Hi-Net 350™ and Supra™ Cables Offer Guaranteed Delay Skew Headroom

Manchester, NH July 2002: Hitachi Cable Manchester's engineers have investigated the role of signal timing in data transmission and are recommending that the existing TIA and ISO propagation delay and delay skew requirements may not be stringent enough to support new applications. In particular, since delay skew affects signal timing and the re-fresh rate of transmitted data, the quality of video transmission (where red, green, and blue color channel information is transmitted over different pairs) could benefit from reduced delay skew. It is probable that, in order to deliver optimum picture quality, future video applications will require significantly better channel delay skew than the 50 nanosecond limit imposed by the TIA standards.

In response to the findings, Hitachi Cable developed a design strategy to reduce the maximum delay skew in their premium cables at no additional cost to the customer. The enhanced design, which optimizes the electrical properties of the insulation dielectric and the copper conductor to best match signal propagation speeds between the cable pairs, employs FEP on all pairs to avoid having to compensate for skew introduced by mixed dielectrics. The result is a design with over 45% less delay skew than the standards' specified worst case. To ensure next generation applications support, Hitachi Cable guarantees that the maximum delay skew on their Hi-Net 350™ (category 5e with headroom) and Hi-Net Supra™ (category 6 with headroom) cables shall not exceed 25 nanoseconds.