Abstract: In one embodiment of the invention, service providers generate bloom filters with the user ID codes of registered users and exchange the bloom filters with one another. In response to a request to locate a first user, a first service provider will query its own registration database to determine if the first user is registered with the first service provider. If the first user is not registered with the first service provider, then the first service provider will query its bloom filters to identify other service providers with which the first user may be registered. A positive response from a bloom filter indicates that the first user may or may not be registered with the service provider associated with that bloom filter, and a negative response indicates with certainty that the first user is not registered with the service provider associated with that bloom filter.

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 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. The central distributor in some embodiments can implement a heterogeneous audio/video conference. In such a conference, different participants can participate in the conference differently. For instance, different participants might use different audio or video codecs.

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: 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: 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: 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: 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: 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: 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: 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: 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 a method for modifying a composite display of a first mobile device that is engaged in a video conference with a second device. The method presents, on the first device, the composite display having a first video captured by the first device and a second video captured by the second device. The method receives, at the first device, an input for modifying the composite display during the video conference. The method modifies the composite display based on the received input.

Abstract: Some embodiments provide a method for managing a video conference between a first device and a second device. The method identifies a first ceiling bit rate for transmitting video conference data to the second device through the communication channel. The method identifies a current bit rate that is less than the first ceiling bit rate. The method receives networking data regarding the communication channel from the second device. The method determines, from the received network data, that the communication channel will sustain an increase in the current bit rate. The method increments the current bit rate. The method iteratively performs the receiving, determining, and incrementing operations until a determination is made that the communication channel will not sustain the increase in the current bit rate.

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: Some embodiments provide a method for allowing a first device that is in a video conference with a second mobile device to remotely control the second mobile device. The method sends images captured by a camera of the first device to the second device. The method receives images captured by a camera of the second device. The method sends a command through a communication channel of a real-time communication session to the second device. The command is for instructing the second device to perform an operation that modifies the images captured by the camera of the second device.

Abstract: Some embodiments provide a method for conducting a video conference between a first mobile device and a second device. The first mobile device includes first and second cameras. The method selects the first camera for capturing images. The method transmits images captured by the first camera to the second device. The method receives selections of the second camera for capturing images during the video conference. The method terminates the transmission of images captured by the first camera and transmits images captured by the second camera of the first mobile device to the second device during the video conference.

Abstract: Some embodiments dynamically designate one of several network nodes as a network hub of a star network, at the start of a network communication session among the several network nodes that is facilitated by a mesh network and the star network. Some embodiments dynamically designate a new network hub when the previously designated network hub leaves the communication session, which continues among the other network nodes. Different embodiments use different techniques to dynamically designate the network hub of the star network. For instance, some embodiments use communications transmitted along the mesh network to dynamically identify the network hub at the start of the network communication session or after the departure of a previously designated network hub.

Abstract: An apparatus, method, and machine-readable medium are described for establishing, maintaining and utilizing backup channels in a peer-to-peer (“P2P”) network. For example, in one embodiment, each mobile device can establish a primary P2P communication channel with one or more other mobile devices. Once the primary channel is established, each mobile device can use the primary channel to exchange secondary channel connection data and can subsequently open one or more secondary P2P communication channels with the other mobile devices. Upon detecting that the primary P2P communication channel has failed or has degraded below a specified threshold (e.g., a bandwidth or bitrate threshold), one of the secondary P2P communication channels can be automatically promoted to a primary P2P communication channel.

Abstract: A first computing device distributes audio streams to several computing devices of participants in a communication session. Some embodiments establishes a star network with the first computing device as a central network hub for receiving audio streams from other computing devices, compositing the audio streams and distributing the composited audio streams to the other computing devices. Through the star network, the first computing device receives audio streams from the other computing devices. The first computing device generates at least two different composite audio streams for at least two different computing devices by (i) identifying a set of silent participants in the communication session, and (ii) eliminating redundant audio processing operations that produce the same composite audio streams for different computing devices because of the identified set of silent participants. The first computing device sends each computing device the composited audio stream for the device.