FRAMEWORK FOR END-TO-END QOS MEASUREMENT OVER DVB-RCS NETWORK

Satellites are popular due to their wide area coverage and for providing connectivity in remote regions of the world. The future development of satellite systems providing services based on the Internet Protocol (IP) needs to be validated on a real satellite network. This paper presents the end-to-end quality of service (QoS) measurements taken at European Space Agency (ESA) testbed over DVB-RCS infrastructure. The applications chosen for these experiments are file transfer (FTP), web browsing (HTTP), video streaming and P2P filesharing. File transfer, web browsing and P2P file-sharing require reliable transport mechanism as a corrupted bit will hinder the intact data delivery. Therefore, these applications use transmission control protocol (TCP) as the transport protocol. TCP involves a three way handshake, which introduces extra delay during data transfer. Video streaming is a real time application, so, it is time-sensitive and requires lesser reliability compared to the other three applications. Hence, it employs user datagram protocol (UDP) at the transport layer, which do not offer any guarantee of reliable data delivery but is fast. The parameters that have been used to evaluate quality of service (QoS) are packet timestamps, file download time, round trip delay, packet sizes and packet loss rate. Also similar applications and results will be measured from a satellite emulation testbed, PLATINE. It is based on Linux operating system, in which most of the DVB-S and DVBRCS satellite network functions have been implemented. These functions include network topology configuration, Quality of Service (QoS), Demand Assigned Multiple Access (DAMA), traffic encapsulation using both Asynchronous Transfer mode (ATM) and ULE/MPEG, satellite network entities configuration and support for both IPv4 and IPv6. The paper concludes with the comparative analysis of the QoS of the applications in both real and emulation environments