Motorola Corporation

Motorala, Inc.

Jay R Krebs

Thomas A Freeburg

Timothy M Burke

Scott W Noble

Anatoly S Belkin

Timothy J Wilson

Paul M Erickson

Kenneth J Zdunek

Louis D Finkelstein

Kamala D Urs

Daniel P Brown

Daniel J Coombes

Robert L Epsom

Laura A Christensen

Jennifer Ann Pierce

Sikendar Fidai

Gayle K Haller

A calling communication unit (210) transmits a dispatch communication request to a communication infrastructure (202). The dispatch communication request includes at least a dispatch identification of a called communication unit (e.g.,216). In response to the dispatch communication request, the communication infrastructure generates an alert message that includes a dispatch identification of the calling communication unit and determines a telephone number associated with the called communication unit. The communication infrastructure then transmits the generated alert message to the called communication unit based on the telephone number associated with the called communication unit.

Method and apparatus for alerting a communication unit in a

A dispatch communication system (100) that includes a system controller (101), multiple base sites (103-105), and a group of communication units (107-111) employs a method and apparatus for communicating therein. A system device (either the system controller or a communication unit) establishes a dispatch communication between the group of communication units. Once the communication is established, the system device starts a timer and continuously determines a first length of time (call time) since establishment of the communication. The system device also determines whether an event indicative of call reassignment has occurred during the communication. When such an event has occurred, the system device determines a second length of time (hang time) based on the call time, wherein the hang time commences upon the occurrence of the event. Upon determining the hang time, the system device further determines whether call reassignment has occurred within the hang time. When call reassignment has not occurred within the hang time, the system device terminates the call.

Method and apparatus for communicating in a dispatch communication system

A communication system (100) that includes a plurality of communication units (101-108) and infrastructure equipment (110-115, 140, 141) employs a method and apparatus for providing communication services to a communication unit (e.g., 101). The infrastructure equipment includes a plurality of base sites (110-115) that provide communication services to corresponding service coverage areas (120-125). The service coverage areas (120-125) are further arranged into paging location areas (130-132). When the communication unit (101) becomes active in the system (100), the communication unit (101) determines its registration type. When the communication unit (101) is of a first registration type, the communication unit (101) transmits a registration message to the infrastructure equipment (e.g., 141) whenever the unit (101) enters a new location area (130-132). When the communication unit (101) is of a second registration type, the communication unit (101) transmits the registration message to the infrastructure equipment (141) whenever the unit (101) enters a new service coverage area (120-125). Thus, when the infrastructure equipment (141) receives a communication destined for the communication unit (101), the infrastructure equipment (141) conveys the communication to the communication unit (101) based on the unit's registration type. However when the communication unit is of a first registration type corresponding to the first registration process, in which the infrastructure pages the communication unit prior to conveying a communication to the unit, and the location area containing the communication unit consists of a 'single service coverage area' communication is conveyed directly to the communication unit without first paging the unit.

Method and apparatus for providing communication services to a

Apparatus and method for enabling a single communication system (100) to support at least two communication services. For example, one can support both cellular telephone services and trunked dispatch services by sharing some, but not all, of the system infrastructure. Access control gateways (201) and base stations (203) comprise common infrastructure elements, while two separate processors provide control for each service, these being a communication agent processor (104) to support telephone services, and a dispatch call processor (106) to support dispatch call services. These two independent processors each include a data base (303 and 307) that includes information concerning communication units (204-206) operating within the system. During a call set-up sequence, the access control gateway (201) receives a call request from a communication unit via a base station, and passes the request to the appropriate processor, which uses its corresponding database to support the requested service.

Method and apparatus for supporting at least two communication services

A communication system (100) employs a method of messaging between a subscriber unit (105) and an infrastructure communication center (101). A messaging key associated with a subscriber unit reference number is provided (203, 403) to the subscriber unit (105) and to the infrastructure communication center (101). An authentication key and/or an identifier for the subscriber unit (105) is then produced (300, 407) by either the subscriber unit (105) or the infrastructure communication center (101). The authentication key and/or the identifier is encrypted (207, 413) with the messaging key and is subsequently communicated (209, 415) between the subscriber unit (105) and the infrastructure communication center (101).

Method of messaging in a communication system

In a communication system, a method that efficiently utilizes bandwidth of communication resources when transmitting first and second bandwidth messages to a communication unit may be accomplished in the following manner. When a central processor receives a message for the communication unit, it determines whether the message is of a first bandwidth message type or a second bandwidth message type. When the message is of the first bandwidth message type, the central processor transmits the message to the communication unit via a communication resource that is used primarily for transceiving first bandwidth type messages. When the message is of the second bandwidth message type, the central processor prepares a first bandwidth notification message and transmits it to the communication unit via the communication resource. The first bandwidth notification message informs a user of the communication unit that the central processor has the second bandwidth type message for it. When the user desires to receive the message, a request is sent to the central processor, which subsequently transmits the message on a communication resource that is primarily used for transceiving second bandwidth type messages.

Method for efficient bandwidth utilization when transceiving varying

An improved protocol for a radio communications system (100) having a base station (103), radio units (101), an inbound channel (107) for conveying information from the radio units to the base station, an outbound channel (105) for conveying information from the base station to the radio units, a first unit of time is defined as a microslot (201, 203, 205), and a second unit of time is defined as a slot (207), the slot comprising an integral number of consecutive and contiguous microslots. The base station sends timing information to the radio units, and indicates to the radio units when the inbound channel is idle by, first, determining when a microslot time period has expired (303) and, when this occurs, then determining when a slot time period has expired (305). If a slot has expired, the base station then determines whether the inbound channel is idle. If the inbound channel is idle (307), the base station then sends (311) a first symbol to the radio units on the outbound channel, but if the inbound channel is busy, the base station sends (309) a second symbol to the radio units on the outbound channel. Otherwise, if a slot has not expired, the base station sends (313) a third symbol to the radio units on the outbound channel. In a four-level frequency shift keying (FSK) system, for instance, the first (idle) and second (busy) symbol may use a -3 and -3 relative FSK frequency offsets, and the third symbol may use either a +1 or -1 relative FSK frequency offset.

Communications protocol using microslots

Method and apparatus are disclosed for accommodating diverse signalling methods and protocols within a single, unified Radio Data Communications system without interference. In this way, improvements and new products may be integrated within a pre-established communications system without the need of discarding older equipment. Further, separate operating systems may be effectively merged without permanently modifying the merged system to one or another of the previous systems' signalling formats.

Radio data communications system with diverse signaling capability

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.

Shared data/voice communication system with programmable data priority

A data signalling system for transmitting signals between at least one primary station and a plurality of secondary stations. The system is well adapted for use in multiple unit radio communications systems capable of noise and data communications. A register model is utilized which permits a highly flexible signalling system compatable with a wide range of communications networks. Data transfer is accomplished using fixed length data packets which are error correction encoded and transmitted utilizing PSK modulation.

Data signalling system

A data communications system is described in which variable length messages are communicated between a general communications controller (GCC) and a plurality of portable and mobile radios. The variable length messages include a bit synchronization field, a message synchronization field and a plurality of channel data blocks for efficiently and reliably handling long strings of data or text. Each channel data block includes an information field, a parity field for error-connecting the information field and a channel state field indicating whether or not the radio channel is busy or free. The GCC is coupled to a cellular arrangement of channel communications modules (CCM's), which each include a radio transmitter and/or radio receiver. The mobile and portable radios communicate with the GCC by way of the CCM's.

Growing community of inventors

Crystal Lake, IL, United States of America

Jay R Krebs