Abstract: Methods are disclosed for determining a link Op from among a plurality of host devices on a LAN, for exchanging control messages between a communication server and one or more sites having a link Op and a listening Op and for the link Op and/or listening Op to detect and recover from missing packets in a sequence of IP packets received from the server. The link Op and listening Op join a control multicast group address to receive control messages from the server. The link Op establishes a reliable message transfer session with the server. Upon the link Op detecting a missing packet, the link Op may request that the communication server resend the packet. Upon the listening Op detecting a missing packet, the listening Op determines whether the link Op will request retransmission of the missing packet.

Abstract: A Packet Network for use in association with a wireless communication system employs packet distribution and call set-up methods optimized to select from a plurality of network routing devices, a single node (i.e., Rendezvous Point (VP) or.multicast core) as a function of attributes exhibited by the communication devices involved in the call or as a function of various communication system performance and/or quality of service (QOS) attributes, including but not limited to, bandwidth requirements, resource availability, network processing capacity, network response time, network traffic data, information technology and other knowledge and know-how regarding system equipment, system software, system integration, installation and/or deployment, bit error rate (BER), received signal strength indication (RSSI), quality of service (QOS) metrics, and any other measure of system performance or call quality.

Abstract: A method of call control in a packet-based communication system having consoles, distributed among one or more console sites, that are adapted to monitor talkgroup calls. The console sites are served by console site links having a limited available bandwidth. Upon receiving a request for a talkgroup call, there is identified a number of priority consoles requesting participation in a talkgroup call. For example, the priority consoles (or console operators) may indicate that monitoring of the talkgroup call is “critical” for those consoles. Based on the location of the priority consoles, a number of priority console sites are identified for the talkgroup call. If sufficient bandwidth (e.g., call units of bandwidth) is available (or made available) to each of the priority console sites, the call is granted. Alternatively or additionally, the call may be granted to certain non-priority console sites if bandwidth is available.

Abstract: A packet-based communication system and method of call control that allows variable numbers of calls of potentially multiple types (e.g., conventional and trunking calls) to proceed concurrently over shared links of an IP network without exceeding available bandwidth. Call counts are determined for one or more paths between endpoints, defining numbers of calls that are supportable by the one or more paths. The call counts may be apportioned between first and second types of call (e.g., between trunking and conventional calls). Upon receiving call requests that require use of one or more paths, the call requests are granted if they do not exceed the call counts associated with the one or more paths. Optionally, the call requests may be denied or busied if they exceed the call counts associated with the one or more paths. As another option, call requests of one type (e.g.

Abstract: Methods for implementing talkgroup calls in an IP multicast network among competing sources, including console dispatch takeover of an active call from a subscriber, subscriber unit attempted takeover of an active call from a console, and operation of communication devices in different receive modes. In the takeover or attempted takeover situation, the methods allow for a first group of participating devices (e.g., consoles) to hear both competing sources, and for a second group of participating devices (e.g., base site repeaters) to hear only the higher priority source. The methods allow for different dekeying sequences between the competing sources after the takeover or attempted takeover, as appropriate, such that participating devices will hear the remaining source. Where multiple payloads are addressed to the same multicast group address, an exclusive receive mode enables a group of communication devices (e.g.

Abstract: Network access delays are minimized by using affiliation messages to pre-establish communications in a wireless communication network (100). A controller (102), upon receiving an affiliation message from a first site (104), establishes connections between the first site and a second site (105), the connections being uniquely associated with a talkgroup/site affiliation indicated by the affiliation message. Additional sites can be added by modifying the connection to include the additional sites. Using a multicast SVC as the connection between the first and second site eliminates the need for a multicast server and its associated delays.

Abstract: Network access delays are minimized by using affiliation messages to pre-establish communications in a wireless communication network (100). In a first embodiment, connections between a site and a multicast server are not pre-assigned. A controller (102), upon receiving an affiliation message from a site (104), establishes connections between the site and a multicast server (111), the connections being uniquely associated with a talkgroup/site affiliation indicated by the affiliation message. In a second embodiment, connections between the site and the multicast server are pre-arranged. Thus, responsive to the affiliation message received from the site, the controller informs the multicast server that a talkgroup is affiliated with the site. Regardless of whether the first or second embodiment is used, the multicast server routes packetized information corresponding to the talkgroup to those sites with which the talkgroup is affiliated.

Abstract: Listening capacity of a signal destination is augmented through the provision of a master switching center (207) and a slave switching center (209) linked via a dedicated communication port (203). Under direction of the master switching center (207), the slave switching center (209) sums communication system data signals received from shared communication ports (201) and presents the resulting summed communication data to the dedicated communication port (203). The master switching center (207) presents the summed communication data, received via the dedicated communication port (203), to the signal destination, thus augmenting listening capacity of the signal destination.

Abstract: In communication system, multiple communication units are selected to receive a message via multiple broadcast units. A communication resource controller identifies a set of broadcast units needed to transmit the message, which are further identified as contending and non-contending broadcast units based on contention information. Identification of each of the contending broadcast units is stored and the non-contending broadcast units are allowed to simultaneously transmit the message. When contention for the contending broadcast units is alleviated, the contending broadcast units transmit the message.

Abstract: When a group communication group call is initiated in a multi-site communication system, the communication processing information for that particular communication group call must be established. The communication processing information is formatted by a central controller which in turn transfers that information to a destination data base of a processing multiplexer switch. The information is then stored in the destination data base such that the particular communication group call may be quickly processed. When the communication unit that initiated the call ceases to transmit and another communication unit begins to transmit, the communication processing information is updated to reflect the change in the transmitting communication unit. This continues to happen until the particular communication group call has ended; once it has ended, the communication processing information is deleted from the destination data base.

Abstract: In a communication system network that includes a central controller that is operably coupled to a processing multiplexer switch, system configuration information may be transferred between the central controller and the processing multiplexer by establishing a communication link between the central controller and the processing multiplexer switch. Once the link is established, the central controller requests site interface configuration information from the processing multiplexer. The site interface information indicates the status of the interfaces and the type of site coupled to the interface. Once this has been relayed to the central controller, the central controller determines the particular type of site coupled to the site interface. If the site is of a first site type, the central controller assigns the link between the site and the site interface a unique link address.

Abstract: An operator MUX interface (OMI) (102) includes a data base manager (203) that manages at least two data bases. The first comprises a substantially non-temporary data base, and the second comprises a substantially temporary data base. The latter includes information from both the first data base, and other information as well. The data base manager (203) automatically alters the data storage structure of the second data base whenever either the data storage structure for the first data base is changed, or whenever new information must be added to the second data base, and the data storage structure of the second data base will not readily accommodate that addition.

Abstract: The present invention discloses a communication system network that comprises a plurality of communication system and a processing multiplexer. The communication systems, which may be either conventional communication systems and/or trunked communication systems, transmit digitized audio signals and communication system data to the processing multiplexer. The processing multiplexer comprises a plurality of communication system interface modules that each store configuration information of the processing multiplexer. The configuration information is updated periodically or when a portion of it changes such that each communication system interface module has the latest configuration information.

Abstract: A central controller of a communication system network may more efficiently expand an audience of a communication in the following manner. When a communication unit of a first communication group within a first communication system transmits a request for service, the central controller determines whether the audience of that predetermined communication is to be expanded. When the audience of the predetermined communication is to be expanded, the central controller combines at least part of at least one other communication group with the first communication group based upon a predetermined grouping arrangement. Having combined the groups, the central controller processes the predetermined communication among the communication units in the first communication group and the communication units in the at least part of the least one other communication group.

Abstract: In a communication system network that includes a processing multiplexer and a plurality of communication systems, wherein each of the communication systems includes a plurality of signal sources, a plurality of signal destinations, and a processing interface means and wherein the processing multiplexer includes system data database means that stores information pertaining to communication system configuration data, a method for maintaining the system data database is described. Maintaining the system data database means comprises querying the processing multiplexer interface means of at least one communication system for information pertaining to communication system configuration data. Upon receiving the information, allocating entries in the system data database means for the information pertaining to communication system configuration data and entering the information into the allocated entries.

Abstract: In a digital summing process that sums non-linear digital signals by converting them to linear signals, computing their two's complement, summing the two's complements together and converting the resultant into a non-linear resultant, the fidelity of the summing process may be verified in the following manner. When only one non-linear digital signal is being summed, an algorithm determines whether the one non-linear digital signal being summed is equivalent to a predetermined value which, when passed through the summing process, will yield a different value than the one inputted. If the algorithm determines that the one non-linear digital signal is equivalent to a predetermined value, it sets a flag which indicates that the resultant over written with the predetermined value. Once the resultant is overwritten with the predetermined value, the flag is reset.

Abstract: In a communication system network that includes a processing multiplexer, a plurality of communication units, and a plurality of communication systems, each of the plurality of communication systems includes a base interface modules for interfacing the communication system with a limited number of repeaters that transceive information amongst the plurality of communication units and a processing multiplexer interface module for interfacing the communication system with the processing multiplexer. Each processing multiplexer interface module includes a base interface database that stores base interface status information of the base interface module of each of the plurality of communication systems that is periodically updated. The base interface database is updated when a processing multiplexer interface module of one of the plurality of communication systems detects a change in the base interface status information of the one of the plurality of communication systems.

Abstract: During an existing communication between a first communication unit and at least a second communication unit, any communication unit in the existing communication may add another communication unit to the communication. This may be accomplished by initiating a request to add another communication unit. The request is routed to the affiliated system data database circuits, wherein each system data database circuit reserves an entry in each signal destination field affiliated with a communication unit that is participating in the communication when an entry is available. With the entries reserved, each of the system data database circuits adds, in the entries, individualized information of the new communication unit such that the new communication unit can now participate in the communication.

Abstract: In a communication system network that comprises a plurality of communication systems and a processing multiplexer, each of the plurality of communication systems is equipped with fallback operation circuitry. The fallback operation circuitry enables a communication system to operate as a standalone system when the interface buses that connect it to the processing multiplexer fail. In addition, the fallback operation circuitry enables the communication system to be reconnected to the processing multiplexer when the interface buses resume proper operation.

Abstract: In a communications system network that comprises a plurality of communication systems and a processing multiplexer, a method and apparatus for selectively muting particular signal sources of a communication system is disclosed. In each communication system, a processing multiplexer interface module detects when a mute request is generated and injects a null audio signal into a corresponding TDM slot of a source interface bus. This process can be used to localize audio communications of a particular signal source in a communication system or may be used for individual communication system testing of its audio signal bus.