CA2035390A1 - Cellular mobile radio system - Google Patents
Cellular mobile radio systemInfo
- Publication number
- CA2035390A1 CA2035390A1 CA002035390A CA2035390A CA2035390A1 CA 2035390 A1 CA2035390 A1 CA 2035390A1 CA 002035390 A CA002035390 A CA 002035390A CA 2035390 A CA2035390 A CA 2035390A CA 2035390 A1 CA2035390 A1 CA 2035390A1
- Authority
- CA
- Canada
- Prior art keywords
- base stations
- switching center
- radio signals
- radio
- signals
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/08—Access point devices
- H04W88/085—Access point devices with remote components
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/25—Arrangements specific to fibre transmission
- H04B10/2575—Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
- H04B10/25752—Optical arrangements for wireless networks
- H04B10/25753—Distribution optical network, e.g. between a base station and a plurality of remote units
- H04B10/25754—Star network topology
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Mobile Radio Communication Systems (AREA)
- Optical Communication System (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
In a mobile-radio system with a switching center and with base stations, in which the base stations (FS1-FSn) transmit radio signals of mobile subscribers (MS) and receive these from them, according to the invention, the radio signals are not generated or processed in the base stations, but in the switching center (1). The switching center (1) thus contains a microwave transmitter/receiver (SE1-SEn) for each base station (FS1-FSn) which converts the signals to be transmitted to the base stations into radio signals and converts the radio signals received from the base stations into the base band position. This has the advantage that carrier frequency devices can be used jointly for a large number of base stations, so that the costs of the system are reduced.
In a mobile-radio system with a switching center and with base stations, in which the base stations (FS1-FSn) transmit radio signals of mobile subscribers (MS) and receive these from them, according to the invention, the radio signals are not generated or processed in the base stations, but in the switching center (1). The switching center (1) thus contains a microwave transmitter/receiver (SE1-SEn) for each base station (FS1-FSn) which converts the signals to be transmitted to the base stations into radio signals and converts the radio signals received from the base stations into the base band position. This has the advantage that carrier frequency devices can be used jointly for a large number of base stations, so that the costs of the system are reduced.
Description
2~3~39~
CELLULAR MOBILE RADIO SYSTEM
BACKGROUND _F THE INVENTION
Field of t~he Invention The invention relates to a mobile-radio system comprising a switching center and base stations, with the switching center connected to the base stations via lines, and the base stations transmitting radio signals to mobile subscribers and rece:iving radio signals from said mobile subscribers, and devices for generating the radio signals to be transmitted and for processing the received radio signals. A system of this type is known from Elektrisches Nachrichtenwesen, Vol. 63, No. 1, 1989, pp. 45-51, or from telcom-report 12 (1989) No. 5, pp. 142-145. This involves the standardized cellular mobile-radio system known throughout Europe as the so- ;
called GSM System.
In this system, a switching center, referred to as a "Mobile Ccmmunications Transmission Point" is connected via lines with several base stations (in a star-shaped or linear manner), and the switching center transmits those signals that the base stations are supposed to transmit via a radio connection to mobile subscribers, in the base band po~ition, eOg., as PCM 30 signals, to the base sta~ionsO The base stations have carrier frequency units which convert the signals to be transmitted ~rom the base band position into microwave signals, so that they can be transmitted via the radio connection to the mobile subscribers. The radio ignals received from the mobile subscribers are converted i.n the base stations to the base band position and are transmitted to th~ switching center ln this position. The devices generating the radio signals to be transmitted by the base stntions and ~or :
.
i 3 D~3 (~
converting the radio signals received from the mobile subscribers to the base band position are thus part of the base stations in the known system. No signals are converted to other frequencies in the switching center;
signals are merely switched through to the corresponding connections of t!he call.
If the radio tra~fic to ble handled is so dense that the cells serviced by a base station are appropriately s~lected to be vlery small, i.e., if one changes to so-called "micro-cells", then a very large number of cells and, thus, a very large number o~ base stations are required to supply a specific geographic area. If the known system is used Eor this purpose, this means high costs, because a very large number of base stations must be present, and each of these is expensive, primarily because of its HF carrier unit.
SUMMARY OF THE INyENTION
It is therefore an object of the invention to provide a mobile-radio~system of the type mentioned above, which, particularly in the case of a large number o~ existing cells~ offers cost advantages over the known system.
The problem is solved using a switching center, a plurality of base stations transmitting radio signals to mobile subscribers and receiving radio signals from aid mobile subscribQrs, optical waveguides connecting the switching center to the base stations, means disposed in the switching center for generating the radio signals to be transmitted and ~or processing the received radio signals, and optiaal transmitters and optical receivers located in the switching center and the base station ~or optically transmitting the radio .
' ~
: ' , .
: ~ ' 6~
signals between the switching center and the base stations. ~he arrangement according to the invention of the devices required in the system in order to generate the radio signals to be transmitted by the base stations and to process the radio signals received by the base stations offers the cost advantage that expensive components, e.g., osc:illators for carrier frequencies~ can be used jointly ~or a large number o~
carrier frequency devices present in the switching centar according to the invention. There is also the advantage that changes in the system can be carried out during expansion or during a new cell assignment in the switching center, and the base stations can remain unchanged.
DESCRIPTION OF THE DRAWINGS
Figure 1 shows a schematic overview o~ the mobile- -radio system according to the invention.
Figure 2 is a more detailed representation of the transmission devices of one of the transmission sections between a base station and the switching center.
DETAIL~D DESCRIPTION OF TH~ PREFERRED EMBODIMENT
The system according to Figure 1 includes a switching center 1, base stations FS1-FSn, for mobile stations MS and ~or lines Ll-Ln, each o~ which connects a base station with the swikching center. The lines Ll-Ln are optical waveguides, and optlcal signals with dif~erent wavelengths, e~g., 1300 nm and 1550 nm, are transmitted over these in the two transmission directions. Each base station is located in a ., ~-3 .. , , , .. , , ~ . ~ .,, . . .. . . - . . .. .
, , ., :. ., : ... . . ... .
~3~31~1~
geographical cell, cell l-cell n, and handles the radio traf~ic with the mobile stat.ions located within the cell. As in the known system, the switching center is connected to the public telephone network. However, it can also be connected with a h:igher-ranking switching center which, in turn, is connect2d to the public telephone network. In this case also, it is the switching center for the base stations connecked to it.
The signals to be transmitted from the public telephone network to mobile subscribers of a cell are already converted according to the invention in the switching center to radio signals with the frequency position in which they are to be transmitted by the base stations. In the reverse transmission direction, radio signals received by a base station from mobile subscribers are not already processed in the base station, but only in the switching center, i.e., they are converted to the base band position for ~urther transmission in the public telephone network. ..
For this purpose,-the switching center 1, as shown in Figure 1, contains a microwave transmitter/receiver ~or each base station connected to it. If the base sta~ions use the frequency channels assigned to them in a frequency-jump process and in time-division multiplex ~operation, as is the case in th~ known system, then the functions of the microwave transmitters/receiver6 also include the functions necessary ~or this, because these are related directly to th~ generation and processing of the radio signals transmitted or received by the base stations. The base stations only house the func~ions connected dlreckly with the transmisslon or . ~ .
2~s~
reception of the radio signals, i.e., es~entially a transmitter end stage and a reception amplifier.
In Figure 1, the above-melltioned microwave transmitters/receivers are des:ignated by SE1-SEn. At their inputs, which are shown only schematically, in the base band position the signals intended for one base station in each case are :inputted ~rom the public telephone network, or at their outputs, the signals received from a base station are outputted in the direction of the public telephone network.
Figure 2 provides a more detailed representation of which transmission directions o~ the total system are present in which parts of the system. In the left-hand part of Figure 2, one of the microwave transmitters/receivers SEl-SEn, designated as SEi, is shown as a component of the switching center indicated by a dashed line~ This microwave transmitter/receiver is connected via an optical waveguide Li with the associated base station, which is designated by FSi.
The actual microwave transmitter that has the above-described function of converting the signals intended for the ba~e station from tha base band position to the ~-HF position, and where applicabler of occupying the available frequency channels by the fre~uency-jump process and in a time-division multiplex mode is a unit designated by Tx, which has the reference number 2. At its output, it supplies the radio ~ignals to be transmitted by the base station FSi. Since the line Li is an optical waveguide~ the radio signals are converted in an electrical-to-optical transducer 3 into an optical si~nal, for example, with a wavelength of 1550 nm and are transmitted via a wavelength multiplexer/demultiplexer 4 and the optical waveguide Li to the base station FSi. There the optical ~ignal .. , . . , . . . . , ~ . . . . . . . . . . . ` .
q~
with the wavelength ~1 passes into a wavelength multiplexer/demultiplexer 5, which outputs the optical signal with the wavelength ~1 at an output that is connected with the input of an optical-to-eleckrical transducer 6. At the output of the optical-to-electrical transducer there appear the radio signals to be transmitted by the base station FSi, which only undergo an amplification in a transmitter end stage 7 and pass through a frequency se!paration filter ~, until they are transmitted by the antenna 9 of the base station.
Radio signals that are received by mobile subscribers from the antenna 9 of the base station pass through the frequency separation filter 8 to a reception amplifier 10 and, after amplification in this amplifier, are converted in an electrical-to-optical transducer 11 to an optical signal with a wavelength ~2 of, for example, 1300 nm, that is transmitted via the wavelength multiplexer/demultiplexer 5 and the optical waveguide Li to the switching center 1. There it passes via the wavelength multiplexer/demultiplexer 4 into an optical-to-electrical transducer 12, tuned to the wavelength ~2~ which converts it back into the radio siynals that the base station has received.
Finally, these pass from the output of the optical~to-electrical transducer 12 to the actual microwave receiver 13 (designated by Rx) which converts them into the base band position for further processing in the switching center.
- As shown in Figure 2~ the base station contains only simple and inexpensive components, such as amplifiers and filters for transmission and reception of the radio signals and conventional low-cost components ~or optical transmission of the radio : ~. ,.. ,.~. ,,,., , -. .. -- , , . , .: . , . ... ,, ,, . : : ,, . - . , ., . . , : . .
~ ~ 3 ~
s-gnals in the wavelength multiplexer. Since little transmitting power is required ~or the supply of small cells, the amplifier of the transmitter end stage 7 also does not represent any significant cost.
The ampli~ying transmitter end stage 7 can even be omitted if the base station for a very small cell is provided, e.g., a so-called l'micro-cell" with a cell diameter of approximately 100 m or a so-called "pico-celll' with the size of a room. In such cases, instead of the amplifying transmitter end stage 7, a passive matching network is connected in series with th~
optical-to-electrical transducer 6, with the output of the said ne work leading via the frequency separation filter 8 to the antenna 9. !:
If the optical-to-electrical transducer 6 is one which uses a PIN diode as the transducing element, then th~ whole transmission device of the base station is a passive device.
Instead of a PIN diode, the optical-to electrical transducer 6 can ~lso contain an Avalanche Photodiode (APD). In that case, the tran mitting device is an active transmitting device. Current amplification factors of more than 10 can currently be achieved with Avalanche Photodiodes.
In each of the two cases, the transmitting device has the advantage o~ not containing any electronic ampli~iers, which typically generally cause a band limitation and usually also contain critical non-linearities.
Variants of the exemplifying embodiment described so far will be explained below/ relating to the conduction of the optical waveguides connecting the base stations with the switching center and to the transmission proc-ss applied to this. In the ~33~3~
exemplifying embodiment described above, the base stations are connected in a star-shaped manner via one optical waveguide each with the switching center.
Instead of this, they can also be connected with the switching center in a line manner, via a single optical wav~guide, by being connected t:o this optical waveguide by couplers.
With this configuration, the transmission can be carried out as follows:
A separate wavelength pair is used for each base station, e.g., the wavelength pair 1300/1550 nm for FS1, the wavelength pair 1310/1560 nm for FS2, etc., in each case with the first wavelength of the pair for one transmission direction and the second wavelength of the pair for the other direction. Only the optical wavelength is fixed. The radio siynals transmitted by a base station at any moment and the radio signals received by a base station can be selected "at will". ~ -A flexible channel assignment and freguency-jump processes are also easily possible with this configuration.
Base stations that are freguently far apart, so that mutual interferences with the radio tra~fic are excluded, can use that same frequencies for the radio signals to be transmitted or received by them.
The wavelength pairs of the various base stations connected to a single optical waveguide can also be used several times, if the signals of different base ~tations dif~er from each other in other criteria, e.g.
by different time positions ~time-division multiplex) or different codes for digital signals (code multiplex).
' , .
CELLULAR MOBILE RADIO SYSTEM
BACKGROUND _F THE INVENTION
Field of t~he Invention The invention relates to a mobile-radio system comprising a switching center and base stations, with the switching center connected to the base stations via lines, and the base stations transmitting radio signals to mobile subscribers and rece:iving radio signals from said mobile subscribers, and devices for generating the radio signals to be transmitted and for processing the received radio signals. A system of this type is known from Elektrisches Nachrichtenwesen, Vol. 63, No. 1, 1989, pp. 45-51, or from telcom-report 12 (1989) No. 5, pp. 142-145. This involves the standardized cellular mobile-radio system known throughout Europe as the so- ;
called GSM System.
In this system, a switching center, referred to as a "Mobile Ccmmunications Transmission Point" is connected via lines with several base stations (in a star-shaped or linear manner), and the switching center transmits those signals that the base stations are supposed to transmit via a radio connection to mobile subscribers, in the base band po~ition, eOg., as PCM 30 signals, to the base sta~ionsO The base stations have carrier frequency units which convert the signals to be transmitted ~rom the base band position into microwave signals, so that they can be transmitted via the radio connection to the mobile subscribers. The radio ignals received from the mobile subscribers are converted i.n the base stations to the base band position and are transmitted to th~ switching center ln this position. The devices generating the radio signals to be transmitted by the base stntions and ~or :
.
i 3 D~3 (~
converting the radio signals received from the mobile subscribers to the base band position are thus part of the base stations in the known system. No signals are converted to other frequencies in the switching center;
signals are merely switched through to the corresponding connections of t!he call.
If the radio tra~fic to ble handled is so dense that the cells serviced by a base station are appropriately s~lected to be vlery small, i.e., if one changes to so-called "micro-cells", then a very large number of cells and, thus, a very large number o~ base stations are required to supply a specific geographic area. If the known system is used Eor this purpose, this means high costs, because a very large number of base stations must be present, and each of these is expensive, primarily because of its HF carrier unit.
SUMMARY OF THE INyENTION
It is therefore an object of the invention to provide a mobile-radio~system of the type mentioned above, which, particularly in the case of a large number o~ existing cells~ offers cost advantages over the known system.
The problem is solved using a switching center, a plurality of base stations transmitting radio signals to mobile subscribers and receiving radio signals from aid mobile subscribQrs, optical waveguides connecting the switching center to the base stations, means disposed in the switching center for generating the radio signals to be transmitted and ~or processing the received radio signals, and optiaal transmitters and optical receivers located in the switching center and the base station ~or optically transmitting the radio .
' ~
: ' , .
: ~ ' 6~
signals between the switching center and the base stations. ~he arrangement according to the invention of the devices required in the system in order to generate the radio signals to be transmitted by the base stations and to process the radio signals received by the base stations offers the cost advantage that expensive components, e.g., osc:illators for carrier frequencies~ can be used jointly ~or a large number o~
carrier frequency devices present in the switching centar according to the invention. There is also the advantage that changes in the system can be carried out during expansion or during a new cell assignment in the switching center, and the base stations can remain unchanged.
DESCRIPTION OF THE DRAWINGS
Figure 1 shows a schematic overview o~ the mobile- -radio system according to the invention.
Figure 2 is a more detailed representation of the transmission devices of one of the transmission sections between a base station and the switching center.
DETAIL~D DESCRIPTION OF TH~ PREFERRED EMBODIMENT
The system according to Figure 1 includes a switching center 1, base stations FS1-FSn, for mobile stations MS and ~or lines Ll-Ln, each o~ which connects a base station with the swikching center. The lines Ll-Ln are optical waveguides, and optlcal signals with dif~erent wavelengths, e~g., 1300 nm and 1550 nm, are transmitted over these in the two transmission directions. Each base station is located in a ., ~-3 .. , , , .. , , ~ . ~ .,, . . .. . . - . . .. .
, , ., :. ., : ... . . ... .
~3~31~1~
geographical cell, cell l-cell n, and handles the radio traf~ic with the mobile stat.ions located within the cell. As in the known system, the switching center is connected to the public telephone network. However, it can also be connected with a h:igher-ranking switching center which, in turn, is connect2d to the public telephone network. In this case also, it is the switching center for the base stations connecked to it.
The signals to be transmitted from the public telephone network to mobile subscribers of a cell are already converted according to the invention in the switching center to radio signals with the frequency position in which they are to be transmitted by the base stations. In the reverse transmission direction, radio signals received by a base station from mobile subscribers are not already processed in the base station, but only in the switching center, i.e., they are converted to the base band position for ~urther transmission in the public telephone network. ..
For this purpose,-the switching center 1, as shown in Figure 1, contains a microwave transmitter/receiver ~or each base station connected to it. If the base sta~ions use the frequency channels assigned to them in a frequency-jump process and in time-division multiplex ~operation, as is the case in th~ known system, then the functions of the microwave transmitters/receiver6 also include the functions necessary ~or this, because these are related directly to th~ generation and processing of the radio signals transmitted or received by the base stations. The base stations only house the func~ions connected dlreckly with the transmisslon or . ~ .
2~s~
reception of the radio signals, i.e., es~entially a transmitter end stage and a reception amplifier.
In Figure 1, the above-melltioned microwave transmitters/receivers are des:ignated by SE1-SEn. At their inputs, which are shown only schematically, in the base band position the signals intended for one base station in each case are :inputted ~rom the public telephone network, or at their outputs, the signals received from a base station are outputted in the direction of the public telephone network.
Figure 2 provides a more detailed representation of which transmission directions o~ the total system are present in which parts of the system. In the left-hand part of Figure 2, one of the microwave transmitters/receivers SEl-SEn, designated as SEi, is shown as a component of the switching center indicated by a dashed line~ This microwave transmitter/receiver is connected via an optical waveguide Li with the associated base station, which is designated by FSi.
The actual microwave transmitter that has the above-described function of converting the signals intended for the ba~e station from tha base band position to the ~-HF position, and where applicabler of occupying the available frequency channels by the fre~uency-jump process and in a time-division multiplex mode is a unit designated by Tx, which has the reference number 2. At its output, it supplies the radio ~ignals to be transmitted by the base station FSi. Since the line Li is an optical waveguide~ the radio signals are converted in an electrical-to-optical transducer 3 into an optical si~nal, for example, with a wavelength of 1550 nm and are transmitted via a wavelength multiplexer/demultiplexer 4 and the optical waveguide Li to the base station FSi. There the optical ~ignal .. , . . , . . . . , ~ . . . . . . . . . . . ` .
q~
with the wavelength ~1 passes into a wavelength multiplexer/demultiplexer 5, which outputs the optical signal with the wavelength ~1 at an output that is connected with the input of an optical-to-eleckrical transducer 6. At the output of the optical-to-electrical transducer there appear the radio signals to be transmitted by the base station FSi, which only undergo an amplification in a transmitter end stage 7 and pass through a frequency se!paration filter ~, until they are transmitted by the antenna 9 of the base station.
Radio signals that are received by mobile subscribers from the antenna 9 of the base station pass through the frequency separation filter 8 to a reception amplifier 10 and, after amplification in this amplifier, are converted in an electrical-to-optical transducer 11 to an optical signal with a wavelength ~2 of, for example, 1300 nm, that is transmitted via the wavelength multiplexer/demultiplexer 5 and the optical waveguide Li to the switching center 1. There it passes via the wavelength multiplexer/demultiplexer 4 into an optical-to-electrical transducer 12, tuned to the wavelength ~2~ which converts it back into the radio siynals that the base station has received.
Finally, these pass from the output of the optical~to-electrical transducer 12 to the actual microwave receiver 13 (designated by Rx) which converts them into the base band position for further processing in the switching center.
- As shown in Figure 2~ the base station contains only simple and inexpensive components, such as amplifiers and filters for transmission and reception of the radio signals and conventional low-cost components ~or optical transmission of the radio : ~. ,.. ,.~. ,,,., , -. .. -- , , . , .: . , . ... ,, ,, . : : ,, . - . , ., . . , : . .
~ ~ 3 ~
s-gnals in the wavelength multiplexer. Since little transmitting power is required ~or the supply of small cells, the amplifier of the transmitter end stage 7 also does not represent any significant cost.
The ampli~ying transmitter end stage 7 can even be omitted if the base station for a very small cell is provided, e.g., a so-called l'micro-cell" with a cell diameter of approximately 100 m or a so-called "pico-celll' with the size of a room. In such cases, instead of the amplifying transmitter end stage 7, a passive matching network is connected in series with th~
optical-to-electrical transducer 6, with the output of the said ne work leading via the frequency separation filter 8 to the antenna 9. !:
If the optical-to-electrical transducer 6 is one which uses a PIN diode as the transducing element, then th~ whole transmission device of the base station is a passive device.
Instead of a PIN diode, the optical-to electrical transducer 6 can ~lso contain an Avalanche Photodiode (APD). In that case, the tran mitting device is an active transmitting device. Current amplification factors of more than 10 can currently be achieved with Avalanche Photodiodes.
In each of the two cases, the transmitting device has the advantage o~ not containing any electronic ampli~iers, which typically generally cause a band limitation and usually also contain critical non-linearities.
Variants of the exemplifying embodiment described so far will be explained below/ relating to the conduction of the optical waveguides connecting the base stations with the switching center and to the transmission proc-ss applied to this. In the ~33~3~
exemplifying embodiment described above, the base stations are connected in a star-shaped manner via one optical waveguide each with the switching center.
Instead of this, they can also be connected with the switching center in a line manner, via a single optical wav~guide, by being connected t:o this optical waveguide by couplers.
With this configuration, the transmission can be carried out as follows:
A separate wavelength pair is used for each base station, e.g., the wavelength pair 1300/1550 nm for FS1, the wavelength pair 1310/1560 nm for FS2, etc., in each case with the first wavelength of the pair for one transmission direction and the second wavelength of the pair for the other direction. Only the optical wavelength is fixed. The radio siynals transmitted by a base station at any moment and the radio signals received by a base station can be selected "at will". ~ -A flexible channel assignment and freguency-jump processes are also easily possible with this configuration.
Base stations that are freguently far apart, so that mutual interferences with the radio tra~fic are excluded, can use that same frequencies for the radio signals to be transmitted or received by them.
The wavelength pairs of the various base stations connected to a single optical waveguide can also be used several times, if the signals of different base ~tations dif~er from each other in other criteria, e.g.
by different time positions ~time-division multiplex) or different codes for digital signals (code multiplex).
' , .
Claims
WHAT IS CLAIMED IS:
A mobile-radio system, comprising:
a switching center;
a plurality of base stations transmitting radio signals to mobile subscribers and receiving radio signals from said mobile subscribers;
optical waveguides connecting the switching center to the base stations;
means, disposed in the switching center, for generating the radio signals to be transmitted and for processing the received radio signals; and optical transmitters and optical receivers located in the switching center and the base stations for optically transmitting the radio signals between the switching center and the base stations.
A mobile-radio system, comprising:
a switching center;
a plurality of base stations transmitting radio signals to mobile subscribers and receiving radio signals from said mobile subscribers;
optical waveguides connecting the switching center to the base stations;
means, disposed in the switching center, for generating the radio signals to be transmitted and for processing the received radio signals; and optical transmitters and optical receivers located in the switching center and the base stations for optically transmitting the radio signals between the switching center and the base stations.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4002851.8 | 1990-02-01 | ||
| DE4002851 | 1990-02-01 | ||
| DE4004847 | 1990-02-16 | ||
| DEP4004847.0 | 1990-02-16 | ||
| DE19904008165 DE4008165A1 (en) | 1990-02-01 | 1990-03-15 | Cellular mobile radio system |
| DEP4008165.6 | 1990-03-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2035390A1 true CA2035390A1 (en) | 1991-08-02 |
Family
ID=27200778
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002035390A Abandoned CA2035390A1 (en) | 1990-02-01 | 1991-01-31 | Cellular mobile radio system |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0440081A3 (en) |
| JP (1) | JPH04213230A (en) |
| CA (1) | CA2035390A1 (en) |
| CS (1) | CS21791A2 (en) |
| FI (1) | FI910506A (en) |
| NO (1) | NO910261L (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2008900C (en) * | 1989-04-04 | 1998-01-20 | Ta-Shing Chu | Optical fiber microcellular mobile radio |
| CA2051496C (en) * | 1990-09-17 | 1996-05-07 | Katsumi Emura | Mobile communication system |
| JP2897492B2 (en) * | 1991-10-24 | 1999-05-31 | 日本電気株式会社 | Mobile communication device |
| WO1993012596A1 (en) * | 1991-12-16 | 1993-06-24 | Motorola, Inc. | Optical distribution system |
| US6101400A (en) * | 1997-08-20 | 2000-08-08 | Interwave Communications, Inc. | Methods and apparatus for improved base station transceivers |
| US5896568A (en) * | 1996-09-06 | 1999-04-20 | Northern Telecom Limited | Wireless architecture having redistributed access functions |
| US6205133B1 (en) | 1996-11-25 | 2001-03-20 | Ericsson Inc. | Flexible wideband architecture for use in radio communications systems |
| JP2001103016A (en) * | 1999-09-30 | 2001-04-13 | Oki Electric Ind Co Ltd | Between-road and communication system by radio transmission using optical fiber |
| DE60105392T2 (en) * | 2000-02-03 | 2005-09-22 | Ericsson Inc., Plano | SYSTEM AND METHOD FOR A CORDLESS CONNECTION BETWEEN BASE STATION AND EXTERNAL EQUIPMENT |
| US6801767B1 (en) * | 2001-01-26 | 2004-10-05 | Lgc Wireless, Inc. | Method and system for distributing multiband wireless communications signals |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3135231A1 (en) * | 1981-09-05 | 1983-04-07 | Standard Elektrik Lorenz Ag, 7000 Stuttgart | Information transmission system |
| JPS6212298A (en) * | 1985-07-10 | 1987-01-21 | Hitachi Ltd | Communication system for moving body |
| JPH029240A (en) * | 1988-06-28 | 1990-01-12 | Kokusai Electric Co Ltd | Communication system |
| GB8826476D0 (en) * | 1988-11-11 | 1988-12-14 | British Telecomm | Communications system |
| CA2008900C (en) * | 1989-04-04 | 1998-01-20 | Ta-Shing Chu | Optical fiber microcellular mobile radio |
| CA2051496C (en) * | 1990-09-17 | 1996-05-07 | Katsumi Emura | Mobile communication system |
-
1991
- 1991-01-23 EP EP19910100806 patent/EP0440081A3/en not_active Withdrawn
- 1991-01-23 NO NO91910261A patent/NO910261L/en unknown
- 1991-01-30 CS CS91217A patent/CS21791A2/en unknown
- 1991-01-31 JP JP3010613A patent/JPH04213230A/en active Pending
- 1991-01-31 CA CA002035390A patent/CA2035390A1/en not_active Abandoned
- 1991-02-01 FI FI910506A patent/FI910506A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| EP0440081A2 (en) | 1991-08-07 |
| FI910506A (en) | 1991-08-02 |
| NO910261L (en) | 1991-08-02 |
| FI910506A0 (en) | 1991-02-01 |
| EP0440081A3 (en) | 1992-06-24 |
| NO910261D0 (en) | 1991-01-23 |
| JPH04213230A (en) | 1992-08-04 |
| CS21791A2 (en) | 1991-09-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4063419B2 (en) | Optical transmission system | |
| US7127176B2 (en) | Optical transmission system of radio signal over optical fiber link | |
| EP0476569B1 (en) | Mobile communication system | |
| US5278690A (en) | Apparatus and method for synchronizing a plurality of remote transmission and receiving stations and providing automatic gain control of the synchronizing signal | |
| CA2044670C (en) | Radio communication system | |
| EP0346925B1 (en) | Private branch radio communication system using optical fibers | |
| JP2616468B2 (en) | Optical microcell transmission system | |
| EP1113594B1 (en) | Radio base station system and central control station with unified transmission format | |
| US5880863A (en) | Reconfigurable ring system for the transport of RF signals over optical fibers | |
| EP1501206A1 (en) | Access method and connection system by means of optical fiber using dwdm/scm hybrid techniques between base stations and remote antennas in a radiocommunication system | |
| US20020103012A1 (en) | Distributed antenna device for intermediate frequency conversion / process | |
| EP0859478B1 (en) | Wireless communications systems employing free-space optical communications links | |
| JPH09200840A (en) | Private radio communication system | |
| KR20000069456A (en) | Wireless communications station and system | |
| US6513163B1 (en) | Embedded forward reference and control | |
| EP0468688B1 (en) | Method and apparatus for providing wireless communications between remote locations | |
| WO2015024453A1 (en) | Ftth network based optical fiber, and wireless hybrid access system and hybrid access method | |
| CA2035390A1 (en) | Cellular mobile radio system | |
| US6731938B1 (en) | Wireless communication system for increasing reverse link capacity | |
| KR100330407B1 (en) | Apparatus for allocating sectors dynamically in a connected base station of optical repeater system for mobile telephone and method thereof | |
| KR100338625B1 (en) | Base station transceiver system using wavelength division multiplexing | |
| KR20000001105A (en) | Apparatus of optical transmission within wireless telecommunication base station system | |
| CN1055847A (en) | Cellular mobile radio system | |
| KR20010004636A (en) | Regenerator of optical signal and wireless communication base station system using it | |
| KR100681905B1 (en) | Reverse Path Integrated Optical Repeater |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19930731 |