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 method of registration in a communication system includes the steps of detecting (201) an elevated registration level of at least a part of a communication system, selecting (203) a group recovery time, determining (205) a first random registration time that is less than or equal to the group recovery time, registering (209) a first communication unit (111) from a first talkgroup at the first random registration time, and upon receiving (212) a group activity message for the first talkgroup, delaying (213) registration by at least a second communication unit (113) from the first talkgroup.

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 are described that enable host devices of a multicast IP network to reliably join multicast group address(es) in talkgroup or point-to-point calls. For a talkgroup call, a sourcing host sends “hello” packets or payload to one or more network devices, addressed to a multicast group address. The receiving host issues a join command to the one or more network devices in an attempt to reliably join the multicast group address. If any packets are received by the receiving host within a designated time period associated with the attempt, the receiving host is reliably joined to the multicast group address. For a point-to-point call, a controller sends a pair of multicast group addresses, one designated for sourcing packets and the other designated for receiving packets, to a first and second host participating in the point-to-point call. The designated “source” and “receive” multicast group address are complementary for the first and second hosts.

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: A multi-site trunked radio communication system (100) in accordance with a preferred method (500) assigns communication resources (117-124) in response to an assigned or requested service level. The service level is determined based upon a number of parameters (128) including affiliated communication site, time, user override service data, network override service data and other service mode assignment data. The parameters are used to dynamically generate and periodically update a subscriber unit service participation mode (SPM) for each subscriber unit (114-116) operating in the communication system. Additionally, an existing service participation mode assignment may be overridden by the user from the subscriber unit and/or by a network operator/manager.

Abstract: A method of registration in a communication system includes the steps of detecting (201) an elevated registration level of at least a part of a communication system, selecting (203) a group recovery time, determining (205) a first random registration time that is less than or equal to the group recovery time, registering (209) a first communication unit (111) from a first talkgroup at the first random registration time, and upon receiving (212) a group activity message for the first talkgroup, delaying (213) registration by at least a second communication unit (113) from the first talkgroup.

Abstract: A local resource controller (409) from among a plurality of local resource controllers, receives a service request sourced by a communication unit (411). The local resource controller (409) selects (503) any one of at least two service controllers (301, 303, 305) where the service request is to be routed. The service request is routed to the first service controller (505) via a network (307), which is coupled to the service controllers (301, 303, 305) and the plurality of local resource controllers (409).

Abstract: A radio communication system includes a plurality of sites that each belong to one of a plurality of zones. The plurality of zones are each linked to a zone controller and the plurality of sites are employed to facilitate communications among a plurality of communication units affiliated therewith. A method of establishing a communication between two of the plurality of communication units that are presently affiliated with sites not belonging to a common zone includes the step of determining a preferred zone for at least one of the plurality of communication units. After identifying a usable site that belongs to the preferred zone, the communication unit then affiliates with the usable site to facilitate the communications with the second communication unit.

Abstract: A method of handling busy calls, performed by a controlling entity (ZC1) in a multiple-zone system, includes the steps of issuing (201) a request to participate in a call to one or more participating zones (101, 103, and 105) and concluding (203) that at least one zone of the participating zones (101, 103, and 105) is unable to grant the call, thereby resulting in a busy status for the call. The controlling entity (ZC1) informs the participating zones (101, 103 and 105) of the busy status. A resource available notification is received (209) from a first zone, and the controlling entity (ZC1) determines (211) if a predetermined number of the participating zones (101, 103, and 105) have indicated ability to grant the call. When at least one zone of the one or more participating zones has not indicated ability to grant the call, the controlling entity (ZC1) issues (213) a still busy notification to the first zone, which still busy notification indicates that the call still has a busy status.

Abstract: A communication system includes a central unit (18), a plurality of remote units and a plurality of uplink and downlink communication resources (10, 12) for communication between the central unit (18) and the plurality of remote units. A signaling channel is provided on one of the plurality of downlink communication resources (10) and traffic channels are provided on the plurality of uplink communication resource (12). Signaling information is provided on the downlink signaling channel indicating positively which of one or more of the plurality of uplink communication resources (12) is to be used for temporary transmission of message data by at least one of the plurality of remote units, independent of downlink communication resource (10) allocation.

Abstract: Communication units organized into user groups are divided into user groups that distinguish whether a member of the user group may or may not interrupt active calls. Communications will not be interrupted (303) by units that are not allowed to interrupt active calls. Communications are interrupted (304) only by units that are allowed to interrupt active calls.

Abstract: A method for a non-registered communication unit to access a communication system consists of sending a service request. Upon receiving a service request, the communication resource allocator assigns an entry in the communication system database to the non-registered unit and assigns system default features to the entry such that the unit has default access to the communication system. Thus allowing a communication unit that has subscribed to system services and has not been recognized by the system manager to access the system utilizing default parameters until the system manages properly registers the unit.

Abstract: A radio communication system (100)provides for management of system attributes for communication units. The system includes communication sites (111, 112, 113) managed at least in part by a central controller (110), and communication units (121, 122, 123, 124) affiliated with each communication site (111, 112, 113). Each communication site (111, 112, 113) maintains a site database (305) including attributes for affiliated communication units. The central controller (110) maintains a central database (205) which includes attributes of communication units affiliated with the communication sites managed by the central controller (110). The central controller (110) receives at least a subset of attributes from the site database (305) of a communication site, and updates the central database (205) accordingly.

Abstract: A communication unit (105) may influence communication resource allocation within a communication system in the following manner. A list of pending communication requests intended for the communication unit (105) is shown on a display of the communication unit (105). An order in which the pending communication requests are to be processed is selected and transmitted by the communication unit (105) to the infrastructure (101, 102, 103, and 107) of the communication system. The infrastructure then processes the pending communication requests for the communication unit (105) based on the order selected by the communication unit (105).

Abstract: In a multi-site communication system, a communication unit (106) transmits a communication request (208) that includes information identifying the sites (100 and/or 101) where the user desires to communicate with members of his user group. Communication resources are allocated (308) using the communication request and current resource allocation for the user group.

Abstract: In a communication system, the following describes a method for the communication system to more efficiently process control information when the control channel is temporarily used as a voice channel. When a communication unit has control information to transmit to the communication resource allocator, it determines whether the monitored voice channel is busy. When the monitored voice channel is not busy, the communication unit transmits the control information to the communication resource allocator on the monitored voice channel. Regardless of whether the monitored voice channel is busy or not, the communication resource allocator transmits recommended channel parameters on the monitored channel wherein the recommended channel parameters comprises at least one recommended channel. When the monitored voice channel is busy, the communication unit decodes the recommended channel parameters to ascertain the at least one recommended channel.

Abstract: In a communication system network, an operator station, for a particular communication group, may select communication systems wherein a communication group service will be performed for the particular communication group. This is accomplished when the operator station selects, for the particular communication group, the group service to be performed and which communication systems the service is to be performed in. Once these parameters are selected, the operator station transmits them to the central controller which determines whether at least one communication unit of the particular communication group is registered in the selected communication systems. When at least one communication unit of the particular communication group is registered in the selected communication systems, the central controller allocates a communication resource in the selected communication system to the operator when a communication resource is available such that the selected communication group service can be performed.