1. Chapter 5 standards for multimedia communications
5.1 Introduction
5.2 reference models
5.3 standards relating to interpersonal communications
5.4 Standards relating to interactive applications over the internet
5.5 standards for entertainment applications

2. 5.1 introduction
In this chapter we present an overview of the standards that have been defined for use with multimedia communication
A reference model is used for defined the various standards

3. 5.2 reference models
The standards associated with the three types of application,show in figure5.1
The functionality of each set of standards is as follows:
Application standards
Network interface standards
Internal network standards

4. Figure5.1(a)

5. Figure 5.1(b)(c)

6. 5.2 reference models-5.2.1 Tcp/ip reference model (figure 5.2)
Physical layer
Link layer
Network layer
Transport layer
Application layer

7. Figure 5.2

8. 5.2 reference models-5.2.2 Protocol basics
The protocol to be used at each layer is chosen to meet the needs of a particular application/network combination
Protocol control information(PCI)
Protocol data unit(PDU)
Show figure 5.3

9. Figure 5.3(a)

10. Figure 5.3(b)

11. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications circuit-mode networks
Circuit-mode network is show in figure 5.4
Network interface standard
Transport layer
Multiplexer / demultiplexer
System control application
Audio and video codecs
Multipoint communications service(MCS)

12. Figure 5.4

13. Table 5.1

14. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications circuit-mode networks-cont
H.320
The H.320 standard is intended for use in end systems that support a range of multimedia application over an ISDN
Audio:G.711,G.722,G.728
Video:H.261
User data:T.120
System control/call setup:Q.391
Multiplexing:H.221

15. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications circuit-mode networks-cont
H.324
Over bit rate switched networks such as a PSTN
Video:H.261,H.263
Audio:G.723.1,G.729
User data:T.120
Multiplexing
Total channel bandwidth is divided into a number of separate logical channels
Bit-oriented protocol ,the principles of which are shown in figure 5.5

16. Figure 5.5

17. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications circuit-mode networks-cont
Adaptation
In order to allow for the possibility of transmission errors being present in the received byte stream associated with each logical channel
The adaptation layer supports three difference schemes-AL1,2 and 3
Multipoint conferencing:H.324
System control :h.245 is concerned with the overall control of the end system

18. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications circuit-mode networks-cont
H.321/H.310
Intended for use with terminals that provide a range of multimedia application over a B-ISDN
H.322
Intended for use with end systems that support interpersonal communication applications over a local area network(LAN)

19. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications packet-switched networks
H.323
Attached either to the same LAN or to different LANs
H.323 is intended for use with LANs that provide a non-guaranteed QoS
Figure 5.6 show structure

20. Figure 5.6

21. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications packet-switched networks-cont
Audio and video coding
Audio codec:either G.711 or G.728
Video codec:either H.261 or H.263
Call setup:H.323 gatekeeper can be used
Figure 5.7 two-party call setup procedure using an h.323 gatekeeper
Figure 5.8 H.323 multiplexing/ demultiplexing

22. Figure 5.7

23. Figure 5.8

24. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications packet-switched networks-cont
Interworking
End system that are attached to a circuit-mode network is achieved. This is through H.323 gateway
Figure 5.9

25. Figure 5.9

26. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications packet-switched networks-cont
IETF
Early IETF provided a basic two-party telephony service between two IP hosts
Later IETF provided a more versatile facility supporting both multiparty conferencing and broadcast services
Signaling protocol
Session initiation protocol (SIP)
Sip provides services for user location,call establishment,and call participation management

27. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications packet-switched networks-cont
Session description protocol(SDP)
When a user is invited to join in a call/session

28. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications electronic mail
Internet mail
Figure over the internet
User agent(UA)
Message transfer agent(MTA)
Message store(MS)
Simple mail transfer protocol(SMTP)
Domain name server(DNS)

29. Figure 5.10

30. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications electronic mail-cont
MIME(multipurpose internet mail extensions)
RFC 822: messages are written in English and are made up of just ASCII characters
Extensions to the basic format defined in RFC 822 were added.these are defined in RFC 2045 and are known as MIME

31. 5. 3 standards relating to interpersonal communications-5. 3
5.3 standards relating to interpersonal communications electronic mail-cont
gateways
Show figure 5.11
Two problem:
Format of the mail message is often different
The application protocol are also different
To overcome these problems,a device known as an gateway is used,show figure 5.12

32. Figure 5.11

33. Figure 5.12

34. 5.4 standards relating to interactive applications over the internet-5.4.1 information browsing
Figure 5.13 show information browsing

35. figure 5.14

36. 5.4 standards relating to interactive applications over the internet-5.4.2 electronic commerce
To send detail of your credit card in order to purchase
Figure 5.15 electronic commerce
Common gateway interface(CGI)
security

37. Figure 5.15

38. 5.4 standards relating to interactive applications over the internet-5.4.3 intermediate systems
Communication between the client and server is achieved through a networking device
Show figure 5.16
Security gateway
Packet filtering
Proxy server

39. Figure 5.16

40. 5.4 standards relating to interactive applications over the internet-5.4.4 Java and JavaScript
Figure 5.17
Applet
Virtual machine
Bytecode
Javascript
Embed java code into an HTML page directly

41. Figure5.17

42. 5. 5 standards for entertainment applications –5. 5
5.5 standards for entertainment applications –5.5.1 Movie/video-on-demand
Transmission format (figure 5.18)
Elementary streams
Packetized ES (PES)
System time clock(STC)
Pack
System clock reference(SRC)

43. Figure 5.18

44. 5. 5 standards for entertainment applications –5. 5
5.5 standards for entertainment applications –5.5.1 Movie/video-on-demand-cont
Distribution network
Figure5.19(a) show telephony company architecture
Figure5.19(b) show cable TV company architecture

45. Figure 5.19

46. 5. 5 standards for entertainment applications –5. 5
5.5 standards for entertainment applications –5.5.2 Interactive television
Base on MPEG-2 format
TV program multiplexing(a)PS and TS generation (b) TS format (figure 5.20)
System-level
Program allocation table(PAT)
Program map table(PMT)
Conditional access table(CAT)

47. Figure 5.20