Data receiving terminal in network data transmission system

Abstract

An embodiment of the invention provides a data receiving terminal in a network data transmission system. The network data transmission system further comprises a front data transmission terminal, a transmission network and an access network. The front data transmission terminal comprises a convergence switch, a transceiving port of the convergence switch is forcedly set to transmit only, and the front data transmission terminal is used for encoding and IP (internet protocol) packing of audio-video data and the like and outputting an IP data packet in an IP broadcasting or multicast mode via the convergence switch. The transmission network is a cable television broadcasting network which is used for unidirectional and transparent transmission of the IP packet at the speed of 1Gb or above. The access network comprises a first switch and is used for obtaining the IP data packet from the transmission network via the first switch which is a broadcasting switch or a multicast switch. The data receiving terminal is used for obtaining the IP data packet from the access network and unpacking and decoding the IP data packet so as to play the audio-video data.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a data receiving terminal in a network data transmission system. Background technique [0002] 1. Analog cable TV [0003] Analog cable TV network (its transmission method such as Figure 7 Shown) The development is the process of moving wireless analog TV transmitting technology and wireless receiving technology to wired network. Through the use of adjacent frequency technology and supplementary channel technology, the number of transmission channels has been greatly increased. [0004] Figure 8 It shows a schematic diagram of wireless transmission of analog TV. The wireless transmission mechanism of analog TV is that the modulator modulates the audio and video stream to be transmitted to the pre-specified channel carrier frequency, and then the transmitter transmits the modulated carrier frequency to space. Under the action of the antenna, it is transmitted to the TV ...

AI Technical Summary

Problems solved by technology

[0010] The disadvantages of analog cable TV are: first, due to the use of modulation technology, the actual number of channels is far less than the number of planned channels due to the influence of space wireless channels; second, it is difficult to maintain operating indicators because of the use of analog modulation technology; Guarantee service quality

[0014] The disadvantages of digital cable television are: the transmission method still cannot get rid of the modulation and demodulation technology, so there are the following problems: first, it is still affected by the space wireless channel, and the actual number of channels is far less than the number of planned channels; second, because the planned bandwidth is 1000M , it cannot meet the bandwidth requirements when it develops to high-definition or 3D TV in the later stage; third, because the broadcasting network is a one-way network, it must be transformed into two-way with the business development to realize the development of interactive services

[0022] Disadvantages of this method: First, a carrier-class data network is built on the basis of the original network, which increases the cost and difficulty of network bidirectional transformation; second, it increases maintenance costs and maintains two networks

[0027] The disadvantages of this method are: the standards are not uniform, and the home bandwidth is low. For example, when the bandwidth requirements are raised according to the five-category line home access standard, the coverage cost and home access cost will increase sharply.

[0032] The disadvantage of this method is: low bandwidth for home access. For example, when the bandwidth requirement is raised according to the CAT-5 line home access standard, the coverage cost and home access cost will increase sharply

[0039] The disadvantage of this method is that although the fiber-to-the-home has been realized, the transmission method of the A platform still cannot get rid of the modulation and demodulation technology, so there are the following problems: First, it is still affected by the space wireless channel, and the actual number of channels is far less than the plan The number of channels; second, because the planned bandwidth is 1000M, it cannot meet the bandwidth requirements when developing to high-definition or 3D TV in the later stage

[0044] The disadvantage of this method is that, because the modulation and demodulation technology is cancelled, the same amount of compression and the transmission bandwidth of a set of programs will be increased by 4-5 times, which will increase the bandwidth pressure of the IP metropolitan area network (when a multiplexing stream is 38M, QAM modulation After that, only 8M transmission bandwidth is required)

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