Motorola Solutions, Inc.

Motorola Corporation

Satyanarayan R Panpaliya

Dipendra M Chowdhary

David G Wiatrowski

Thomas B Bohn

Badarinath Patibandla

Yueh Ching Chung

Hun Weng Khoo

Sanjaykumar S Karpoor

Teik Choon Teh

Thomas J Senese

John P Belmonte

Tejal S Patel

Guo-Jin Wei

Rui Yang

Hesham H Naim

Shiying Ning

Chebron Padmanaba

Zhijun Zhu

Stephen Lee

Grace Zhong

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 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 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

A new group call request is received from a subscriber station at a rest channel repeater at a first network location. Corresponding new group call notifications are then transmitted to each of the other network locations over a wide area network to a current one of the repeaters acting as a rest channel repeater at each of the other network locations. Subsequently, an identity of a traffic channel repeater hosting the new call is received from each of the respective other network locations. An over-the-air notification is transmitted to other subscriber stations at the first network location identifying one of the first rest channel and another available channel as a channel for the new group call. Data received from the first subscriber station is then forwarded to each of the identified traffic channel repeaters at each of the other network locations via the wide area network.

Method and system for peer to peer wide area network communication among radio sites having dynamic rest channel base repeater stations

Within a two way radio frequency communication system, a repeater transmits an identity of a rest channel when transmitting during an active communication call on a channel other than the rest channel. A subscriber unit communicating within the active communication, receives the identity of the rest channel, leaves the active communication; and initiates a new communication on the rest channel.

Method for initiating a communication while participating in another communication

A method and system for scanning a TDMA channel by a subscriber unit in a wireless communications landscapeis disclosed. The subscriber unit locks onto a channel that is preprogrammed in the subscriber unit. A base radio transmits a control message to the subscriber unit. The control message informs the subscriber unit of activity present on the channel. The subscriber unit receives and decodes the control message to determine whether there is activity on the channel. If there is, the subscriber unit determines whether the activity is of interest. If it is, then the subscriber unit remains on the channel to receive the activity present on the channel.

Growing community of inventors

Palatine, IL, United States of America

Satyanarayan R Panpaliya