1. IP Broadcasting over Unidirectional Satellite Link Kanchana Kanchanasut Patcharee Basu Tippyarat Tansupasiri Internetworking Research Lab, AIT, Thailand

2. Introduction Focus on an IP broadcast environment over unidirectional satellite link Two types of applications: Time sensitive streaming Massive content delivery A time-sharing scheme for these two groups of flows

3. Examples of Applications Time sensitive: telemedicine, real- time classroom, entertainment Content delivery: massive file transfer, cache and proxies, distribution of educational materials

4. Technological Components Unidirectional Satellite Link Dynamic QoS (D-QoS) Reliable Multicast on Unidirectional Satellite Link (RMUS) RMUS and D-QoS

5. Unidirectional Satellite Link Two types of stations: Feed station Receivers High bandwidth unidirectional downstream satellite link with long delay Narrow return path

6. Unidirectional Satellite Link UDL feed Network A Network C Network B UDL Receivers Request

8. Dynamic QoS (D-QoS) Scheme Dynamically reconfigure QoS settings Active networking concept Triggered by super user requests Generate interruption on nodes Two operation modes: Differentiated Services – Class-based Queueing (CBQ) Interruption – Priority Queue (PQ)

9. Interruption Made by a Telesurgery Flow

10. Reliable Multicast on Unidirectional Satellite Link (RMUS) Reliability – error detection and retransmission Dynamically adjust the transmission rate make effective use of the bandwidth congestion avoidance Periodically send data in T MON Amount of data transmitted in each T MON depends on the network condition T MON = T SEND + RTT UDL + T BACKOFF

11. RMUS Data Transmission

12. D-QoS and RMUS Relax the interrupt condition Based on time-sharing scheme Interleave RMUS traffic with D-QoS T MARGIN =  T MAX –  T

13. Interleaving RMUS traffic and D-QoS

14. RMUS Data Transmitted (per T MON ) ApplicationTelesurgeryVoIPVideo Conferencing  T MAX (msec) 330400500

15. Analysis Calculate the 10 MB file transmission time 7 Mbps Telesurgery flow Assumptions: Diffserv allocates 75% of link bandwidth to telesurgery flow and the rest to file transfer in the DiffServ-RMUS scheme Each T MON is 850 msec for both schemes

16. Transmission Time for a 10 MB File Transfer

17. Thank You