H.320 and H.323 Who are the future of video?
Snow Chuan 2003/03/14
As two mainstream video standards, how to develop H.320 and H.323? What is your own advantages? This will determine their future path. In 1964, the technical and image combination of speech and image was introduced, and the product was a Picture Phone Mod-i developed by Bell Lab. It belongs to a TTC Standard for TTC, Japan, Japan to develop TTC standards for visual telephone production and application. In the 1990s, CCITT proposed the H.261 protocol for TV conferences, visual calls, and quickly replaced TTC standards globally. As a basis for global interoperability, with the continuous development of television conference, data business is also integrated and developed into "video service". At the same time, new protocol frameworks and standard texts have emerged, and a series of full regulations for performance indicators, compression algorithms, information structures, control commands, procedures, and forming television conference network principles for video services and products. At present, mainstream video equipment is basically adopted by H series standards. China is even more, and the video service launched by Telecom operators basically uses H series standards as guidelines, or uses a mature H.320 series agreement, or Adopt emerging H.323 series agreement. H.320: Strong development H.320 protocol is mainly used for circuit switched networks, which is based on China Communication Network, which is the "narrowband" application, which is usually said, etc., due to substantially network line dedication. Ways, image quality, stability, etc. have guaranteed. From the application side, users are more focused on their technical maturity, and the market can choose equipment. Moreover, due to the only ISDN in the global video transmission network, the Equipment based on H.320 technology standards is more common in cross-country video network construction. At the same time, this technology is usually the primary choice for government, military, finance, etc. From the view of the market opportunity, since the original is to establish this agreement, this agreement is used to make full use of the current public network resources, and the space existing in the product provider and the price option is relatively comparable. small. H.323: The development of the new pet operator broadband construction and the development of related technologies have matured, making the video protocol based on TCP / IP technology easier to acquire the market, and the agreement against this market is H.323 protocol standard. According to the H.323 protocol, a multimedia confession application system should be used by terminal, gatekeeper (also known as gatekeeping), gateway, multipoint controller (MC), multipoint processor (MP), and Multi-point control unit (MCU) and other components, seem complicated, but there is not much job that the user needs to do, this is also the advantage of TCP / IP. Since the maximum transmission rate in ISDN can only be maintained at 30 frames / sec, it may also be reduced to 10 frames / second or even 5 frames / second when the network occurs, and the normal TV image quality is 33 frames / sec, so the public Network or enterprise-class video applications more inclined to select H.323 protocols and corresponding TCP / IP networks. Also, relatively, video network deployment based on TCP / IP protocols is also more flexible and simple, and maintenance is also relatively convenient. However, since the QoS problem of the IP network itself has not been completely resolved, video technology applications are prone to network jitter, order confusion, network congestion, etc., system stability is not based on H.320 video system.
