Abstract: Synchronizing uplink and downlink transmissions by a wireless user equipment (UE) device. A connection with a network may be established via a wireless link with a cell. The UE may operate in an active state during first periods of time in which uplink or downlink communications may be performed between the UE and the network. The UE may operate in a reduced-power state during second periods of time in which uplink and downlink communications are not performed. The first periods of time may alternate with the second periods of time in a repeating manner. Uplink data generated by the UE may be buffered during second periods of time and transmitted during first periods of time. Buffering uplink data in this manner may prevent the UE from immediately transitioning from the reduced-power state to the active state to transmit uplink data, which may conserve battery of the UE.

Abstract: A method and apparatus for adapting transmission to improve quality of service in a mobile wireless device that includes an application processor and a transceiver. An application service connection is established between the mobile wireless device and a remote device. The transceiver in the mobile wireless device monitors real time properties of a radio frequency access link that transports packets for the application service between the mobile wireless device and a wireless communication network. The transceiver provides local feedback to the application processor of updated values of the monitored real time properties. The application processor adjusts packet data generation and transmission in response to the updated values to manage quality of service for the application service connection.

Abstract: Some embodiments provide an architecture for establishing multi-participant video conferences. This architecture has a central distributor that receives video images from two or more participants. From the received images, the central distributor generates composite images that the central distributor transmits back to the participants. Each composite image includes a set of sub images, where each sub image belongs to one participant. In some embodiments, the central distributor saves network bandwidth by removing each particular participant's image from the composite image that the central distributor sends to the particular participant. In some embodiments, images received from each participant are arranged in the composite in a non-interleaved manner. For instance, in some embodiments, the composite image includes at most one sub-image for each participant, and no two sub-images are interleaved.

Abstract: A first computing device distributes audio signals to several computing devices of participants in a communication session. In some embodiments, the first computing device serves as a central distributor for receiving audio signals from other computing devices, compositing the audio signals and distributing the composited audio signals to the other computing devices. The first computing device prioritizes the received audio signals based on a set of criteria and selects several highly prioritized audio signals. The first computing device generates composite audio signals using only the selected audio signals. The first computing device sends each computing device the composited audio signal for the device. In some cases, the first computing device sends a selected audio signal to another computing device without mixing the signal with any other audio signal.

Abstract: A step-wise approach to automatically determining the bandwidth of a communication channel includes dividing the channel's potential bandwidth into a number of ranges. An initial range is then selected and a series of data packets specific to the selected range are transmitted from a first endpoint to a second endpoint, with the second endpoint determining one or more channel metrics based on the transmitted packets (e.g., measured transmission rates). If the metrics indicate the current range accurately reflects the channel's bandwidth, a measured transmission rate of the transmitted data packets is used as the channel's bandwidth. Otherwise, another range is selected and the process is repeated. The described approach rapidly determines channel bandwidth, even when the channel between the two endpoints is asymmetric. Techniques described herein are particularly beneficial when used in conjunction with multimedia conferencing applications.

Abstract: Coded video data may be transmitted between an encoder and a decoder using multiple FEC codes and/or packets for error detection and correction. Only a subset of the FEC packets need be transmitted between the encoder and decoder. The FEC packets of each FEC group may take, as inputs, data packets of a current FEC group and also an untransmitted FEC packet of a preceding FEC group. Due to relationships among the FEC packets, when transmission errors arise and data packets are lost, there remain opportunities for a decoder to recover lost data packets from earlier-received FEC groups when later-received FEC groups are decoded. This opportunity to recover data packets from earlier FEC groups may be useful in video coding and other systems, in which later-received data often cannot be decoded unless earlier-received data is decoded properly.

Abstract: An apparatus and method for detecting and analyzing spikes in network jitter and the estimation of a jitter buffer target size is disclosed. Detected spikes may be classified as jump spikes or slope spikes, and a clipped size of detected spikes may be used in the estimation of the jitter buffer target. Network characteristics and conditions may also be used in the estimation of the jitter buffer target size. Samples may be modified during playback adaptation to improve audio quality and maintain low delay of a receive chain.

Abstract: Synchronizing uplink and downlink transmissions by a wireless user equipment (UE) device. A connection with a network may be established via a wireless link with a cell. The UE may operate in an active state during first periods of time in which uplink or downlink communications may be performed between the UE and the network. The UE may operate in a reduced-power state during second periods of time in which uplink and downlink communications are not performed. The first periods of time may alternate with the second periods of time in a repeating manner. Uplink data generated by the UE may be buffered during second periods of time and transmitted during first periods of time. Buffering uplink data in this manner may prevent the UE from immediately transitioning from the reduced-power state to the active state to transmit uplink data, which may conserve battery of the UE.

Abstract: A method for adaptive audio codec selection during a communication session is disclosed. The method can include negotiating a set of audio codecs for use during the communication session. The method can further include defining multiple audio tiers. Each audio tier can be associated with a network condition and can define an audio codec from the set of audio codecs for use in the associated network condition. The method can also include using a first audio codec during the wireless communication session. The method can additionally include determining a changed network condition selecting a second audio codec by determining the audio tier corresponding to the changed network condition. The method can further include, in response to the changed network condition, switching from the first audio codec to a second audio codec that is defined by an audio tier having an associated network condition corresponding to the changed network condition.

Abstract: In video conferencing over a radio network, the radio equipment is a major power consumer especially in cellular networks such as LTE. In order to reduce the radio power consumption in video conferencing, it is important to introduce an enough radio inactive time. Several types of data buffering and bundling can be employed within a reasonable range of latency that doesn't significantly disrupt the real-time nature of video conferencing. In addition, the data transmission can be synchronized to the data reception in a controlled manner, which can result in an even longer radio inactive time and thus take advantage of radio power saving modes such as LTE C-DRX.

Abstract: A method for detecting and recovering from a transmission channel change during a streaming media session is disclosed. The method can include a wireless communication device detecting a stall condition resulting from a transmission channel change. The method can further include the wireless communication device capturing a snapshot of a current transmission parameter state of the streaming media session in response to detecting the stall condition. The method can also include the wireless communication device using the snapshot to restore the streaming media session to the transmission parameter state captured by the snapshot following completion of the transmission channel change.

Abstract: A method for refreshing blocked media packets for a streaming media session over a wireless network in a stall condition is disclosed. The method can include a wireless communication device maintaining a buffer at an application layer. The buffer can contain at least a portion of media packets provided to a baseband layer by the application layer for transmission. Media packets provided to the baseband layer can be queued in a baseband queue prior to transmission. The method can further include the wireless communication device generating at least one new media packet for the streaming media session during the stall condition; flushing at least a portion of the media packets queued in the baseband queue; and replenishing the baseband queue by providing the baseband layer with at least a portion of the media packets contained in the buffer and at least one new media packet.

Abstract: Methods for establishing a direct peer-to-peer (“P2P”) connection between two computers are disclosed. In particular, the methods are designed to work in cases where one or both of the computers are connected to a private network, such private networks being interconnected via a public network, such as the Internet. The connections between the private network and the public network are facilitated by network address translation (“NAT”).

Abstract: Some embodiments provide an architecture for establishing a multi-participant conference. This architecture has one participant's computer in the conference act as a central content distributor for the conference. The central distributor receives data (e.g., video and/or audio streams) from the computer of each other participant, and distributes the received data to the computers of all participants. In some embodiments, the central distributor receives A/V data from the computers of the other participants. From such received data, the central distributor of some embodiments generates composite data (e.g., composite image data and/or composite audio data) that the central distributor distributes back to the participants.

Abstract: Some embodiments use several different types of networks to relay several different types of media content among several different computing devices. The media content of some embodiments is data that a computing device can process in order to provide a presentation of the media content to a user of the device. Examples of types of such media content include audio data, video data, text data, picture data, game data, and/or other media data. In some embodiments, two different networks relay media content of two different types among multiple computing devices. Specifically, in some embodiments, a first network routes among the computing devices one type of media data content (e.g., game data), while a second network routes among the computing devices another type of media data content (e.g., audio and/or video data of game participants). The two networks differ in some embodiments based on their topology.

Abstract: A video coding system and method for increasing a transmitted output bit rate of a video encoding system by altering the content of the bit stream. A video encoder may receive a coding mode signal from a computer application for coding source video data, the coding mode signal indicating a target bit rate having a risk factor related to transmission error associated to the target bit rate. The coded bitstream may be modified based on the risk factor indicated in the coding mode signal. A modified coded bitstream may be outputted at the target bit rate and at a reduced coding efficiency, and the channel may be tested for transmission errors. Based on the test results, a revised coding mode signal indicating the same target bit rate, but a revised risk factor may be provided. The coded bitstream may be revised by removing the modifications previously made to the coded bitstream and a revised coded bitstream having greater coding efficiency may be output at the target bit rate.

Abstract: Some embodiments provide an architecture for establishing multi-participant video conferences. This architecture has a central distributor that receives video images from two or more participants. From the received images, the central distributor generates composite images that the central distributor transmits back to the participants. Each composite image includes a set of sub images, where each sub image belongs to one participant. In some embodiments, the central distributor saves network bandwidth by removing each particular participant's image from the composite image that the central distributor sends to the particular participant. In some embodiments, images received from each participant are arranged in the composite in a non-interleaved manner. For instance, in some embodiments, the composite image includes at most one sub-image for each participant, and no two sub-images are interleaved.

Abstract: Some embodiments provide a method for encoding digital video. The method receives a digital video image. The method encodes the digital video image. The method generates error correction information for the encoded digital video image using only data from the encoded digital video image. The method transmits the generated error correction information with the encoded digital video image. In some embodiments, the method determines a level of error protection for the encoded digital video image based on an image type of the encoded digital video image.

Abstract: A method and apparatus of a device that distinguishes multiplexed media and signaling data traffic is described. In an exemplary embodiment, the device receives, on a single port, a packet of the multiplexed data traffic, where the multiplexed data traffic includes a plurality of packets and each of the plurality of packets is one of a media packet and an encapsulated signaling packet. The device further examines an initial data element of a header of the received packet to determine if the received packet is one of a media packet and a signal packet. The device further forwards the packet to a corresponding module for further processing based on the examining.

Abstract: Some embodiments provide an architecture for establishing a multi-participant conference. This architecture has one participant's computer in the conference act as a central content distributor for the conference. The central distributor receives data (e.g., video and/or audio streams) from the computer of each other participant, and distributes the received data to the computers of all participants. In some embodiments, the central distributor receives A/V data from the computers of the other participants. From such received data, the central distributor of some embodiments generates composite data (e.g., composite image data and/or composite audio data) that the central distributor distributes back to the participants.