Motorola Corporation

Motorola Solutions, Inc.

Hans Christopher Sowa

Daniel J McDonald

Scott James Pappas

David J Chater-Lea

Dennis R Newkirk

Walter F Anderson

Jason J Johur

Randy Kremske

Glen B Walton

Thomas J Senese

Chris A Kruegel

Michelle M Bray

Yunhai Yang

Michael W Bright

Glenn Brian Walton

Mark J Sherly

Dennis Newkirk

Daniel J Mc Donald

Scotta J Pappas

A device, system and method for preventing audio loss is provided. A device receives scheduling data, for a plurality of timeslots, indicative of when different communication types are to occur in a present voicecall, the plurality of timeslots including at least one data timeslot for transmitting data on the present voicecall. When a state of the present voicecall associated with a potential collision with the data for transmission in the at least one data timeslot is determined, the device cancels transmission of the data in the at least one data timeslot.

Device, system and method for preventing audio loss

A method and apparatus for assigning a talk group to a radio within a communication system is provided herein. During operation a router receives a communication from a radio over a channel. The communication uses a first talk group that is not assigned to the channel. In response, the router will forward identification information for the user over the channel using a pre-arranged second talk group. Once communication is received using the second talk group (at, for example a console), the receiver will program the radio with an appropriate talk group.

Method and apparatus for assigning a talk group to a radio within a communication system

Disclosed is a radio system, method, and device for a mobile station to indicate to an authentication controller, in an authentication response message, which of a plurality of group key link layer encryption keys (GKEK)s it currently has in its possession, and to work with the authentication controller to more intelligently manage multiple GKEKs. The authentication controller can use the information obtained from the authentication response message to determine which of a plurality of GKEKs to advertise in a key announcement broadcast. Furthermore, individual requests for a future LLE key (LEK) to be used for link layer encryption (LLE) encrypting and decrypting inbound and outbound group communications between base station(s) and mobile station(s) are responded to with a broadcast GKEK-encrypted transmission including the future LEK. Only the requesting mobile station transmits an acknowledgment packet in response to the broadcast.

Method and device for managing encrypted group rekeying in a radio network link layer encryption system

A plurality of encryption keys is generated, and each encryption key is associated with one geographical area of a plurality of geographical areas. Each encryption key is forwarded to one or more base stations in the geographical area associated with the encryption key. At least one of the plurality of geographical areas that is adjacent to a first geographical area is determined, yielding one or more adjacent geographical areas, and an encryption key for at least one of the one or more adjacent geographical areas is forwarded to at least one base station covering the first geographical area.

Method and apparatus for storing and distributing encryption keys

Disclosed is a method of rekeying radios for link layer encryption (LLE) in a radio network using a bifurcated crypto period. During a first portion of a first LLE crypto period during which a first LLE key (LEK) is used to LLE encrypt communications between a base station and mobile stations operating within a corresponding coverage area of the base station, a radio network communications device prevents individual ones of the mobile stations from requesting a second LEK to be used during a second LLE crypto period after the first LLE crypto period. During a second portion of the first LLE crypto period, the radio network communications device allows individual ones of the mobile stations to request the second LEK. A mobile station configured to operate in accordance with the bifurcated crypto period, and provide information regarding keys in its possession via an authentication response ISP, is also disclosed.

Method and device for rekeying in a radio network link layer encryption system

A home location register stores key material related to mobile stations associated with the home location register. A first visited location register associated with a first site in a first zone stores key material related to a first mobile station of the mobile stations associated with the home location register. When the first mobile station roams to a second site in a second zone associated with a second visited location register, the key material related to the first mobile station is encrypted with an interkey, yielding encrypted key material, wherein the interkey is used only by infrastructure system devices other than a mobile station for encrypting at least the key material for transport between at least the first and second zones. The encrypted key material is forwarded to the second visited location register.

A first infrastructure system device other than a mobile station generates key material and forwards the key material to a second infrastructure system device other than a mobile station. A determination is made as to whether a mobile station for which the key material is directed is active on the system, and if so the key material is forwarded to a base station where the mobile station is active. The base station forwards the key material to the mobile station.

A first infrastructure system device other than a mobile station generates an encryption key and encrypts the encryption key with a first intrakey associated with a first zone that includes a second infrastructure system device other than a mobile station, yielding a first encrypted encryption key. The first intrakey is used only by infrastructure system devices other than a mobile station for encrypting at least the encryption key prior to transport within the first zone. The first infrastructure system device forwards the first encrypted encryption key to the second infrastructure system device.

A method includes receiving an authentication request from a mobile station () and determining whether to forward the request to an authentication agent. When it is determined to forward the request, the request is forwarded to the authentication agent (). A random number and a random seed are received from the authentication agent (). The random number and the random seed are forwarded to the mobile station (). A response to the random number and the random seed from the mobile station () is received and forwarded to the authentication agent (). The authentication agent () compares the response with an expected response. When the authentication agent () authenticates the mobile station (), a derived cipher key is received from the authentication agent ().

Method and apparatus for providing authentication in a communication system

A method of key distribution includes generating, by a first system device (), key material and forwarding the key material from the first system device () to a second system device (). It is determined whether a mobile station (), for which the key material is directed, is active on the system. When the mobile station is active, the key material is forwarded to a base station () where the mobile station () is active, and the base station () forwards the key material to the mobile station ().

A secure communication system (100) that is capable of over-the-air-rekeying (OTAR) employs a key management controller (108) to provide secure communications for a requested call. The key management controller determines (403) when the requested call has been initiated and identifies (405) some of the plurality of radios as being members of the requested call. A call key is then transmitted (409) to the members of the requested call where it is used (514) for the duration of the requested call. In this manner, secure communications between the members of the requested call is provided.

Method and apparatus for providing secure communications for a requested

A key management system permits a high degree of autonomous rekeying activity by communication units (105) in a secure communication system (100). Responsive to time reference information transmitted by a key management controller (101), the communication units (105) activate a designated key index at a predetermined activation time. If conditions so indicate, a communication unit may transmit a rekey request.

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Schaumburg, IL, United States of America

Hans Christopher Sowa