Real-time video traffic, such as video conferencing, generally exhibits a high peak-to-mean (P2M) rate ratio because of the video encoding methodology. In the video encoder, picture frames are encoded in a group-of-picture (GoP) structure. Each GoP consists of I-frames (independently encoded frames), P-frames (predictively encoded frames) and possibly B-frames (bi-directionally predicted frames). I-frames usually have a much larger size than P/B frames, and can be as much as 6 times larger. Therefore, the instantaneous bit rate of a real-time video flow has a high P2M ratio due to the transmission of I frames and P/B frames at different times.
During the delivery of video flow to different nodes, a plurality of video flows are typically transmitted over the same set channels between network nodes. When a large number of video flows are transmitted over the same set of channels, the I-frames are unlikely to be aligned with each other. As a result, the aggregated video flow typically has a lower P2M ratio than any of the individual flows. It should be understood that in the context of a wireless network, it is less common to have a plurality of video flows carried on the same wireless link, especially on wireless links between transmit points (TPs) such as base stations, and wireless terminals such as a user equipment (UE). If traffic to a UE is planned with sufficient capacity allocated to the video flow to allow the peak transmission rates to be accommodated, wireless links will have unused capacity, as sufficient capacity has been allocated for the transmission of I-frames, and much of the allocated capacity will be unused during the transmission of smaller frames. Thus, many of the problems dealing with the management of video traffic flows have been unaddressed in wireline networking because of the planning benefits of video traffic aggregation.
USPTO Backgrounds
USPTO Backgrounds