CA2145998A1 - Arrangement in mobile telecommunications systems for providing for synchronization of the transmitters of the base stations - Google Patents
Arrangement in mobile telecommunications systems for providing for synchronization of the transmitters of the base stationsInfo
- Publication number
- CA2145998A1 CA2145998A1 CA002145998A CA2145998A CA2145998A1 CA 2145998 A1 CA2145998 A1 CA 2145998A1 CA 002145998 A CA002145998 A CA 002145998A CA 2145998 A CA2145998 A CA 2145998A CA 2145998 A1 CA2145998 A1 CA 2145998A1
- Authority
- CA
- Canada
- Prior art keywords
- time
- time information
- base stations
- real
- common
- 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
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/155—Ground-based stations
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04H—BROADCAST COMMUNICATION
- H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
- H04H20/65—Arrangements characterised by transmission systems for broadcast
- H04H20/67—Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
- H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
- H04B7/2662—Arrangements for Wireless System Synchronisation
- H04B7/2671—Arrangements for Wireless Time-Division Multiple Access [TDMA] System Synchronisation
- H04B7/2678—Time synchronisation
- H04B7/2687—Inter base stations synchronisation
- H04B7/2693—Centralised synchronisation, i.e. using external universal time reference, e.g. by using a global positioning system [GPS] or by distributing time reference over the wireline network
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J3/00—Time-division multiplex systems
- H04J3/02—Details
- H04J3/06—Synchronising arrangements
- H04J3/0635—Clock or time synchronisation in a network
- H04J3/0682—Clock or time synchronisation in a network by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Mobile Radio Communication Systems (AREA)
- Synchronisation In Digital Transmission Systems (AREA)
- Electric Clocks (AREA)
- Information Transfer Systems (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
Abstract
The invention relates to an arrangement in a mobile telecommunication system which operates with two or more base stations operating with transmitters. The base stations are provided with, on the one hand, transmitting elements which, are each arranged to operate with a real-time clock allocated to it and, on the other hand, time-comparing elements. A
central coordinating unit in the system is arranged to transmit a first time signal to an element arranged in the base station for receiving the said first common time information. The first time information is then transferred together with a second time information to the time-comparing element. The second time information is set up by the real-time clock in the transmitting element. The said first common time information and said second time information are placed in relation to one another and, in dependence on the relationship between these and existing criteria, for example delays and the like, the time-comparing element effects influences on/adjustments of the said real-time clock so that synchronization is carried out.
central coordinating unit in the system is arranged to transmit a first time signal to an element arranged in the base station for receiving the said first common time information. The first time information is then transferred together with a second time information to the time-comparing element. The second time information is set up by the real-time clock in the transmitting element. The said first common time information and said second time information are placed in relation to one another and, in dependence on the relationship between these and existing criteria, for example delays and the like, the time-comparing element effects influences on/adjustments of the said real-time clock so that synchronization is carried out.
Description
21~9~
wo 94/10768 PCr/SE93/00849 TITLE
Arrangement in mobile telecommunications systems for providing for synchronization of the tr~nsmitters of the base stations.
TECHNICAL FIELD
The present invention relates to an arrangement for producing, in mobile t~lecoTnT-~ur ic~tion s~l~ s which operate with base stations transmitting to 10 mobile units, a central synchronization of the transmitters of each respective base station, taldng into consideration propagation time delay, delays in the cabling, tr~nsmit~ers and so forth The in~ention is also of the type which operates with information-receiving 15 elemen~s, a real-time clock and comr~ring eleme~
PRIOR ART
Base stations operate in mobile radio co~ununication systerns with coverage 20 areas. When the coverage areas partly overlap one another or interfere with one another, a manual or automatic synchronization process is used. In automatic synchronization syste~ls, it is usually a base station ~e internal dock of which is assumed to be a reference clock, a master dodc. The base station which is provided with the master clock then carries out a seql~erti~l 25 synchrorli7~tion of the inp~l clocks, slave clocks, of the other affected base stations. Using a referel-ce time signal, tr~nsmissiQn takes place from the affected base station which operates with the reference clock, the master clock.The signal is rece~ved in the regular rec~v~ of the other affected base stationswhich receiv~s adjust their internal clo~ks to the refelel,ce time. After that, 30 the synchronized base st~tion establishes communication with a new base sbtion which is then synchroni~ed to it, and so forth The base station which is provided with a refer~ce clock f~nc~ior-/master clock function is frequently arranged with an atomic clocl~
3~ In cor~ on with mobile s~ u,s belor~n~ to this category, a plurality of metllo-lc have been proposed for synchronizing the transmitters in the base shtions. The me~ods have included synchronization of single base stations or parts of the transmill~ nelnro.k SUBSTlTUTE SI~EET
214~9g8 WO 94/10768 PCr/SE93/00849 ACCOUNT OF THE INVENTION
TECHNICAL PROBLEM
5 Today's n~o~iern mobile telecommunication syst~m y~ es~ose that the mobile units can flexibly move within the tohl propagation range of the srs~ s at the same time as the greatest possible atterlhon can be paid to the mobile units being located within areas, where the coverage areas of one or more base stations overlap one another, when it is of hi~hest priority that the 10 base stations are synchronized with one another with re~e~l to time.
It should be possible to carry out this synchroni7afion in such a manTI~r that the synchronization is e~e~ted at the same time in all transmitters of the base stations which are to be synchronized on the occasion in question.
15 Furthennore, the synchroni~aficn shc~ not occupy chann~ resources in the mobile sy:,k~L It shQ~ be possihle to carry out the synchro~i7~tion in such a manner that the synchron~zation effects influences on/adjustments of the internal real-time clocks with which the base stations are operating. The invention is inten~ierl to solve the abov~m~ntione~l problem~, among others.
In one embodin~ent of the subject matter of the invention, an internal real-time clock is utilized in the base stations, which dock should be able to be allocated a st~n~a~ ed time or be re~ d to such a time. This time should be the same for all lr~ rs of the base stations in the total sys~ . The ion is intended to solve this problem as well.
In one embo~inlent of the subject matter of the inventior, a comr~on time infc,l~ation is ~-tili~edl, which is i~ etl from a central coor~ ati~ UIUt.
It should be possible for this time informatiQn to consist of a 5pndardized time30 signal which should be rere.le.i to a s~n~rdized tune or consist of such a time. The invention also intPn~ls to solve this problem. In one embo~ ent of the invenhon, it should be possible to c~ sale for a time delay which is produced in the station S itself. The invention is also ir~terltle~l to solve this problem.
In one embodiTr~ t of the il-v~ or, it shoult be possible to synchronize the total cove~age area of the whole mobile telecomml~nication system. The i..v~ ion is also int~nde~1 to solve this proWem.
SUBSTITUTE SHEET
wo 94/10768 PCr/SE93/00849 TITLE
Arrangement in mobile telecommunications systems for providing for synchronization of the tr~nsmitters of the base stations.
TECHNICAL FIELD
The present invention relates to an arrangement for producing, in mobile t~lecoTnT-~ur ic~tion s~l~ s which operate with base stations transmitting to 10 mobile units, a central synchronization of the transmitters of each respective base station, taldng into consideration propagation time delay, delays in the cabling, tr~nsmit~ers and so forth The in~ention is also of the type which operates with information-receiving 15 elemen~s, a real-time clock and comr~ring eleme~
PRIOR ART
Base stations operate in mobile radio co~ununication systerns with coverage 20 areas. When the coverage areas partly overlap one another or interfere with one another, a manual or automatic synchronization process is used. In automatic synchronization syste~ls, it is usually a base station ~e internal dock of which is assumed to be a reference clock, a master dodc. The base station which is provided with the master clock then carries out a seql~erti~l 25 synchrorli7~tion of the inp~l clocks, slave clocks, of the other affected base stations. Using a referel-ce time signal, tr~nsmissiQn takes place from the affected base station which operates with the reference clock, the master clock.The signal is rece~ved in the regular rec~v~ of the other affected base stationswhich receiv~s adjust their internal clo~ks to the refelel,ce time. After that, 30 the synchronized base st~tion establishes communication with a new base sbtion which is then synchroni~ed to it, and so forth The base station which is provided with a refer~ce clock f~nc~ior-/master clock function is frequently arranged with an atomic clocl~
3~ In cor~ on with mobile s~ u,s belor~n~ to this category, a plurality of metllo-lc have been proposed for synchronizing the transmitters in the base shtions. The me~ods have included synchronization of single base stations or parts of the transmill~ nelnro.k SUBSTlTUTE SI~EET
214~9g8 WO 94/10768 PCr/SE93/00849 ACCOUNT OF THE INVENTION
TECHNICAL PROBLEM
5 Today's n~o~iern mobile telecommunication syst~m y~ es~ose that the mobile units can flexibly move within the tohl propagation range of the srs~ s at the same time as the greatest possible atterlhon can be paid to the mobile units being located within areas, where the coverage areas of one or more base stations overlap one another, when it is of hi~hest priority that the 10 base stations are synchronized with one another with re~e~l to time.
It should be possible to carry out this synchroni7afion in such a manTI~r that the synchronization is e~e~ted at the same time in all transmitters of the base stations which are to be synchronized on the occasion in question.
15 Furthennore, the synchroni~aficn shc~ not occupy chann~ resources in the mobile sy:,k~L It shQ~ be possihle to carry out the synchro~i7~tion in such a manner that the synchron~zation effects influences on/adjustments of the internal real-time clocks with which the base stations are operating. The invention is inten~ierl to solve the abov~m~ntione~l problem~, among others.
In one embodin~ent of the subject matter of the invention, an internal real-time clock is utilized in the base stations, which dock should be able to be allocated a st~n~a~ ed time or be re~ d to such a time. This time should be the same for all lr~ rs of the base stations in the total sys~ . The ion is intended to solve this problem as well.
In one embo~inlent of the subject matter of the inventior, a comr~on time infc,l~ation is ~-tili~edl, which is i~ etl from a central coor~ ati~ UIUt.
It should be possible for this time informatiQn to consist of a 5pndardized time30 signal which should be rere.le.i to a s~n~rdized tune or consist of such a time. The invention also intPn~ls to solve this problem. In one embo~ ent of the invenhon, it should be possible to c~ sale for a time delay which is produced in the station S itself. The invention is also ir~terltle~l to solve this problem.
In one embodiTr~ t of the il-v~ or, it shoult be possible to synchronize the total cove~age area of the whole mobile telecomml~nication system. The i..v~ ion is also int~nde~1 to solve this proWem.
SUBSTITUTE SHEET
- 2~998 - ~vo 94/10768 PCr/SE93/00849 In one emho~ nt of the invPntion, a buffer is ~hli~P~l in which it should be possible to distribute outgoing t~ it data with respect to time to affe~led mobile units in such a m~r~n~Pr that the tr~n~mission is synchronized for one or more base stations. The invention is also intended to solve this problem.
In one Pmbo~ ent of the invention, el~Pmpr~tc for receiving a common time inform~tion are ~lfili7e~l It should be possible to adapt this time information to a format which is comprel~e~.sihle to the system. The invention is also int~Pn~le~3 to solve this problem.
In one em~iin~e~t of the arrangemer.t, communic~tion elementc are ~ e~l in which it should be possible to input tr~nsmit data as is a common time Lation. The in~,el~lion is also i~tenrle-l to solve this problem.
1~ If desired, the invention should constitute a digital telecommunication .~ s~ste.l., base stations operating with ~ a, which stations operate withpaging. The invention solves this problem as well.
THE SOLUTlON
That which can be mainly considered as being characterizing of an arrangement acc~r~ g to ~e invention is that all base stations in ~e sysk,-are provided with, on the one hand, l~ c~ g elemer.tc which are arranged 2~ to Gl,e~ate with a real-time clock allocated to them and, on the other, time-comparing elements. A fur~er charactenstic is that t`he sysle~l. is provided with a coordinating unit which is arranged to ~ -.it a common time information to the base stations in the s~al~l and that the said base stations are arranged with elementâ for recelv~lg the comnlQn time infG-u ation and 30 supplying the common time i~lu~ation to the time-comparing element together with a second time information. This second time information in established in the base station and related to a time which a real-time clock in~he transmitting elerrlert is operating with. Furthermore, the comparing ele~r~Pnt is arranged to put the said common time i~lfo.mation and the said - 3~ second time i.~ ffon into rPl~tion with one another. The relation l,et~-l the c~-..-n~n time i.~,...~n and the seco~d time i~.fo..~.~tion together with existin-g criteria, for example delays and the like, effects influences onladjustments to the real-time dock included in the base station in such a ~nAr~ ?r that the synchroni7~iQr~ is cArri~ out.
wo 94/10768 2 1 ~ 5 ~ 9 8 pcr/sE93/oo84s In one emborliment of the conoept of the invention, the internal real-time dock is allocated a real-time which refers to or is constituted by a refelellce time to solar time at the zero rneri~iian in lon~t~ , UTC tirne.
S In a further embo~limer~t of the concept of the invention, the common time infolu.ation which is trancmitte~ from the said coordinating unit to the ~eoeivi..g elementc of the base stationc is a standardized signal, a GPS signal.
In a further embo~lim~t of the concept of the iuve~ Qn~ the time delay which 10 is ocraciQne~ in the station S itself is compensated for by the internal real-time doclc in each base station being set/adjusted to the time unit T in advanoe of the current time.
In a further en~ho~liment of the subject matter of the invention, the said time 15 synchronization ir~ es all` base stations operating with tran~mitt~-s in the total coverage area of the ,*l~o t~
In a fu.lher embo~iment of the concept of the invention, a dosed phase-lodcing :~y~ is establi~he~l in which the c~mraring elemer~t together with 20 the element for recE:vil.g the first common time information, the internal real-time clock and existing criteria form the said system.
In a further embodiment of the subject matter of the invention, the tra..~-..itl;~ elemen{ts included in the base stations are arranged to operate 25 with a buffer function. This buffer function is co~l~led to a pulse-generatdng unit which generates the signals which are required for synchronized transmission In a f~ulher embo~ ent of the subject matter of the invention, the element 30 for receivi~.g the con~n~on time ~G~ ~a~or, which ~l~a~t is c~.s~ te~l by a GPS sigr ~l, is ~-ocesse~l into a coull,rehensible format before it comes into the comparing elpnlerlt~ i.e. the same format as the one that the internal real-timeclock ~ates with 35 In a further embo~im~nt of the subject matter of the invention, the base station is arranged with communication PlPmer~ts. These communication elements are on the one hand set up for trancmifflng transmit data to the tr~n~ tl~r and on the other hand set up for t~ g ~ime ~-fo~ ation (the C;PS signal) to the co ~ a- ;-~g element.
SUBSTITUTE SHEET
2~4599g - WO 94/10768 pcr/sE93/oo84s s In a further ernbodiment of the subject matter of the invention, the said mobile communication s~ts~ is a digital mobile network. The digital mobile network operates with paging. The mobile units which are served are pagers.
ADVANTAGES
An effective synchronization of one or more base stations operating with transmitters can be effected by what has been proposed above. The synchronization is carried out simultaneously in two or more base stations 10 operating with transmitters in the mobile telecomn~unication sys~e~. The invention is also arranged in such a ~l~nT~er that consideration can be given tothe i~terrl~l delays which can be produced by the system per se, delays in ~ak~ g, trans~rutters, antennas and so forth The invention is arranged in such a m~ er that all transmitters in the system can be encompassed by the 15 synchronization. All tr~cmitters in the s~sLt:... will the.efore always effect tr~nc~icsion of u~lu~ation in coor~lin~tion with one another. The result of this is that a mobile unit (pager) in the s~sleu- can always make large movements. The mobile unit also always obtains a time-coordinated ..ation from the base stations in situatiorLC in which the mobile unit is located in areas where the coverage areas of two or more base stations overlap one another.
SHORT DESCRI~IlON OF THE DR~WINGS
A currently ~ro~osed embo~liment of an arrangment which exhibits the char~ctenctics significant of the i~v~llion will be described below whilst at the same time re~.ulg to the att~che~ drawings in which Flgure 1 shows in basic diagram form a mobile telecorrununication s~ste.
including a oentral coordinating unit, Figure 2 shows in basic diagram form a base station including receiving elements, comparing elemf~ and transmitting elements and Flgure 3 shows in basic diagram fonn a oentral c~orl1in~hng unit.
- ' DEIAILED DESCRIPIION OF A PREFERRED EMBODIM~T
Flgure 1 shows a mo~ile telecomlmi~tion :~5l~-. A number of base s~tio~c is cor nected to the sysle~L These are represer~t~ by 1, 2, 3 ,4 in the figure. TheSuBS~I~uT~ s~EE~ -Yo 94/10768 pcr/sE93/oo84s base stations, in turn, are co~nect~l via a fixed connection 5, 6, 7, 8 to a number of nlobile telephone P~cchar~es rel,lesellted by 9 and 10. The mobile telephone e~arl~es, in turn, are connected via swit~l~ing stations 11, 12 to the landline telephone nel~ro.l~ 13. A number of mobile units 14~14~14n~ 15 is connected to S the base stations 1, 2, 3, 4~ On a call to a mobile unit 14~ 14~ 14n~ 15~ a contact is es~ablishe 1 from the public telephone networlc i3 via the switching stations 11, 12 to the mobile telephone eY~h~n~es 9,10, which command the base stations 1~ 2~ 3~ 4 to make a call to the l~uired mobile unit 14~ 14~14 ~ 15. The base station 1, 2, 3, 4, within whose coverage area the mobile unit 14~ 14~ 14n~ 15 is 10 located establishes contact, whereupon the call information is transferred (;-.fo~ tion on the caller's identity in a paging system). In those cases where the mobile unit 15 is located within the coverage area of one or more base stations 2, 3, the mobile unit decides ~nth the aid of, among others, the strength of the carrier wave, which base station 2, 3 it should connect itself to.
15 When the n~.~kile unit 15 is l~te~l within the area where the coverage areas of one or more base s~ior~c 2, 3 overlap one another, it is highly ~r~.ed that the call goes out synchronously from the affe.led base sPt~Qr~s 2, 3. To obtain a synchronous trancmission from all the base stations 1, 2, 3, 4 in the syst~n a coor~ tin~ unit 16 is arranged. The coor~linating unit 16 transfers a cornmon 20 tirne information to elements for reception-17, 18, 19, 20 inten-led for thispurpose and arranged at each respective base station 1, 2, 3, 4. This cornmon time ~ ation is compa~ed with a second time information set up by the said base stations 1, 2, 3, 4. This second time information is lefe~led to or corsistc of a ~me which is r~f~led to solar time at the zero meridian in 25 lor~ 3e, UTC tine, and is ~r~ecte~ by the time delays which are produced in the station itself. The common t me inform~ti~n is then placed into relation, in the comp~ing ~lement 21, 22, 23, 24 of the al~led base stations, with the said seco~l time h~.mation, wheieu~ol- the comparing element effects infl~ences on/adj!~c~ ents of the real-time docks in ~e affected base shtions 30 so that a time syl~ ro~ ation of the base stations 1, 2, 3, 4 is carried out.
Figure 2 shows a base station included in the mobile teleco~rununication system. The base station is provided with a transmitting element 24 for outgoing transmit data, a time~ g elenlent 25 and an element 26 35 receivillg the c~mmon time i.~fo~mation. Outgoing data which are to be transmitte~ from the lr-~-s-~ Plen~t 24 arrive at the base station via a first communication element 27. The first communication element 27 is co~necte~ to &e n~obile telephone eY~h~nge via a l~ndline connec~ion 2~. The outgoing transmit data are then ~ s~..ed to a buffer 29 included in the SUBST~TUTE SHEET
2~45~8 - /0 94/10768 - PCr/SE93/00849 transrnitting element 24. The outgoing transrnit data in the buffer are then clocked out to the transrnitter with the aid of s~ s which are generated h a pulse-generating unit 30. The pulse-generating unit is connected to the internal real-time clock 31 of the base station. The hternal real-time of the base 5 station is refe..ed to or is constituted by a time which is refe~,ed to solar time at the zero meridian in longitude, the so-called UTC time. In order to synchronize the base station shown in Figure 1, a first time information common to all base stations is transmitted in from a centrally arranged coordinating unit, in the form of a GPS signal, to an elP~nPT~t, arranged at the10 base station, for receiving the first common time information 26. The common time information which has come in is reprocessed in a comrnunication e1ement 32 provided for this purpose and is transferred to the time-comparing elen~e~t 25 in a format which is comprP~encible to the base station. A second time information is then transferred from the internal real-1~ time clock 31 to the time-comparing element 25 whereupon the time-comparing element places the com-non time information in relation to the second time information. Existing criteria, for example delays and the like, arethen introduced into the comp~ring element 25 from a unit 33 inten~e~l for this purpose. The comparing element 25 then effects influences 20 on/adjustrnents of the internal real-time clock in dependence on introduced criteria and on the relation between the common time information and the - second time info.lllation, thereby providing for time synchronization of two or more base stations.
~lgure 3 shows a central coorli, ating unit. The central unit is provided with a2S clock 34, ~re~erably an ~tomic clocl~ The atomic clock sends clock signals to a converter 3S which converts the clock pulses from the atomic clock to GPS
signals. The GPS signals are then transferred from the converter to a tr~ncmitter 36 arranged in the central unit. An ~ntenrl~ element 37 is arranged at the transmitter 36. The transrnitter 36 establishes contact with the base 30 stations which are to be syncllroni~ed (~.eferably all the base stations in the s~sl~) and transrnits synchronously to these base stations.
The in~rention is not limited by the embo~ erlt shown as an example above but can be sul,je~ed to mo~ or c wi~in the scope of the subsequent patent 35 claims and the concept of the il~v~:nlion.
SUBSTITU~E SHEET
In one Pmbo~ ent of the invention, el~Pmpr~tc for receiving a common time inform~tion are ~lfili7e~l It should be possible to adapt this time information to a format which is comprel~e~.sihle to the system. The invention is also int~Pn~le~3 to solve this problem.
In one em~iin~e~t of the arrangemer.t, communic~tion elementc are ~ e~l in which it should be possible to input tr~nsmit data as is a common time Lation. The in~,el~lion is also i~tenrle-l to solve this problem.
1~ If desired, the invention should constitute a digital telecommunication .~ s~ste.l., base stations operating with ~ a, which stations operate withpaging. The invention solves this problem as well.
THE SOLUTlON
That which can be mainly considered as being characterizing of an arrangement acc~r~ g to ~e invention is that all base stations in ~e sysk,-are provided with, on the one hand, l~ c~ g elemer.tc which are arranged 2~ to Gl,e~ate with a real-time clock allocated to them and, on the other, time-comparing elements. A fur~er charactenstic is that t`he sysle~l. is provided with a coordinating unit which is arranged to ~ -.it a common time information to the base stations in the s~al~l and that the said base stations are arranged with elementâ for recelv~lg the comnlQn time infG-u ation and 30 supplying the common time i~lu~ation to the time-comparing element together with a second time information. This second time information in established in the base station and related to a time which a real-time clock in~he transmitting elerrlert is operating with. Furthermore, the comparing ele~r~Pnt is arranged to put the said common time i~lfo.mation and the said - 3~ second time i.~ ffon into rPl~tion with one another. The relation l,et~-l the c~-..-n~n time i.~,...~n and the seco~d time i~.fo..~.~tion together with existin-g criteria, for example delays and the like, effects influences onladjustments to the real-time dock included in the base station in such a ~nAr~ ?r that the synchroni7~iQr~ is cArri~ out.
wo 94/10768 2 1 ~ 5 ~ 9 8 pcr/sE93/oo84s In one emborliment of the conoept of the invention, the internal real-time dock is allocated a real-time which refers to or is constituted by a refelellce time to solar time at the zero rneri~iian in lon~t~ , UTC tirne.
S In a further embo~limer~t of the concept of the invention, the common time infolu.ation which is trancmitte~ from the said coordinating unit to the ~eoeivi..g elementc of the base stationc is a standardized signal, a GPS signal.
In a further embo~lim~t of the concept of the iuve~ Qn~ the time delay which 10 is ocraciQne~ in the station S itself is compensated for by the internal real-time doclc in each base station being set/adjusted to the time unit T in advanoe of the current time.
In a further en~ho~liment of the subject matter of the invention, the said time 15 synchronization ir~ es all` base stations operating with tran~mitt~-s in the total coverage area of the ,*l~o t~
In a fu.lher embo~iment of the concept of the invention, a dosed phase-lodcing :~y~ is establi~he~l in which the c~mraring elemer~t together with 20 the element for recE:vil.g the first common time information, the internal real-time clock and existing criteria form the said system.
In a further embodiment of the subject matter of the invention, the tra..~-..itl;~ elemen{ts included in the base stations are arranged to operate 25 with a buffer function. This buffer function is co~l~led to a pulse-generatdng unit which generates the signals which are required for synchronized transmission In a f~ulher embo~ ent of the subject matter of the invention, the element 30 for receivi~.g the con~n~on time ~G~ ~a~or, which ~l~a~t is c~.s~ te~l by a GPS sigr ~l, is ~-ocesse~l into a coull,rehensible format before it comes into the comparing elpnlerlt~ i.e. the same format as the one that the internal real-timeclock ~ates with 35 In a further embo~im~nt of the subject matter of the invention, the base station is arranged with communication PlPmer~ts. These communication elements are on the one hand set up for trancmifflng transmit data to the tr~n~ tl~r and on the other hand set up for t~ g ~ime ~-fo~ ation (the C;PS signal) to the co ~ a- ;-~g element.
SUBSTITUTE SHEET
2~4599g - WO 94/10768 pcr/sE93/oo84s s In a further ernbodiment of the subject matter of the invention, the said mobile communication s~ts~ is a digital mobile network. The digital mobile network operates with paging. The mobile units which are served are pagers.
ADVANTAGES
An effective synchronization of one or more base stations operating with transmitters can be effected by what has been proposed above. The synchronization is carried out simultaneously in two or more base stations 10 operating with transmitters in the mobile telecomn~unication sys~e~. The invention is also arranged in such a ~l~nT~er that consideration can be given tothe i~terrl~l delays which can be produced by the system per se, delays in ~ak~ g, trans~rutters, antennas and so forth The invention is arranged in such a m~ er that all transmitters in the system can be encompassed by the 15 synchronization. All tr~cmitters in the s~sLt:... will the.efore always effect tr~nc~icsion of u~lu~ation in coor~lin~tion with one another. The result of this is that a mobile unit (pager) in the s~sleu- can always make large movements. The mobile unit also always obtains a time-coordinated ..ation from the base stations in situatiorLC in which the mobile unit is located in areas where the coverage areas of two or more base stations overlap one another.
SHORT DESCRI~IlON OF THE DR~WINGS
A currently ~ro~osed embo~liment of an arrangment which exhibits the char~ctenctics significant of the i~v~llion will be described below whilst at the same time re~.ulg to the att~che~ drawings in which Flgure 1 shows in basic diagram form a mobile telecorrununication s~ste.
including a oentral coordinating unit, Figure 2 shows in basic diagram form a base station including receiving elements, comparing elemf~ and transmitting elements and Flgure 3 shows in basic diagram fonn a oentral c~orl1in~hng unit.
- ' DEIAILED DESCRIPIION OF A PREFERRED EMBODIM~T
Flgure 1 shows a mo~ile telecomlmi~tion :~5l~-. A number of base s~tio~c is cor nected to the sysle~L These are represer~t~ by 1, 2, 3 ,4 in the figure. TheSuBS~I~uT~ s~EE~ -Yo 94/10768 pcr/sE93/oo84s base stations, in turn, are co~nect~l via a fixed connection 5, 6, 7, 8 to a number of nlobile telephone P~cchar~es rel,lesellted by 9 and 10. The mobile telephone e~arl~es, in turn, are connected via swit~l~ing stations 11, 12 to the landline telephone nel~ro.l~ 13. A number of mobile units 14~14~14n~ 15 is connected to S the base stations 1, 2, 3, 4~ On a call to a mobile unit 14~ 14~ 14n~ 15~ a contact is es~ablishe 1 from the public telephone networlc i3 via the switching stations 11, 12 to the mobile telephone eY~h~n~es 9,10, which command the base stations 1~ 2~ 3~ 4 to make a call to the l~uired mobile unit 14~ 14~14 ~ 15. The base station 1, 2, 3, 4, within whose coverage area the mobile unit 14~ 14~ 14n~ 15 is 10 located establishes contact, whereupon the call information is transferred (;-.fo~ tion on the caller's identity in a paging system). In those cases where the mobile unit 15 is located within the coverage area of one or more base stations 2, 3, the mobile unit decides ~nth the aid of, among others, the strength of the carrier wave, which base station 2, 3 it should connect itself to.
15 When the n~.~kile unit 15 is l~te~l within the area where the coverage areas of one or more base s~ior~c 2, 3 overlap one another, it is highly ~r~.ed that the call goes out synchronously from the affe.led base sPt~Qr~s 2, 3. To obtain a synchronous trancmission from all the base stations 1, 2, 3, 4 in the syst~n a coor~ tin~ unit 16 is arranged. The coor~linating unit 16 transfers a cornmon 20 tirne information to elements for reception-17, 18, 19, 20 inten-led for thispurpose and arranged at each respective base station 1, 2, 3, 4. This cornmon time ~ ation is compa~ed with a second time information set up by the said base stations 1, 2, 3, 4. This second time information is lefe~led to or corsistc of a ~me which is r~f~led to solar time at the zero meridian in 25 lor~ 3e, UTC tine, and is ~r~ecte~ by the time delays which are produced in the station itself. The common t me inform~ti~n is then placed into relation, in the comp~ing ~lement 21, 22, 23, 24 of the al~led base stations, with the said seco~l time h~.mation, wheieu~ol- the comparing element effects infl~ences on/adj!~c~ ents of the real-time docks in ~e affected base shtions 30 so that a time syl~ ro~ ation of the base stations 1, 2, 3, 4 is carried out.
Figure 2 shows a base station included in the mobile teleco~rununication system. The base station is provided with a transmitting element 24 for outgoing transmit data, a time~ g elenlent 25 and an element 26 35 receivillg the c~mmon time i.~fo~mation. Outgoing data which are to be transmitte~ from the lr-~-s-~ Plen~t 24 arrive at the base station via a first communication element 27. The first communication element 27 is co~necte~ to &e n~obile telephone eY~h~nge via a l~ndline connec~ion 2~. The outgoing transmit data are then ~ s~..ed to a buffer 29 included in the SUBST~TUTE SHEET
2~45~8 - /0 94/10768 - PCr/SE93/00849 transrnitting element 24. The outgoing transrnit data in the buffer are then clocked out to the transrnitter with the aid of s~ s which are generated h a pulse-generating unit 30. The pulse-generating unit is connected to the internal real-time clock 31 of the base station. The hternal real-time of the base 5 station is refe..ed to or is constituted by a time which is refe~,ed to solar time at the zero meridian in longitude, the so-called UTC time. In order to synchronize the base station shown in Figure 1, a first time information common to all base stations is transmitted in from a centrally arranged coordinating unit, in the form of a GPS signal, to an elP~nPT~t, arranged at the10 base station, for receiving the first common time information 26. The common time information which has come in is reprocessed in a comrnunication e1ement 32 provided for this purpose and is transferred to the time-comparing elen~e~t 25 in a format which is comprP~encible to the base station. A second time information is then transferred from the internal real-1~ time clock 31 to the time-comparing element 25 whereupon the time-comparing element places the com-non time information in relation to the second time information. Existing criteria, for example delays and the like, arethen introduced into the comp~ring element 25 from a unit 33 inten~e~l for this purpose. The comparing element 25 then effects influences 20 on/adjustrnents of the internal real-time clock in dependence on introduced criteria and on the relation between the common time information and the - second time info.lllation, thereby providing for time synchronization of two or more base stations.
~lgure 3 shows a central coorli, ating unit. The central unit is provided with a2S clock 34, ~re~erably an ~tomic clocl~ The atomic clock sends clock signals to a converter 3S which converts the clock pulses from the atomic clock to GPS
signals. The GPS signals are then transferred from the converter to a tr~ncmitter 36 arranged in the central unit. An ~ntenrl~ element 37 is arranged at the transmitter 36. The transrnitter 36 establishes contact with the base 30 stations which are to be syncllroni~ed (~.eferably all the base stations in the s~sl~) and transrnits synchronously to these base stations.
The in~rention is not limited by the embo~ erlt shown as an example above but can be sul,je~ed to mo~ or c wi~in the scope of the subsequent patent 35 claims and the concept of the il~v~:nlion.
SUBSTITU~E SHEET
Claims (8)
1. Arrangement in a mobile telecommunication system including, on the one hand, a number of base stations operating with transmitters and, on the other, a unit coordinating the base stations, to provide for a time coordination of a number of transmitters of the base stations, characterized in that the said base stations are provided with, on the one hand, transmitting elements which are each arranged to operate with a real-time clock allocated to it and, on the other, time-comparing elements, in that the said coordinating unit is arranged to transmit a first common time information to the said base stations, in that the said base stations are arranged with elements for receiving the said first common time information and supplying the said first common time information to the time-comparing element together with a second time information, set up from the real-time clock in the transmitting element, in that the said time-comparing element places the said first common time information in relation to the said second time information, in that the said time-comparing element, in dependence on existing criteria, for example delays and the like, and the relation between the said first common time information and the said second time infor-mation, effects influences on/adjustments of the said real-time clock so that synchronization is carried out and that the said comparing element together with the said element for receiving the first common time information, the internal real-time clock and existing criteria form a closed phase-locking system wherein said element for receiving the common time information processes the time information which has come in into a format comprehen-sible to the comparing element/into the same format which the internal real-time clock is operating with.
2. Arrangement according to Claim 1, characterized in that the internal realtime said real-time clock is allocated is referred to or consists of UTC-time.
3. Arrangement according to Claim 1 or 2, characterized in that the common first time information which is transmitted from the said coordinating unit is a GPS signal.
4. Arrangement according to any one of the preceding Claims, characterized in that the time delay which is produced in the station S itself is compensated for by the internal real-time clock being set to the time unit T in advance of the actual time.
5. Arrangement according to any one of the preceding Claims, characterized in that the said synchronization embraces all the base stations in the transmitter network.
6. Arrangement according to any one of the preceding Claims, characterized in that the transmitting element is arranged to operate with a buffer where outgoing transmit data wait to be clocked out to the transmitter and in that the said transmitting element includes a pulse-generating unit for generating the signals which are required for the synchronized transmission.
7. Arrangement according to any one of the preceding Claims, characterized in that communication elements are set up for, on the one hand, transferring transmit data to the transmitter and, on the other, transferring time information to the comparing element.
8. Arrangement according to any one of the preceding Claims, characterized in that the said communication system is a digital network, preferably a paging system.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE9203137A SE470037C (en) | 1992-10-27 | 1992-10-27 | Device for mobile telecommunication systems to enable synchronization of the transmitters of the base stations |
| SE9203137-6 | 1992-10-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2145998A1 true CA2145998A1 (en) | 1994-05-11 |
Family
ID=20387570
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002145998A Abandoned CA2145998A1 (en) | 1992-10-27 | 1993-10-18 | Arrangement in mobile telecommunications systems for providing for synchronization of the transmitters of the base stations |
Country Status (12)
| Country | Link |
|---|---|
| US (1) | US5809426A (en) |
| EP (1) | EP0667069B1 (en) |
| JP (1) | JP3471016B2 (en) |
| KR (1) | KR100297010B1 (en) |
| CN (1) | CN1051890C (en) |
| AT (1) | ATE214526T1 (en) |
| AU (1) | AU676226B2 (en) |
| CA (1) | CA2145998A1 (en) |
| DE (1) | DE69331701T2 (en) |
| SE (1) | SE470037C (en) |
| TW (1) | TW279295B (en) |
| WO (1) | WO1994010768A1 (en) |
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-
1992
- 1992-10-27 SE SE9203137A patent/SE470037C/en not_active IP Right Cessation
-
1993
- 1993-09-25 TW TW082107979A patent/TW279295B/zh active
- 1993-10-18 WO PCT/SE1993/000849 patent/WO1994010768A1/en active IP Right Grant
- 1993-10-18 CA CA002145998A patent/CA2145998A1/en not_active Abandoned
- 1993-10-18 JP JP51094894A patent/JP3471016B2/en not_active Expired - Lifetime
- 1993-10-18 EP EP93924247A patent/EP0667069B1/en not_active Expired - Lifetime
- 1993-10-18 AT AT93924247T patent/ATE214526T1/en not_active IP Right Cessation
- 1993-10-18 AU AU53797/94A patent/AU676226B2/en not_active Ceased
- 1993-10-18 US US08/411,630 patent/US5809426A/en not_active Expired - Lifetime
- 1993-10-18 DE DE69331701T patent/DE69331701T2/en not_active Expired - Lifetime
- 1993-10-26 CN CN93119415A patent/CN1051890C/en not_active Expired - Lifetime
- 1993-10-26 KR KR1019930022281A patent/KR100297010B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| US5809426A (en) | 1998-09-15 |
| AU676226B2 (en) | 1997-03-06 |
| JP3471016B2 (en) | 2003-11-25 |
| SE9203137D0 (en) | 1992-10-27 |
| JPH08502866A (en) | 1996-03-26 |
| CN1051890C (en) | 2000-04-26 |
| ATE214526T1 (en) | 2002-03-15 |
| TW279295B (en) | 1996-06-21 |
| SE9203137L (en) | 1993-10-25 |
| SE470037B (en) | 1993-10-25 |
| KR940010557A (en) | 1994-05-26 |
| EP0667069A1 (en) | 1995-08-16 |
| EP0667069B1 (en) | 2002-03-13 |
| CN1101188A (en) | 1995-04-05 |
| SE470037C (en) | 1995-03-23 |
| AU5379794A (en) | 1994-05-24 |
| KR100297010B1 (en) | 2001-10-24 |
| DE69331701T2 (en) | 2002-10-02 |
| DE69331701D1 (en) | 2002-04-18 |
| WO1994010768A1 (en) | 1994-05-11 |
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Legal Events
| Date | Code | Title | Description |
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| EEER | Examination request | ||
| FZDE | Discontinued |