PIS frame supplementing algorithm based on multicast and unicast hybrid strategy

Abstract

The invention discloses a PIS frame supplementing algorithm based on a multicast and unicast hybrid strategy, data frame supplementing is realized by using a UDP unicast and multicast hybrid strategy,and for ground broadcast control and vehicle-mounted broadcast control, the network environment is different (the ground network environment is relatively wider, and the limitation is small; the vehicle-mounted network bandwidth is strictly limited), the broadcast control numbers are different (the ground broadcast control number is huge, and the vehicle-mounted number is relatively limited), a UDP unicast and multicast mixed frame supplementing strategy is adopted, multicast frame supplementing is conducted for ground broadcast control, unicast frame supplementing is conducted for vehicle-mounted broadcast control, the network bandwidth for frame supplementing is effectively saved on the whole, and the expenditure of a streaming media server is reduced. According to the invention, the original audio and video frame transmission and frame supplement are two independent behaviors, and the packaging format of the original audio and video frame remains unchanged, so that the PIS frame supplementing algorithm has stronger application scene adaptability, for example, some clients (such as a play controller) do not support a frame supplement protocol, and the system can also work normally under the condition that the packet loss is not obvious.

Description

technical field [0001] The invention relates to the field of information technology, in particular to a PIS frame complement algorithm based on a mixed strategy of multicast and unicast. Background technique [0002] In the urban rail transit industry, the Passenger Information System (PIS) is a necessary part of information construction, and it generally consists of a central subsystem, a station subsystem, an on-board subsystem, and a network subsystem. The central subsystem (as a server) pushes train information, live video streams, advertisement information, etc. to the playback controller of the station (as a client) through network technology, and the process of pushing network data involves TCP (Transmission Control Protocol) Or the use of UDP (User Datagram Protocol). [0003] The ground network is generally relatively stable, and the packet loss rate is very low; when using the vehicle-to-ground wireless network to transmit the video stream to the moving train, due...

AI Technical Summary

Problems solved by technology

[0006] The network bandwidth requirement may be very high: in the case of a large number of playback controller networking applications, if the frame loss or packet loss is serious, many playback controllers will make a reissue request, and the streaming media server will respond accordingly. How much bandwidth does it need to consume? Uncertainty, there may be high requirements for bandwidth, which will bring difficulties from bandwidth planning and design to actual application supply;

[0007] High overhead of the streaming media server: Since all retransmission requests of the playback controllers require point-to-point responses from the streaming media server, the pressure on the server is caused by the large number of playback controllers and high frame loss or packet loss rate. Very large, even consider setting up a special supplementary frame or supplementary packet server to respond

Images