Abstract: A communication system that provides communication services to a plurality of communication devices over one or more wireless channels. The communication system includes a main system component that normally serves all of the plurality of the communication devices. However, when the main system component goes out of service, a backup system component only serves some of the communication devices. As such, backup service is provided in accordance with the service priority as subscribed by the communication devices.

Abstract: In addition to a hang timer (405), a second timer (403) (session timer) is introduced. A base station (101, 102) monitors a dispatch call, and if there exists no activity for a period of time greater than the hang-timer threshold, the base station (101, 102) will drop the over-the-air channels broadcasting the call to the remote units (113-118). All active participants to the call will be maintained until the session timer expires. Once the session timer expires, the talk-group participants will be reset to their original members.

Abstract: A method 900 of and wireless communications unit 800 for effecting a handoff from a first Internet Protocol (IP) connection 221 to a second IP connection 331 for a time critical communication is disclosed. The method includes communicating 905 between a first wireless station 219 and a second station 331 using the first IP connection and a first IP address 223 for the first wireless station; setting up 907 the second IP connection with a second IP address for the first wireless station, the first IP connection being a primary connection and the second IP connection being a secondary connection, both existing concurrently; determining 915 that the second IP connection should be the primary connection; and changing 917 the second IP connection to the primary connection by informing the second station that the second IP address is the primary address using stream control transmission protocol (SCTP) messages, wherein the time critical communication is immediately switched over to the second IP connection.

Abstract: A method and apparatus for a fast handover of a link with a communications unit between a first and a second wireless communications network includes a receiving device (203, 231) for receiving signals from a first and a second wireless communications network (106, 120), a controller (207) for detecting a condition indicative of initiating a communication over the first network, and a transmitting device (205, 233) operating cooperatively with the receiving device and the controller to operate exclusively on the first wireless communications network and to facilitate registration with the second wireless communications network when the condition is detected.

Abstract: A communication unit (10) includes a mobility agent (225) for providing handoffs between a cellular network and a wireless local area network (11). The communication unit (10) determines if it should switch between the wireless local area network (11) and the cellular network for obtaining service, requests a handoff to the wireless local area network (11) or to the cellular network by sending a SIP message addressed to either a public number (229) or a private number (231) associated with the communication unit (10) upon making the determination. The communication unit (10) accepts a new call from an enterprise server (12) over the determined network. Corresponding methods of providing a hand-off is described.

Abstract: In addition to a hang timer (405), a second timer (403) (session timer) is introduced. A base station (101, 102) monitors a dispatch call, and if there exists no activity for a period of time greater than the hang-timer threshold, the base station (101, 102) will drop the over-the-air channels broadcasting the call to the remote units (113-118). All active participants to the call will be maintained until the session timer expires. Once the session timer expires, the talk-group participants will be reset to their original members.

Abstract: A method 900 of and apparatus for effecting a handoff from a first Internet Protocol (IP) connection 221 to a second IP connection 331 is disclosed.

Abstract: A mobile wireless router (100) includes a first wireless transceiver (102) for accessing a wireless packet data channel (206), and a network interface (106) for coupling to a first network (204). The mobile wireless router also includes a processor (104) coupled to the first wireless transceiver and coupled to the network interface for controlling and communicating with the first wireless transceiver and the network interface. The processor is programmed to provide an internet protocol (IP) router function to terminal equipment (TE) (202) coupled to the mobile wireless router through the first network, and is further programmed to appear, to another device (214) in a second network (220) coupled via the wireless packet data channel, to be an ordinary router.

Abstract: A controller 103 in a communications system (FIG. 1) for controlling communications with a group 125 of associated subscriber units and method thereof, where the controller includes a receiver (part of 603) operable to receive a request for a subscriber unit to communicate with the group of associated subscriber units; and a processor 605 coupled to the receiver and operable as a comparator 619 to provide a comparison of a first association constraint (FIG. 3) corresponding to the subscriber unit and a second association constraint (FIG. 4) corresponding to the group; and a decision function 621 that allows, only when the comparison is favorable, communications between the subscriber unit and any other subscribers of the group of associated subscribers that also have such communications allowed or enabled.

Abstract: A controller 103 for a dispatch communications system 100 that is arranged and constructed for limiting a transmission in the dispatch communications system, methods thereof, and communications units 115, 117, 123 for use within the system have been discussed. The controller comprises: a processor 405, cooperatively operating with a transceiver 403, to; grant and provide a first right to talk to a first user203; monitor a dispatch call resulting from the grant of the first right to talk to the first user to evaluate whether the first user should retain the first right to talk207, 209; and notify, when the evaluation so determines, a second user 211 that the first right to talk is no longer applicable.

Abstract: An electronic device (103, 200) employs a method and apparatus for selectively audibly alerting a user as to the status of the device's DC power source (119). The device receives input from the user indicating a time period during which the audible low power alert is not to be emanated from the device. After receiving such input, the device determines whether a low power condition exists during the time period and deactivates the audible low power alert if such a condition is met. Alternatively or additionally, after receiving the time period input from the user, the device may determine the likelihood of a low power condition occurring during the time period and activate the audible alert prior to commencement of the time period if such a condition is likely to occur, thereby providing the user advance notice of the potential for such a condition.

Abstract: An electronic device (103, 200) employs a method and apparatus for selectively audibly alerting a user as to the status of the device's DC power source (119). The device receives input from the user indicating a time period during which the audible low power alert is not to be emanated from the device. After receiving such input, the device determines whether a low power condition exists during the time period and deactivates the audible low power alert if such a condition is met. Alternatively or additionally, after receiving the time period input from the user, the device may determine the likelihood of a low power condition occurring during the time period and activate the audible alert prior to commencement of the time period if such a condition is likely to occur, thereby providing the user advance notice of the potential for such a condition.

Abstract: An agent (100) is associated with each of a plurality of devices (201-204) for arbitrating between a talk stream generated by the device and a listen stream intended for the device and generated by another device on a network (210). In the agent a “Talk Mode” (300) is defined in which the agent passes the talk stream from the device to other devices participating in the conference while blocking all listen streams intended for the device, and a “Listen Mode” (400) is defined in which the agent blocks the talk stream of the device from the network and passes a single listen stream from the network to the device. The agent makes a decision to enter one of the Talk Mode and the Listen Mode, wherein the decision is based upon a presence of at least one of the talk stream and the listen stream, and wherein the decision is further based upon a comparison of source identifiers of the talk and listen streams when required to resolve a conflict.

Abstract: A method 900 of and wireless communications unit 800 for effecting a handoff from a first Internet Protocol (IP) connection 221 to a second IP connection 331 for a time critical communication is disclosed. The method includes communicating 905 between a first wireless station 219 and a second station 331 using the first IP connection and a first IP address 223 for the first wireless station; setting up 907 the second IP connection with a second IP address for the first wireless station, the first IP connection being a primary connection and the second IP connection being a secondary connection, both existing concurrently; determining 915 that the second IP connection should be the primary connection; and changing 917 the second IP connection to the primary connection by informing the second station that the second IP address is the primary address using stream control transmission protocol (SCTP) messages, wherein the time critical communication is immediately switched over to the second IP connection.

Abstract: A method 900 of and apparatus for effecting a handoff from a first Internet Protocol (IP) connection 221 to a second IP connection 331 is disclosed.

Abstract: To facilitate fair access to a channel, a controller (200) adds a member-specific channel-access delay, including adding at least one of a first member-specific delay (308) to a transmission of a free channel indication from the controller to a member (118-128) after the channel becomes free; and a second member-specific delay (314) before processing a request to talk received by the controller from the member. The controller selects (302) the member-specific channel-access delay such that a time required for the member to gain access to the channel after the channel becomes free is essentially equal to the time required for any other participating member to gain access to the channel after the channel becomes free.

Abstract: A communication system provides in-band speaker arbitration in a multi-participant communication session by use of RTP floor control messages that include a speaker arbitration command embedded in a data packet header extension.

Abstract: An apparatus and method for establishing an IP session between a host 105 using a session initiation protocol and a device or mobile station 103 without an IP address is described. The apparatus includes a network interface 405 for receiving, via an IP connection, a session request that includes a host contact corresponding to the host and a device identifier corresponding to the device; a controller 407 for parsing the session request to determine the device identifier; preparing a message for the device that includes the device identifier and the session request, and presenting the message to the network interface, the message to be delivered to the device via a non-IP connection and to result in the device obtaining a device IP address and sending an acknowledgment of the SIP session request that includes the device IP address.

Abstract: In order to alleviate network congestion, replication of packets is performed after the packets are received over a wide-area network (250). In particular, a voice packet received from a particular remote unit (201) by a particular base station (211) will be replicated, once for each downlink replicator involved in the call. These voice packets will be transmitted over the wide-area network (250) and will be received by the downlink replicators, again replicated, and transmitted to the appropriate base stations (212-215) where they are provided to their respective remote units (202-206).

Abstract: When any remote unit (113-118) desires to create a talk group, it transmits an inbound message to a group call database (112). The inbound message includes the identity of the requesting communication device, and the participants of the talk group. Upon receiving the request, group the call database (112) provides an outbound message to all members of the newly created talk group giving them a chance to opt out of inclusion into the new talk group. The database (112) then creates a database entry with the new talk group and those remote units that positively responded to the outbound message.