On practical crosslayer aspects in 3GPP video services.

In this work we introduce 3GPP video services and discuss both the concept of service provision and Quality-of-Service (QoS) achievement. 3GPP video services are supported by many different QoS tools, which are applied depending on network conditions and service constraints. Despite the fact that the 3GPP QoS concept does not encourage complex cross-layer design, it is nevertheless possible to improve the performance of 3GPP video services tremendously by using the appropriate combination of tools. Three examples in the area of multimedia telephony and multimedia broadcast are provided, which support this statement.