Idaho Public Television (IDPTV) is a statewide network of five full-power NTSC transmitters and 36 translators. It currently has one DTV transmitter located in Boise, but there are plans to construct three more during 2002 and a fourth in 2003. The Boise market serves approximately 450,000 people.
The goals of IDPTVâ€™s KAID-DT facility were to be up and on the air with DTV in a timely fashion and not have to fully rebuild its MC facility at the same time as it built its transmitter plant. Being a PBS affiliate, it knew that it could provide a pass-thru of the satellite-fed â€śpre-encodedâ€ť transport streams, but it wanted its own PSIP, logo and control of those streams.
The AgileVision AGV-1000 was the core technology used for the project. It is fed an ASI stream by satellite receivers with one tuned to the PBS SD 4-channel multicast and one tuned to the HD feed. They monitor the transport stream output prior to distributing the stream for confidence decoding and to their STL link. The receiver offers both ASI and SMPTE-310 outputs at their transmitter site.
The AgileVision product was a good match for many reasons. First, it gave KAID-DT great performance and flexibility options. Secondly, the advanced feature set allowed the crew to experiment and provide services that normally canâ€™t be done in the compressed transport stream arena. Third, the crew foresees options for re-purposing the unit after a full digital rebuild of its MC and distribution facility is complete.
KAID-DT has had positive results. It has been able to brand each multicast channel and its HD channel uniquely and switch between the two streams. It also has been able to insert accurate PSIP data right from the start. The main benefit has been identity. KAID-DT had signed on with two other DT stations at the same time and noticed that its PSIP data enabled the set-top box it was experimenting with to tune to its channels much quicker and with less input from the user.