Method for radio transmission in an alarm signaling system

• US 20040224713A1
• Filed: 04/16/2004
• Published: 11/11/2004
• Est. Priority Date: 04/16/2003
• Status: Active Grant

• Current Assignee: Siemens Schweiz AG (Siemens AG)
• Original Assignee: Siemens AG
• Inventors: Schreyer, Karlheinz, Schropp, Werner
• Granted Patent: US 7,248,854 B2
• Time in Patent Office: Days
• US Class Current: 455/521
• CPC Class Codes: G08B 25/007 Details of data content structure of message packets; data protocols
• CPC Class Codes: G08B 25/009 Signalling of the alarm condition to a substation whose identity is signalled to a central station, e.g. relaying alarm signals in order to extend communication range
• CPC Class Codes: G08B 25/014 Alarm signalling to a central station with two-way communication, e.g. with signalling back
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence

Abstract

In a radio alarm signaling system with a central station (Z) and a plurality of bidirectional (BT1 to BT5) and unidirectional (UT1, UT2) subscribers, the unidirectional subscribers (UT1, UT2) attempt to send messages via one of the bidirectional subscribers (BT1 to BT5) to the central station. In this case the message sent by a unidirectional subscriber (UT2) is received by all bidirectional subscribers (BT1, BT2, BT5) 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 (BT1, BT2, BT5) 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 (BT1) forwards the message so that no overloading of the radio system occurs.

Claims

1. A method for radio transmission of messages in an alarm signaling system with a central station and a plurality of bidirectional and unidirectional subscribers, in which the central station and the bidirectional subscribers each feature a send and receive unit while the unidirectional subscribers merely possess a send unit and whereby the unidirectional subscribers located outside the radio coverage area of the destination of a message of the unidirectional subscriber, which as a rule is the central station, attempt to send messages via one of the bidirectional subscribers to the destination, comprising the steps of:

receiving a message sent by a unidirectional subscriber by all bidirectional subscribers within its radio coverage area,

waiting by each bidirectional subscriber that has received the message for a period of time individually assigned to the subscriber to send a confirmation and/or to forward the message to the destination or to the central station,

during the wait time, switching to receive by each subscriber in order to monitor a radio channel to see if another subscriber with a shorter wait time has already confirmed the message and/or forwarded it to the central station, and

as soon as a subscriber receives a confirmation of the message or the fact that it has been forwarded, suppressing its own confirmation or forwarding of the message.

2. The method in accordance with claim 1, wherein, all bidirectional subscribers first wait to see if the central station has received and confirmed the message before they confirm or forward the message in their next available time slot.

3. The method in accordance with claim 1, wherein, the order of the wait times and thereby the wait times of the bidirectional subscribers is defined by their address within the radio cell.

4. The method in accordance with claim 2, wherein, the order of the wait times and thereby the wait times of the bidirectional subscribers is defined by their address within the radio cell.

5. The method in accordance with claim 1, wherein, in the central station the identification of the unidirectional subscriber is checked and in accordance with this check, the message is either accepted or rejected.

6. The method in accordance with claim 4, wherein, in the central station the identification of the unidirectional subscriber is checked and in accordance with this check, the message is either accepted or rejected.

7. A method for radio transmission of messages in an alarm signaling system with a central station and a plurality of bidirectional and unidirectional subscribers, comprising the steps of:

receiving a message sent by a unidirectional subscriber by all bidirectional subscribers within its radio coverage area,

waiting for an individually assigned period of time by each bidirectional subscriber that has received the message to send a confirmation and/or to forward the message to the destination or to the central station, wherein during the wait time, each subscriber switches to a receive mode in order to monitor a radio channel,

monitoring whether another subscriber with a shorter wait time has already confirmed the message and/or forwarded it to the central station, and

as soon as a subscriber receives a confirmation of the message or the fact that it has been forwarded, suppressing its own confirmation or forwarding of the message.

8. The method in accordance with claim 7, wherein, the order of the wait times and thereby the wait times of the bidirectional subscribers is defined by their address within the radio cell.

9. The method in accordance with claim 8, wherein, the order of the wait times and thereby the wait times of the bidirectional subscribers is defined by their address within the radio cell.

10. The method in accordance with claim 7, wherein, in the central station the identification of the unidirectional subscriber is checked and in accordance with this check, the message is either accepted or rejected.

11. The method in accordance with claim 9, wherein, in the central station the identification of the unidirectional subscriber is checked and in accordance with this check, the message is either accepted or rejected.