Motorola Solutions, Inc.

Duminda A Dewasurendra

Mahes M Ekanayake

Mark A Boerger

Wayne M Phang

John K McKinney

Lorenzo Cruger, Jr

Lorenzo Cruger Jr

A wireless method and apparatus for late entry in frequency hopping systems that, during call setup, computes a random permutation sequence through a hop set of frequencies, chooses preamble frequencies to omit data thereon in lieu of preamble data, and swaps frequencies in the random permutation sequence such that synchronization frequencies lie next to the preamble frequencies with an expected delay such that late entrants can join. The wireless method and apparatus meets the FCC requirement of maintaining a pseudorandom hopping pattern and equal distribution of all frequencies in a hop set while guaranteeing late entry and having no effect on battery performance of radios.

Method and apparatus for late entry in asynchronous frequency hopping systems using random permutation sequences

A digital radio communication system () uses a repeater () to relay calls which can not be completed in a direct talk-around mode between two radios. The repeater () establishes early synchronization in advance of a pending call by listening to an originator radio () attempt to make a direct talk-around call to a target radio (). Asynchronous digital two-way radio communication systems can benefit from the reduction in voice call connect time.

Method and apparatus for establishing a call in a digital radio communication system

A method for communicating a group call within a communication network comprising at least one repeater and a plurality of communication devices includes: receiving at least one preamble slot and at least one synchronization slot from an originator communication device by the repeater and a communication device; operating the communication device to receive one or more calls directly from the originator device via eavesdropping on the repeater uplink channel when a received signal strength indication (RSSI) of the direct preamble and synchronization slots is greater than a threshold; and operating the communication device to receive one or more calls from the originator device via the repeater on a repeater downlink channel of the repeater when the direct RSSI is not greater than the threshold.

Method for group call communication

A method for call setup in an asynchronous frequency hopping digital two-way communication system includes transmitting in adjacent time slots, by a caller device, a preamble slot over a first unique fixed frequency selected from a frequency hopset and a synchronization slot over a second unique fixed frequency selected from the frequency hopset. Further, the method includes one or more target devices transmitting an acknowledgement signal upon receiving the preamble slot over the first unique fixed frequency and the synchronization slot over the second unique fixed frequency, and followed by the caller device establishing the data communication link between the caller device and the one or more target devices over at least one random frequency selected from the frequency hopset, in response to receiving the acknowledgement signal from the one or more target devices.

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Plantation, FL, United States of America

Duminda A Dewasurendra