Section: New Results

Multimedia streaming

Participants : Kamal Singh, Gerardo Rubino, César Viho.

There is a growing demand for efficient multimedia streaming applications over the Internet and next generation mobile networks. The third generation (3G) mobile systems are designed to further enhance the communication by providing high data rates of the order of 2 Mbps. High Speed Downlink Packet Access (HSDPA) is an enhancement to 3G networks that supports data rates of several Mbps, making it suitable for applications like multimedia, in addition to traditional services like voice calls. Services like person-to-person two-way video calls or one-way video calls, aim to improve person-to-person communication. Entertainment services like gaming, video streaming of a movie, movie trailers or video clips are also supported in 3G. Many more of such services are possible due to the augmented data rates supported by the 3G networks and because of the support for Quality of Service (QoS) differentiation in order to efficiently deliver required quality for different types of services.

We studied the provisioning of QoS over High Speed Downlink Packet Access (HSDPA) making it suitable for multimedia applications. The key point of HSDPA is its fast and adaptive packet scheduling. We studied [76] a new QoS aware HSDPA scheduler and compared it with the existing HSDPA schedulers. These schedulers were evaluated with a focus on download centric services in a 3G network. A mixed scenario was considered for evaluating the performance. In terms of the maximum number of users that can be served at one time it was found that QoS aware schedulers performed better. For the low load conditions Best Effort schedulers could satisfy different users, but as the load was increased, only QoS schedulers were able to guarantee a minimum quality to the 90% of the video users. The trade-off was the lower per-user throughput that the BE users were getting in comparison. Nevertheless, the QoS-aware schedulers were still dividing the remaining capacity among the BE users in a fair manner.

In a different area, we continued our work on the design of Peer-to-peer architectures for the implementation of a video Content Delivery Network. In [36] we continued on the description of an open-source P2P system for video streaming applications and in [35] we discussed some performance evaluation issues about that architecture. Related to the area, we started a new collaborative project called VIPEER, where the idea is to explore the use of the boxes of the customers of a provider to help in the distribution of video flows (see  7.8 in this report).