Abstract: The present invention relates to a method and a communication system for transmission of multimedia streams. Multimedia streams are transmitted in the communication system from a sending communication device to a receiving communication device at least partly via a wireless communication network. Information about the multimedia stream is transmitted to the receiving communication device comprising at least one parameter of the transmission of the multimedia stream for reservation of network resources. The parameter is the maximum bit rate which is needed for the transmission or the maximum service data unit size to be used in the transmission. It is also possible that both the mentioned parameters will be transmitted as attributes of the session description protocol. In an advantageous embodiment the receiving communication device informs the sending communication device about the QoS profile parameters which the wireless communication network granted for the transmission.

Abstract: A method and system for adaptively controlling level of a receiver buffer in a client in a multimedia streaming network. The multimedia streaming network has a server for providing streaming data to the client. The server is responsible for adapting the transmission rate to the reception rate or congestion control, and for adapting the sampling rate to the transmission rate. Thus, the server manages the shift and keeps it within the rate adaptation operating range. The client is responsible for compensating for the packet transfer delay variation, which is also known as network jitter. The client is also responsible for setting parameters of the server rate adaptation operating range. The client chooses and sends the shift parameters to the server, but it is up to the server to adapt its encoding rate or transmission rate when responding to the parameters.

Abstract: The present invention relates to a method for transmitting video information, in which a bitstream is formed comprising a set of frames comprising macroblocks. At least one switching frame is formed into the bitstream, macroblocks of the switching frame are arranged into a first and a second group of macroblocks, each macroblock of the first group of macroblocks are encoded by a first encoding method to provide a switching point for continuing the transmission of video information with another bitstream formed from the video information; and macroblocks of the second group of macroblocks are encoded by another encoding method. Errors in transmission of video information are reduced by forming at least one SP-encoded frame by predictively encoding the macroblocks; replacing part of the SP-encoded macroblocks with intra encoded blocks; and transmitting the encoded frame containing both predictively and intra encoded macroblocks instead of the SP-encoded frame.

Abstract: A method to provide to a sender of RTP packets the actual receiver buffer fullness level in a receiver of the RTP packets at a certain time instant represented as remaining playout duration in time. The receiver sends in an RTCP report the sequence number of a selected RTP packet in the receiver buffer and the time difference between the scheduled playout time of this packet and the current time. Based on this timing information, the sender calculates the amount of time it would take for the receiver buffer to empty if the receiver continues to playout at normal speed and no further RTP packets arrive to the receiver buffer. This receiver buffer fullness level information can be used at the sender to adjust the transmission rate and/or nominal playout rate of the RTP packets in order to maintain a targeted receiver buffer fullness level.

Abstract: A method for the client in a multimedia streaming network to control the receiver buffer fullness by way of effectively shifting the transmission clock in the server who provides streaming data to the client. In order to avoid buffer underflow or overflow, the client sends a message to the server requesting the shift of the transmission clock either forward or backward depending on whether the client wants to increase or decrease the receiver buffer. Based on the message, the server adjusts the data transmission amount by effectively shifting its transmission clock. The request from the client can be sent through RTCP or RTSP.

Abstract: The invention relates to a method for packet switched streaming of media, such as video and/or audio, from a streaming server (111) to a mobile client device (101) over an air-interface. The method comprises noticing a change in a downlink air-interface bandwidth, sending from the mobile client device (101) to the streaming server (111) a request for adapting streaming server transmission bit rate, receiving the request at the streaming server (111) and adapting the streaming server transmission bit rate in accordance with the request. According to the method, the request indicates to the streaming server (111) a current downlink air-interface bandwidth and that said adapting of the streaming server transmission bit rate is performed in accordance with said current downlink air-interface bandwidth.

Abstract: A method and system for adaptively controlling level of a receiver buffer in a client in a multimedia streaming network. The multimedia streaming network has a server for providing streaming data to the client. The server is responsible for adapting the transmission rate to the reception rate or congestion control, and for adapting the sampling rate to the transmission rate. Thus, the server manages the shift and keeps it within the rate adaptation operating range. The client is responsible for compensating for the packet transfer delay variation, which is also known as network jitter. The client is also responsible for setting parameters of the server rate adaptation operating range. The client chooses and sends the shift parameters to the server, but it is up to the server to adapt its encoding rate or transmission rate when responding to the parameters.

Abstract: The present invention relates to a method for transmitting video information, in which a bitstream is formed comprising a set of frames comprising macroblocks. At least one switching frame is formed into the bitstream, macroblocks of the switching frame are arranged into a first and a second group of macroblocks, each macroblock of the first group of macroblocks are encoded by a first encoding method to provide a switching point for continuing the transmission of video information with another bitstream formed from the video information; and macroblocks of the second group of macroblocks are encoded by another encoding method. Errors in transmission of video information are reduced by forming at least one SP-encoded frame by predictively encoding the macroblocks; replacing part of the SP-encoded macroblocks with intra encoded blocks; and transmitting the encoded frame containing both predictively and intra encoded macroblocks instead of the SP-encoded frame.

Abstract: A method for signaling and negotiation between a resource-limited client and a server in a multimedia streaming service regarding packet data delivery. In order to avoid dropping packets at the client side due to its maximum packet rate capability, the client signals to the server declaring the maximum packet rate capability. This capability can be signaled to the client via a capability exchange mechanism or using a multimedia streaming protocol. The client inserts a parameter indicative of the maximum packet data rate capability in a request sent to server. It is up to the server to take the necessary action and make the packet delivery rate adjustment.

Abstract: A method of signaling and negotiation between a client and a server in a multimedia streaming service regarding the adaptation of the data delivery process. In order to make sure that the client supports the adaptation mechanisms or capabilities to be used in data delivery, one of the parties provides information indicating the adaptation mechanism or capability that it supports to the other party. Upon receiving the information, the other party uses well-defined RTSP response to indicate the support of that mechanism or capability. Either the server or the client can initiate the negotiation. The implementation of the signaling and negotiation covers an AVPF usage, RTP Retransmission Playload Format usage, and an SPTP usage in a particular 3G PSS session.

Abstract: A method for the client in a multimedia streaming network to control the receiver buffer fullness by way of effectively shifting the transmission clock in the server who provides streaming data to the client. In order to avoid buffer underflow or overflow, the client sends a message to the server requesting the shift of the transmission clock either forward or backward depending on whether the client wants to increase or decrease the receiver buffer. Based on the message, the server adjusts the data transmission amount by effectively shifting its transmission clock. The request from the client can be sent through RTCP or RTSP.

Abstract: A method to provide to a sender of RTP packets the actual receiver buffer fullness level in a receiver of the RTP packets at a certain time instant represented as remaining playout duration in time. The receiver sends in an RTCP report the sequence number of a selected RTP packet in the receiver buffer and the time difference between the scheduled playout time of this packet and the current time. Based on this timing information, the sender calculates the amount of time it would take for the receiver buffer to empty if the receiver continues to playout at normal speed and no further RTP packets arrive to the receiver buffer. This receiver buffer fullness level information can be used at the sender to adjust the transmission rate and/or nominal playout rate of the RTP packets in order to maintain a targeted receiver buffer fullness level.

Abstract: Apparatus, and an associated method, for selecting the encoding bit rate at which an encoder encodes selected video frames of a sequence of video frames at a video sending device. Selection is made to provide a constant-consistency quality level and constant frame rate of display of the video frames at a video receiving device. Selection of the encoding bit rate is made responsive to a targeted frame rate and allowable communication rates upon a communication channel upon which encoded representations of the video frames are to be communicated.

Abstract: The present invention relates to a method and a communication system for transmission of multimedia streams. Multimedia streams are transmitted in the communication system from a sending communication device to a receiving communication device at least partly via a wireless communication network. Information about the multimedia stream is transmitted to the receiving communication device comprising at least one parameter of the transmission of the multimedia stream for reservation of network resources. The parameter is the maximum bit rate which is needed for the transmission or the maximum service data unit size to be used in the transmission. It is also possible that both the mentioned parameters will be transmitted as attributes of the session description protocol. In an advantageous embodiment the receiving communication device informs the sending communication device about the QoS profile parameters which the wireless communication network granted for the transmission.

Abstract: The invention relates to a method for packet switched streaming of media, such as video and/or audio, from a streaming server (111) to a mobile client device (101) over an air-interface. The method comprises noticing a change in a downlink air-interface bandwidth, sending from the mobile client device (101) to the streaming server (111) a request for adapting streaming server transmission bit rate, receiving the request at the streaming server (111) and adapting the streaming server transmission bit rate in accordance with the request. According to the method, the request indicates to the streaming server (111) a current downlink air-interface bandwidth and that said adapting of the streaming server transmission bit rate is performed in accordance with said current downlink air-interface bandwidth.

Abstract: A method and device for enabling packet transfer delay compensation in multimedia streaming. In order to enable a streaming server to optimally operate its rate-control and rate-shaping algorithms to compensate for packet transfer delay variation, information indicative of jitter buffering capabilities of the streaming client is conveyed to the streaming server. The information contains the client's chosen pre-decoding parameters so that the client's jitter buffering capabilities can be determined by the server based on the difference between the client's chosen pre-decoding parameters and the pre-decoding buffering parameters provided by the streaming server.

Abstract: The invention relates to a method for transmitting video images between video terminals (1, 1′) in a data transmission system. Video images comprise frames (T0, T1,. . . T9), which are divided into slices (S1-S8, SX). Every frame (T0, T1, . . . , T9) comprises at least two slices (S5, S3, S6; S1, SX, S2; S7, S4, S8) which are at least partly adjacent to each other, and consecutive frames (T0, T1, . . . , T9) have corresponding slices (S5, S1, S7; S3, SX, S4; S6, S2, S8). The slices (S1-S8, SX) are interleaved into packets, and the packets are transmitted. The interleaving is performed in such a way that adjacent slices (SX, S1; SX, S2) in the same frame (T1) are transmitted in different packets, and that corresponding slices (S5, S1, S7; S3, SX, S4; S6, S2, S8) of two consecutive frames (T0, T1, T2) of video images are transmitted in different packets.

Abstract: Apparatus, and an associated method, for selecting the encoding bit rate at which an encoder encodes selected video frames of a sequence of video frames at a video sending device. Selection is made to provide a constant-consistency quality level and constant frame rate of display of the video frames at a video receiving device. Selection of the encoding bit rate is made responsive to a targeted frame rate and allowable communication rates upon a communication channel upon which encoded representations of the video frames are to be communicated.