of signal outputs, (4) at least one receptor means positioned in the base unit in a signal path between the input and the group of outputs, (5) and directional coupler means, (6) wherein the directional coupler means is received by and detachable from the receptor means such that the signal transmission characteristics of the path are selectable as required by choice of directional coupler means, (7) wherein the directional coupler means is separable from and insertable into the base unit independent of the group of signal outputs.