Patent EP0401974A2 successfully refreshed from Google Patents.
EP0401974A2
Expired / Lapsed
EP
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Single frequency radio transmission system
Assignee: Tunstall Telecom Ltd
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Filing: 1990-05-04
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Granted: —
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Expires: 2010-05-04
Abstract
Abstract A radio transmission system designed to operated on a single defined frequency channel. The system comprises a central receiver (12), at least one transmitter (14) remote from the receiver and a plurality of repeaters (13) arranged in zones (Z1 to Zn) arround the receiver. Each repeater can receive a signal from a transmitter and re-transmit the message so that it eventually reaches the receiver by way of one or more repeaters. The system includes protection means for protecting the message against loss or corruption, for example by using unique time delays before re-transmission or by addressing a certain sequence of repeaters with alternate paths being provided to guard against the message being lost.
Inventors
- 👤 Christopher A. Burns
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 07:05
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/155
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
97 words
A radio transmission system designed to operate on a single defined frequency channel, comprising a central receiver, at least one transmitter remote from the central receiver and, located between said receiver and transmitter, a plurality of repeaters each adapted to receive a message from a transmitter or from another repeater and to re-transmit said message to the receiver either directly or via at least one other repeater, in which the system includes protection means associated with the repeaters for protecting said message against loss or corruption during transmission of said message from said transmitter to said receiver.
Claim 2
Dependent Claim
97 words
A radio transmission system designed to operate on a single defined frequency channel, comprising a central receiver, at least one transmitter remote from the central receiver and, located between said receiver and transmitter, a plurality of repeaters each adapted to receive a message from a transmitter or from another repeater and to re-transmit said message to the receiver either directly or via at least one other repeater, in which the system includes protection means associated with the repeaters for protecting said message against loss or corruption during transmission of said message from said transmitter to said receiver.
Claim 3
Dependent Claim
27 words
A radio transmission system according to claim 1 in which the protection means comprises means for preventing simultaneous transmission of said message by two or more repeaters.
Claim 4
Dependent Claim
51 words
A radio transmission system according to claim 1 or claim 2 in which each repeater includes delay means for imposing a time delay between receipt of said message by said repeater and re-transmission of said message by said repeater, the time delay associated with each repeater being unique to that repeater.
Claim 5
Dependent Claim
22 words
A radio transmission system according to claim 3 in which the delay means comprises information stored in memory means of said repeater.
Claim 6
Dependent Claim
90 words
A radio transmission system according to any one of the preceding claims in which each repeater has a unique identification address, memory means storing a list of identification addresses relating to those repeaters within its range and control means operative to cause the repeater to re-transmit said message to a first identification address on said list and, in the event that said re-transmitted message is not received or is incorrectly received by the first addressed repeater, to re-transmit said message again, but to a second identification address on said list.
Claim 7
Dependent Claim
27 words
A radio transmission system according to claim 5 in which said identification addresses are arranged on said list in order of proximity of repeaters to said receiver.
Claim 8
Dependent Claim
50 words
A radio transmission system according to claim 5 or claim 6 in which each repeater includes logic means for analysing a message received from another repeater to detect the identification address and to re-transmit the message only if said identification address corresponds to the identification address of the receiving repeater.
Claim 9
Dependent Claim
39 words
A radio transmission system according to any one of the preceding claims in which each repeater includes interrogation means for interrogating said frequency channel to ensure that there is no traffic on the channel prior to re-transmitting said message.
Claim 10
Dependent Claim
59 words
A radio transmission system according to any one of the preceding claims in which said repeaters are arranged in zones around said receiver, each repeater has a zone address number as part of an identification code for that repeater, and zone address numbers for repeaters closer to said receiver are lower than for repeaters more distant from said receiver.
Claim 11
Dependent Claim
40 words
A radio transmission sytem according to any one of the preceding claims in which each repeater has a mains electrical supply, a stand-by battery and means for transmitting a fail message to said receiver in the event of mains failure.
References Cited (Backward Citations)
No citation records indexed.
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