Motorola Solutions, Inc.

Motorola Corporation

Dipendra M Chowdhary

David G Wiatrowski

Thomas B Bohn

John P Belmonte

Yueh Ching Chung

Satyanarayan R Panpaliya

Hun Weng Khoo

Badarinath Patibandla

Sanjaykumar S Karpoor

Tejal S Patel

Satish R Panpaliya

Bradley Michael Hiben

Kevin G Doberstein

Bob LoGalbo

Teik Choon Teh

Thomas J Senese

Michael W Bright

Chris A Kruegel

Timothy Woodward

Kok Seng Ang

Xiao-Yu Li

Kevin M Ittner

Guo-Jin Wei

Abhishek Kumar

Larry Murrill

Hemant J Patel

Warren Ludcke

Puneet K Puri

Colin Gould

Roopak M Ingole

Delia M Marchosky

Zhijun Zhu

Stephen Lee

Grace Zhong

Rui Yang

Hesham H Naim

Shiying Ning

Chebron Padmanaba

Tianfang Liu

Timothy G Woodward

A method and device for zero configuration direct fallback communication is provided. In one aspect a method comprises selecting a channel in a fallback radio band based on at least a portion of at least one system operating parameter for a primary radio band. The method further comprises switching to the selected channel in the fallback radio band. The method also comprises communicating over the selected channel in the fallback radio band.

Method and device for zero configuration direct fallback communication

A process for connecting a user equipment to a radio access network in which communication frequencies are dynamically allocated from a shared radio spectrum. In operation, the user equipment maintains a radio frequency scan list that indicates a prioritized order with which a plurality of radio frequencies selected from the shared radio spectrum are to be scanned. The user equipment scans the radio frequencies in accordance with the prioritized order that is indicated in the radio frequency scan list and selects a target radio frequency from the radio frequencies based on the scanning of the radio frequencies. The target radio frequency corresponds to a frequency band that is dynamically allocated from the shared radio spectrum to a radio access network associated with the user equipment. The user equipment then connects to the radio access network using the frequency band corresponding to the target radio frequency.

Method of operating a user equipment to connect to a radio access network

A radio receives audio information on a first traffic channel in a radio frequency (RF) site. The radio receives, on the first traffic channel, an announcement of alternative traffic channels on which the audio information is also transmitted in adjacent RF sites. The radio determines signal strength indicators for the alternative traffic channels in the adjacent RF sites while continuing to receive the audio information on the first traffic channel. The radio determines that a signal strength associated with the first traffic channel is below a first threshold. Based on the determination and as a function of the scanning, the radio roams to a second traffic channel, selected from the alternative traffic channels, in an adjacent RF site where a signal strength associated with the second traffic channel is above a second threshold. The radio receives the audio information via the second traffic channel.

Apparatus and method for enabling efficient handover of a receiving radio between radio frequency sites

A method for enhanced data throughput on a windowed revert repeater channel in a radio communication system includes requesting, by a subscriber unit and via a control channel of the radio communication system, a window in which to transmit data updates on the windowed revert repeater channel of the radio communication system; receiving, by the subscriber unit and via the control channel, an assigned window on the windowed revert repeater channel for the data updates; monitoring, by the subscriber unit, the control channel repeater and determining a timing of the windowed revert repeater channel based on the monitoring; and reverting to the windowed revert repeater channel based on the timing and the assigned window, and transmitting the data updates during the assigned window. A subscriber unit and radio communication system are also disclosed.

Enhanced location data throughput on a windowed data channel in a radio communication system

A process for resolving call collisions in a digital conventional direct mode includes monitoring a direct mode communication channel for transmissions from other direct mode radios in the plurality of direct mode radios. In response to detecting a new call request: identifying a last radio to transmit on the direct mode channel, transmitting a new call request for receipt by the last direct mode radio to transmit, monitoring the direct mode channel for a response from the last radio to transmit, and if a call grant granting the new call request is received from the last radio to transmit, initiating the new direct mode call on the direct mode communication channel. If the call grant is not received, at least temporarily refraining from initiating the new direct mode call.

Method and apparatus for resolving call collisions in a digital conventional direct mode

A radio controller monitors a radio channel for a first period of time and determines a first indication of signals received without detecting synchronization or with detecting synchronization but failing error correction during that time. Responsive to determining that the first indication is above a predetermined threshold indicative of an interference condition, causing an instruction to be broadcast identifying a subset of subscriber devices allowed transmitting random access requests on the radio channel. The radio controller monitors the radio channel for a second period of time and determines a second indication during that time. If the second indication is an improvement over the first indication, the radio controller determines that the interference condition is caused by the mass random access event.

Method and apparatus for responding to a potential mass random access event

A radio affiliates, via a first channel, with at least one talk group the radio is interested in receiving calls from, sends a request to transmit location information on a separate revert channel, and receives a first grant time period to transmit location information on a particular revert channel. The radio moves at substantially the first grant time period, away from the first channel to the revert channel to transmit location information or request a second grant time period on the revert channel, receives an announcement on the revert channel during the first grant time period that a call of interest associated with the at least one talk group started while the radio was on the revert channel, determines an assigned traffic channel for the call of interest, and switches from the revert channel to the assigned traffic channel in order to receive the call of interest.

Method and apparatus for informing a radio of a group-call started while the radio was away from a control channel

A system and method for interrupting a transmitting device during a call. In the system, calls are transmitted from a first device on a communication channel as a series of channel frames. At predetermined times during the transmission, the transmitting device is configured to drop channel frames, resulting in open channel frame periods where the transmitting device is not transmitting on the communication channel. During these open channel frame periods, the transmitting device is also configured to switch to a receiving mode. Other devices in the system are capable of switching into a transmitting mode during the open channel frame periods and, when applicable, sending an interrupt request on the communication channel to the transmitting device in order to request access to the channel.

System and method for interrupting a transmitting device in a communication system

Methods of communicating location information from a subscriber to a repeater are described. The subscriber switches from a working channel to a data revert channel, transmits a request for a periodic or one-time window to transmit an update, and determines from grant information in the response announcement the allocated window and frame before switching back to the working channel. Before the allocated time, the subscriber switches to the data revert channel, confirms whether it remains scheduled to transmit the update from a repeater announcement, and if so transmits the location update in either the current or reserved window. The announcements from the repeater contain the identity of the next window and frame and the subscriber reserved to use the window in addition to grant information. The subscribers may or may not be time-aligned and the data and data revert channels may or may not be synchronized.

Channel structure for non-contention based windows and contention based random access requests

Disclosed is a method of automatic establishment of a location-based talk group call with reduced messaging overhead. The initiating device may be a subscriber unit (SU). The SU determines a geographic reference location and generates location data representative of the location. The SU broadcasts a location-based talk group call header including the location data and including a location-based talk group call identifier field set to cause other SUs receiving the call header to receive and output subsequent data associated with the call header responsive to determining that its current geographic location satisfies the location criterion of the call. The location criterion may be fully determined by the initiating SU and specified in the call header, and may take the form of a specified radius that extends from the geographic reference location represented in the call header.

Method and device for automatic creation of a location-based talk group call with reduced messaging overhead

A method and apparatus for confirming delivery of group data to a plurality of radio communication devices in a wireless communication system. The wireless communication system includes a plurality of radio communication devices in communication with a sender. In operation, the sender sends group data to the plurality of radio communication devices and further determines a call hang time sufficient to contain a dedicated acknowledgment slot for each of the plurality of radio communication devices. The sender reserves an acknowledgment slot in the determined call hang time for each radio communication device and further sends an acknowledgment polling signal to each radio communication device, where the acknowledgment polling signal identifies the respective acknowledgment slot that is reserved for each radio communication device to acknowledge receipt of the group data. The sender accordingly receives an acknowledgment from the radio communication devices during its respective reserved acknowledgment slot.

Method and apparatus for confirming delivery of group data to radio communication devices in a wireless communication system

In operation, a transmitting device selects a synchronization pattern associated with the desired timeslot that is at least mutually exclusive from synchronization patterns associated with other timeslots on the same frequency in the system. Once selected, the transmitting device transmits a burst embedding the synchronization pattern that was selected, where appropriate. If the receiving device detects the synchronization pattern, it immediately synchronizes with the timeslot with confidence that it is synchronizing to the desired timeslot by using sets of synchronization patterns associated with the desired timeslot that are at least mutually exclusive from synchronization patterns associated with the other timeslots on the same frequency.

Method of efficiently synchronizing to a desired timeslot in a time division multiple access communication system

A first subscriber unit (SU) operating in a two-way radio frequency (RF) communications system having at least one fixed terminal, one or more channels, and a plurality of subscriber units, generates a first burst of data for transmission to the at least one fixed terminal. The first SU calculates a cyclic redundancy check (CRC) or checksum value over (i) at least a first portion of the first burst of data and (ii) at least a portion of a first private data. The first SU transmits the first burst of data and the calculated CRC/checksum value, but not the first private data, to the at least one fixed terminal. The fixed terminal then calculates its own CRC/checksum over the received burst and its own copy of the first private data, and compares the result with the received CRC/checksum. The fixed terminal authenticates the received burst if the values match.

Method and apparatus for restricting radio access to a system

In a peer to peer trunked radio network having a plurality of network locations, each network location includes a plurality of repeaters and a dynamically selected at least temporarily act as a rest channel repeater at each network location. A first repeater at the first network location may determine a first timing at which to broadcast an intra-site beacon and a second timing at which to broadcast an inter-site roaming beacon, the intra-site beacon including at least a rest channel identifier indicating a rest channel of the first network location and the inter-site roaming beacon including at least remote rest channel repeater information identifying a second repeater at a second network location that is currently acting as a rest channel repeater at the second network location. The first repeater may then broadcast the intra-site beacon at the first timing and the inter-site roaming beacon at the second timing.

Method and system for roaming in a peer to peer network among radio sites having dynamic rest channel base repeater stations

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Hoffman Estates, IL, United States of America

Dipendra M Chowdhary