Protocols and Algorithms for
Adaptive Multimedia Systems
Lectio Praecursoria
Varun Singh
02.06.2015
Espoo
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Video is Everywhere!
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Dominance of Video
• ~ 60% of the broadband Internet is Video Content
• ~ 70% of the mobile Internet is Video Content
• ~ 10% of the mobile Internet is Video Calls
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Internetworking
• Available capacity varies over time mainly due to
sharing with
1. various types of cross traffic
2. wireless networks
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Emergence of low-delay Video
• Live video
• delivered within seconds
• Interactive video
• at most hundreds of milliseconds
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Multimedia Systems
• connected to a network
• capture and transmit media
• receive and render media
• video codecs: e.g., H.264, VP8, …
• audio codecs: e.g., G.711, Opus, …
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Protocols (RTP)
Internet Protocol (IP)
User Datagram Protocol (UDP)
Session Traversal
Utilities for NAT
(STUN)
RTP
SSRC
#2
SSRC
#1
TURN
SSRC
#3
SSRC
#4
Transmission
Control Protocol
(TCP)
Signalling Protocol
(e.g., SIP, Jingle, …)
DTLS
Note: *RTP can be sent over UDP or TCP.
Similarly, signalling protocols can be
designed to transmit over UDP or TCP.
Secure RTP
(SRTP) Keying
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Sender Receiver
RTP media packets
Sender and Receiver
Reports
Adaptation
1. Short-term
2. Long-term
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Congestion Control
*Rate Control
!
Time
Instant per packet delay
Threshold 2
Threshold 1
(2) Short-term delay peak
(1) Time period of excessive delay
(5) Integral under
the delay curve
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End-to-end Congestion Control
Network
Ethernet
Wireless
Cable/xDSL
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Network Assistance
notifications
notifications
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Multiple paths
Wifi and 3G/LTE
…
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Conclusion
• Classification of congestion control cues.
• Adaptive error-resilience
• Congestion control for real-time media
• Multipath RTP
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