The Layer-Independent Descriptor Concept

With the fast improvements of broadband technologies, more and more demanding services can be accessed. Broadband access is supported by a range of wireless and wireline technologies. Well known representatives are WLAN and UMTS for wireless and xDSL for wireline access. However, the highly varying nature of wireless channels and the crosstalk behavior of the DSL channel are typical traits, and most challenging to combat. Moreover, the stringent requirements of real-time applications require enhancements in service delivery. The tremendous interest in communication has driven the deployment of new access systems. Hence, for the End-to-End point of view, the service delivery multifarious due to the heterogeneity of the underlying transport network. Therefore, to enable a transport independent path set-up, application and network properties that may influence the user-perceived quality need to be unified. Thereby, media scalability plays a key role. Recently, cross-layer communication is getting acceptance as a method that efficiently increases the system performance. Unlike previous works that mainly addressed the issue of application based feedback, we focus on the information that the application can provide to guide the network for local stream management. We present the necessary set of Application Layer information for scalable audiovisual streams to offer individual QoS, at lowermost packet overhead. Finally, we show the sustainable gain in system performance based on a DSL use-case.