EP0274857B1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Mobile radio systems
Assignee: British Telecommunications PLC
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Filing: 1987-12-04
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Granted: 1994-01-19
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Expires: 2007-12-04
Abstract
Abstract A repeater for enhancing performance in poor signal areas has a bank of frequency-agile, single channel amplifiers (13), and monitoring and control means (14, 16). The monitoring means (14) scans the channels of the band and, upon identifying a channel carrying traffic, enables one of the amplifier units (13) to operate on that channel.
Inventors
- 👤 Michael Neil Turner
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 18:13
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/155; H04B7/15528; H04B7/15542; H04B7/24; H04B7/26; H04B7/2603; H04B7/2606; H04W; H04W16/00; H04W16/24; H04W16/26
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
111 words
A radio repeater for a frequency band containing a plurality of channels, comprising monitoring and control means (14, 16, 17; 16') operable to scan the channels of the band so that the monitoring and control means can identify a channel carrying traffic from amongst a plurality of channels, characterised by a plurality of single channel amplifier units (13; 13') operable in conjunction with the monitoring and control means so that when a channel carrying traffic is identified from the plurality of scanned channels by the monitoring and control means, one of the single channel amplifier units (13; 13') can be enabled to receive and transmit on the identified traffic carrying channel.
Claim 2
Dependent Claim
22 words
A repeater according to claim 1, in which each unit amplifier has, for duplex operation, forward and reverse amplifying paths (20-27, 20'-27').
Claim 3
Dependent Claim
61 words
A repeater according to claim 1 or 2, in which the number of amplifier units (13; 13') is smaller than the number of said channels, the amplifier units (13; 13') are of selectable frequency, and the monitoring and control means (14, 16, 17; 16') are arranged, in use, to select the frequency of each unit for assignment to a traffic-carrying channel.
Claim 4
Dependent Claim
75 words
A repeater according to claim 3, in which each amplifier unit (13) has, in each amplifying path, a frequency changer (21, 21') for converting input signals down to an intermediate frequency, a band-pass filter (23, 23'), and a second frequency changer (25, 25') for converting the filtered signals up to the original frequency, the filter frequency being fixed, and the channel assignment of the unit being controllable by controlling the frequency changer local oscillator frequency.
Claim 5
Dependent Claim
49 words
A repeater according to claim 4, in which the intermediate frequencies for the forward and reverse paths (20-27, 20'-27') of an amplifier unit (13) differ by an amount corresponding to the transmit-receive frequency spacing of the channels, whereby a single local oscillator (29) may be used for the unit.
Claim 6
Dependent Claim
27 words
A repeater according to any one of the preceding claims, in which the monitoring and control means (14, 16, 17) is common to all the amplifier units.
Claim 7
Dependent Claim
77 words
A repeater according to claim 6 when appendant to claim 3, for use in a mobile radio system, in which one channel is designated as a signalling channel, the monitoring and control means (14, 16, 17; 16') is arranged, in the event that a traffic-carrying channel is identified when one amplifier unit (13; 13') is assigned to the signalling channel and the remaining units are in use, to reassign said one amplifier unit to the identified channel.
Claim 8
Dependent Claim
36 words
A repeater according to any one of claims 1 to 5, in which the control means (16') is common to all the amplifier units (13'), and in which each amplifier unit incorporates its own monitoring means.
Claim 9
Dependent Claim
26 words
A repeater according to claim 8, in which the monitoring means of each amplifier unit (13') includes a synthesiser and address decoding and data multiplexing circuits.
Claim 10
Dependent Claim
40 words
A repeater according to claim 9, in which the control means (16') is constituted by a control unit having a central processor, a program memory and a non-volatile data memory, the control unit being interfaced with the amplifier units (13').
Claim 11
Dependent Claim
46 words
A repeater according to claim 10, in which the control unit (16') is effective to select a first of the amplifier units (13') as a signalling channel of predetermined frequency, and to command the synthesiser of said first amplifier unit to tune to said predetermined frequency.
Claim 12
Dependent Claim
48 words
A repeater according to claim 11, in which the control unit (16') is effective to select a second of the amplifier units (13') as a voice channel scanner, and to command the synthesiser of said second amplifier unit to tune to the frequency of the voice channel scanner.
Claim 13
Dependent Claim
55 words
A repeater according to claim 12, in which the control unit (16') is effective to interrogate said second amplifier unit (13') to determine whether that unit is receiving a signal whose strength is greater than a predetermined threshold, and to enable that amplifier unit (13') if said predetermined threshold is exceeded by the received signal.
Claim 14
Dependent Claim
82 words
A repeater according to claim 12, wherein, where the received signal is less than said predetermined threshold, the control unit (16') may be effective to command the synthesiser of said second amplifier unit (13') to tune to the frequencies of the other voice channels in turn, to interrogate the other amplifier units (13') to determine whether any unit is receiving a signal whose strength is greater than said predetermined threshold, and to enable that amplifier unit if said predetermined threshold is exceeded.
Claim 15
Dependent Claim
37 words
A repeater according to claim 13 or claim 14, in which the control unit (16') is effective to allocate a third of the amplifier units (13') as the voice channel scanner upon an amplifier unit being enabled.
Claim 16
Dependent Claim
42 words
A repeater according to any one of the claims 10 to 15, in which the control unit (16') is effective to scan the amplifier units (13') and to release any enabled unit whose received signal strength does not exceed said predetermined threshold.
Claim 17
Dependent Claim
45 words
A mobile radio system including at least one base station (1) covering an area, and a repeater (5) according to any one of the preceding claims for enhancing communication between the base station (1) and mobile stations (3) within a sub-area of the area covered.
References Cited (Backward Citations)
No citation records indexed.
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