Abstract:
The invention refers to supporting a communication established between a first mobile terminal (18) towards a telecommunications network (1), the telecommunications network (1) comprising a first radio access network (13) and a second radio access network (14) and an application server (10), wherein the application server performs the steps of receiving an identifier that a session setup was initiated with respect to the first mobile terminal (18), wherein the identifier is adapted to identify the session, entering the identifier into an identifier list comprising one or a plurality of a identifiers for identifying sessions with respect to the first mobile terminal (18), receiving an indication of a session transfer form the first radio access network (13) to the second radio access network (14) or vice versa, and providing the identifier list in response to the indication. The invention further refers to an application server (10) and corresponding computer program.
Abstract:
The present invention relates to methods for improving speech quality in e.g. an IP-telephony system. The invention reduces audio artefacts being due to overrun or underrun in a playout buffer caused by the sampling rates at a sending and receiving side not being at the same rate. The inventive solution modifies an LPC-residual on a sample-by-sample basis. The LPC-residual block comprising N samples is converted to a block comprising N+1 or N-1 samples. A sample rate controller 400 decides whether samples should be added to or removed from the LPC-residual. The exact position where to add respective remove samples is either chosen arbitrarily or found by searching for low energy segments in the LPC-residual. A speech synthesiser module 430 then reproduces the speech. By using the proposed sample rate conversion method the playout buffer 440 can be continuously controlled. Furthermore, since the method works on a sample-by-sample basis the buffer can be kept to a minimum and hence no extra delay is introduced.
Abstract:
The present invention relates to a receiver system in a communication system supporting packet-based communicatior (e.g., an IP-network), including a receiver, speech decoder ( 40 ) and a jitter buffer ( 20 ) for handling delay variations in the reception of a speech signal consisting of packets containing frames with encoded speech. A jitter buffer controller ( 50 ) is provided for keeping information about the functional size of the jitter buffer ( 20 ) and for providing the speech decoder ( 40 ) with control information, such that the speech decoder ( 40 ), based on that information. provides a dynamic adaptation of the size of the jitter buffer ( 20 ) using the received encoded, packetized speech signal. The invention also relates to a method of adapting the functional size of the jitter buffer of a receiver system.
Abstract:
The invention is concerned with a method and an apparatus, wherein information data is sent between at least two transceivers in a telecommunication system. The information data is transmitted from the sender of a transceiver to the receiver of one or more other transceivers in form of digital signals having a given sampling frequency. The signals are played out by the receiver in a controlled way. The invention is mainly characterized by estimation of the sender's sampling rate at the sending side of a transceiver, transmitting the estimation to the receiving side of an another transceiver, and controlling the playout of the information data at the receiving side by means of the sampling rate estimated at the sending side to avoid delays and/or interrupts in the presentation. The invention is especially suitable in connection with packet based networks wherein the information data is sent between the transceivers in the telecommunication system in form of packet data frames, such as audio frames.
Abstract:
The invention is concerned with a method and an apparatus, wherein information data is sent between at least two transceivers in a telecommunication system. The information data is transmitted from the sender of a transceiver to the receiver of one or more other transceivers in form of digital signals having a given sampling frequency. The signals are played out by the receiver in a controlled way. The invention is mainly characterized by estimation of the sender's sampling rate at the sending side of a transceiver, transmitting the estimation to the receiving side of an another transceiver, and controlling the playout of the information data at the receiving side by means of the sampling rate estimated at the sending side to avoid delays and/or interrupts in the presentation. The invention is especially suitable in connection with packet based networks wherein the information data is sent between the transceivers in the telecommunication system in form of packet data frames, such as audio frames.
Abstract:
An improved forward error correction (FEC) technique for coding speech data provides an encoder module which primary-encodes an input speech signal using a primary synthesis model to produce primary-encoded data, and redundant-encodes the input speech signal using a redundant synthesis model to produce redundant-encoded data. A packetizer combines the primary-encoded data and the redundant-encoded data into a series of packets and transmits the packets over a packet-based network, such as an Internet Protocol (IP) network. A decoding module primary-decodes the packets using the primary synthesis model, and redundant-decodes the packets using the redundant synthesis model. The technique provides interaction between the primary synthesis model and the redundant synthesis model during and after decoding to improve the quality of a synthesized output speech signal. Such "interaction," for instance, may take the form of updating states in one model using the other model.
Abstract:
The present invention relates to a receiver system in a communication system supporting packet-based communicatior (e.g., an IP-network), including a receiver, speech decoder ( 40 ) and a jitter buffer ( 20 ) for handling delay variations in the reception of a speech signal consisting of packets containing frames with encoded speech. A jitter buffer controller ( 50 ) is provided for keeping information about the functional size of the jitter buffer ( 20 ) and for providing the speech decoder ( 40 ) with control information, such that the speech decoder ( 40 ), based on that information. provides a dynamic adaptation of the size of the jitter buffer ( 20 ) using the received encoded, packetized speech signal. The invention also relates to a method of adapting the functional size of the jitter buffer of a receiver system.
Abstract:
A method for presentation of media objects of a multimedia presentation document (104) in a device (105) for presentation of such documents. The media objects are stored in storage means (102), which are remotely located from said device (105) and connected to a network infrastructure (103). The method comprises the steps of: providing said multimedia presentation document with metadata relating to properties of the media objects; processing said metadata in the presentation device (105); determining when to fetch each of said media objects from the storage means (102) to the presentation device (105) via the network infrastructure (103) based on said processing; fetching the media objects from the storage means (102) at the determined moments and presenting the fetched media objects in the presentation device (105). The invention also relates to a multimedia presentation system, a multimedia presentation document, a computer program product and a multimedia presentation device.
Abstract:
A method for presentation of media objects of a multimedia presentation document (104) in a device (105) for presentation of such documents. The media objects are stored in storage means (102), which are remotely located from said device (105) and connected to a network infrastructure (103). The method comprises the steps of: providing said multimedia presentation document with metadata relating to properties of the media objects; processing said metadata in the presentation device (105); determining when to fetch each of said media objects from the storage means (102) to the presentation device (105) via the network infrastructure (103) based on said processing; fetching the media objects from the storage means (102) at the determined moments and presenting the fetched media objects in the presentation device (105). The invention also relates to a multimedia presentation system, a multimedia presentation document, a computer program product and a multimedia presentation device.