Motorola Corporation

General Dynamics C4 Systems, Inc.

Google Inc.

Motorola Mobility LLC

Bradley J Rainbolt

Stephen Rocco Carsello

Marc Andre Boillot

Bernard Richard McKibben

Ty B Lindteigen

Stuart S Kreitzer

Keith M Klug

Brent M McKay

Fred R Villa

Michael A Savage

Bryce Sutherland

Barbara S Winterfield

William C Neubauer, Iii

Jerry D Ray

Michael J Rudowicz

Anthony Rodrigues

A method and apparatus for secure communication in a digital two way radio protocol is disclosed herein. The method includes the step of, at an originating radio, generating at least one control value (). The method further includes the step of generating an encryption key based on the at least one control value and a personal identification code at the originating radio (). The method further includes the steps of encrypting data traffic with the encryption key to provide encrypted data traffic at the originating radio (), transmitting the at least one control value to at least one target radio (), and transmitting the encrypted data traffic to the at least one target radio ().

Method and apparatus for secure communication in a digital two way radio protocol

A method and system for selecting scanning rates in a multi-mode communication device is disclosed herein. The method can include the step of&#x2014;at a multi-mode communication device&#x2014;measuring at least one parameter associated with an interaction between a first network and the multi-mode communication device. The method can further include the step of&#x2014;in response to measuring the parameter&#x2014;selecting a scanning rate of the multi-mode communication device for a second, different network that interacts with the multi-mode communication device. In the method, the first network and the second network can have independent synchronization procedures.

Method and apparatus for selecting scanning rates in a multi-mode communication device

Methods and apparatus are provided for secure communication techniques in a communication system. The system can include a first device which communicates with a second device over a channel. A security association can be established during a first session between the devices via an asymmetric key exchange. The security association comprises a Traffic Encryption Key (TEK) and a first state vector. The TEK comprises a shared, secret symmetric key. The security association is stored in each of the devices for use during a second session between the devices to expedite security association establishment during call set-up of the second session. The security association can be associated with the second device in the first device, and with the first device in the second device. An updated state vector can be generated at the first device. A second session can be established between the first device and the second device by using the TEKs from the first session and the updated state vector. The security association can be used to encrypt voice packets being sent from the first device to the second device. The security association and updated state vector can then be used to decrypt the encrypted voice packets received by the second device from the first device.

Method and apparatus for fast secure session establishment on half-duplex point-to-point voice cellular network channels

An apparatus () and corresponding methods (FIG.) to facilitate maintaining crypto synchronization while processing communication signals in a communication unit includes a vocoder () configured to convert input audio band signals to vocoder output frames; a crypto processor () configured to encrypt the vocoder output frames to provide encrypted output frames; and a synchronizer () configured to substitute in a predetermined manner synchronization information corresponding to an encryption state of the crypto processor for a portion of the encrypted data in a portion of the encrypted output frames to provide resultant output synchronization frames suitable for synchronizing a decryption process at a target communication unit.

Crypto-synchronization for secure communication

Techniques are provided for secure group communications in a wireless dispatch system which includes a group of devices. The group of devices can include a first secure device which communicates with a plurality of second secure devices over a channel.

Method and apparatus for rapid secure session establishment on half-duplex AD-hoc group voice cellular network channels

A method (or) and system of reducing collisions in an asynchronous communication system can include the steps at a transmitter () of generating () a set of known preamble waveforms and transmitting () at least one distinguishable preamble waveform based on an association with a call type and a receiver identifier. The method () can also include the steps at a receiver () of receiving () at least one preamble waveform among a set of different preamble waveforms which toggle between two symbol frequencies, the different preamble waveforms being distinguishable by at least having one among a different symbol frequency spacing and a different symbol toggling duty cycle. The method further includes the step of selecting () to decode a preamble waveform based on at least one among the different symbol frequency spacing and the different symbol toggling duty cycle.

Method and system of reducing collisions in an asynchronous communication system

A processor () determines () a channel metric from a data signal received on a diversity branch. The processor calculates () an index into a final metrics buffer (), the index determined from a position of the channel metric within an interleaved frame of data. The processor places () a value derived from the channel metric into the final metrics buffer at a location defined by the index. A corresponding method and apparatus as well as communications receiver utilizing the processor () are described.

Method and apparatus for facilitating efficient deinterleaving and diversity-combining of a data signal

A system, wireless device () and method receive a set of soft metrics () associated with a block of symbols during a predetermined time interval, use the set of soft metrics () to form an initial interference power estimate, form a moving-average estimate of interference power () corresponding to each predetermined time interval, and scale the set of soft metrics () according to the corresponding interference power estimate resulting in a set of scaled metrics (). Then they limit the dynamic range of the set of scaled metrics (), linearly quantize the limited metrics, and output the linearly quantized limited metrics () to a memory buffer. The size of the memory buffer containing the linearly quantized limited metrics () is smaller than the size of a memory buffer required to store the received soft metrics (). The linearly quantized limited metrics () are then used as input to a decoder.

Interference estimation and scaling for efficient metric storage and interference immunity

Apparatus and corresponding method in a wireless mobile device () for classifying each of a plurality of audio bits obtained from a vocoder () into one class of a plurality of classes according to a predetermined importance of each audio bit, wherein each of the plurality of classes has an associated error correction process and an associated repeat diversity process. Error correction and repeat diversity are applied to a portion of the plurality of classes based on the associated error correction and repeat diversity processes. The method may be implemented by a processor () executing routines stored in a memory ().

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Sunrise, FL, United States of America

Bradley J Rainbolt