Ericsson Gmbh

Mark D Priest

Steven T Dreon

Laurence A La Fratta

Peter M Mangum

Timothy J Doiron

Clyde R Butler, Jr

Gary J Pitcher

A radio communication system assigns one repeater the role of priority repeater, whereupon that priority repeater exclusively relays all messages between one or more portable radios and a base site. The priority repeater monitors various indica relating to its level of activity, and transitions to a non-priority state when the level of activity exceeds a prescribed threshold. In one embodiment, the repeater includes a counter for counting the number of transactions performed since the repeater was assigned the role of priority repeater, wherein the count serves as the activity level measure. In another embodiment, the repeater includes a timer for determining the amount of time which has transpired since the repeater assumed the role of priority repeater, wherein this time value serves as the activity measure. Still another embodiment uses battery level as a proxy for activity level. The above techniques may be employed in a non-trunked type of repeater or a trunked type of repeater. In the later case, the priority repeater transmits a message containing its activity level on a control channel to other idle repeaters in the vicinity. These idle repeaters compare the activity level embedded in the message with their own activity level. If an idle repeater determines that its activity level is higher than the current priority repeater's activity level, then it will transmit a message to the priority repeater requesting that the priority repeater relinquish priority status. In this manner, the present invention ensures that a repeater will not deplete its battery during its tenure as priority repeater.

Method and system of load sharing and prioritization of radio repeaters

A base station is configured to facilitate its rapid deployment to provide trunked radio communication system. The base station includes a receiving section and a transmitting section functioning as a repeater operating on a single trunked duplex channel. The base station also includes another receiving section for interrogating the presence of pre-existing RF energy in a given geographic area before allowing the base station to become active. This prevents a newly introduced deployable base station from interfering with pre-existing deployable or fixed base stations.

Transportable base station for a trunked radio communication system

A battery-powered portable radio conserves battery power while the radio monitors messages transmitted over a radio channel, e.g., a radio control channel, Message processing circuitry processes a detected message and stores that message in memory. Before processing a subsequently detected message, the subsequent message is compared with the stored message. It they do not match, the subsequently detected message is subjected to further processing including voting, matching, validity, checking, etc. However, if they match, the subsequent message is ignored as a redundant message and a power savings mode is entered to conserve battery power.

Method and apparatus for conserving power in portable, battery-operated

A vehicular repeater system communicates with a portable mobile radio using the same RF communication band and digital trunking protocol that it communicates with a base site. The repeater station may employ an operational radio within a vehicle which communicates with the base site. A separate repeater radio module is connected to the operational radio, preferably through hardwired links. The separate repeater radio module includes a transmitting section which receives messages from the base site through the operational radio, and forwards these messages through a passive RF interface to a portable radio. The separate repeater also includes a receiving section which receives messages from the portable radio, and forwards these messages through the operational radio to the base site. Additionally, the receiver section may include a padded receiving section with low power amplification and additional receiver attenuation for monitoring other nearby vehicular repeater systems for potential interference prior to allowing its own vehicular repeater to become active.

In-band vehicular repeater for trunked radio system

A base station-based communications system provides radio communication with battery-operated, portable radios, each radio including predetermined radio operating parameters corresponding to particular radio operating conditions. Each portable radio determines for itself one or more current radio operating condition(s), and based thereon, adjusts one or more radio operating parameters.

Method and apparatus for controlling operation of a portable or mobile

A digital radio has standardized 'key' storage for several different cryptosystems (DES, VGE, VGS, etc.). Cryptographic keys are stored in a table in non-volatile memory such as EEPROM. The 'keys' are stored in an 'encrypted' form such that their identities are not readily revealed by a 'dump' of memory contents. Additional security is provided in accordance with the present invention by extracting the 'keys' from the stored table and re-'encrypting' the entire table each time a key loader device is attached to the radio. Multiple key banks are used to provide enhanced voice security by increasing the number of encryption keys available for use by a radio.

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Rustburg, VA, United States of America

Mark D Priest