Abstract:
A method of reducing an audio gap in a signal connection with a communication unit during handoff in a cellular communication system is provided. The method includes the steps of providing a temporary signal connection (17) with the communication unit (11) from a mobile switching center (MSC) (12) of a source base site, through the source base site (15-16) to a handoff target base site (18-19) and establishing a trunk connection (14) from the MSC of the source base site to an MSC of the target base site. The method further includes the step of interconnecting (33), at the target base site, the temporary signal connection, trunk connection, and communication unit; and re-routing the signal connection with the communication unit through the trunk connection.
Abstract:
A direct sequence code-division multiple access (DS CDMA) communication system schedules conveyance of blocks (400) of information such that the blocks arrive at a base-site (130) just-in-time for transmission during a discrete frame (301-305) of an air-interface. The DS CDMA communication system implements both circuit switching and packet switching approaches to provide trunking efficiencies while balancing between system loading constraints and time delay of blocks (400) during conveyance.
Abstract:
An electronic device (20), such as a radiotelephone, is connectable to a variable-level power source (22). The electronic device (20) includes a rechargeable power source (70) as a portion thereof. Power source control signals (28) are generated for application to the variable-level power source (22) indicative of voltage levels of the rechargeable power supply (70). The voltage levels of the operative power generated by the variable-level power source (22) is caused to be of levels responsive to measured levels of the voltage of the rechargeable power supply (70). The voltage levels of the operative power of the variable-level power source (22) thereby track the voltage levels of the rechargeable power supply (70).
Abstract:
A unique method for memory dialing for cellular telephones includes storing a recall sequence having a variable number, and replacing the variable number with a directory number in response to a prompt from the telephone when employing memory dialing. In particular, the method comprises the steps of selecting a memory location in a telephone for designating a recall sequence and storing within the memory location the recall sequence including at least one predetermined number which is automatically dialed by the cellular telephone and at least one variable number to be inserted by the user (59); accessing a memory location (60); responding to a prompt from the telephone (64); and replacing the variable number to complete a calling sequence (66). Finally, the present method provides for the transmission of both data and DTMF tones.
Abstract:
A method to implement multiple talk-around communication links using the communication resources of one repeater. A system resource controller (13) determines whether talk-around is possible for any two communication units (11) intending to engage in a point-to-point communication link. Assignment of a talk-around repeater (15) depends on the geographic locations of the two communication units, and a predetermined range criterion between them. In addition, the talk-around communication must not interfere with any existing talk-around communication already in the system. When talk-around communication is possible, an enabling communication grant is issued to the units, and the talk-around repeater's communication resources are assigned to support the link. Otherwise, a repeater (16) for normal trunking is assigned.
Abstract:
A communication system (200), and associated method, which permits a user of a remote-site transceiver (340) operable in a cellular communication system to receive information, including telephonic identification codes, associated with the geographic area in which the remote-site transceiver is located. The remote-site transceiver (340) includes circuitry to receive signals generated by global position system satellites, thereby permitting the geographic location of the remote-site transceiver to be ascertained. The remote-site transceiver thereafter transmits signals identifying the geographic location thereof to a base station (268) of the cellular communication system. The base station (268), in turn, accesses information stored in a memory (984) associated with the geographic area in which the transceiver is located. When the stored information includes telephonic identification codes of emergency facilities associated with various areas, the telephonic identification code of a most-appropriate emergency facility is provided to the transceiver, thereby permitting a telephonic communication link to be effectuated with the most-appropriate, emergency assistance facility.
Abstract:
A receiver (202) may reduce the effects of distortion when determining signal usability in the following manner. Upon receiving a signal (201), the receiver (202) separates a desired component, an undesired component, and a distortion component, wherein the desired component includes the signal that was originally transmitted and the undesired component includes interference and noise. Hving isolated the distortion component, it can be mitigated such that the usability of the signal received can be determined based on a ratio between the desired and undesired components.
Abstract:
An RF tagging system including an RF tag (10, 30) and an RF tag reader (80). The RF tag includes a plurality of RF resonant circuits. Each RF resonant circuit is resonant at a different specific frequency. Each plurality of RF resonant circuits divided into a group of decoder circuits (12, 32) and a group of data RF circuits (14, 34). The group of data RF circuits have resonant frequencies corresponding to a predetermined identification code when the resonant frequencies of the data RF circuits are decoded in accordance to the one decoding modality. The RF tag reader detects the resonant frequencies of the decoder RF circuits to determine the one decoding modality. The RF tag reader is operative in each of the predetermined decoding modality. The decoder RF resonant circuits may also indicate the number of data RF resonant circuits on the RF tag. The RF tag reader determines the number of RF circuits from the decoder RF resonant circuits to confirm the accurate detection of the data RF resonant circuits.
Abstract:
A method and system (300) for encoding data comprising a variable rate trellis coder (302) which receives a plurality of discrete data elements - e.g., input bits - and trellis encodes the information pursuant to a known set of coding rules, producing a plurality of trellis encoded symbols (303). Further, another variable input is used by the trellis coder (302) to determine the coding rate - i.e., symbols (303) are encoded and outputted to a dimensional formatter (306) at a rate which is determined by a rate control signal (305) as output by the variable rate controller (304). The dimensional formatter (306) acts in response to input from the variable rate controller (304), providing formatted symbols (308) to a modulator (310). The modulator (310), which in a preferred embodiment is a QAM modulator, is used to modulate the information signal onto a carrier signal for transmission over the communication channel.
Abstract:
A method and apparatus, performed by a communication unit (101), for substantially eliminating undesired noise in an audible output signal (113) while a determined quality measure (114) of a received signal (107) is below a predetermined threshold (201). At least a portion of the received signal (107) is stored for a predetermined period of time to produce a stored signal (109). A measure of pitch period (111) of the stored signal (109) is determined. When the determined quality measure (114) of the received signal (107) drops below the predetermined threshold (201), at least a portion of the stored signal (109) is used, responsive to the detrmined measure of the pitch period (111), to produce the audible output signal (113). When the determined quality measure (114) of the received signal (107) rises above the predetermined threshold (201), the received signal (107) is used to produce the audible output signal (113).