Title: Research of Transmission and Control of Real-time MPEG-4 VideoStreaming for Multi-Channel Over Wireless QoS Mechanism
1Research of Transmission and Control of Real-time
MPEG-4 VideoStreaming for Multi-Channel Over
Wireless QoS Mechanism
- ? ? ?
- firecar_at_netopia.knu.ac.kr
2Contents
- Introduction
- Wireless QoS mechanism
- Wireless network real-time video streaming
- RTP seal for MPEG-4 video streaming
- RTCP feedback sending code rate control algorithm
ECN - Experiments tests
- Conclusion
3Introduction
- This paper researches a implement of end-to-end
real-time video transmission system of RTP/UDP/IP
based on QoS controlling over WLAN. - RTP provides the end-to-end network transmission
function. - RTCP uses to examine transmission quality.
- ECN algorithm based on RTCP feedback rate control
algorithm-TFRC.
4Wireless QoS mechansm
- Wireless network problem
- Time Delay, high packet loss, high error
probability - ARQ for QoS
5RTP/RTCP (1/2)
Application FTP, HTTP, HTTPS, IMAP, IRC, NNTP, POP3, SMTP, SIP, SNMP, SSH, UUCP, RTP
Transport TCP, UDP, SCTP, DCCP, ...
Network IP, IPv4, IPv6, ICMP, ARP, IGMP
Link Ethernet, FDDI, PPP
Physical RS-232, EIA-422, RS-449
6RTP/RTCP (2/2)
- RTP ??
- UDP? TCP? ?? ???? ?? ??, ? ??? ???? ???. ??? UDP?
??? ???? RTP? ???. - RTP? ? ??? QoS ???? ???? ???? ??.
- ?? ??? ?? ??? ??? ??? ???.
- RTCP ??
- RTP? ??? ???.
- RTP ??? ??? --gt ???? ? ??? ? ??, RTCP? ? ???.
- ????? ??? ??, ?? ?? ? QoS ??? ???.
- RTP ??? ???? ?? ???? ??? ???.
- 5 ??? RTCP ?? ? ???.
7ECN (Explicit Congestion Notification)
ECN Negotiated during connection establishment
ECT set
ECN enabled receiver
ECN enabled router
ECT ECN Capable Transport
8ECN (Explicit Congestion Notification)
ECT set
CE set
thmax
thmin
CE Congestion Experienced
9ECN (Explicit Congestion Notification)
Congestion!!! Let me inform the sender
CE set
ECN enabled sender
ECE set in ACK
ECN enabled receiver
10ECN (Explicit Congestion Notification)
Congestion reduce cwnd
ECE set ACK
ECN enabled receiver
11ECN (Explicit Congestion Notification)
Incipient Congestion, reduce cwnd, Set CWR
ECN enabled sender
CWR set
ECN enabled receiver
CWR Congestion Window Reduced
12Wireless network real-time video streaming
- Multi-Channel transmission model
13RTP seal for MPEG-4 video streaming
- MPEG-4 video streaming transmission form
14RTCP feedback sending code rate control algorithm
ECN
- The model of ECN algorithm
15Experiments tests
- Sending rate and packet loss probability
16Conclusion
- Experiments show that the transmission method can
obtain good quality. - Congestion control is used to prevent or reduce
network throwing package.