Signal transmission systems
First Claim
1. A signal distribution system for distributing wireless communications network signals, the system comprising:
- a plurality of rf transmitters for transmitting rf signals to serve communications devices in a plurality of network cells or sectors; and
characterised in that the system further comprises;
a multiplexer, coupled to the rf transmitters, for multiplexing output signals from the transmitters and outputting a multiplexed transmitter signal;
a signal transporter, coupled to the multiplexer, for transporting the multiplexed transmitter signals to each of the network cells or sectors served by the transmitters; and
a multiplexed signal receiver at each served cell or sector, coupled to the signal transporter, for selecting and receiving a transmitter signal from an rf transmitter serving the cell or sector from the multiplexed transmitter signal.
1 Assignment
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Accused Products
Abstract
Signal transmission systems for second and third generation mobile communications networks are described. A signal distribution system comprises a plurality of rf transmitters for serving a plurality of network cells. The system is characterised by a multiplexer coupled to the transmitters for multiplexing the transmitter outputs, a signal transporter for transporting the multiplexed signals to each of the network cells, and a multiplexed signal receiver at each cell for selecting and receiving a signal from a transmitter serving the cell. The invention also provides a complementary signal reception system, and corresponding methods. Preferably, the multiplexed signals are transported over a fibre optic network such as an existing cable TV network. The system simplifies the deployment of network infrastructure for third generation mobile communications systems.
188 Citations
68 Claims
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1. A signal distribution system for distributing wireless communications network signals, the system comprising:
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a plurality of rf transmitters for transmitting rf signals to serve communications devices in a plurality of network cells or sectors; and
characterised in that the system further comprises;
a multiplexer, coupled to the rf transmitters, for multiplexing output signals from the transmitters and outputting a multiplexed transmitter signal;
a signal transporter, coupled to the multiplexer, for transporting the multiplexed transmitter signals to each of the network cells or sectors served by the transmitters; and
a multiplexed signal receiver at each served cell or sector, coupled to the signal transporter, for selecting and receiving a transmitter signal from an rf transmitter serving the cell or sector from the multiplexed transmitter signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 27, 28, 30, 31, 32, 68)
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12. A signal reception system for receiving wireless communications network signals, the system comprising:
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at least one rf receiver for receiving rf signals from communications devices in a corresponding plurality of network cells or sectors served by the receiver; and
characterised in that the system further comprises;
a signal transporter for transporting signals from each served cell or sector to a demultiplexer;
a cell or sector signal transmitter at each cell or sector, coupled to the signal transporter, for receiving a signal from a communications device in the cell or sector and for transmitting a cell or sector signal onto the signal transporter to make up at least part of a multiplexed cell or sector signal on the signal transporter; and
a demultiplexer, coupled to the signal transporter and to the rf receiver, for demultiplexing the multiplexed cell or sector signal on the signal transporter and for outputting a plurality of demultiplexed cell or sector signals to the receiver.
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23. A system for distributing signals from an rf transmitter to a plurality of antennas for transmitting to a plurality of coverage regions, the system comprising:
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an rf-to-optical converter for converting an rf input signal from the transmitter into an optical output signal;
a fibre optic cable, coupled to the rf-to-optical converter, for transporting the optical signal; and
a plurality of optical-to-rf converters, each coupled to the fibre optic cable, for providing an rf output signal corresponding to the rf signal from the transmitter to the plurality of antennas.
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26. A method of distributing signals for a communications network, the communications network having a plurality of cells or sectors each served by a transmitter, the method comprising:
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multiplexing output signals from the transmitters to provide a composite signal comprising transmissions for each of the plurality of cells or sectors;
distributing the composite signal to each of the cells or sectors; and
selecting, at a said cell or sector, the transmission for the cell or sector from the composite signal.
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29. A method of receiving signals for a communications network, the communications network having a plurality of cells or sectors each served by a receiver, the method comprising:
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receiving signals from communications devices in the plurality of cells or sectors;
forming a multiplexed signal comprising the signals received in the cells or sectors;
transmitting the multiplexed signal to a demultiplexer;
demultiplexing the received signals using the demultiplexer; and
providing the or each receiver with a received signal from each said cell or sector.
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33. A method of communicating signals for a communications network, the communications network having a plurality of cells or sectors each served by a transmitter and receiver, the method comprising:
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multiplexing output signals from the transmitters to provide a composite signal comprising transmissions for each of the plurality of cells or sectors;
distributing the composite signal to each of the cells or sectors; and
selecting, at a said cell or sector, the transmission for the cell or sector from the composite signal; and
receiving signals from communications devices in the plurality of cells or sectors;
forming a multiplexed signal comprising the signals received in the cells or sectors;
transmitting the multiplexed signal to a demultiplexer;
demultiplexing the received signals using the demultiplexer; and
providing the or each receiver with a received signal from each said cell or sector; and
wherein said distributing and said transmitting use separate fibres of a single fibre optic cable. - View Dependent Claims (36, 37, 38, 40)
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34. A method of distributing an rf transmitter signal to cells or sectors of a wireless communications network, the method comprising:
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converting the rf transmitter signal to an optical signal;
distributing the optical signal to the cells or sectors of the network over a fibre optical cable; and
converting the optical signal to an rf signal for transmission at each said cell or sector.
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35. A multiplexer for multiplexing rf output signals from a plurality of transmitters onto a multiplexed output signal, each transmitter serving at least one cell or sector in a cellular communication network, the multiplexer comprising:
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a plurality of rf-to-optical converters to convert the rf outputs of the plurality of transmitters to a corresponding plurality of optical signals; and
an optical multiplexer to multiplex the plurality of optical signals to provide a multiplexed optical output signal from which a signal for serving a cell or sector is selectable.
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39. A demultiplexer for receiving and demultiplexing a multiplexed optical signal, the multiplexed signal comprising signals received from a plurality of cells or sectors of a cellular communications network, the demultiplexer comprising:
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an optical demultiplexer to demultiplex the multiplexed optical signal into a plurality of separate optical signals, each corresponding to a signal received from a said cell or sector; and
a plurality of optical-to-rf converters, each coupled to the optical demultiplexer, for converting the plurality of optical signals to a corresponding plurality of rf signals for output to a plurality of rf receivers serving the said plurality of cells or sectors.
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41. A signal receiver for a cell or sector of a cellular communications network, the signal receiver comprising:
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an optical input, to receive a multiplexed optical signal;
an optical selector to select a part of the multiplexed optical signal comprising an optical signal carrying information for an rf signal for the cell or sector; and
an optical-to-rf converter, having an input coupled to the optical selector and an output for receiving and converting the selected part of the multiplexed signal into an rf signal, and for outputting the rf signal for transmission by the cell or sector. - View Dependent Claims (43)
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42. A signal transmitter for a cell or sector of a cellular communications network, the signal transmitter comprising:
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an rf input for inputting an rf signal received from a cell or sector antenna;
an rf-to-optical converter, coupled to the rf input, for converting the rf input signal to an optical signal; and
an optical multiplexer, coupled to the rf-to-optical converter, to multiplex to the optical signal into a multiplexed optical signal comprising optical signals provided from one or more other cells or sectors.
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44. A system for coupling cell transceivers of a cellular mobile communications network to respective cell antennas, the system comprising:
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a plurality of said cell transceivers and cell antennas;
a transceiver signal combiner/separator coupled to the plurality of transceivers and to a signal bearer to combine transceiver output signals from the transceivers for output onto the signal bearer and to separate combined transceiver input signals received from the bearer for input to the transceivers;
a signal bearer coupled to the combiner/separator to carry the combined transceiver input and output signals between the transceivers and each cell; and
a plurality of cell signal combiner/separators, each coupled to the signal bearer and to a said cell antenna, to combine a signal received at the cell antenna with other signals on the signal bearer received at other cell antennas to provide said combined transceiver input signals, and to separate a transmit signal for the cell antenna from said combined transceiver output signals. - View Dependent Claims (45, 46, 47, 48, 49, 50, 51)
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52. A cellular communications sub-system comprising a plurality of transceivers each serving a respective cell, each cell having a cell antenna;
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characterised in that the transceivers for a plurality of said cells are substantially co-located, and in that the system further comprises;
transceiver interface means to combine rf interfaces of a plurality of the transceivers into a combined signal interface;
transport means to transport signals between the combined signal interface and two or more of said cells; and
coupling means to selectively couple signals between said transport means and each said cell antenna. - View Dependent Claims (53, 54, 55, 56, 58, 59, 60)
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57. A signal distribution system for distributing signals for a wireless communications network in which a geographical area covered by the network is divided into cells, the system comprising:
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a first wireless transmitter to provide a first signal output for serving a first cell;
a second wireless transmitter to provide a second signal output for serving a second cell;
a multiplexer having inputs coupled to the first and second wireless transmitters to receive the first and second signal outputs from the transmitters and having an output, to multiplex the received transmitter outputs onto a multiplexed output signal;
a signal transporter coupled to the multiplexer output to transport the multiplexed signal to first and second cell sites; and
a first signal selector at the first cell, coupled to the signal transporter to select a first signal from the multiplexed signal corresponding to the signal output from the first transmitter, for serving the first cell.
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61. A signal transmission system for transmitting signals between a plurality of transmitters and/or receivers and a corresponding plurality of antennas, each antenna serving a separate cell of a cellular communications system, the signal transmission system comprising a fibre optic cable for coupling the transmitters and/or receivers and corresponding antennas, characterised in that:
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the fibre optic cable includes a loop; and
in thatthe system further comprises a monitor to monitor integrity of signal transmission on the cable loop and a switch responsive to the monitor to reverse a direction of signal transmission on the cable loop and/or to select an end of the cable loop for reception of signals from a cell of the communication system in response to the monitor signalling that the integrity of signal transmission is or has been adversely affected. - View Dependent Claims (62, 63)
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64. A signal distribution system for a GSM mobile communications network comprising a digital communications network, at least one Base Station Controller (BSC) and a plurality of Base Transceiver Stations (BTSs), each Base Transceiver Station having a digital interface coupled to the Base Station Controller via the digital communications network, characterised in that:
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the system further comprises a common digital interface device to the digital communications network; and
in thateach of the Base Transceiver Stations is coupled to the common interface device to provide a shared digital connection for the Base Transceiver Stations to the Base Station Controller. - View Dependent Claims (65)
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66. A signal distribution system for a IMT-2000 mobile communications network comprising a digital communications network, at least one Radio Network Controller (RNC) and a plurality of Node Bs, each Node B having a digital interface coupled to the Radio Network Controller via the digital communications network, characterised in that:
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the system further comprises a common digital interface device to the digital communications network; and
in thateach of the Node Bs is coupled to the common interface device to provide a shared digital connection for the Node Bs to the Radio Network Controller. - View Dependent Claims (67)
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Specification