NGN's streaming media service not only provides video stream services, such as broadcast and television and VoD, but also integrates voice, data, and video services for common and commercial users, for example, Caller-IDonTV ).
At present, the NGNRelease1 architecture established by ITU-TFGNGN-FRA includes the IP Multimedia Service Section (including the simulation service of PSTN/ISDN) and the simulation service section of PSTN/ISDN, however, there is no in-depth research on the stream media and other multimedia services of NGN architecture. ITU-TSG9 and cable TV Laboratory (CableLabs) began to define the multimedia structure framework of integrated speech, data and video services. On the basis of in-depth research on the development of IPTV services at home and abroad, this paper summarizes the latest development of the next generation network architecture supporting IPTV services.
1. Architecture of NGN Release1
The main research contents of ITU-T in Release1 include service requirements, network architecture, QoS and security. The proposed NGN service and transport layer architecture 1 are shown in.
Figure 1 service and transport layer architecture of NGN
The service layer of NGN consists of four parts.
(1) IP Multimedia Service Section. The IP Multimedia Service uses SIP-based control. The IP Multimedia Service uses the IMS-based core network to provide IP multimedia services and PSTN/ISDN simulation services, the simulation service of PSTN/ISDN mainly emphasizes that only some services of the existing PSTN/ISDN need to be implemented. At the same time, because the terminals used are different from the existing analog terminals, the user experience can be different from the existing service experience.
(2) simulation service section of PSTN/ISDN. The PSTN/ISDN simulation business mainly emphasizes the inheritance of the Next Generation Network to the existing PSTN/ISDN business. On the one hand, it needs to inherit the access mode of the existing analog terminal. On the other hand, the user experience must be exactly the same as the existing business experience, and the user will not be aware of the changes on the network side.
(3) streaming media business section. NGN can provide streaming media services defined in the first phase of NGN, such as content delivery services, multimedia multicast and broadcast services.
(4) other multimedia services.
At present, there is no in-depth research on streaming media and other multimedia services in the NGN architecture.
It is precisely for this reason that the system architecture of NGN should be developed as soon as possible to better promote the popularization and promotion of IPTV services.