Abstract: Methods for informing a mobile device of adjacent sites in a RF communication system wherein the RF communication system comprises a first network and a second network are disclosed. A mobile device in the first network of the RF communication system updates a signaling gateway with position information of the mobile device wherein the signaling gateway interfaces between the first network and the second network and receives a list of adjacent sites in the second network from the signaling gateway.

Abstract: A transmission capability of a mobile station that requests to be affiliated with a talk group is received. It is then determined whether to alter a current transmission mode of the talk group based at least in part upon the transmission capability of the mobile station, the current transmission mode of the talk group, and the transmission mode of one or more radio frequency (RF) sites associated with the talk group.

Abstract: Granting multiple communication paths for a single talkgroup call for interrupting a transmission or allowing a dispatch operator to listen to multiple units transmitting simultaneously on the same talkgroup call is disclosed. Upon a first unit being keyed, the controller assigns a first communication channel to a call, whereby the first unit begins transmitting using an inbound link of the first communication channel. If a second unit participating in the call is keyed during the call, the controller assigns a second communication channel to the call, and the second unit begins transmitting on the inbound link of the second communication channel. The call information for both transmissions from the first and second units may be simultaneously routed to dispatch consoles monitoring the call. If the controller determines that the first unit should be interrupted, the transmission from the second unit is broadcast by the base sites involved in the call.

Abstract: A first infrastructure system device other than a mobile station generates an encryption key and encrypts the encryption key with a first intrakey associated with a first zone that includes a second infrastructure system device other than a mobile station, yielding a first encrypted encryption key. The first intrakey is used only by infrastructure system devices other than a mobile station for encrypting at least the encryption key prior to transport within the first zone. The first infrastructure system device forwards the first encrypted encryption key to the second infrastructure system device.

Abstract: A network element (300) can facilitate allocating first and second communication resources (such as, but not limited to, FDMA and TDMA communication resources) in support of supergroup communications. By one approach this comprises identifying (101) communication talkgroups as are to comprise a part of the communication supergroup and then determining (102) whether any of the communication talkgroups comprise first resource-only talkgroups. When any one of the communication talkgroups comprises a first resource-only talkgroup, the network element allocates (103) communication resources to support the communication supergroup wherein the communication resources do not comprise second resource communication resources (for example, the network element allocates first resource communication resources).

Abstract: The present disclosure provides an efficient and effective method for allocating provisional PUIDs and PGIDs to subscriber units and groups during a failure, such that when the communication system recovers, there is a decrease in or elimination of the number of dropped or missed communications. The present disclosure reserves a range of provisional PUIDs and PGIDs for resource controllers operating in a region of system failure to assign when subscriber units roam into the region of failure in the communication system. The present disclosure addresses creating PUID and PGID ranges for resource controllers to assign to roaming subscriber units in order to allow for assignment of PUIDs and PGIDs during periods of subsystem isolation and site trunking, i.e., when the particular site or subsystem cannot communicate with the rest of the communication system. The present disclosure also addresses recovering from these situations, re-registration, and reallocation of PUIDs and PGIDs.

Abstract: A method and apparatus are provided for allocating radio frequency carriers in a radio service area having a plurality of radio frequency TDMA carriers and FDMA carriers. The method includes the steps of receiving a call, when the received call is a FDMA call and a FDMA carrier is not available for the FDMA call, then preempting a pre-existing call on a TDMA carrier of the plurality of radio frequency TDMA carriers for the FDMA call and when the received call is a TDMA call and a TDMA slot is not available for the TDMA call, then preempting a pre-existing FDMA call on a TDMA capable carrier of the plurality of radio frequency TDMA carriers for the TDMA call.

Abstract: A system and method for dynamically altering detection criterion value at a receiving device based on the portion of a call signal being received. A receiving device is configured to extract a first call signal portion from the call signal, and compare the first call signal portion to a plurality of call information portions, wherein each call information portion has a detection criterion value. If the first call signal portion matches one of the call information portions, the receiving device adjusts the detection criterion value for at least one of the plurality of call information portions, extracts a second call signal portion from the call signal, and compares the second call signal portion to the plurality of information portions.

Abstract: A system and method for effectively and reliably terminating a voice call in any burst within a multi-burst superframe. A transmitting unit generates a termination burst upon detecting a dekey event. The termination burst includes a data synchronization pattern, a slot type field indicating an end of a call, and an information field surrounding the data synchronization pattern and the slot type field. The information field is encoded from a predetermined voice encoder frame unique to the termination burst. Once all buffered voice information is transmitted, the termination burst is transmitted prior to the end of the multi-burst superframe. A base station or other receiving unit monitors the incoming signal. Upon detecting the data synchronization pattern, the receiving unit decodes the slot type field and the information field.

Abstract: A receiving device in a trunked radio communications system determines a transmit frequency, wherein the transmit frequency is calculated by subtracting a voice channel number from 759, multiplying by a channel spacing and adding a base frequency to yield the transmit frequency. The receiving device determines a receive frequency by a base frequency+[(759?a voice channel number)*25,000 Hz], where the base frequency is at least one of 851.0125 MHz, 851.0250 MHz, and 851.000 MHz. In any case, the voice channel number is communicated in an outbound signaling message defined by Motorola's 3600-baud radio trunking protocol.

Abstract: A receiving device in a trunked radio communications system determines a transmit frequency, wherein the transmit frequency is calculated by subtracting a voice channel number from 559, multiplying by a channel spacing and adding a base frequency to yield the transmit frequency, if the voice channel number is between 559 and 320. The receiving device determines a receive frequency by 851.0250 MHz+[(559?a voice channel number)*12,500 Hz], if the voice channel number is between 559 and 320. In any case, the voice channel number is communicated in an outbound signaling message defined by Motorola's 3600-baud radio trunking protocol.

Abstract: A method includes receiving an authentication request from a mobile station (401) and determining whether to forward the request to an authentication agent. When it is determined to forward the request, the request is forwarded to the authentication agent (107). A random number and a random seed are received from the authentication agent (107). The random number and the random seed are forwarded to the mobile station (401). A response to the random number and the random seed from the mobile station (401) is received and forwarded to the authentication agent (107). The authentication agent (107) compares the response with an expected response. When the authentication agent (107) authenticates the mobile station (401), a derived cipher key is received from the authentication agent (107).

Abstract: A system and method for processing calls in a communication system utilizing distributed signaling. When a call signal having distributed identification data is received on a communication channel, the call information (such a voice, data, video, etc.) is initially passed through the system without verification until sufficient identification data (such as the color code) has been obtained to determine whether the source of the call is valid. Once sufficient identification data has been obtained, the source is verified. If the source is valid, the call information continues to be passed through the system. However, if source is invalid, the call information is blocked for the present call as well as for subsequent calls on the same communication channel, and passing of the call information through the system does not resume until a received call is subsequently assessed to be valid.

Abstract: A method for providing a mobile device in a packet data network access to a channelized network is disclosed. At a gateway between the two networks, a first channelized network message that is encapsulated in a first IP data packet from the packet data network is received. The first channelized network message is retrieved and reformatted for sending over the channelized network. The gateway then receives a second channelized network message from the channelized network. An identifier of a mobile device associated with the second channelized network message is retrieved and an IP address for the identified mobile device is determined. Then, the gateway encapsulates the second channelized network message into a second IP data packet and sends the encapsulated second channelized network message to the identified mobile device in the packet data network.

Abstract: A device receives a communication request for a time division multiple access (TDMA) communication. Upon receipt of the communication request, the device identifies a first communication channel that currently has at least one available TDMA slot and that is currently supporting a greatest number of active TDMA communications amongst a plurality of communication channels. Once the device identifies the first communication channel, the device allocates a first available TDMA slot for the TDMA communication on the first communication channel.

Abstract: A system and method for transmitting call information in a communication system having sites with long link delays. Upon a call being initiated within the communication system, a zone controller determines the participating sites that are to be involved in the call and assigns an IP multicast group address for the call. The zone controller also determines whether any of the participating sites have a long link delay. If any of the participating sites do have a long link delay, the zone controller also assigns an IP unicast address for each such site. The call information is then transmitted both on the IP multicast address as well as on each assigned IP unicast address to ensure that the call is received by each participating site without the loss of call information.

Abstract: A method includes receiving an authentication request from a mobile station (401) and determining whether to forward the request to an authentication agent. When it is determined to forward the request, the request is forwarded to the authentication agent (107). A random number and a random seed are received from the authentication agent (107). The random number and the random seed are forwarded to the mobile station (401). A response to the random number and the random seed from the mobile station (401) is received and forwarded to the authentication agent (107). The authentication agent (107) compares the response with an expected response. When the authentication agent (107) authenticates the mobile station (401), a derived cipher key is received from the authentication agent (107).

Abstract: A system and method for interrupting a transmitting communication unit in a communication system. When a call is first initiated, the call is assigned to a communication channel and broadcast from a base site using the assigned communication channel. If it is determined that a transmitting communication unit should be interrupted, a zone controller signals a base site to generate an interrupt message. The base site generates an interrupt message containing an identification code for the transmitting communication unit and broadcasts the interrupt message on an outbound link of the communication channel. The transmitting communication unit, while transmitting on an inbound link of the communication channel, continuously monitors the outbound link. If the transmitting communication unit receives, on the outbound link, an interrupt message containing an identification code matching its own identification code, the transmitting communication unit stops transmitting.

Abstract: System and method for efficiently managing communication channel assignments within talkgroups having dual mode communication units capable of operating on a first communication channel type and on a second communication channel type, and single mode communication units capable of operating only on the first communication channel type. If, at a base site, each of the communication units associated with a talkgroup is a dual mode communication unit, a call for that talkgroup is assigned to be broadcast using a channel of the first communication channel type. If, at least one of the communication units associated with the talkgroup at the base site is a single mode communication unit, the call for that talkgroup is assigned to a channel of the second communication channel type. As communication units roam between sites, channel assignments are continuously updated based on the types of communication units at each base site at any one time.

Abstract: A method for informing a mobile device of adjacent sites in a RF communication system is disclosed. The RF communication system comprises a first network and a second network. At a site in the second network of the RF communication system, information is maintained of adjacent sites wherein the adjacent sites are within the first network, and a first list of adjacent sites is broadcast to at least one mobile device within coverage of the site in the second network.