Improving QoS in satellite networks using cross-layer mechanisms

Quality of service (QoS) support can be enforced across several protocol layers by enhancing specific mechanisms such as resource management, power control, scheduling, queuing models and transport protocols. However, even if designed independently, one single layer adaptation impacts other layers, for example, coding rate adaptation at the physical layer impacts the available rate for transport protocols and can induce buffer overflow and congestion. We argue throughout the present study that collaborative mechanisms are efficient and allow an adaptation to network changes at all layers more than single layer standard mechanisms. The main idea is to use available information from layers that are not adjacent in order to optimize the overall performance of a system. The network is seen as a collaborative layer system, where decisions are taken to increase the QoS offered to end-users. We search to bring to light specific layer mechanisms and illustrate how QoS can be improved on the forward and return link in bent-pipe geostationary satellite systems. (5 pages)