Abstract: In a communications system having at least one service entity and a plurality of endpoints each including a logical entity and a terminal, a method facilitates a session between at least two of the endpoints in the system. The method includes: receiving a first message having information that includes a request for a session between a first endpoint that includes a non-dispatch terminal and at least one other endpoint; detecting that the first endpoint includes a non-dispatch terminal as a function of the first endpoint being unable to perform at least one function; and causing the at least one function to be performed on behalf of the first endpoint by the at least one service entity to facilitate the session between the first endpoint and the at least one other endpoint.

Abstract: A method and apparatus that establishes peer-to-peer communications is disclosed. The method may include determining a group to which a first device belongs, determining the identity of other devices in the group, sending an initial communication to the other devices to indicate that the first device will be joining the group, informing the other devices of applications that are available at the first device, and informing the applications about each equivalent application that is available in other devices in the group.

Abstract: A method and apparatus that provides services in a peer-to-peer communications network is disclosed. The method may include determining at least one group to which a first application is associated, determining if there is at least one second application in the group, and if there is a second application, then sharing information with the second application.

Abstract: In a communications system having at least one service entity and a plurality of endpoints each including a logical entity and a terminal, a method facilitates a session between at least two of the endpoints in the system. The method includes: receiving a first message having information that includes a request for a session between a first endpoint that includes a non-dispatch terminal and at least one other endpoint; detecting that the first endpoint includes a non-dispatch terminal as a function of the first endpoint being unable to perform at least one function; and causing the at least one function to be performed on behalf of the first endpoint by the at least one service entity to facilitate the session between the first endpoint and the at least one other endpoint.

Abstract: A method and apparatus that establishes peer-to-peer communications is disclosed. The method may include determining a group to which a first device belongs, determining the identity of other devices in the group, sending an initial communication to the other devices to indicate that the first device will be joining the group, informing the other devices of applications that are available at the first device, and informing the applications about each equivalent application that is available in other devices in the group.

Abstract: In a communications system having a plurality of endpoints each including a logical entity and its physical counterpart, a method for group affiliation. The method including the steps of: receiving a first message from a requestor via application layer routing that includes an affiliation request; generating a response to the affiliation request as a function of the type of affiliation request received; and communicating the response to the affiliation request to the requestor via application layer routing.

Abstract: In a communications system having a plurality of endpoints (240,242,246) each including a logical entity and its physical counterpart, a system for controlling and managing session between at least two endpoints. The system including a registration manager (202), an application layer router (204), a session controller (206), a group database manager (208), and at least one group entity (210).

Abstract: In a communications system having a plurality of endpoints each including a logical entity and its physical counterpart, a method for managing a pool of multicast addresses. The method including the steps of: generating a pool of available multicast addresses; receiving a request for a multicast address; allocating a multicast address for usage subject to at least a first limitation; monitoring the usage of the allocated multicast address; and reclaiming the allocated multicast address if as a function of the monitoring it is detected that a first condition is met, and causing the allocated multicast address to be placed into the pool of available multicast addresses.

Abstract: A method for controlling and managing individual directed sessions between at least two endpoints in a communications system. The method including the steps of: intercepting a first message sent from an initiating endpoint via application layer routing to at least one other endpoint requesting an individual directed session; communicating the requested individual directed session to a service entity for determining the state of the session as a function of communication system resources and capabilities and resources of the endpoints to be included in the requested session, and if the requested individual directed session is accepted determining a set of corresponding session parameters; and communicating the state of the requested individual session to the initiating endpoint via application layer routing, and if the requested session is accepted also communicating the state of the session the at least one other endpoint via application layer routing.

Abstract: A method for controlling and managing individual directed sessions between at least two endpoints in a communications system. The method including the steps of: intercepting a first message sent from an initiating endpoint via application layer routing to at least one other endpoint requesting an individual directed session; communicating the requested individual directed session to a service entity for determining the state of the session as a function of communication system resources and capabilities and resources of the endpoints to be included in the requested session, and if the requested individual directed session is accepted determining a set of corresponding session parameters; and communicating the state of the requested individual session to the initiating endpoint via application layer routing, and if the requested session is accepted also communicating the state of the session the at least one other endpoint via application layer routing.

Abstract: In a communications system having a plurality of endpoints each including a logical entity and its physical counterpart, a method for managing a pool of multicast addresses. The method including the steps of: generating a pool of available multicast addresses; receiving a request for a multicast address; allocating a multicast address for usage subject to at least a first limitation; monitoring the usage of the allocated multicast address; and reclaiming the allocated multicast address if as a function of the monitoring it is detected that a first condition is met, and causing the allocated multicast address to be placed into the pool of available multicast addresses.

Abstract: In a communications system having a plurality of endpoints (240,242,246) each including a logical entity and its physical counterpart, a system for controlling and managing session between at least two endpoints. The system including a registration manager (202), an application layer router (204), a session controller (206), a group database manager (208), and at least one group entity (210).

Abstract: A method and system for group communications between a plurality of endpoints in a system is described.

Abstract: In a communications system having a plurality of endpoints each including a logical entity and its physical counterpart, a method for group affiliation. The method including the steps of: receiving a first message from a requestor via application layer routing that includes an affiliation request; generating a response to the affiliation request as a function of the type of affiliation request received; and communicating the response to the affiliation request to the requestor via application layer routing.

Abstract: A digital radio receiver is described. The digital receiver of the present invention contemplates a digital radio receiver which operates on a received analog signal which has been converted to a digital form after preselection at the output of the antenna. The digital receiver of the present invention comprises a preselector, a high-speed analog-to-digital (A/D) converter, a digitally implemented intermediate-frequency (IF) selectivity section having an output signal at substantially baseband frequencies, and digital signal processor (DSP) circuit performing demodulation and audio filtering. The radio architecture of the present invention is programmably adaptable to virtually every known modulation scheme and is particularly suitable for implementation on integrated circuits.

Abstract: A digital FM demodulator is described. According to the principles of the present invention, a digital FM signal is demodulated by processing sampled input vectors of a quadrature FM digital signal centered approximately zero frequency. The sampled quadrature input vectors are quantized to lie within a predetermined magnitude range. The quantized vectors are coupled to a phase accumulator which generates a current coarse phase value related to input vectors of the quadrature FM signal. The output of the phase accumulator is also coupled to a vector rotation means which rotates the input vector to a predetermined quadrant to determine a fine phase value based on said rotated input signal vector. The fine and coarse values are then summed and output as a composite phase value, and digitally filtered by subtracting the value of the previous composite phase angle sample from the value of the current composite phase angle sample to produce a demodulated message sample.