British Telecommunications Public Limited Company

Timothy Sean Stevens

Rory Stewart Turnbull

Stephen Clifford Appleby

Ian Christopher Kegel

Ian Barry Crabtree

Michael Erling Nilsson

Andrew Gordon Davis

Jeremy M Thorne

Jason Morphett

Martin Russ

Brahim Allan

Ivan Roper

Andrew Wills

Douglas L Williams

Joshan Meenowa

Adam Hay

Dale Robertson

Alex Sj Palmer

Philip Coackley

Louie Ks Lim

Ludvig Lohse

Michael Eilling Nilsson

Described is a method of delivering content over a network using an approach referred to as 'Multicast Assisted Unicast Delivery' (MAUD), as a multicast network is used to assist, rather than substituting for, an otherwise unicast path. Content is requested by client devices from a content server over unicast. The responses containing the requested content are separated into two components: a first component containing elements that are specific to individual client devices (for example session specific data), and a second component that is common to all client devices (typically this is the video content being requested). The first component can be delivered over unicast and the second component over multicast. Identifiers are introduced into each of the first and second components to aid recombination of the components to form the original responses. The separation and recombination are handled by suitably configured proxy servers.

Multicast assisted delivery

Described is a method of delivery of content to a client device. In particular, the method can be applied to hybrid unicast/multicast delivery networks, where content is provided by a content server to a root proxy, and that root proxy delivers the content to edge proxies over multicast. However, requests for that content in the form of HTTP GET requests from a client device are received by an edge proxy, which subsequently sends an HTTP HEAD request for header information associated with that content directly to the content server. The content server responds over unicast with a suitable response to the HTTP HEAD request, which is received by the edge proxy. The edge proxy takes the response together with the payload from the content segment received over multicast, to generate a client specific content segment for delivery to the client device over unicast.

Content delivery

Described is a method of managing a network for delivering content in a hybrid unicast/multicast network, where content is requested by clients over unicast, but all or some of the content is delivered in part over multicast. A client requests content (in the form of segments) and receive the responses (segments) over unicast via a first proxy. The first proxy measures the time between requests and associated requested segment sizes. These measurements are used to effectively determine a unicast request rate given by the segment size divided by the time between requests. Subsequent requested segments can then be delivered over multicast over a portion of the route to the client using a multicast rate that is set as a function of (for example, 110% of) the unicast request rate. In general, the multicast path will be from a second proxy to the first proxy.

Presented are methods for converting a multicast media stream to unicast segments, for delivery over generic IP networks such the Internet. The unicast segments can be converted back again to a multicast stream that is identical to the original multicast stream closer to the consuming client device. Information required to regenerate a multicast stream from the generated unicast segments that is identical to the original multicast stream is also encoded into the file name of the generated unicast segments. Additionally, RTP header information from the multicast stream that is not required when the unicast segments are generated are stored in files linked to the generated unicast segments, enabling the multicast stream that is regenerated to be identical to the original multicast stream even at the RTP level.

Multicast to unicast conversion

Examples of the present invention provide a method of converting a multicast stream into unicast segments. In particular, sequence identifiers are generated based on a clock reference field in the transport stream packets that make up the multicast stream. Every time a new sequence identifier is calculated, a new unicast segment is generated and assigned with the new sequence identifier. Transport stream packets are placed into the new segment until a packet is processed that causes a new sequence identifier to be generated, at which point another new segment is generated and packets placed into that segment. In an improved method, random access indicators in the transports stream packets are used to further constrain when a new segment is generated, to ensure that new segments are coincident with a packet having a random access indicator. This improvement makes random access easier back and forth between and within a stream.

Methods, apparatus and systems are disclosed for managing streamed communication (such as video, audio, or audio-visual communication) between client devices and remote devices via a digital data communication network in situations where the data communication network comprises one or more routers operable to receive streamed data from one or more client devices and/or from one or more other routers, and to forward such streamed data to one or more remote devices and/or to one or more other routers such as to enable the client device and potentially-varying subsets of the one or more remote devices to participate in a communication session.

Managing streamed communication

A wireless access point () connected to a fixed telecommunications network () broadcasts codes relating to one or more network identities () identifying availability of wireless connection to the access point, If connection to the telecommunications network () is lost, it suspends one of the identity codes () and replaces it with a special identity code for a network identity () configured to co-operate with a mobile terminal () equipped to recognize the special identity code and transmit a message over another communications link () to alert a service center () to the fault ().

Network access fault reporting

Examples of the present invention present a method of controlling content delivery in a network. A global quality of experience measure, QoE, is calculated based on the packet loss rate in the network. As packet loss rate varies as a result of congestion conditions in the network, so will QoE. A server delivering content over the network will attempt to reach QoEfor the content in its respective session. Those sessions with a quality of experience, QoE, less than QoEwill have its packet dispatch rate increased, and those with a QoE higher than QoEwill reduce its packet dispatch rate, subject to any delivery deadlines associated with the session. If the delivery deadlines of the sessions can be met without exceeding QoE, then all sessions will end up achieving QoE. Since QoEis only a function of packet loss rate that all sessions miming over the same shared network agree upon, all sessions should converge on the same QoE.

Deadline driven content delivery

The invention presents a method of providing a modified manifest to a video client for streaming a video sequence associated with the manifest. An original manifest is modified to replace references to locations of lower quality, or bit rate, segments with references to equivalent segments at a higher quality, or bit rate, if the higher quality segment is cached locally. Then, when the video client determines that a given quality of segment should be streamed, it uses the modified manifest to retrieve the appropriate reference for that segment, and if a replacement has taken place, will be provided with the reference to the replacement segment at the higher quality. Thus, the client will always be provided with the highest possible quality segment taking into account local caching.

Video caching

A loss of connection between a wireless access point and a network is reported to a network-based service platform by the wireless access point by automatically establishing wireless contact with a second wireless access point, and transmits a predetermined fault report message to a predetermined network platform address by way of the second wireless access point and the second network interface. Authentication credentials are stored in the access point allowing automatic access to the service platform without user intervention, to allow the report to be generated without user intervention. The message may include data on recent usage of the access point, or may be repeated when a user attempts to use the access point, in order to prioritize the fault reported at the service platform.

A method and apparatus for encoding media content. In the field of video compression, temporal compression generates I-frames and dependent P-frames and B-frames. The placement of I-frames is determined by the presence of scene switches in the video. In order to improve the ability of a user to seek to interesting parts of the video, a video encoder considers semantic data identifying narrative points of interest within the video. The encoding process generates encoded video data having I-frames present at scene transitions and also at narratively interesting parts of the video.

Media data encoding apparatus and method

Metadata is associated with media elements in a content store during automatic composition of media articles. The metadata includes relationship data indicating how what is portrayed by that media element relates to what is portrayed by one or more other media elements. Because relationship metadata is included media articles can be generated automatically with the need for the production of a detailed framework describing that media article.

Automatic media article composition using previously written and recorded media object relationship data

A computer apparatus which uses a database () to offer persistent storage of metadata () describing the content of media files (). Metadata is used to create a personalized media article () from those media files. That metadata also indicates relationships between those media files. In order to accelerate the creation of the personalized media article (), media element metadata items are stored in a cache. The usefulness of this cache is improved further by reading related media elements data from retrieved metadata items (), and then pre-fetching those items and placing them in the cache. Because the relatedness of the data items means that the related data item is more likely to be required in the near future, the caching method is more useful than known caching methods. Furthermore, the improved usefulness of the cache is achieved without placing constraints on where the data items are placed in the persistent storage.

Growing community of inventors

Woodbridge, United Kingdom

Timothy Sean Stevens