Siemens Aktiengesellschaft

Siemens Gebaudesicherheit Gmbh & Co. Ohg

Werner Schropp

Karlheinz Schreyer

A method for radiotransmission in a danger alarm system that operates by way of repeaters but has a current-saving design, so that battery operation is possible. The reception means are switched on cyclically at preassigned points in time, and transmission-ready participants send a preamble leading to the result that the intended recipient participants, in event of reception, remain switched on until the end of the complete preamble, and in the event that no preamble is received, are switched on again. In the preamble, a point in time is transmitted at which the receiver switches on again, to receive the data telegram proper.

Method of radio transmission in a danger alarm system

On registration of a new subscriber in a radio system with a central system and a plurality of subscribers the new subscriber first sends a search telegram to all the subscribers that it can reach in its radio range and selects from the subscribers that respond a first router. Via this router it sends a registration request in the form of a message with a provisional own address to the central system. If it accepts the registration request the central system sends a response telegram via the router which contains a subscriber number and a system identifier for the new subscriber, which is integrated when the subscriber number is accepted into the radio system.

Procedure for registering a new subscriber in a radio system through routers

In a radio alarm signaling system with a central station (Z) and a plurality of bidirectional (BTto BT) and unidirectional (UT, UT) subscribers, the unidirectional subscribers (UT, UT) attempt to send messages via one of the bidirectional subscribers (BTto BT) to the central station. In this case the message sent by a unidirectional subscriber (UT) is received by all bidirectional subscribers (BT, BT, BT) in its radio coverage area. Each bidirectional subscriber that has received this message waits until a time slot individually assigned to it before forwarding the message. During the wait time each of these bidirectional subscribers (BT, BT, BT) monitors the radio channel to see whether another subscriber has already forwarded the message. If this is the case it suppresses its own forwarding. This ensures that only one of the bidirectional subscribers (BT) forwards the message so that no overloading of the radio system occurs.

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Munich, Germany

Werner Schropp