Abstract: The present invention is a system and method for detecting and locating the transmission of radio frequency signals from within a defined geographical area. The system uses statistical confidence limits to detect outliers caused by transmissions in the defined geographical area. The source of the transmission can then be located with triangulation.

Abstract: The present invention is a system and method for detecting and locating the transmission of radio frequency signals from within a defined geographical area. The system uses statistical confidence limits to detect outliers caused by transmissions in the defined geographical area. The source of the transmission can then be located with triangulation.

Abstract: A method and system for optimizing a Quality of Service (QoS) for an application is provided. The method comprises generating (205) a dynamic database (110 or 150) of statistical information regarding at least one of the applications and one or more communication network (115, 120 and 125). Further, the method comprises selecting (210) the application to operate on the communication network. The dynamic database is then analyzed (215) to determine at least one network configuration based on desired QoS requirement. Based on the analysis of at least one network configuration a connection (220) is made to the requested application.

Abstract: A wireless communication device (102) includes a multi-mode transceiver (204) that is operable to communicate with a plurality of communication networks. The device (102) also includes a memory (216) for storing: an electronic address book (226) that includes a plurality of identifiers (302), each identifier (302) identifying a call destination device; a plurality of access network choices (304) for at least one of the identifiers (302); and a plurality of service choices (308) for at least one of the identifiers. The device (102) further includes a controller (210) having access to the memory (216) for determining a preferred call model and selecting one of the plurality of access network choices and one of the plurality of service choices as a preferred call model for at least one of the identifiers.

Abstract: A radio system user (126) is alerted (129) as to the occurrence of a financial transaction by a customer (118). Data (122) is obtained from the customer (118) and used to identify a radio system user (126), who is authorized to conduct the financial transaction. A message, indicative of the financial transaction, is automatically provided to a radio system and broadcast (129) to the radio system user (126), thereby alerting the user (126) to the financial transaction.

Abstract: A shared data/voice communication system wherein data traffic may be guaranteed priority at a set, but programmable, level of system capacity and wherein interference between such data and voice traffic is effectively minimized. The system operates on standardized channel access rules in the data mode, as well as requesting permission to operate in the voice mode, which if granted, effects a specific protocol to condition the system for voice traffic and manage the same during such pendency. Long and short timers are selectively activated depending upon whether the system is in the voice or data mode to minimize collisions of the system radio data terminals requesting channel access.

Abstract: A trunked communication system wherein channel assignment information is provided to a requesting subscriber unit in a dual word format that includes separate and specific information regarding both a transmit frequency and a receive frequency. The transmit and receive frequency information is provided in a coded form, which can be decoded by the subscriber unit with reference to a table of information stored therein in conjunction with a simple algorithm.

Abstract: An improved communication system is disclosed wherein at least one reprogramming station is added to a communication system. The reprogramming station is constructed and arranged to communicate with the subscriber units thereby either reprogramming or regrouping them. The subscribing units receive the reprogramming command and acknowledge individually, altering a memory means until either reprogrammed back to the original state, or to another state. In another mode, the reprogramming station transmits a regrouping command wherein two or more groups are combined to form a super group.

Abstract: All subscribers operating within a communication system initially generate and transmit a random password and their ID code to the operation (control) center of a communication system. Thereafter, in a first embodiment, subscribers are commanded to modify (in a predetermined manner) and re-transmit their password and ID code either periodically or upon requesting access to the communication system. The modified password is retained as the current (authorized) password by both the subscriber and the system. In a second embodiment, subscribers are commanded to generate and transmit a new random password and their ID code to the system, which maintains a history of each subscriber's current and previous passwords. According to the invention, some of the subscribers having an unauthorized (duplicated) ID code may be inactive (off) when the subscriber is commanded to modify or generate a password.

Abstract: A trunked communications system that accommodates encrypted secure communications. The system uses both non-encrypted message detectors and encrypted message detectors to assure that the trunked central control unit receives the signals it must receive in order to properly allocate and maintain channel assignments.

Abstract: Disclosed is a method to dynamically allocate a number of data channels on a trunked radio system (100). The data activity is monitored during a predetermined time interval. If activity is above a predetermined maximum, an additional channel may be reserved for data use. Conversely, if data traffic is low, a data channel may be reallocated for voice message use. Moreover, should the amount of data traffic among the available data channels be unbalanced, the present method contemplates reassigning subscriber units (114 or 116) to the available data channels to balance the data traffic load, thereby providing superior access time and system performance.

Abstract: Selected regional trunking systems are equipped with telephone interconnect capability and provided with local computers (106), which communicate with a national hub computer (110). At each selected trunking system, several IDs are reserved as "roaming IDs" to be temporarily assigned to roaming subscribers (112). When a subscriber determines that it has roamed into a new trunked system, it requests a roaming ID. A roaming ID is assigned and transmitted to the subscriber, which thereafter operates within the new trunked system using its roaming ID. The roaming assignment is also transmitted to the national hub computer (110) so that interconnect calls may be approximately properly forwarded. The roaming subscriber (112) continues to operate under the assigned roaming ID until it roams out of the range of the current system and into yet another trunked system. In this way, the subscribers may roam from system to system.

Abstract: An improved communication system is disclosed wherein at least one reprogramming station is added to a communication system. The reprogramming station is constructed and arranged to communicate with the subscriber units thereby either reprogramming or regrouping them. The subscribing units receive the reprogramming command and acknowledge individually, altering a memory means until either reprogrammed back to the original state, or to another state. In another mode, the reprogramming station transmits a regrouping command wherein two or more groups are combined to form a super group.

Abstract: A trunked communication signalling method is provided by a unifying signalling protocol in which subscribers request communication channels using only their individual IDs encoded into a single ISWs. The central decodes the call request, extracts the requesting subscriber's individual ID, which is cross referenced to determine the subscriber's talk-group affiliation(s). If the requesting subscriber's affiliation(s) are not known, the central commands the subscriber to transmit its affiliation using dual ISW signalling. In another aspect of the present invention, each subscriber automatically informs the central of a change in talk-group affiliation, thereby providing continual affiliation updates. In this way, many thousand subscribers are afforded access to a single trunked system, and control channel traffic congestion is minimized.

Abstract: The system requires the use of the permanent ID of the requesting unit in every channel request made on a control channel before every transmission. The channel grant will include the ID along with the channel number and these may be recorded for possible later reference. A channel assignment is retained for a brief period after each transmission, allowing a conversation to be continued on the same channel without a break. Units can access the control channel with a channel request and be assigned a channel even while the dispatcher is using the voice channel. In the case of a need for communication with a larger group, a dispatcher can form a temporary "patch" group of all involved units, with a temporary ID assigned to that group. A channel request from a member of the larger group must then include, not only the permanent ID of the requesting unit, but the temporary ID of the "patch" group.

Abstract: A method and means for controlling telephone interconnect traffic on a trunked radio system is described. The present invention continuously monitors all types of communication traffic on the system and in response to an increasing dispatch access delay, reserves certain repeaters for dispatch use only during a predetermined period. The present invention also contemplates a system in which the number of simultaneous telephone interconnect calls permitted on the system during a predetermined period is dynamically altered in response to system loading. In addition, the present invention establishes a variable, periodically updated, maximum interconnect call length based on the current system dispatch access delay.

Abstract: A DPSK digital signal receiver is disclosed that has a dual bandwidth offset Costas loop that is switchable from an acquire bandwidth to a narrower tracking bandwidth in response to detection of a start code preceding a message signal included in the digital signal. Detection of the start signal may occur before absolute carrier lock on, which then is completed in the narrow-band tracking mode. Thus, carrier acquisition is achieved much faster than that obtained by prior art circuits requiring absolute carrier lock on before switching bandwidths.

Abstract: The encoder processes M information characters, each of bit length m, followed by k-1 flush out bits, through an (n,k) convolutional encoder. Each resulting output character is stored as one row of an output register matrix. A transmission bit stream is formed by extracting bits from the register on a column by column basis, thereby interleaving the characters.The decoder fills an input storage basis on a column by column basis, thereby restoring each character in its appropriate row. The characters are sequentially switched to an (n,k) convolutional decoder which outputs the original m bit information character. The characters are, in turn, stored in corresponding rows of an output register matrix, where they are available as recovered data.