CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Submission Under 35 U.S.C. § 371 for U.S. National Stage Patent Application of International Application Number: PCT/EP2016/079929, filed Dec. 6, 2016 entitled “QUALITY OF SERVICE FOR A VIDEO STREAMING SERVICE,” the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

The invention relates to streaming of video services across a telecommunications network to a User Equipment (UE). In particular, the invention relates to reducing the usage of network resources for streaming video services.

BACKGROUND

The Policy and Charging Control (PCC) architecture in telecommunications networks permits the integration of both policy and charging control. The PCC architecture is specified in 3GPP TS 23.203 for Evolved 3GPP Packet Switched domain, including both non-3GPP accesses and 3GPP accesses, such as GSM EDGE Radio Access Network (GERAN), Universal Terrestrial Radio Access network (UTRAN) and Evolved Universal Terrestrial Radio Access network (E-UTRAN).

FIG. 1shows an exemplary PCC architecture comprising, amongst other network nodes, a Policy and Charging Rules Function (PCRF)100, a Policy and Charging Enforcement Function (PCEF)102, a Traffic Detection Function (TDF)104and

Subscription Profile Repository (SPR)106.The PCRF100is a functional element that performs policy control decision and flow based charging control. The PCRF100provides network control regarding the service data flow detection, gating, QoS and flow based charging (except credit management) towards the PCEF102.The PCEF102encompasses service data flow detection, policy enforcement and flow based charging functionalities. Deep Packet Inspection (DPI) technology, which may be embedded in the PCEF102, is configured to inspect/analyse the contents of Internet Protocol (IP) data packets beyond the so called “IP 5 tuples”. The IP 5 tuples are the heading elements of an IP data packet comprising: IP source address, IP destination address, source transport address, destination transport address, and protocol over IP (e.g. Transmission Control Protocol (TCP) or User Datagram Protocol (UDP)). Therefore, DPI technology is configured to inspect and analyse the application layer information conveyed by IP data packets. As a result of DPI analysis, service classification information can be obtained, which allows IP packets to be classified.The TDF104corresponds to a stand-alone entity implementing the DPI technology.The SPR106is a logical entity comprising all subscriber/subscription related information needed for subscription-based policies and Internet Protocol Connectivity Access Network (IP-CAN) bearer level PCC rules by the PCRF100.

Current video solutions divide TCP based video services provided to a User Equipment (UE) into phases.FIG. 2shows the phases of a video service. At the beginning of a download phase200the video service buffers video data during a buffering phase202undertaken so that a sufficient amount of video content may be stored locally at the UE to allow the video to be played. The buffering phase202starts with the first transfer of the video content and ends when the first frame of the video is displayed. In general terms, buffering occurs when there is not enough information in the video buffer of the player so the UE cannot play the video.

After the buffering phase202has ended and there is enough video content in the buffer, the UE begins to play the stored video content in a playout phase204. During a first part206of the playout phase204, video content is still being downloaded until the transfer of video content is ended and the remainder of the video is played during a second part208of the playout phase204. Using some content provider services, once the initial buffering phase202has finished, the UE typically periodically downloads some video frames in order to keep the buffer state over the minimum needed to play the video content.

An important metric in the use of video services is the time taken to begin playback of video content, that is, the time taken for the buffering phase202.

SUMMARY

The inventors have appreciated that use of a large amount of network resource during certain phases of a video service is justified because those phases should be completed relatively quickly, for example the buffering phase202should be as short as possible. However, during other phases of the video service, less network resource is required to maintain adequate playback of the video content, for example during the playout phase204. Accordingly, the inventors have appreciated that the usage of network resource may be reduced at a particular stage, e.g. after a buffering phase, of a video service.

According to an aspect of the invention, there is provided a network node for use as a Policy and Charging Rules Function, PCRF, in a Policy Charging Control architecture of a telecommunications system. The network node comprises a receiving means, which may be a receiver, configured to receive from a Policy Control Enforcement Function, PCEF, a notification indicating that a video service has started for streaming video content to a User Equipment, UE, of a user. The network node comprises a quality determining means, which may be a quality determiner, configured to determine a first Quality of Service, QoS, setting for streaming the video service to the UE. The network node comprises a transmitting means, which may be a transmitter, configured to transmit first QoS setting data identifying the first QoS setting to the PCEF. The receiver is further configured to receive a further notification from the PCEF indicating that the video service has reached a particular stage. The quality determiner is further configured, in response to the further notification, to determine a second QoS setting specifying a lower QoS than the first QoS setting and for streaming the video service after the particular stage. The transmitter is configured to transmit second QoS setting data identifying the second QoS setting to the PCEF.

Optionally, the particular stage of the video service is the end of a buffering phase and/or the beginning of a playout phase. In an embodiment, and generally applicable throughout this specification, the particular stage of the video service may correspond to the end of a buffering phase, the beginning of a playout phase, or any phase close to, or between, them.

Optionally, the receiver is configured to receive playout period data from the PCEF indicating whether the video service is in an on period or an off period of the playout phase, wherein the quality determiner is configured to determine the second QoS setting if the playout period data indicates an on period, and to determine a third QoS setting specifying a lower QoS than the second QoS setting if the playout period data indicates an off period, and wherein the transmitter is configured, if the third QoS setting is determined, to transmit third QoS setting data identifying the third QoS setting to the PCEF.

Optionally, the receiver is further configured to receive subscription information for the user from a Subscription Profile Repository, SPR, the network node further comprising a video service managing means, which may be a video service manager, configured, based on the received subscription information, to determine whether the video service should be monitored to identify one or more particular stages, wherein the transmitter is configured to transmit to the PCEF video service monitoring data identifying whether the video service should be monitored.

Optionally, a lower QoS is specified in a QoS setting with a higher QoS Class Identifier, QCI, value; and wherein a higher QoS is specified in a QoS setting with a lower QCI value.

According to the invention in a further aspect, there is provided a method for operating a network node for use as a Policy and Charging Rules Function, PCRF, in a Policy Charging Control architecture of a telecommunications system. The method comprises receiving, by a receiver from a Policy Control Enforcement Function, PCEF, a notification indicating that a video service has started for streaming video content to a User Equipment, UE, of a user. The method comprises determining, by a quality determiner, a first Quality of Service, QoS, setting for streaming the video service to the UE. The method comprises transmitting, by a transmitter, first QoS setting data identifying the first QoS setting to the PCEF. The method comprises receiving, by the receiver, a further notification from the PCEF indicating that the video service has reached a particular stage. The method comprises determining, by the quality determiner and in response to the further notification, a second QoS setting specifying a lower QoS than the first QoS setting and for streaming the video service after the particular stage. The method comprises transmitting, by the transmitter, second QoS setting data identifying the second QoS setting to the PCEF.

Optionally, the particular stage of the video service is the end of a buffering phase and/or the beginning of a playout phase.

Optionally, the method further comprises receiving, by the receiver from the PCEF, playout period data indicating whether the video service is in an on period or an off period of the playout phase; determining, by the quality determiner, the second QoS setting if the playout period data indicates an on period, or determining, by the quality determiner, a third QoS setting specifying a lower QoS than the second QoS setting if the playout period data indicates an off period; and if the third QoS setting is determined, transmitting, by the transmitter to the PCEF, third QoS setting data identifying the third QoS setting.

Optionally, the method further comprises receiving, by the receiver from a Subscription Profile Repository, SPR, subscription information for the user; determining, by a video service manager and based on the received subscription information, whether the video service should be monitored to identify one or more particular stages; and transmitting, by the transmitter to the PCEF, video service monitoring data identifying whether the video service should be monitored.

Optionally, a lower QoS is specified in a QoS setting with a higher QoS Class Identifier, QCI, value; and wherein a higher QoS is specified in a QoS setting with a lower QCI value.

According to the invention in a further aspect, there is provided a network node for use as a Policy Control Enforcement Function, PCEF, in a Policy Charging Control architecture of a telecommunications system. The network node comprises a video service monitoring means, which may be a video service monitor, configured to determine whether a video service has started for streaming video content to a User Equipment, UE, of a user. The network node comprises a transmitting means, which may be a transmitter, configured to transmit to a Policy and Charging Rules Function, PCRF, a notification indicating that the video service has started. The network node comprises a receiving means, which may be a receiver, configured to receive from the PCRF first Quality of Service, QoS, setting data identifying a first QoS setting for streaming the video service to the UE. The network node comprises a quality assigning means, which may be a quality assigner configured to assign the first QoS setting to the video service. The video service monitor is further configured to monitor video content packets downloaded to the UE from a video server during the video service, and to detect that the video service has reached a particular stage. The transmitter is further configured to transmit a further notification to the PCRF indicating that the particular stage has been reached. The receiver is further configured to receive, from the PCRF, second QoS setting data identifying a second QoS setting that specifies a lower QoS than the first QoS setting. The quality assigner is configured to assign a QoS setting that corresponds to the received second QoS setting data to the video service.

Optionally, the particular stage of the video service is the end of a buffering phase and/or the beginning of a playout phase.

Optionally, the video service monitor is configured to determine that the end of a buffering phase and/or the beginning of a playout phase has been reached based on a rate at which the video content packets are downloaded.

Optionally, the video monitor is configured to determine playout period data indicating whether the video service is in an on period or an off period of the playout phase based on the rate at which the video content packets are downloaded.

Optionally, the transmitter is configured to transmit the playout period data to the PCRF, wherein the receiver is configured to receive third QoS setting data identifying a third QoS setting that specifies a lower QoS than the second QoS setting if the playout period data indicates an off period, and wherein the quality assigner is configured to assign a QoS setting that corresponds to the received third QoS setting data to the video service.

Optionally, a lower QoS is specified in a QoS setting with a higher QoS Class Identifier, QCI, value; and wherein a higher QoS is specified in a QoS setting with a lower QCI value.

Optionally, each QoS setting is associated with particular Radio Access Bearer, RAB, data.

According to the invention in a further aspect, there is provided a method for operating a network node for use as a Policy Control Enforcement Function, PCEF, in a Policy Charging Control architecture of a telecommunications system. The method comprises determining, by a video service monitor, whether a video service has started for streaming video content to a User Equipment, UE, of a user. The method comprises transmitting, by a transmitter to a Policy and Charging Rules Function, PCRF, a notification indicating that the video service has started. The method comprises receiving, by a receiver from the PCRF, first Quality of Service, QoS, setting data identifying a first QoS setting for streaming the video service to the UE. The method comprises assigning, by a quality assigner, the first QoS setting to the video service. The method comprises monitoring, by the video service monitor, video content packets downloaded to the UE from a video server during the video service. The method comprises detecting, by the video service monitor, that the video service has reached a particular stage. The method comprises transmitting, by the transmitter to the PCRF, a further notification indicating that the particular stage has been reached. The method comprises receiving, by the receiver from the PCRF, second QoS setting data identifying a second QoS setting that specifies a lower QoS than the first QoS setting. The method comprises assigning, by the quality assigner, a QoS setting that corresponds to the received second QoS setting data to the video service.

Optionally, the particular stage of the video service is the end of a buffering phase and/or the beginning of a playout phase.

Optionally, the method further comprises determining, by the video service monitor, that the end of a buffering phase and/or the beginning of a playout phase has been reached based on a rate at which the video content packets are downloaded.

Optionally, the method further comprises determining, by the video service monitor, playout period data indicating whether the video service is in an on period or an off period of the playout phase based on the rate at which the video content packets are downloaded.

Optionally, the method further comprises transmitting the playout period data, by the transmitter to the PCRF; receiving, by the receiver, third QoS setting data identifying a third QoS setting that specifies a lower QoS than the second QoS setting if the playout period data indicates an off period; and assigning, by the quality assigner to the video service, a QoS setting that corresponds to the received third QoS setting data.

Optionally, a lower QoS is specified in a QoS setting with a higher QoS Class Identifier, QCI, value; and wherein a higher QoS is specified in a QoS setting with a lower QCI value.

Optionally, each QoS setting is associated with particular Radio Access Bearer, RAB, data.

According to the invention in a further aspect, there is provided a computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out any method described herein.

According to the invention in a further aspect, there is provided a carrier containing the computer program above, wherein the carrier is one of an electronic signal, optical signal, radio signal, or non-transitory computer readable storage medium.

