Designing A High Definition Television Laboratory For Technology Students

Over the course of the last year we have developed a course on High Definition Television (HDTV) for technology students. One of the major steps in providing practical experience for students is the implementation of a cost-effective HDTV laboratory. As it can be expected, the equipment needed to implement a full-fledged, realtime, broadcast HDTV lab is cost prohibitive and technically problematic. However, a meaningful laboratory environment can be designed around a somewhat limited budget. Our proposal is as follows: a meaningful lab environment must give practical experience with a full range of HDTV related issues. The most major concerns for laboratory equipment are video acquisition, MPEG encoding, broadcast capabilities, reception and decoding. Signal broadcast, reception and decoding are the easiest issues to resolve if we think creatively. We propose to enhance our existing local area network (LAN) laboratory such that it will serve as our broadcast and reception hardware. HDTV is, after all, digital. An upgrade of a few Hubs and Ethernet switches to 100 Mbps equipment along with network performance monitoring software will allow a double check of actual bandwidth used. The addition of MPEG decoders to existing computers is relatively inexpensive and sound capabilities are built into most machines already in place. This leaves image acquisition and MPEG encoding as the only obstacles to overcome. These, however, are not minor obstacles. MPEG hardware-encoders range in price from a low of four thousand dollars to a high of well above $50,000.00. MPEG software-encoders cost considerably less. Funding sources for the low range or software MPEG-encoders can be found. The unfortunate problem of the lack of AC-3 audio encoding in the lower price range can be turned into an educational positive. Audio can be captured and resampled later. This process will preclude the possibility of live broadcasting. It is estimated that the cost of the upgrades to the LAN lab for costeffective HDTV lab is about $5,000.