E.f. Johnson Company

E.f. Johnson Technologies, Inc.

Jeffery E Benshetler

Arindam Roy

A method and system are provided for peer-to-peer communication among a plurality of sites in a land mobile radio (LMR) system. The sites are interconnected by a data network, such as an IP network. When a site, referred to as the initiating site, intends to communicate with other sites, the initiating site transmits a call request message. The call request message is multicast over the data network to the intended recipients. The initiating site receives an acknowledgement message from the other sites confirming their willingness to communicate with the initiating site. The initiating site then sends a voice message, via multicasting, to the other sites interested in the call.

Method and system for peer-to-peer communication among sites

A method and system for authentication of sites in a land mobile radio (LMR) system and encryption of messages exchanged by the sites. In some embodiments, the method includes transmitting a certificate created by a trusted authority by applying a function to a first site public key using the trusted authority's private key to generate a reduced representation, which is encrypted with the trusted authority's private key. Other sites may receive the certificate, decrypt it using the trusted authority's public key, and authenticate the first site. The method may further include generating a session key, encrypting it with the public key of the first site, and transmitting the encrypted session key to the first site. The first site decrypts the encrypted session key with the first site's private key, and transmits a message encrypted with the shared session key to other sites for decryption using the session key.

Method and system for encryption of messages in land mobile radio systems

An integrated Land Mobile Radio (LMR) system enables communication between a trunking LMR system and a conventional LMR system. The trunking LMR system includes a trunking site controller including a first network gateway router. The trunking LMR system includes at least one trunking control channel and a plurality of trunking traffic channel. The trunking traffic channels each are assigned to a specific trunking LMR subscriber by the trunking site controller to enable the trunking LMR subscribers to communicate with one another. The conventional LMR system includes a conventional site controller including a second network gateway router connected to the first network gateway router by a data network. The conventional LMR system includes a plurality of conventional traffic channels. The conventional traffic channels are each assigned to a specific conventional LMR subscriber by the conventional site controller to enable the conventional LMR subscribers to communicate.

Method and system for integration of trunking and conventional land mobile radio systems

A method and system is provided for peer-to-peer communication among a plurality of sites in a land mobile radio (LMR) system. The sites are interconnected by a data network, such as an IP network. When a site, referred to as the initiating site, intends to communicate with other sites, the initiating site transmits a call request message. The call request message is multicast over the data network to the intended recipients. The initiating site receives an acknowledgement message from the other sites confirming their willingness to communicate with the initiating site. The initiating site then sends a voice message, via multicasting, to the other sites interested in the call.

A method and system for authentication of a plurality of sites in a land mobile radio (LMR) system and for encryption of messages exchanged by the sites. The plurality of sites are connected by a data network (e.g., IP network). The method includes transmitting by a first site its certificate. The certificate is created by a trusted authority by applying a selected function to the public key, the ID and other relevant information of the first site with the trusted authority's private key to generate a reduced representation and then encrypting the reduced representation with the trusted authority's private key. The method further includes receiving, by the other sites in the LMR system, the certificate transmitted by the first site. The method further includes decrypting, by the other sites, the certificate transmitted by the first site and authenticating the first site, wherein the certificate is decrypted using the trusted authority's public key. The method further includes generating a session key, encrypting the session key with the public key of the first site, and transmitting the encrypted session key to the first site. The method further includes decrypting, by the first site, the encrypted session key with the first site's private key, and transmitting, by the first site, a message encrypted with the shared session key. The method further includes multicasting the encrypted message over the data network. The method further includes receiving, by the other sites in the LMR system, the encrypted message transmitted by the first site, and decrypting the message with the session key.

An integrated Land Mobile Radio (LMR) system enables communication between a trunking land mobile radio (trunking LMR) system and a conventional land mobile radio (conventional LMR) system. The trunking LMR system includes a trunking site controller including a first network gateway router. The trunking LMR system includes at least one trunking control channel and a plurality of trunking traffic channel. The trunking traffic channels each are assigned to a specific trunking LMR subscriber by the trunking site controller to enable the trunking LMR subscribers to communicate with one another. The conventional LMR system includes a conventional site controller including a second network gateway router connected to the first network gateway router by a data network. The conventional LMR system includes a plurality of conventional traffic channels. The conventional traffic channels are each assigned to a specific conventional LMR subscriber by the conventional site controller to enable the conventional LMR subscribers to communicate.

A method and system for peer-to-peer communication among a plurality of sites in a land mobile radio (LMR) system. The sites are interconnected by a data network, such as an IP network. Each site transmits a periodic broadcast message, which includes the identity of the transmitting site and a list of target groups that the transmitting site is interested in participating. The message is received by the other sites, thus each site becoming aware of the presence of all other sites in the system and Talk Groups they are interested in. When a site, referred to as the initiating site, intends to communicate with other sites, the initiating site transmits a call request message. The call request message is multicast over the data network to the intended recipients. The initiating site receives an acknowledgement message from the other sites confirming their willingness to communicate with the initiating site. The initiating site then sends a voice message, via multicasting, to the other sites interested in the call. Among various advantages, the system reduces hop counts for the call setup, and latency is decreased because call control is distributed among the sites. Furthermore, the system does not have a single point of failure since control and bearer plane traffic need no longer go through a bridge device.

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Plano, TX, United States of America

Jeffery E Benshetler