Abstract: 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.

Abstract: 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.

Abstract: A route-tracing application can measure the performance of a path in a named-data network using trace agents deployed across various network nodes. During operation, a network node can process a route-tracing Interest by performing a lookup operation in a forwarding information base (FIB) using the Interest's name, in which a respective FIB entry may map the name to a forwarding rule. If the FIB does not include an entry for the Interest's route-tracing name, a trace agent at the network node determines one or more outbound interfaces for the route-tracing operation based on the Interest's name, and creates new route-tracing FIB entries that each maps the Interest's name to a forwarding rule for the determined interfaces. The network node returns a Content Object that satisfies the Interest, in which the Content Object includes the names of the new FIB entries, as well as performance information for the path.

Abstract: A route-tracing application can measure the performance of a path in a named-data network using trace agents deployed across various network nodes. During operation, a network node can process a route-tracing Interest by performing a lookup operation in a forwarding information base (FIB) using the Interest's name, in which a respective FIB entry may map the name to a forwarding rule. If the FIB does not include an entry for the Interest's route-tracing name, a trace agent at the network node determines one or more outbound interfaces for the route-tracing operation based on the Interest's name, and creates new route-tracing FIB entries that each maps the Interest's name to a forwarding rule for the determined interfaces. The network node returns a Content Object that satisfies the Interest, in which the Content Object includes the names of the new FIB entries, as well as performance information for the path.

Abstract: A plurality of video streams is transmitted over a transmission link. At intervals, one determines for each video stream at each of a plurality of encoder settings, having regard to the amount of data buffered at a receiver for that stream, a bit rate sufficient to transmit the remainder of that stream at that encoder setting such as to avoid buffer underflow at the receiver. One determines also a critical point equal to the earliest time at which that bit rate can be reduced while still avoiding buffer underflow at the receiver. An encoder setting is chosen for each video stream such that the sum of said bit rates required for transmission of the streams does not exceed the capacity of the transmission link. Any surplus capacity of the transmission link is allocated to the stream that has the earliest critical point.

Abstract: A video sequence is to be transmitted at a selectable quality from a server over a network. A network control protocol operates in response to a control parameter to allocate to the server a share of available transmission capacity in proportion to the value of the control parameter. First, one determines a plurality of transmission rate values that are needed over successive time periods of the sequence for successful transmission of the sequence at a reference quality; then the control parameter is set, proportional to the transmission rate value and communicated to the control protocol at corresponding time instants. The sequences can then be transmitted, encoded at a quality from time to time selected in dependence upon the actual transmission capacity made available by the network to the server.

Abstract: There is proposed a modification to the ECN protocol to remove the one-to-one relationship between the network signalling congestion and the sender response to that congestion. The result is to allow a receiver terminal to exhibit some control of bandwidth share relative to other receiver terminals. The idea is to calculate the average CE arrival frequency from received data packets and to set ECE flags at a rate determined as a function of the average CE arrival frequency. Preferably, the function is a multiplier applied to the average CE arrival frequency. The effect of averaging the CE arrival frequency as well as application of a multiplier is a decoupling of the ECE marked ACKs sent by a receiver to the sender, and control of the resulting transmission rate at the sender.

Abstract: A video sequence is to be transmitted at a selectable quality from a server over a network. A network control protocol operates in response to a control parameter to allocate to the server a share of available transmission capacity in proportion to the value of the control parameter. First, one determines a plurality of transmission rate values that are needed over successive time periods of the sequence for successful transmission of the sequence at a reference quality; then the control parameter is set, proportional to the transmission rate value and communicated to the control protocol at corresponding time instants. The sequences can then be transmitted, encoded at a quality from time to time selected in dependence upon the actual transmission capacity made available by the network to the server.

Abstract: There is proposed a modification to the ECN protocol to remove the one-to-one relationship between the network signalling congestion and the sender response to that congestion. The result is to allow a receiver terminal to exhibit some control of bandwidth share relative to other receiver terminals. The idea is to calculate the average CE arrival frequency from received data packets and to set ECE flags at a rate determined as a function of the average CE arrival frequency. Preferably, the function is a multiplier applied to the average CE arrival frequency. The effect of averaging the CE arrival frequency as well as application of a multiplier is a decoupling of the ECE marked ACKs sent by a receiver to the sender, and control of the resulting transmission rate at the sender.

Abstract: A plurality of video streams is transmitted over a transmission link. At intervals, one determines for each video stream at each of a plurality of encoder settings, having regard to the amount of data buffered at a receiver for that stream, a bit rate sufficient to transmit the remainder of that stream at that encoder setting such as to avoid buffer underflow at the receiver. One determines also a critical point equal to the earliest time at which that bit rate can be reduced while still avoiding buffer underflow at the receiver. An encoder setting is chosen for each video stream such that the sum of said bit rates required for transmission of the streams does not exceed the capacity of the transmission link. Any surplus capacity of the transmission link is allocated to the stream that has the earliest critical point.

Abstract: An index to a plurality of entities is built, where each entity is represented by a point defined in a space. Entities whose points are furthest apart are identified. A first area is created, the extremities of which first area are given by the points representing the identified entities. Entities falling within the first area are assigned to a storage area corresponding to the first area. The first area is divided into a plurality of second areas. For each of the plurality of second areas, a. each of the plurality of second areas is linked to the first area, and, b. the above steps are repeated until the first area includes a single point. Storage areas corresponding to each of the first area are then written to the index.

Abstract: Information sources are selected in accordance with a subject matter of interest to a user, where the subject matter of interest is identifiable by a plurality of sets of subject-related data, and each set has an indication of at least one context in which the set is of interest to the user. The state of the user is tracked, one or more contexts are identified from the tracked state, at least some sets of subject-related data are selected in accordance with a predetermined relationship between at least some of the identified contexts and said indication of context, a list of information sources is generated based on the selected sets of subject-related data, and the list is transmitted to a terminal associated with the user so as to allow the user to select an information source of interest and thereby to access information from the source.

Abstract: A method of changing a user profile involves the system suggesting a change which includes one or more selection choices representative of the suggested change. The user makes one or more selections which results in temporal modification of the user profile. The method further involves monitoring user action in respect of the temporal modification, and, in accordance with the user action satisfying predetermined criteria, permanently changing the user profile based on the user selections.

Abstract: Retrieving points that can be plotted in a predetermined area are achieved where the locations of the points are indexed in an index that includes regional data. The regional data defines a plurality of regions, and each region encompasses one or more of the points. In addition, the index includes linking data, which, for each region, identifies the point or points encompassed by that region. The method includes (i) reviewing the regional data in the index to identify regions that are wholly contained by the predetermined area; and (ii) reviewing the linking data to retrieve points encompassed by the identified regions.

Abstract: The invention is concerned with a method of selecting information sources in accordance with a subject matter of interest to a user, where the subject matter of interest is identifiable by a plurality of sets of subject-related data, and each set has an indication of at least one context in which the set is of interest to the user.

Abstract: The invention is concerned with a method of building an index to a plurality of entities, where each entity is represented by a point defined in a space.

Abstract: The invention is concerned with a method of changing a profile representing subject matter of interest to a user, where the profile includes a plurality of sets of subject-related data.

Abstract: The present invention relates to a method of retrieving points that can be plotted in a predetermined area, where the locations of the points are indexed in an index that comprises regional data. The regional data defines a plurality of regions, and each region encompasses one or more of the points. In addition, the index comprises linking data, which, for each region, identifies the point or points encompassed by that region.

Abstract: In a telecommunications network, such as the public switched telephone network, account must be taken of faults which can occur in the network. For instance, on occurrence of a local exchange failure, it is known to apply control such as route gapping and code blocking. The invention is concerned with detection of failure of a local exchange (116, 118) in a communications network. It relies on a combination of parameters, each parameter in the combination having to meet predetermined criteria. In particular, a local exchange failure is recognized when the Bids per Circuit per Hour (BCH) along selected traffic routes exceed a first threshold and the magnitude of a decrease in the average Answer Seizure Ratio (ASR) on selected traffic routes exceeds a second threshold. Controls might be applied to parent or far-end trunk exchanges, and can be removed when the ASR and Percentage Occupancy (OCC) meet further criteria.