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1/14/05

Summary of Special Meeting of the D/I Committee

January 10, 2005

Listen to the meeting.

The D/I Committee of the NPR Board of Directors met by teleconference in open session at 3:30 pm ET, January 10, to address issues that have recently been raised regarding the technology planned for transmitting programs as live streams in the PRSS ContentDepot. The meeting was also made available to public radio stations, program distributors, and other interested parties via the web and through a closed circuit satellite interconnect.

Specifically, the Committee discussed the issue of latency (delay) associated with IP audio over satellite transmission, and the 400 milliseconds of latency this technology would add to the approximately 300 milliseconds of delay experienced in the current satellite system. The Committee heard from staff its assessment that the additional 400 milliseconds of latency would not create any significant operational issues for ContentDepot users, which was reinforced by similar views expressed by callers during the public comment segment of the meeting. After extensive discussion, a vote was called on a motion that would require the live streaming solution for ContentDepot to have no greater latency than today's system. This motion was defeated.

Additionally, the Chair raised the issue of performance of the receivers that have been selected for streaming programs in the ContentDepot. It was noted that this equipment fully meets its design specifications; however, preliminary testing of pilot units at 18 field sites indicated a higher than expected susceptibility to interference in some locations. Staff reported that most of the interference cases had been eliminated through a combination of local downlink alignment and filtering, and continued refinements in the streaming hardware systems. Project staff stated its belief that a combination of further hardware improvements and local site maintenance at locations where it is needed will successfully address the remaining interference issues. The Committee directed staff to pursue proactively interference mitigation efforts. The costs of major site work, if any proves to be required, will be discussed with the Committee at its February meeting.

Committee members affirmed the importance of high quality sound to public radio, and the need to maintain the high standards of performance experienced with today's distribution system. Staff conveyed its commitment to the same standards, and expressed high confidence in the IP audio over satellite technology selected for use in the ContentDepot. Based on the outcome of this meeting, staff is proceeding with implementation of the IP streaming solution in accordance with the Committee's guidance and recommendations.