Applications
Applicatioin MPEG-4 HD for ENG vans
The digital upgrade of analog Electronic News Gathering (ENG) vans via the NEXTEL upgrade program is providing MPEG-2 SD encoding capability for remote news feeds. The new digital microwave links will provide 8 MHz RF channels (Full channel operation) or 4 MHz, Half channel operation in congested markets. Depending upon modulation type selected a range of data rates are supported for a Full, 8 MHz RF channel allocation:
Modulation:
Minimum data rate:
- 4.98 Mbps
- 9.95 Mbps
- 14.9 Mbps
Maximum data rate:
- 10.6 Mbps
- 21.1 Mbps
- 31.7 Mbps
The lower data rates offer the most Forward Error Correction and protection for Path anomalies. Realistically, most full RF channel application will operate in the 15-20 Mbps range and Half RF channel systems will operate in the 8-10 Mbps. The Full RF channel systems will have sufficient bandwidth to support MPEG-2 HD transmissions. However, Half RF channel systems will need to consider MPEG-4 for its improved compression capability and consequent reduction of occupied bandwidth.