Abstract:
A selective call receiving device (10) such as a pager is controlled to dynamically change a base frame assigned to the device and subsequent control frames derived therefrom. The time that the device is operative to look for its address in a received signal can thus be dynamically changed to improve the efficiencies of a mixed systems environment without substantially reducing the battery life of the selective call receiving device (10). In two embodiments of the invention a new base frame for the device is derived from an originally assigned base frame that is stored in the selective call receiving device. In another embodiment, a new base frame for the device is derived from the device's address along with frame management information that is received by the selective call receiving device.
Abstract:
A non-real time messaging system (200) for targeting messages to a subscriber unit (222) comprises a synchronized profile of where a subscriber unit should be located (a predetermined base transmission area for transmission of messages to the subscriber unit) maintained between a controller (212) and the subscriber unit. The subscriber unit detects when the subscriber unit is not within the receiving range of a predetermined base transmission area, informs the controller and the controller directs subsequent transmissions to an area identified by the subscriber unit and otherwise transmits subsequent messages to the predetermined base transmission area. The system further includes a plurality of base receivers (217) coupled to the controller for receiving transmissions from the subscriber units and allowing the controller to detect when the subscriber unit is not within the receiving range of a predetermined base transmission area.
Abstract:
A battery saving interval utilized for communicating with a portable subscriber unit (122) in a radio communication system is dynamically adjusted. An occurrence of a predetermined triggering event associated with the portable subscriber unit is observed (504), and the battery saving interval utilized for communicating with the portable subscriber unit is adjusted (506) in response to the predetermined triggering event, while battery saving intervals of other portable subscriber units in the system are left unchanged.
Abstract:
A method and apparatus allocates a first predetermined plurality of frame time slots (102) to a first protocol, and allocates a second predetermined plurality of frame time slots (102) to a second protocol having a base frame management capability. The base frame management capability is applied such that portable selective call receiving devices (10) utilizing the second protocol normally perform battery saving throughout the first predetermined plurality of frame time slots (102).
Abstract:
A communication system is used for transmitting error-tolerant messages to a selective call receiver (122). The communication system includes a transmitter circuit and a controller (112). The controller (112) applies an error-correction algorithm to an original message and repeats the application step to the by-product therefrom until a message has been generated that is sufficiently error-tolerant (506, 508). The error-tolerant message is transmitted to the selective call receiver (122), which receives the error-tolerant message using a receiver circuit. A processor (310) of the selective call receiver (122) applies an inverse error-correction algorithm to the error-tolerant message, and repeats the application step to the by-product therefrom until the original message has been reconstructed (604, 606).
Abstract:
A method and apparatus prioritize communications in a two-way communication system (102, 104) serving portable subscriber units (122) in a coverage area (500). A fixed portion (102) of the two-way communication system (102, 104) requests (904) location information (824, 224, 826) from a subset of the portable subscriber units (122) in response to having a need to communicate therewith, and then receives (906) the location information (824, 224, 826) from the subset of the portable subscriber units (122). The location information (824, 224, 826) includes mobility index values (826) determined by the subset of the portable subscriber units (122) for indicating mobility of each portable subscriber unit (122). The fixed portion (102) then prioritizes (908) the communications based upon the mobility index values (826).
Abstract:
An etiquette controller (112) in a transmitter (14) in a first radio frequency (RF) communications system (10) enables radio frequency communications in a frequency bandwidth shared with heterogeneous RF communication systems (15). The etiquette controller (112) monitors the first RF signals in an isochronous frequency channel in a sub-band of the shared frequency bandwidth to determine whether (124) a frequency channel is free or whether (130, 136) the frequency channel comprises a communication channel which is free. In addition, the etiquette controller (112) causes the RF transceiver (102) to transmit (148) a channel relinquishment signal, monitors (150) the isochronous frequency channel for a predetermined monitoring time, and determines (152) whether the isochronous frequency channel is then free for the channel access.
Abstract:
A communication system includes a plurality of organizational layers, a plurality of portable communication units, and a plurality of base stations. Each layer comprises a plurality of nodes. The plurality of nodes includes a plurality of base stations in the first layer, and a plurality of communication services nodes organized into higher layers. Each communication services node includes a database possibly containing information on the locations of one or more portable communication units. The databases constitute a distributed database containing the necessary and sufficient information on the locations of some of the portable communication units within the system, such that any active portable communication unit in its service area will be located using the most direct route. A tracing strategy is realized by the transmission of control messages informing the system of a moving portable communication unit's location. The system tries to set up a connection to the home address of the called portable communication unit, unless some information is found along the path to the home address of the called unit. In case there is information on the called unit its location is indicated by the address chain in the distributed database.
Abstract:
In order to allocate frequency channels to transmitter units, the transmitter units are grouped in zones, each zone having one or more transmitter units (10, 20, 30) therein. A system controller (40) calculates a zone priority value which is a function of the zone's message traffic level and message latency. The zone priority value determines the order in which a zone is assigned a frequency channel. A channel priority value is calculated for each channel or sub-channel that can be accessed by the transmitter units (10, 20, 10) in the zone based on a probability of success and a mean quality margin value wherein the priority value of a channel determines the order in which an available channel is considered for assignment to a zone. A proposed channel is assigned to a given zone only if the proposed channel passes a channel quality check. The channel quality check may be based on co-channel and adjacent channel interference values. Alternatively, the channel quality check may be based on a determination of whether a channel proposed for assignment to a given zone is currently in use by another zone that is correlated with the given zone. Zones are merged and divided in order to provide increasing system capacity and better channel quality as the customer demands grow.
Abstract:
A base station (21, 22, 23) in a radio communication system (20) comprises a channel allocator (62) for allocating communication channels in accordance with a fully distributed dynamic channel allocation method. The channel allocator accesses a Preferred Channel List (PCL) (64) to allocate the communication channels. The PCL ranks channels (116) in accordance with the occurrence of prior events on the channels (112), such as interrupted calls (122), blocked call setup requests (118), and calls successfully completed (106) and in regards to the mean quality margin (110) and the current channel quality (114). The channel allocator (62) allocates (140) the first available channel (128) in the PCL having a free timeslot (132) and with good current channel quality (136). Alternatively, the channel allocator (62) allocates communication channels in accordance with an optimal dynamic channel allocation method. A list of channels assigned to the base station is updated by removing channels (372) that are locally heavy loaded (366) and in poor quality (370) and by adding channels (390) if the channels are locally heavy loaded (384), and in good quality (394) for a period of time (392). Unassigned channels may be borrowed (388) if they are in good quality (382), are in a locally lightly loaded period (384), and have been idle for a predetermined period of time (386). The assigned channels of the base station (340) are allocated first (356, 360), with the borrowed channels being allocated (350) when no assigned channels are available (340).