Edge node control

Abstract

There is provided a method for providing edge node fault management and bandwidth, BW, control for transmission of a data stream in a packet-based network. The method comprises adaptively transmitting a data stream DS by controlling an outgoing data stream being transmitted to one or more client devices by analyzing at least one data stream characteristics of a corresponding received data stream of the one or more receiving client devices and providing a transmission strategy for the outgoing data stream based on said analyzed data stream characteristics. Thereby accurate adjustment of consumed BW and an associated recovery scheme based on applying adaptive bitrate, ABR, to maintain highest achievable performance when it comes to video quality and also affect on other services, are provided.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional of U.S. application Ser. No. 16 / 079,347, filed Aug. 23, 2018, which is a national phase under 35 U.S.C. § 371 of PCT International Application No. PCT / EP2017 / 054290 which has an International filing date of Feb. 24, 2017, which claims priority to Sweden Application No. 1650254-4, filed Feb. 26, 2016, the entire contents of each of which are hereby incorporated by reference.FIELD OF THE INVENTION[0002]The present invention relates to broadcasting and media distribution over IP (Internet Protocol) networks, and more particularly to edge node fault management and bandwidth (BW) control for transmission of a data stream in a packet-based network.BACKGROUND OF THE INVENTION[0003]Video distribution for live TV over a packet-network, like the Internet, has some challenges. In today's solution, the normal mechanisms for transferring data files is the so called TCP transmission control protocol. This protocol ensur...

AI Technical Summary

Benefits of technology

[0011]It would be advantageous to at least provide an improved and reliable method of transmission of data streams which prevents congestion in the network and which is suitable for live distribution of media content, such as TV / video / audio streams, in an IP network like the Internet. This object is achieved by a method according to the present invention as defined in claim 1.

[0012]There is provided a method of adaptively transmitting a data stream comprising for at least one outgoing data stream being transmitted to at least one client device analyzing at least one data stream characteristics of a corresponding received data stream of the at least one client device, and providing a transmission strategy for the outgoing data stream based on the analyzed data stream characteristics. This is advantageous to provide accurate adjustment of the consumed BW and associated recovery scheme, i.e. FEC and / or retransmission, to maintain highest achievable performance when it comes to video quality and also affect on other services. The step of analyzing of the received data stream is according to an embodiment based on retrieved information associated with the received data stream from the client device, which information can be implicit e.g. packet loss patterns, or explicit e.g. measuring the bitrate. The analysis may be performed continuously, or with predetermined intervals.

[0016]According to an embodiment of the method, the method further comprises providing a coordinated or a common transmission strategy for the plurality of nodes or the group of client devices. Advantageously, the transmission strategy can be selected differently for subareas of a network experiencing different network performance. The benefit of coordinating the strategies for ABR, FEC and retransmissions between several devices is that quality and performance can be optimized between the client devices sharing the resources.

[0017]The problem lies in when a congested state starts to occur in a part of a network. This will cause many clients to lose packets and, using retransmission recovery mechanisms, start resending of packets thereby causing even more data to be sent into the network causing further congestion. This can create so called avalanche effects. In TCP, this is handled conservatively by the use of so called back-off effects. However, for live streaming of video, this causes delays and is therefore not optimal. The other alternative is to use UDP with retransmission and then revert to go down in ABR rates. However, if clients independently make such decisions as is the normal case, oscillation effects may occur. However, by monitoring the packet loss characteristics of all or a subset of clients in a part of the network, a more intelligent decision can be taken to reduce the ABR rate for multiple devices simultaneously before a severe congestion occurs and thereby avoiding avalanche effects and large oscillations in the network.

[0022]With the present inventive concept, a coordinated transmission strategy and thereby a coordinated control of the BW usage of the clients of a group, clients within a specific subarea, or group connected to an aggregation network is provided which advantageously optimizes the overall performance of the network.

[0023]According to an embodiment of the method, the predetermined data stream characteristics are at least one of packet loss patterns, and change in delays, of the received data stream. Analysis of data stream characteristics may thus be performed on e.g. packet loss patterns in the received data stream by determining the existence of short bursts of loss, or long bursts of loss. For example, if the loss pattern is more sporadic it is probably a result of randomly lost packets in a radio access and there is no need to reduce retransmissions. If there are longer bursts of packet loss, the system is more likely overloaded and there is beneficial to reduce the ABR level and / or reduce the BW consumed by FEC and retransmissions.

Problems solved by technology

Video distribution for live TV over a packet-network, like the Internet, has some challenges.

This means that it is not possible to ensure when data arrives and it uses a “fits all” strategy for retransmission.

In such system, the client device needs to buffer data because it is not certain that the network can offer the bandwidth required by the video stream, and for video the client device needs to have video data to present to maintain viewer experience.

Such adjustments introduce delay and the video cannot be considered as live distribution.

For example, in a typical situation the receiver detects a lot of lost packets and requests retransmission of the lost packets, and when the actual BW available for the receiver has decreases because of more devices sharing the same bandwidth, bad connectivity to base station or hotspot or network congestions occur.

The requests for retransmission of lost packets together with the video stream will temporarily consume more capacity than available and therefore worsen the situation.

If that delay is exceeded, the data is accepted as lost.

This means that there is a bounded delay of the transport.

To handle the shifts in BW of the video stream without (or with minimum) interruptions is a challenge.

This is however not good since in a situation where the BW decreases, the sender sends more information which also potentially is redundant.

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