CN1984498A

CN1984498A - Base station switching in a hybrid GSM/CDMA network

Info

Publication number: CN1984498A
Application number: CNA2006101728346A
Authority: CN
Inventors: R·内弗奥; M·瓦库连科; B·E·布里格; W·加德纳; D·卡斯皮; A·门德尔森; S·科洛尔; S·里兹利; I·凯斯勒; A·莱维; D·夏德尔曼; Y·里莫尼
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 1998-07-20
Filing date: 1999-07-19
Publication date: 2007-06-20
Also published as: HK1070226A1; IL140981A0; AU5111499A; MXPA01000672A; CN1547864A; CN1984497B; JP2003526958A; KR20010071009A; KR100667399B1; AU769854B2; CN100350815C; CN1984497A

Abstract

A mobile wireless telecommunication system includes base stations of a first type operating according to a first air interface, and base stations of a second type operating according to a second air interface. Methods and apparatus are provided for handing over a mobile station in the system from a first base station, which is of the first type, to a second base station, which is of the second type. A communications link is established over the first air interface between the mobile station and the first base station. Data are received from the mobile station responsive to a signal received by the mobile station over the second air interface from the second base station, substantially without breaking the communications link with the first base station. The mobile station is handed over from the first to the second base station responsive to the data received therefrom.

Description

Switch base station in hybrid GSM/cdma network

The application is to be application number the dividing an application for the Chinese patent application of " switch the base station in hybrid GSM/cdma network " that be No. 99810295.4 denomination of invention on July 19th, 1999 applying date.

Invention field

The present invention relates generally to aerogram, relate in particular to advanced cellular phone network.

Background of invention

In the many countries in the whole world, in cellular phone network, be used for the global system (GSM) of mobile communication.GSM provides the useful scope of Network and standard.Existing GSM network is based on time division multiple access (TDMA) digital communication technology.In the cellular network based on TDMA, at any given time, each subscriber unit only communicates with single base station.When the user when a sub-district moves to another sub-district, take place " direct-cut operation ", in described direct-cut operation, the user with it the base station of communication disconnect it and user's link, and replace by a new base station.

Code division multiple access (CDMA) is a kind of improved digital communication technology, and it is compared with TDMA, can provide the radio bandwidth more efficient use, and be provided at more reliable between cellular telephone subscribers and the base station, zero-decrement link.Leading CDMA standard is the IS-95 that is announced by telecommunications industry association (TIA).This standard provides " soft handover (handover) " possibility of (or " handover (handoff) "), wherein, is moving to another sub-district from a sub-district, and subscriber unit is temporarily got in touch two or more base stations simultaneously.This standard provides " soft handover " (or " switching ") ability, wherein moves on to the process of another sub-district from a sub-district at subscriber unit, and subscriber unit is got in touch with two or more base stations simultaneously temporarily.Reduce the possibility that junction loss takes place by sign indicating number separating method soft handover in the cards, in direct-cut operation, this junction loss takes place through regular meeting.

Quote described patent PCT patent application PTC/US96/20746 as a reference at this and describe a kind of radio telecommunications system, described system uses CDMA air interface (air interface) (that is basic radio communication agreement) to realize GSM Network and agreement.Use this system, corresponding C DMA device can replace or replenish some TDMA base station (BSS) and subscriber unit at least of existing GSM network.Cdma base station in this system is applicable to that moving the main dispatching centre by standard GSM A-interface and GSM communicates.Therefore kept the core (core) of GSM Network, and the conversion from TDMA to CDMA is transparent for the user.

In PTC patent application WO 95/24771 and WO 96/21999, and in people's such as Tscha the article that is entitled as " cdma mobile station and GSM move the subscriber signaling gateway between the main dispatching centre " (tent too China second universal personal Telecommunication international conference proceedings (1993), the 181-185 page or leaf) also describes hybrid cellular communication network, and be incorporated herein as the reference data in conjunction with GSM and two kinds of unit of CDMA.In these publications, there is not one piece to deliver relevant effective switching of how carrying out subscriber unit between the different base station in this hybrid network especially.

Also quote described patent PTC patent application PTC/US97/00926 as a reference and be described in the method for between the system between CDMA and the TDMA base station, switching in hybrid GSM/CDMA telecommunication system at this.The GSM/TDMA base station produces the pilot beacon signal according to CDMA technology.During call, subscriber unit detects pilot signal, and receiving the signalisation base station controller.Then with subscriber unit from CDMA switch to the TDMA base station and interrupt call not.

Brief summary of the invention

The purpose of this invention is to provide the method and apparatus that uses in hybrid TDMA/cdma cellular communication network.

Another purpose of some aspect of the present invention provides through improved method and apparatus, and it can be in the switching that enables the subscriber unit between TDMA and cdma base station under the situation of not interrupt communication.

In preferred embodiment of the present invention, hybrid TDMA/cdma cellular communication system comprises TDMA and two kinds of base stations of CDMA of being controlled together by mobile main dispatching centre (MSC).The such system of general description quotes described patent as a reference at this in above-mentioned PTC patent application.By suitable switching between TDMA and CDMA air interface, be preferably in and use the GSM procotol on two types the interface, the subscriber unit in network (also being referred to as mobile radio station (MS) here) can communicate with two types base station.The feature of preferred embodiment of the present invention is that communication system can be based on existing GSM/TDMA foundation structure, has additional CDMA BSS, and existing foundation structure is not had other modification basically.

Switch in order to determine when, the MS that communicates with the current base station of a type (CDMA or TDMA) monitors the radiofrequency signal that starts from another base station, and wherein another base station can be the base station of other type (being respectively TDMA or CDMA).Message sequence between current base station and MS makes mobile radio station obtain the relevant suitable synchronizing information of base station newly, and reports this information to current base station.System uses described information to make MS set up air interface with new base station, switches and does not interrupt communication between MS and the network basically by it.

Under the situation of present patent application, this switching between the base station is called " MAHO (mobile-assisted handover) ".Use MAHO in known GSM of prior art and cdma system, wherein the signal strength signal intensity that receives from the base station transmitter adjacent cell was measured and reported to mobile radio station before switching to adjacent cell.Yet, in hybrid GSM/cdma system of mentioning agenda, suppose that mobile radio station can receive at any given time from CDMA or TDMA base station (or the CDMA beacon relevant with the TDMA base station, as above-mentioned PCT patent application PTC/US97/00926) signal (but not being both), therefore can not provide such auxiliary.Principle according to the present invention provides move auxiliary can make to switch carry out more smoothly and more reliable than other possible method.

In preferred embodiments more of the present invention, according to the instruction that the base station that communicates with it from described unit receives, mobile radio station carries out the switching between TDMA and CDMA operation in telephone call.Before switching, mobile radio station receives the signal from TDMA and cdma base station, and to the relevant signal that it is receiving of base station report.The information of so report is turned back to BSC, and base station controller uses described information to start switching.Preferably, mobile radio station comprises the single radio transmitter, and therefore, mobile radio station can communicate with TDMA or cdma base station (but being both) at any given time.Yet (, as mentioned above, according to the principle of IS-95, can communicate by letter with more than one cdma base station simultaneously in the unit.) to notice further that there is its synchronised clock each GSM/TDMA base station, the wherein mobile radio station that will communicate with it and this clock synchronization, and make cdma base station be synchronized with one day real-time (real time ofday) mutually.Therefore, in the handoff procedure between TDMA and CDMA station, mobile radio station all obtains in each case and makes its operation be synchronized with suitable clock signal and not block calls calling basically.

In these preferred embodiments certain is in some, and when mobile radio station was determined to switch to the GSM/TDMA base station to the unit, it was communicating with cdma base station.The interim CDMA transmission of interrupting the mobile radio station transmitter, this period the unit carry out generally according to the GSM neighbor scanning of GSM standard to obtain and to be synchronized with the TDMA base station.Preferably, be the single frame interruption CDMA transmission of 20ms for general length, produce idle time slot according to the IS-95 standard.In identification TDMA base station with after having exchanged suitable message, open the traffic channel between the base station, and mobile radio station is switched to the TDMA base station, and make the interruption of the call that mobile radio station carries out reduce to minimum basically.

In other embodiment of these preferred embodiments, when mobile radio station was determined to switch to cdma base station to the unit, it was communicating with the TDMA base station.For synchronous with cdma base station, mobile radio station preferably obtains constantly by the accurate moment that receives from the TDMA base station, wherein provides to have to produce and broadcast the GSM network of necessary device constantly.Preferably, network comprises the cell broadcasting system (CBS) according to GSM standard, for example, uses the moment that it comes receiving world locational system (GPS) to provide, or receives the moment from one or more cdma base stations, and by network it is broadcast to mobile radio station.On the other hand, in order to obtain and be synchronized with the moment of cdma base station, mobile radio station interrupts TDMA temporarily and receives.Therefore, though tdma slot loss meeting causes the reduction to a certain degree of signal in this manner, compare with other possible aspect, the MAHO from TDMA to CDMA generally is more reliable, and less to the user's of mobile radio station interference.

Though describe preferred embodiment with reference to mobile radio station here with the single transceiver that is used for TDMA and CDMA, but be appreciated that, can similarly use the subscriber unit and the system hardware of other type, especially use a kind of subscriber unit discrete or that have only partly integrated TDMA and CDMA transceiver that has, use principle of the present invention.

Therefore, in comprising according to the first kind base station of first operated and a kind of mobile wireless telecommunication system according to the second class base station of second operated, preferred embodiment according to the present invention provides a kind of method, be used for second base station that switches to second class at the mobile radio station of system from first base station of the first kind, described method comprises:

On first air interface between the mobile radio station and first base station, set up communication link;

Signal in response to mobile radio station receives from second base station by second air interface receives the data from mobile radio station, does not disconnect the communication link with first base station basically; And

Make mobile radio station switch to second base station in response to the data that receive from it from first.

Preferably, receive the measured value that data comprise received signal intensity, and handover of mobile stations comprises comparison from the first and second signal of base station intensity measurements, and carry out the switching of mobile radio station in response to comparative result.Preferably, receive data and comprise signal strength measurement is applied weighted factor, wherein apply weighted factor and comprise according to the network condition in system and change the described factor.Also have, preferably, apply weighted factor and be included on the communication link weighted factor is sent to mobile radio station, wherein said mobile radio station is used for weighted factor to measure.

Preferably, receiving data comprises according to mobile radio station the signal that receives on second air interface being decoded and receives the sign of second base station.

In a preferred embodiment, the frequency meter of the second class base station in system is sent to mobile radio station from first base station, thereby search for received signal under the frequency of mobile radio station in this table.

Preferably, handover of mobile stations comprises from first base station transmission switching command.

Preferably, setting up communication link in response to this signal comprises with the reception data: set up link and the single radio frequency transceiver of use in mobile radio station in mobile radio station place received signal.

In a preferred embodiment, one of first and second air interfaces comprise the TDMA interface, and another interface comprises the CDMA interface, and wherein, the TDMA interface preferably includes the GSM interface, and configuration CDMA interface transmits the GSM internet message.Preferably, the CDMA interface is based on the IS-95 standard.

Preferably, set up communication link and comprise and use single radio resource management protocols layer to manage first air interface, and wherein mobile radio station switches and comprises and use single radio resource management protocols layer to manage second air interface.

Again preferably, receive data from mobile radio station and comprise and being defined in, and when mobile radio station is in the overlay region, trigger mobile radio station reception data by the first area of first air interface service with by the overlay region between the second area of second air interface service.

In a preferred embodiment, first air interface comprises the CDMA interface, and wherein second air interface comprises the GSM/TDMA interface, and comprises the gating mobile radio station with interruption cdma communication link from mobile radio station reception data, thereby receives the decode the GSM/TDMA signal.Preferably, the gating mobile radio station is included in and interrupts cdma communication in duration of IS-95 frame, wherein receives data and comprises according to by mobile radio station the GSM frequency correction of signal and synchronizing channel being decoded and receive the sign of second base station.

In another preferred embodiment, first air interface comprises the GSM/TDMA interface, and second air interface comprises the CDMA interface, and receives data from mobile radio station and comprise the control mobile radio station with the interrupt communication link, thereby receives the CDMA signal and it is decoded.

Preferably, receiving data comprises by GSM/TDMA interface transmission time information (time of dayinformation).Again preferably, transmit time information and comprise that the system by utilization GSM cell broadcaste service broadcasts time information, wherein, the broadcasting time information comprise from system transceiver time of reception of communicating of first kind base station and relevant GSM frame number.Preferably, mobile radio station is decoded to the synchronizing channel of CDMA signal, thereby obtains constantly.

On the other hand or in addition, receive data and comprise the GSM cell broadcast service messages is sent to mobile radio station, search for from the second class signal of base station to start mobile radio station.Preferably, the GSM cell broadcast service messages is sent to mobile radio station comprises transmission message, thereby when mobile radio station was just operated with dedicated mode, mobile radio station received this message.

Preferably, the data that receive from mobile radio station comprise the sign of reception by the CDMA pilot beam of mobile radio station decoding.Again preferably, described method comprises second base station of mapping as the GSM base station, thereby control is switched.

Preferably, control mobile radio station comprise: on the TDMA interface with base station communication in, the control mobile radio station is decoded to signal during the tdma slot of controlling mobile radio station reception CDMA signal during first tdma slot and following, thereby produces base station data to be received.

Further provide a kind of method according to preferred embodiment of the present invention, be used for time information is sent to mobile radio station at the gsm radio communication system, described method comprises:

Time information is input to system; And

Described information broadcast to the mobile radio station in system.

Preferably, the gsm radio communication system comprises a cell broadcasting system, and the broadcasting time information comprises by cell broadcasting system and broadcasts described information.Preferably, the broadcasting time information comprises broadcast, thereby when the station is just with dedicated mode operation, receives this message by mobile radio station.

Again preferably, the broadcasting time information comprises from the transceiver time of reception that communicates with system and relevant GSM frame number, and described method comprises and uses time information to make mobile radio station and CDMA transmission signals synchronous.

In a preferred embodiment, described method comprises in response to by it time information being sent to a plurality of base stations in the system, determines the position of mobile radio station.

Preferably, input time comprises the data call of opening from transceiver with time information to CBC, wherein, opens data call and preferably includes from the GPS device information time of reception.On the other hand, opening data call comprises from the CDMA sub-district time of reception information relevant with gsm system.

According to preferred embodiment of the present invention, further provide a kind of in the gsm radio communication system that comprises first base station sub-system and second base station sub-system (at least one subsystem in the described subsystem is according to the CDMA operated), be used for making the method for carrying out the switching of from first to second base station sub-system at the mobile radio station of search system, described method comprises:

Shine upon at least one in first and second subsystems, described subsystem as the GSM/TDMA subsystem according to the CDMA operated;

Be based upon the communication link between the mobile radio station and first base station sub-system, thereby mobile radio station receives first signal from first base station sub-system;

Receive the communication link that does not interrupt basically from the data of mobile radio station with first base station sub-system in response to what mobile radio station received from the secondary signal of second base station sub-system;

Relatively intensity first and second base station sub-systems of first and second signals are GSM/TDMA subsystems as described first and second base stations basically; And

Comparative result in response to signal strength signal intensity switches to second base station sub-system with mobile radio station from first base station sub-system.

Preferably, mapping comprises according at least one subsystem of CDMA operated GSM frequency and position is distributed to subsystem.

Again preferably, set up communication link and mobile radio station switch comprise via GSM A-interface in system first and second subsystems and mobile switching centre between transmit message.Preferably, first and second base station sub-systems are according to the CDMA operated, and wherein, the mobile radio station switching comprises by the A-interface new IS-95 long code of transmission and do not violate the A-interface protocol basically.

Preferably, receive data from mobile radio station and comprise weighted factor is applied to secondary signal, wherein, comparison signal intensity comprises the comparison weighted signal, wherein, apply weighted factor and comprise weighted factor is sent to mobile radio station that described mobile radio station is applied to secondary signal to weighted factor.Preferably, applying weighted factor comprises according to the change of the network condition in the system factor.

According to preferred embodiment of the present invention, also be provided at the radio communication device that uses in the mobile communication system, described device comprises:

First kind base station, it sends and receives first signal according to first air interface;

The second class base station, it sends and receives the secondary signal according to second air interface; And

Mobile radio station, described mobile radio station is by the secondary signal of second air interface reception from the second class base station, keep communication link simultaneously by first air interface and first kind base station, and in response to secondary signal data are sent to first kind base station, thereby mobile radio station carries out the switching of from first to second base station in response to the transmission data.

Preferably, the data that send by mobile radio station comprise signal strength measurement, thereby compare handover of mobile stations in response to the signal strength signal intensity of first and second signals.Preferably, weighted factor is applied to the measured value of signal strength signal intensity, wherein, changes weighted factor according to the network condition in system.Preferably, on communication link weighted factor is sent to mobile radio station, wherein said mobile radio station is applied to measured value to weighted factor.

Again preferably, mobile radio station is decoded to determine the identifier of the second class base station to secondary signal.

Preferably, first kind base station sends to mobile radio station to the frequency meter of the second class mobile radio station in system, causes the mobile radio station search to receive secondary signal under the frequency in this table.

Preferably, first kind base station sends to mobile radio station to switching command, thereby mobile radio station is switched to second base station from first.

Again preferably, mobile radio station comprises the single radio frequency transceiver, and the described transceiver and the first and second class base stations communicate.

In a preferred embodiment, one of first and second air interfaces comprise the TDMA interface, and another interface comprises the CDMA interface, and wherein, the TDMA interface preferably includes the GSM interface, and the CDMA interface configuration is become to transmit the GSM internet message.Preferably, the CDMA interface is according to the IS-95 standard.Again preferably, mobile radio station use single radio resource management protocols layer manage first and second air interfaces both.

Preferably, when in the overlay region of mobile radio station between the second area of the first area of first air interface service and the service of second air interface, the base station triggers mobile radio station is to be received in the secondary signal on second air interface.

In a preferred embodiment, first air interface comprises the CDMA interface, and second air interface comprises the GSM/TDMA interface, and first kind base station gating mobile radio station is with the interrupt communication link, thereby receives the GSM signal and it is decoded.

Preferably, mobile radio station the IS-95 frame the duration in broken link.

Again preferably, mobile radio station is handled secondary signal so that the synchronizing channel of GSM frequency correction and signal is decoded.

In another preferred embodiment, first air interface comprises the GSM/TDMA interface, and second air interface comprises the CDMA interface, and first kind base stations control mobile radio station interrupt communication link, thereby receives the CDMA signal and it is decoded.

Preferably, first kind base station is sent to mobile radio station to time information by the GSM/TDMA interface.Preferably, described device comprises the GSM CBC, described broadcasting center uses the GSM broadcasting service that time information is sent to mobile radio station by system, wherein, CBC from system the transceiver information time of reception that communicates of first kind base station and relevant GSM frame number.

On the other hand or in addition, mobile radio station is decoded to the synchronizing channel of CDMA signal, thus obtain constantly.

Preferably, the GSM CBC is sent to mobile radio station to cell broadcast service messages to start the search of mobile radio station to secondary signal, and wherein, mobile radio station receives cell broadcast service messages, operates with dedicated mode simultaneously.

On the other hand or in addition, mobile radio station is handled the CDMA pilot signal and is discerned the CDMA pilot beam.

Preferably, mobile radio station receives the CDMA signal during a CDMA time slot, and handles this signal during the CDMA time slot of following, and communicates by TDMA interface and base station simultaneously, thereby produces the data that are transferred to the base station.

The further generator of preferred embodiment according to the present invention, be used for time information is sent to mobile radio station at the gsm radio communication system, described device comprises CBC, and described broadcasting center uses the GSM cell broadcasting system that information broadcast is arrived mobile radio station.

Preferably, described device comprises the transceiver that communicates with system, and described transceiver is constantly sending to CBC with relevant GSM frame number, wherein, transceiver is opened the data call to CBC by system, thereby being sent to the there with relevant frame number constantly.

Preferably, use time information to make mobile radio station be synchronized with the CDMA transmission signals.

Again preferably, mobile radio station receives the information from cell broadcasting system, operates with dedicated mode simultaneously.

In addition, according to preferred embodiment of the present invention generator also, be used for time information is input to communication controler at radio telecommunications system, described device comprises:

Clock signal receiver, it receives the time information in self-clock source; And

Wireless set, it receives the time information from clock signal receiver, and opens the data call to communication controler by system, thereby information is sent to the there.

Preferably, communication controler comprises the GSM CBC, and wherein, wireless set receives the GSM frame number of the base station in the comfortable system, and frame number is sent to CBC with time information.

Preferably, the cdma communication sub-district information time of reception that clock signal receiver comprises wireless, wherein, wireless set comprises radio receiver.

On the other hand, clock signal receiver comprises the GPS device.

Also be provided at the device that is used for mobile radio communications in the GSM telecommunication system in addition according to preferred embodiment of the present invention, described device comprises:

Mobile radio station; And

First and second base station sub-systems send to mobile radio station to first and second signals, and at least one signal in the wherein said signal is the CDMA signal, and this two seeds system map in the gsm system as the GSM base station sub-system,

Wherein, according to the strength ratio of first and second signals that receive from mobile radio station, mobile radio station is carried out from first switching to second subsystem, basically as the first and second two kinds of base station sub-systems according to the GSM/TDMA operated.

Preferably, GSM frequency in system and position are distributed to the subsystem that sends the CDMA signal.Again preferably, via GSM A-interface, transmit message between first and second subsystems in system and the mobile switching centre, wherein, first and second signals comprise the CDMA signal.Preferably, new IS-95 long code is sent to first subsystem from second subsystem, thereby mobile radio station is switched and do not violate the A-interface protocol basically by the A-interface.

Preferably, before comparison signal intensity, mobile radio station is applied to secondary signal to weighted factor.

Further provide a kind of mobile radio station according to preferred embodiment of the present invention, for using in the radio telecommunications system that comprises CDMA and TDMA base station, described mobile radio station comprises:

Single mobile radio transceiver, it and CDMA and TDMA base station communicate;

Modulator-demod, it is encoded and the signal that receives is there decoded the signal that sends by mobile radio station, cause the signal that is used for communicating by letter through the CDMA coding, and be used for encoding through TDMA with the signal of TDMA base station communication with cdma base station; And

Terminal equipment, the user of mobile radio station communicates by described terminal equipment and modulator-demodulator.

Preferably, modulator-demodulator is encoded to signal according to gsm radio interface layer agreement.

Again preferably, mobile radio station receives and handles from the signal of one of CDMA and TDMA base station and do not interrupt existing communication link between mobile radio station and another CDMA and the TDMA base station basically.

Also provide a kind of method according to preferred embodiment of the present invention, be used for message is sent at a plurality of mobile radio stations of the gsm radio communication system that comprises cell broadcaste service with dedicated mode operation, described method comprises:

On cell broadcaste service, information broadcast is arrived mobile radio station; And

Basically do not interrupt the dedicated mode operation of mobile radio station in mobile radio station place reception message.

Be provided for the device of the mobile radio communications in the GSM telecommunication system in addition according to preferred embodiment of the present invention, described device comprises:

CBC, it is by the cell broadcasting system broadcast; And

Mobile radio station, it receives message and communicates with dedicated mode simultaneously, and does not interrupt dedicated mode communication basically.

From below in conjunction with the detailed description of accompanying drawing to preferred embodiment of the present invention, will more fully understand the present invention.

The accompanying drawing summary

Fig. 1 is the schematic block diagram of the hybrid GSM/cdma cellular communication system according to preferred embodiment of the present invention;

Fig. 2 A illustrates according to preferred embodiment of the present invention, the mobile radio station in the system of Fig. 1 and the schematic block diagram of the communication protocol between the base station sub-system;

Fig. 2 B is according to the schematic block diagram of the hybrid GSM/cdma mobile station of preferred embodiment of the present invention;

Fig. 3 A and 3B illustrate according to preferred embodiment of the present invention the schematic block diagram of the communication protocol stack between the element in the system of Fig. 1;

Fig. 4 A is the schematic block diagram according to preferred embodiment of the present invention, is illustrated in that the mobile radio station from cdma base station to the GSM base station switches in the system of Fig. 1;

Fig. 4 B illustrates according to preferred embodiment of the present invention, the schematic block diagram of the signal flow relevant with the switching of Fig. 4 A;

Fig. 5 illustrates according to preferred embodiment of the present invention, the schematic block diagram of the signal flow relevant with time information is provided in the system of Fig. 1;

Fig. 6 illustrates according to preferred embodiment of the present invention, for understanding the schematic diagram that mobile radio station is switched to the useful sub-district hybrid GSM/cdma cellular communication system of the method for cdma base station from the GSM base station;

Fig. 7 illustrates according to preferred embodiment of the present invention, with the relevant signal flow of switching from the GSM base station to cdma base station;

Fig. 8 illustrates according to preferred embodiment of the present invention, the schematic block diagram that the mobile radio station in hybrid GSM/cdma cellular communication system between cdma base station switches;

Fig. 9 illustrates according to preferred embodiment of the present invention, the schematic diagram of the signal flow relevant with the switching of Fig. 8.

The detailed description of preferred embodiment

With reference now to Fig. 1,, this figure is the schematic block diagram of the hybrid GSM/cdma cellular communication system 20 according to preferred embodiment of the present invention.Make system 20 around constructing based on the Public Land Mobile Network (PLMN) 22 of aforesaid gsm communication standard.And the foundation structure that has this network, and in many countries, using widely, the present invention has advantage, can little by little introduce not require together with the cdma service of this network existing foundation structure is carried out main change.Public Land Mobile Nerwork (PLMN) 22 comprises that at least one moves-service switching center (MSC) 24, maybe may be many this centers (moving-service switching center (MSC) though only illustrate one for clarity), it be controlled at the network operation in the geographic area.In the middle of other function, Location Registration and the subscriber unit between the base station that mobile-service switching center (MSC) 24 is responsible for subscriber units switch, and Public Land Mobile Nerwork (PLMN) 22 is linked to public switched telephone network (PTSN) and/or Packet Data Network (PDN) 48.Public Land Mobile Nerwork (PLMN) 22 also comprises network management center (NMC) 26 and CBC (CBC) 28.Further describe these functions below.

System 20 comprises a plurality of mobile radio stations (MS) 40, it under one or more acceptable cellular communication frequencies, by a plurality of base station sub-systems (BSS) 30 on the wireless radio-frequency link and 32 and PLMN22 communicate.The crowd knows and can use basically by the mobile radio station (MS) 40 for subscriber unit GSM TDMA signaling protocol and two GSM BSS30 of standard communicate, and uses the communication means based on CDMA described below, communicates with CDMABSS32.In addition, though in the gsm system of standard, mobile radio station is generally only to receive the broadcasting from CBC (CBC) 28 in idle pulley, but mobile radio station (MS) 40 can will be further described below by receiving this broadcasting during the calling of base station sub-system (BSS) 30.Though mobile radio station (MS) 40, GSM base station sub-system (BSS) 30 and cdma base station subsystem (BSS) 32 in every kind for the sake of clarity only is shown in Fig. 1, be appreciated that, in fact, system 20 generally comprises a plurality of in every kind of this system element.

GSM base station sub-system (BSS) 30 and cdma base station subsystem (BSS) 32 communicate and are subjected to it to control with mobile-service switching center (MSC) 24.Basically carry out GSM base station sub-system (BSS) 30 according to GSM standard and move-communication between service switching center (MSC) 24.Revise cdma base station subsystem (BSS) 32 with respect to IS-95 CDMA standard, thereby communicate according to GSM standard and Public Land Mobile Nerwork (PLMN) 22, especially, communicate, further describe via GSM standard A-interface and mobile-service switching center (MSC) 24 below with reference to Fig. 3 A and 3B.Base station sub-system (BSS) 32 also communicates with CBC (CBC) 28, treats the message broadcasted aloft thereby receive, and comprises a radio adaptation and maintenance centre (OMC-R) 38.Radio adaptation and maintenance centre (OMC-R) communicate by GSM standard Q3 interface and network management center (NMC) 26, preferably use the information model based on GSM 12.XX series specification, wherein are incorporated herein as the reference data.At random, can be linked to general Packet data service (GPRS) 50 to base station sub-system (BSS) 32, such as being advised by ETSI European Telecommunications Standards Institute (ETSI).On the other hand or in addition, the base station sub-system that can be coupled (BSS) 32, be used for grouped data is directly sent to PTSN/ Packet Data Network (PDN) 48 (though for simplicity in the not shown this connection of Fig. 1), preferably, with the link that arrives the Internet by the there.

In the communication of setting up on the CDMA " air interface " between cdma base station subsystem (BSS) 32 and the mobile radio station (MS) 40, the general best IS-95 standard of described air interface according to cdma communication.Set up base station sub-system (BSS) 32 and make it around base station controller (BSC) 34, it control many base station transceivers (BTS) 36 and and they communicate.When mobile radio station (MS) 40 was in the geographic area (or sub-district) of particular base station transceiver (BTS) 36 service, each base station transceiver (BTS) arrived mobile radio station (MS) 40 to emission of radio frequency signals and from mobile radio station (MS) 40 received RF signals.When at mobile radio station during the call (MS) when the sub-district of a cdma base station transceiver (BTS) 36 moves to another, between base station transceiver (BTS), take place " soft handover ", this knows in that CDMA is many in the art.

Yet the zone of system's 20 services may not have CDMA to cover (that is, not having cdma base station transceiver (BTS) 36 in this zone) yet, or covers more weak or more crowded therein.If mobile radio station during call (MS) 40 moves to this zone, mobile radio station (MS) is switched to the base station transceiver (BTS) relevant with GSM base station sub-system (BSS) 30 from cdma base station transceiver (BTS) and do not interrupt this calling.Similarly, if mobile radio station during calling out (MS) 40 enters the sub-district of cdma base station transceiver (BTS) 36 from the zone of only serving by GSM base station sub-system (BSS) 30, then preferably make mobile radio station (MS) 40 carry out switching from GSM to cdma base station subsystem (BSS).Be further described below and between CDMA and GSM/TDMA service, carry out this switching and vice versa, and between a cdma base station subsystem (BSS) 32 and other, carry out this switching.As shown in FIG. 1, the advantage of advantage by this method and system's 20 structures, mobile radio station (MS) 40 receives the benefit of the CDMA service in those zones of serving by the system 20 that carries out service, and does not lose the service in the TDMA zone.Transition between CDMA and TDMA zone is transparent for the user of mobile radio station (MS) 40 basically, because can see higher GSM procotol all in whole system, and during transition only changes more rudimentary radio frequency air interface.

Fig. 2 A is the block diagram according to preferred embodiment of the present invention, is schematically illustrated in the communication protocol stack between mobile radio station (MS) 40 and base station sub-system (BSS) 30 and 32.Mobile radio station (MS) 40 communicates on the GSM Um Interface based on standard TDMA air interface with base station sub-system (BSS) 30, thereby does not need to revise base station sub-system (BSS) 30 or a GSM layer 1 and layer 2 standard interface protocol basically for adaptive mobile radio station (MS) 40.According to the CDMA IS-95 air interface with some modification, mobile radio station (MS) 40 communicates on the CDMA Um Interface with cdma base station subsystem (BSS) 32.Can on GSM Um Interface or CDMA Um Interface, operate at many in the art subscriber units of knowing, but be both.

In order to keep two in these interfaces, mobile radio station (MS) 40 comprises mobile device (ME) 42 (Fig. 1), and it must comprise each of two wireless sets, be disposed for the TDMA operation to one, and another is disposed for the CDMA operation; Or comprise single transceiver, it is dynamically switched between TDMA and CDMA.Mobile device (ME) comprises portable terminal (MT), and it supports to be used for the terminal equipment (te) of speech and/or data input and output.In addition, mobile radio station (MS) 40 comprises the subscriber identification module (SIM) 44 according to GSM standard.

Fig. 2 B is the schematic block diagram according to preferred embodiment of the present invention, is illustrated in the mobile radio station (MS) 40 that comprises the single radio transceiver in the mobile device (ME) 42.Around modulator-demod 59 structure mobile radio stations (MS) 40, described modulator-demod comprises DSP (Digital Signal Processing) core 60 that can produce and handle TDMA and CDMA signal.Preferably, core 60 comprises ASIC (application-specific integrated circuit (ASIC)) device that comprises independent CDMA transmission/reception processing, GSM timing logic 64 and GSM hardware accelerator (or digital signal processor DSP) 62 support it, and have the port for subscriber identification module (SIM) 44.Core 60 receives input and output is sent to terminal equipment (te) 46.In this case, terminal equipment (te) 46 is expressed as audio microphone and loud speaker, and core 60 is carried out D/A and A/D conversion, and the sound code function on audio signal, as knowing the crowd of institute in the art.Still use GSM or CDMA sound sign indicating number with cdma base station subsystem (BSS) 32 contacts according to mobile radio station (MS) 40 and GSM base station sub-system (BSS) 30 contacts.On the other hand or in addition, can be configured to core 60 to work with the terminal equipment (te) that the numerical data I/O is provided 46 such as picture unit.

Core 60 is being the mixed frequency signal output device 66 shown in the numerical data of TDMA form or CDMA form.Install 66 processing said data and it is converted to the Analog Baseband form, for being input to radio frequency sending set 68.Duplexer 70 is sent to suitable GSM or cdma base station to the radiofrequency signal that is produced via antenna.Duplexer 70 is sent to core 60 to the signal that receives from the base station by radio-frequency transmitter 72 and mixed frequency signal output device 74 (carrying out baseband-converted and AGC (automatic gain control) function).Preferably, by core 60 control transmitter 68, receiver 72 and mixed frequency signal device 66 and 74.

For with existing GSM equipment (particularly base station sub-system (BSS) 30) compatibility, the radio frequency by mobile radio station (MS) 40 sends and receives the frequency place in the frequency band that is preferably in GSM 900 or 1800 MHz.Supposing that mobile radio station (MS) 40 includes only is shown among Fig. 2 B, the single transceiver of in the GSM frequency band, operating, and then the CDMA equipment in system 20 also must be configured to and be suitable for operating in this frequency range.

Get back to Fig. 2 A, in order to operate aspectant GSM base station sub-system (BSS) 30 and cdma base station subsystem (BSS) 32 respectively, no matter mobile radio station (MS) 40 comprises that physically a transceiver still is two transceivers, it must be supported in the two

air interface layer

1 and 2 in its protocol stack.CDMA air interface between mobile radio station (MS) 40 and cdma base station subsystem (BSS) 32 comprises the CDMA layer of operating 1 on standard I S-95 agreement, and revises the IS-95 operation therein to adapt to the GSM-CDMA layer 2 of GSM Network needs.Layer 2 is supported in the frame transmission between MS40 and BSS30 or 32.GSM-CDMA layer 2 comprises functional such as prioritisation of messages, priority and division, communicate by letter unsettled and recovering, and generally this is subjected to standard GSM layer 2 rather than CDMA IS-95 supports.Aspectant (vis-a-vis) GSM base station sub-system (BSS) 30,

air interface layer

1 and 2 are not revised basically according to GSM standard.

The standard gsm protocol comprises the 3rd radio interface layer (RIL3), and it is included in GSM layer 1 and three sublayers above the layer 2.Lowermost layer in these three RIL3 sublayers is radio resource (RR) management level, and it is supported in mobile management (MM) and connection management (CM) sublayer above it.With respect to GSM standard, the RIL3 sublayer in GSM base station sub-system (BSS) 30 does not change basically, and GSM mobile management (MM) in mobile radio station (MS) 40 and connection management (CM) sublayer remain unchanged equally basically.The signaling of call treatment is supported to be used in connection management (CM) sublayer, and GSM auxiliary activities and short message service (SMS).The needed signaling of location, discriminating and encryption key management of mobile radio station (MS) 40 is supported to be used in mobile management (MM) sublayer.

In order to support mobile management (MM) and connection management (CM) layer, in mobile radio station (MS) 40 and base station sub-system (BSS) 32 protocol stacks, introduce GSM-CDMA radio resource (RR) layer.Managing radio resources and remain on mobile radio station (MS) 40 and base station sub-system (BSS) 30 and 32 between GSM-CDMA radio resource (RR) layer " realizing " of the radio link two GSM in mobile radio station (MS) 40 protocol stacks and the existence of CDMA lower level (layer 1 and 2).According to the instruction that receives from the base station sub-system (BSS) that communicates with it, it requires suitable lower level in mobile radio station (MS) storehouse to be used in standard RIL3-radio resource (RR) layer on the GSM Um Interface or GSM-CDMA radio resource (RR) layer of the base station sub-system (BSS) 32 on the CDMA Um Interface communicates.Base station sub-system (BSS) 32 is not handled mobile management (MM) layer and connection management (CM) layer but by forwarding between mobile radio station (MS) 40 and mobile-service switching center (MSC) 24, is used for being that transparent way is handled to following CDMA air interface layer basically.Under instruction from mobile-service switching center (MSC) 24 and base station sub-system (BSS), radio resource (RR) layer in mobile radio station (MS) storehouse also is controlled at the switching between the corresponding air interface that defines in the layer 1 and 2, and promotes the cell selecting of switching.

No matter using which air interface, GSM-CDMA radio resource (RR) layer is supported in standard GSM RIL3-mobile management (MM) and connection management (CM) layer above it.Preferably, radio resource (RR) layer provides the complete radio resource management as definition in GSM specification 04.07 and 04.08, quotes described patent as a reference at this.Though CDMA IS-95 standard does not define " RR " radio resource layer itself, the IS-95 radio resource functionality that GSM-CDMA radio resource as described herein (RR) layer also is kept perfectly.

According to GSM standard, radio resource (RR) layer functional comprises two kinds of idle mode operations and dedicated mode business (that is the business of, carrying out) during telephone conversation.The idle mode operations of radio resource (RR) layer comprises automatic cell selecting, and the switching of the free time between GSM and CDMA sub-district and a pair of CDMA sub-district and a pair of GSM sub-district, has the sub-district conversion indication of GSM standard regulation.Radio resource in idle pulley (RR) layer is also carried out as the broadcast channel of GSM and CDMA prescribed by standard and is handled, and sets up radio resource (RR) connection.

With dedicated mode, radio resource (RR) layer is carried out following business:

All other functions that Route Selection business, service request, message transmit and stipulates by GSM standard basically.

Change dedicated channel (switching), comprise as direct-cut operation described below and CDMA switch to soft handover and " softer " of CDMA here.

The pattern setting of radio resource (RR) channel comprises sending mode, channel type and coding/decoding/sign indicating number translative mode.

Mobile radio station (MS) parameter management according to the IS-95 specification.

Mobile radio station (MS) class emblem management according to the GSM specification.

Those skilled in the art that will understand, and just list the feature of above-mentioned radio resource (RR) layer in the mode of summary, according to GSM that is published and CDMA specification, can increase other details and feature.

Fig. 3 A is the block diagram according to preferred embodiment of the present invention, is schematically illustrated in mobile radio station (MS) 40, cdma base station subsystem (BSS) 32 and GSM and moves the protocol stack that uses in the signaling interface between the service switching center (MSC) 24.These interfaces make mobile radio station (MS) 40 move a service switching center (MSC) 24 with GSM on the CDMA air interface and communicate.In above-mentioned PCT patent application PTC/US96/20764, describe the operation of these interfaces in more detail and, quote described patent as a reference at this specifically by the message flow of these interfaces.When mobile radio station (MS) 40 communicates with a mobile service switching center (MSC) 24 via GSM base station sub-system (BSS) 30, do not revise protocol stack basically according to GSM standard.

As described in above here, mobile radio station (MS) 40 and cdma base station subsystem (BSS) 32 switching signal on the CDMA Um Interface are wherein revised mobile radio station (MS) and base station sub-system (BSS) protocol stack and are made it to comprise GSM-CDMA radio resource (RR) layer and layer 2.In Fig. 3 A, be clearly shown that in base station sub-system (BSS) 32 protocol stacks is transmitted a layer, be used to be transmitted in RIL3-connection management (CM) and mobile management (MM) signaling between mobile radio station (MS) 40 and the mobile-service switching center (MSC) 24, do not need widely to handle by base station sub-system (BSS) 32.Here with reference to figure 2A other layer that is included in the Um Interface is described above.

In standard, on the GSM A-interface of not revising basically, cdma base station subsystem (BSS) 32 moves with GSM-and service switching center (MSC) 24 communicates.This interface be according to as in technical field the GSM SS7 that knows of crowd of institute and BSS apply for (BSSAP) agreement partly, preferably, according to GSM 08.08 standard.BSSAP supports the process between mobile-service switching center (MSC) 24 and the base station sub-system (BSS) 32, the described range request of crossing carries out decipher and processing to the message of relevant individual call and resource management, and is moving-transmitting between service switching center (MSC) 24 and the mobile radio station (MS) 40 to call out control and administrative messag movably.Base station sub-system (BSS) 32 becomes to supply the suitable SS7 and the Base Station Subsystem Application Part of mobile-service switching center (MSC) 24 transmission to the CDMA layer 1 of exchange between base station sub-system (BSS) and mobile radio station (MS) 40 and GSM-CDMA layer 2 with radio resource (RR) protocol translation, and vice versa.

Because cdma base station controller (BSC) 34 use standard A-interfaces and GSM move-service switching center (MSC) 24 communicates, so in order to make cdma base station subsystem (BSS) 32 append to gsm system 20, need not move basically-make amendment in the service switching center (MSC) at GSM.In addition, do not need to tell the identification of mobile-service switching center (MSC) 24 between GSM/TDMA base station sub-system (BSS) 30 and cdma base station subsystem (BSS) 32 that any difference is arranged, because both communicate with mobile-service switching center (MSC) on the A-interface in substantially the same mode.Preferably, according to GSM standard, with with the essentially identical mode in GSM/TDMA sub-district by moving-sub-district of the base station transceiver (BTS) 36 that service switching center (MSC) 24 mappings and base station sub-system (BSS) 32 are relevant, so distribute GSM absolute radio frequency channel number (ARFCN) and base station identity code (BSIC) value.Viewpoint from mobile-service switching center (MSC) 24, switching between GSM base station sub-system (BSS) 30 and cdma base station subsystem (BSS) 32, or even the switching between two different cdma base station subsystems (BSS), and having nothing different based on the switching between two the GSM base station sub-systems (BSS) in the system of GSM/TDMA traditionally.Distribute the base station identity code (BSIC) of CDMA sub-district, thereby in system 20, can distinguish with traditional GSM sub-district.

Fig. 3 B is the block diagram according to preferred embodiment of the present invention, schematically illustrates via cdma base station subsystem (BSS) 32 and transmit included protocol stack in the voice data between mobile radio station (MS) 40 and mobile-service switching center (MSC) 24.Voice data between mobile radio station (MS) 40 and base station sub-system (BSS) 32 is encoded, and by the decoding of CDMA vocoder, described vocoder can be included in many in the art any standard I S-95 vocoder agreements of knowing.Base station sub-system (BSS) 32 is translated into GSM E1 tdma signal to CDMA layer 1, and according to the requirement of A-interface standard, the CDMA vocoder data is converted to PCM A-law compression (companded) voice data.Therefore mobile-service switching center (MSC) 24 receives voice datas and do not consider that basically the data between base station sub-system (BSS) and mobile radio station (MS) are through the fact of CDMA coding to mobile radio station (MS) 40 transmission voice datas and from mobile radio station (MS) 40 via base station sub-system (BSS) 32, just operating in the GSM/TDMA pattern as mobile radio station (MS) 40.

Fig. 4 A is the schematic block diagram according to preferred embodiment of the present invention, illustrates for the details of understanding the useful system 20 of a kind of method, and described method is used for from the MAHO of cdma base station subsystem (BSS) 32 to GSM base station sub-systems (BSS) 30.Do not resemble Fig. 1, the base station sub-system that is shown specifically here (BSS) 30 comprises base station controller (BSC) 77 and a plurality of base station transceiver (BTS) 78 and 80.Fig. 4 A illustrates the switching of mobile radio station (MS) 40 one of from the base station transceiver (BTS) relevant with base station sub-system (BSS) 32 (the label here is the BTS 78 of BTS 76 to base station sub-system (BSS) 30).As described in reference to figure 1, base station sub-system (BSS) 32 also comprises GSM/CDMA base station controller (BSC) 34 and base station transceiver (BTS) 36.

When determining that mobile radio station (MS) 40 is in the position that may need this switching, the preferably switching that starts from cdma base station transceiver (BTS) 76 to TDMA base station transceivers (BTS) 78 by base station sub-system (BSS) 32.When the signal that receives from base station transceiver (BTS) 76 is more weak, or when known mobile radio station (MS) 40 will arrive the edge of the CDMA area of coverage, or when the telephone traffic on CDMA Channel is heavier, may this thing happens.On the other hand, base station sub-system (BSS) 32 can command mobile radio station (MS) 40 (irrelevant with any particular pressure of doing like this) search constantly from the signal of base station transceiver (BTS) 78 (or other GSM base station transceiver (BTS)).

Fig. 4 B is the aid flow graph according to preferred embodiment of the present invention, is illustrated in the handoff procedure of Fig. 4 A the signal that transmits between mobile radio station (MS) 40, base station sub-system (BSS) 30 and 32 and move-service switching center (MSC) 24.Base station controller (BSC) 34 commander's mobile radio stations (MS) 40 begin contiguous GSM base station transceiver (BTS) is carried out the search of gated nature, in the short time cycle, mobile radio station (MS) 40 interrupts it searches for and receives tdma signal with communicating by letter of base station transceiver (BTS) 76.Preferably, mobile radio station (MS) 40 is operated on the IS-95 standard, this standard make CDMA be transmitted in the 20ms frame the duration become the free time, can send GSM TDMA neighbor scanning and not interrupt the CDMA Speech Communication basically during this period.On the other hand, under other CDMA standard, also can introduce this idling cycle.Again on the other hand, as mentioned above, mobile radio station (MS) 40 can comprise the discrete TDMA and the CDMA transceiver that can use simultaneously for this purpose.

Preferably, base station controller (BSC) 34 provides the frequency meter of contiguous GSM TDMA sub-district (such as those sub-districts relevant with base station transceiver (BTS) 78 and 80) to mobile radio station (MS) 40.This table is useful for reducing search and finding the 78 needed times of base station transceiver (BTS), because mobile radio station (MS) 40 is as long as search under the frequency of the sub-district on the table.When mobile radio station (MS) 40 when a sub-district moves to another sub-district, upgrade this table, and between the transfer period between TDMA and the cdma base station, preserve described table.

When mobile radio station (MS) 40 received a signal at the frequency place of base station transceiver (BTS) 78, it attempted GSM frequency correction (FCCH) channel in signal and synchronous (SCH) channel are decoded.Finish this decoding and use the CDMA idling cycle of several gatings possibly.In case successfully finished decoding, mobile radio station (MS) 40 is shown the power level of tdma signals, and it is reported to base station sub-system (BSS) 32 with the GSM cell identifier.According to this information, base station sub-system (BSS) determines whether to want and when switch.At a suitable time place, base station sub-system (BSS) 32 starts to the handoff request of mobile-service switching center (MSC) 24.Mobile-service switching center (MSC) 24 is sent to handoff request the GSM base station sub-system (BSS) 30 of confirming this request.Then, base station sub-system (BSS) 30 is sent to mobile radio station (MS) 40 to switching command by mobile-service switching center (MSC) 24 and cdma base station subsystem (BSS) 32, and GSM base station sub-system (BSS) 30 is opened and the new traffic channel (TCH) of mobile radio station (MS).At this moment, finished switching, and mobile radio station (MS) 40 has been switched to base station transceiver (BTS) 78.

No matter when the signal from GSM base station transceiver (BTS) 78 becomes stronger than the signal of cdma base station transceiver (BTS) 76, all may read to start the judgement of switching, but preferably uses other criterion.For example, because CDMA Channel generally provides preferable transmission quality than GSM channel, preferably only just starting switching during than strong certain weighted factor be scheduled to of CDMA signal when the GSM signal.In system 20, can programme in advance, or can be provided with by the user of mobile radio station (MS) 40 to the factor.Can dynamically regulate the described factor according to the parameter such as the relative telephone traffic on the geographical position of mobile radio station (MS) and CDMA Channel in system and the TDMA channel.

Fig. 5 is the schematic block diagram according to preferred embodiment of the present invention, is illustrated in the signal flow (Fig. 1) in the system 20, and is relevant with the relevant GSM base station controller (BSC) and the base station transceiver (BTS) that time information are offered in system.Usually, not the GSM base station sub-system of notifying constantly in system 20 (BSS), because GSM standard does not require this information.On the other hand, IS-95 standard-required cdma base station is synchronous because this be essential synchronously for the identification of signal and decoding and for the soft handover between the sub-district.Therefore, for from the MAHO of the mobile radio station (MS) 40 of TDMA base station transceiver (BTS) 78 to CDMA 76 (as shown in Fig. 4 A, but it is opposite to switch the direction of arrow), system 20 must provide constantly.

The method of Fig. 5 is by using CBC (CBC) 28 broadcasting moment in system, permission provides not need constantly to change in system 20 is moving-service switching center (MSC) 24 or hardware or software in GSM base station sub-system (BSS) 30 or base station transceiver (BTS) 78 and 80 described CBC (CBC) the 28th, the standard part of Public Land Mobile Nerwork (PLMN) 22.Usually, CBC (CBC) 28 provides cell broadcaste service (CBS) according to GSM interface standard 03.41 and 03.49, general short message can be broadcasted and does not confirm defined geographic area in the system 20.When mobile radio station (MS) 40 is being waited for or during idle pulley (that is, when mobile radio station (MS) is not included in the call), it receives this message.Yet for purpose constantly is provided, preferably, mobile radio station (MS) 40 not only can receive CBC (CBC) message when it is idle, as described in top GSM standard, and can receive message with dedicated mode (that is, during call).As shown in fig. 2B, when mobile radio station (MS) includes only the single radio transmitter and receiver, need especially to use CBC (CBC) that time information is offered mobile radio station (MS) 40; When using one to be used for CDMA and another and to be used for the dual-radio of TDMA, when the TDMA radio was used for call, the cdma wireless electricity can the time of reception.

In a preferred embodiment of the present invention, also use CBC (CBC) message to start mobile radio station (MS) 40 searching near districts, as above described with reference to figure 4B.

Make a special mobile radio station (MS) 90 that is equipped with GPS (global positioning system) receiver 91 be arranged in the one or more GSM/TDMA sub-district that needs system 20 constantly.In Fig. 5, according to GSM standard, mobile radio station (MS) 90 be from 91 times of reception of receiver, and the synchronizing signal that sends according to base station transceiver (BTS) 78, and be relevant the identifier of this time and current tdma frame number.On the other hand, can be configured to mobile radio station (MS) 90 not need GPS receiver 91 in this case from cdma base station subsystem (BSS) time of reception.Mobile radio station (MS) 90 is opened the data call to CBC (CBC) 28 via base station transceiver (BTS) 78, base station controller (BSC) 77, mobile-service switching center (MSC) 24 and PSTN/PDN 48, and cell identifier and corresponding current time and frame number are sent to CBC (CBC).On the other hand, mobile radio station (MS) 90 can transmit information by any other suitable method, such as using GSM short message service (SMS).Then, CBC (CBC) 28 sends to the sub-district to this message on cell broadcasting system (CBS), thereby even mobile radio station (MS) 40 is just being operated in the GSM/TDMA pattern, it is the time of reception also.Therefore, when mobile radio station (MS) 40 will switch to cdma base station transceiver (BTS) 76, do not need to obtain synchronously/time information, and switch and to carry out sooner and more level and smooth from cdma base station transceiver (BTS).

Partly need not be connected to moment drawing-in system 20 benefit of CDMA switching in addition for the GSM of system itself.For example, mobile radio station (MS) 40 can send to different GSM base station transceivers (BTS) 78 and 80 to its moment, and can measure the time delay from mobile radio station (MS) to each base station transceiver (BTS) and be used for determining the position of mobile radio station (MS).

Fig. 6 is according to preferred embodiment of the present invention, and the overlapping GSM/TDMA sub-district 92 in network and the schematic diagram of CDMA sub-district 94 illustrate the MAHO aspect from GSM base station transceiver (BTS) 78 to cdma base station transceiver (BTS) 76.The operator of system 20 will understand, and when making mobile radio station (MS) 40 be located at any sub-district among the 1-5 of sub-district shown in Fig. 6, TDMA/CDMA can take place switch.Therefore, CBC (CBC) 28 will comprise following message and instruction cell broadcasting system (CBS) information broadcast to all two-pattern (GSM/CDMA) mobile radio stations (MS) in these sub-districts:

Mobile radio station (MS) begins to search for CDMA signal (search trigger).

Cdma base station transceiver (BTS) frequency in overlapping and adjacent cell.

Move-service switching center (MSC) 24 GSM mapping CDMA sub-district 94 according to GSM.

With number (preferably, the obtaining) identification of current tdma frame constantly, though also can provide constantly with other method from mobile radio station (MS) 90.

At random, as mentioned above, the CDMA signal strength signal intensity multiply by a factor, is used for comparing with tdma signal.

In the 6-10 of sub-district, do not need to broadcast this message.In addition, only be appreciated that two-pattern mobile radio station (MS) programming receiving and to translate this message, and common GSM/TDMA mobile radio station (MS) will be ignored it.Cell broadcasting system (CBS) message trigger is two-pattern mobile radio station (MS), and make it acquisition of information and information is provided to GSM base station sub-system (BSS) 30 and mobile-service switching center (MSC) 24, be used for promoting one of cdma base station subsystem (BSS) to switch, not as the hybrid GSM/cdma system of having advised in the prior art.

Fig. 7 is the block diagram according to preferred embodiment of the present invention, is illustrated in the signal flow in the system 20, and described system 20 is relevant with MAHO from base station transceiver (BTS) 78 to base station transceiver (BTS) 76.As above described with reference to figure 6, begin to switch from sending search trigger and out of Memory.No matter when mobile radio station (MS) 40 is in one of GSM sub-district 1-5 (Fig. 6), or in response to the condition of some other pre-programmed, base station transceiver (BTS) 78 all periodically sends search trigger.

In case receive when triggering, mobile radio station (MS) 40 just cuts off the TDMA traffic of it and base station transceiver (BTS) 78, and at short notice (preferably about 5 milliseconds) its receiver be tuned to appropriate C DMA frequency.Then, mobile radio station (MS) recovered with the communicating by letter of base station transceiver (BTS) 78 after, received the pilot beam of the base station transceiver (BTS) of transmission in order to discern it, for example from base station transceiver (BTS) 76, it attempts any CDMA signal that it receives is decoded.As mentioned above, shining upon base station transceiver (BTS) 76 in system 20, is traditional GSM/TDMA base station transceiver (BTS) as it.Therefore, the report message of the power (at random multiply by aforesaid relative CDMA/TDMA weighted factor) of mobile radio station (MS) 40 signal that it receives from base station transceiver (BTS) 76 expression and the gsm system mapped identification symbol of base station transceiver (BTS) 76 send it back GSM base station transceiver (BTS) 78 together.From GSM base station sub-system (BSS) 30 with move-viewpoint of service switching center (MSC) 24 it seems, do not have difference basically between the message that mobile radio station (MS) 40 sends in this case and the message that will send as the result of common GSM neighbor scanning.

The process of proceeding to measure and reporting determines that up to base station sub-system (BSS) 30 mobile radio stations (MS) 40 should switch to base station transceiver (BTS) 76.At this moment, base station sub-system (BSS) 30 is sent to message mobile-service switching center (MSC) 24 expressions and requires switching.Move-service switching center (MSC) 24 is sent to base station sub-system (BSS) 32 to handoff request, and base station sub-system (BSS) 32 sends it back base station sub-system (BSS) 30 to affirmation by mobile-service switching center (MSC) 24.Then, base station sub-system (BSS) 30 is given 40 1 switching commands of mobile radio station (MS), and opens a traffic channel between mobile radio station (MS) 40 and cdma base station transceiver (BTS) 76, has finished switching.

Therefore, said process allows at full speed to carry out MAHO from GSM/TDMA base station sub-system (BSS) 30 to cdma base station subsystem (BSS) 32 with high reliability, and during calling switched mid-term, service disconnection was minimum.For the purpose of this switching, the GSM sub-district information time of reception in system 20, and the CDMA sub-district is mapped to gsm system, hardware costs is minimum and needn't programme to existing gsm system element basically again.

Even do not have time information can carry out similarly TDMA-CDMA handoff procedure at GSM base station sub-system (BSS) 30 places yet.In this case, after mobile radio station (MS) 40 has obtained the pilot frequency channel signal relevant with base station transceiver (BTS) 76, in order to obtain time information, it must be tuned to base station transceiver (BTS) the CDMA synchronizing channel and synchronizing channel decoded.300 milliseconds of times of this action need, but perceptible still tolerable interruption produced in the voice service during calling out.Again on the other hand, use mobile radio station (MS) can carry out similar handoff procedure, as mentioned above with two transceivers (is used for TDMA, and another is used for CDMA).

Fig. 8 is the schematic block diagram according to preferred embodiment of the present invention, is illustrated in the switching between two the dissimilar CDMA base station sub-systems (BSS) 101 and 103 in the system.Base station sub-system (BSS) 101 comprises base station controller (BSC) 102 and a plurality of base station transceiver (BTS) 106 and 108; And base station sub-system (BSS) 103 comprises base station controller (BSC) 104 and a plurality of base station transceiver (BTS) 110 and 112.Base station sub-system (BSS) 101 is similar to base station sub-system (BSS) 32 basically with 103, and can with its exchange, as shown in FIG. 1 and as mentioned above, and they by GSM A-interface and GSM move-service switching center (MSC) 24 communicates.Though between two cdma base station subsystems (BSS), switch, but it seems from the viewpoint of system, this is the switching between two GSM base station sub-systems (BSS), and wherein mobile-service switching center (MSC) 24 is shone upon base station transceiver (BTS) 108 and 110 respectively as the GSM sub-district.

Fig. 9 is the schematic diagram according to preferred embodiment of the present invention, is illustrated in the process of switching the signal flow between the element of system 20 shown in Figure 8.It has received signal from base station transceiver (BTS) 110 to base station sub-system (BSS) 101 report as mobile radio station (MS) 40, and described signal triggers and switches when having higher power level than the signal of base station transceiver (BTS) 108.Then, base station sub-system (BSS) 101 is switched-is required message to standard GSM and sends to mobile-service switching center (MSC) 24, and the GSM cell identifier of specific base transceiver (BTS) 110 is as switching desired new cell allocation.Mobile-service switching center (MSC) 24 sends to base station sub-system (BSS) 103 to handoff request, it sends to mobile-service switching center (MSC) to the affirmation that has sealed RIL3-RR (RIL3-radio resource) switching command in response, and described RIL3-RR switching command sends back base station sub-system (BSS) 101.Therefore, all message that send between base station sub-system (BSS) 101 and 103 meet the A-interface requirement, and relevant with an IS-95 CDMA parameter maps arrives corresponding GSM parameter, for example, and at the identifier of the 13K QCELP type vocoder of CDMA in the GSM full rate vocoder.Handoff request, affirmation and order by mobile-service switching center (MSC) 24 transmission do not change basically.

After receiving switching command, old base station sub-system (BSS) 101 sends to mobile radio station (MS) 40 to radio resource (RR) switching command message, thereby influence is to the switching of new base station sub-system (BSS) 103.Message to mobile radio station (MS) 40 comprises:

New long code shielding according to the CDMA standard

The nominal power level parameter

Frame departs from

The sign indicating number channel

Layer 2 is confirmed numbering

The forward traffic channel power contorl parameters

The number of preamble

New band level and frequency

Though above with reference to specific blend GSM/CDMA system description preferred embodiment, be appreciated that can also similarly apply principle of the present invention to be implemented in the MAHO in other hybrid communication system.In addition, though the specific communication standard based on TDMA-and CDMA-of preferred embodiment reference, those skilled in the art that will understand, and method as described herein and principle also can be used together with other method of digital coding and signal modulation.Scope of the present invention not only comprises above-mentioned holonomic system and communication process, but also comprises these systems and process, and the various creationary element of their combination and son-combination.

Therefore be appreciated that quoting above-mentioned preferred embodiment is for example, complete scope of the present invention is only limited by the claims.

Claims

1. method that time information is transferred to travelling carriage in the gsm wireless communication system comprises:

Time information is input to system; And

In system, information broadcast is arrived travelling carriage.

2. by the described method of claim 1, it is characterized in that the gsm wireless communication system comprises cell broadcasting system, and wherein broadcast time information and be included in broadcast message on the cell broadcasting system.

3. by the described method of claim 2, it is characterized in that broadcasting time information and comprise broadcast, make it when travelling carriage operates in the dedicated mode, to be moved platform and receive.

4. by the described method of claim 1, it is characterized in that broadcasting time information comprise from the transceiver time of reception of system communication and relevant GSM frame number.

5. by the described method of claim 4, it is characterized in that also comprising and use time information to make travelling carriage and CDMA send signal Synchronization.

6. by the described method of claim 1, it is characterized in that also comprising the position of determining travelling carriage in response to time information being transferred to a plurality of base stations in the system.

7. by the described method of claim 1, it is characterized in that input time comprises the data call of opening from transceiver with time information to CBC.

8. by the described method of claim 7, it is characterized in that opening data call and comprise from the GPS equipment information time of reception and/or from the CDMA sub-district information time of reception relevant with gsm system.

9. an equipment that time information is transferred to travelling carriage in the gsm wireless communication system comprises CBC, and it uses the GSM cell broadcasting system that information broadcast is arrived travelling carriage.

10. by the described equipment of claim 9, it is characterized in that also comprising and the transceiver of system communication that it is constantly sending to CBC with relevant GSM frame number.

11., it is characterized in that transceiver by the data call that system opens to CBC, makes it being transferred to the there with relevant frame number constantly by the described equipment of claim 10.

12., it is characterized in that travelling carriage use time information and CDMA send signal Synchronization and/or when travelling carriage is operated, receive information from CBC in dedicated mode by the described equipment of claim 9.

13. an equipment that time information is input to communication controler in wireless communication system comprises:

Clock signal receiver, it is from the clock source information time of reception; And

Wireless set, it is from the clock signal receiver information time of reception, and by the data call that system opens to communication controler, makes it a message transmission thereunto.

14., it is characterized in that communication controler comprises the GSM CBC by the described equipment of claim 13.

15., it is characterized in that wireless set receives the GSM frame number from the base station in system, and frame number sent to CBC with time information by the described equipment of claim 14.

16. by the described equipment of claim 14, it is characterized in that clock signal receiver comprises radio receiver, it is from the cdma communication sub-district information time of reception.

17., it is characterized in that wireless set comprises radio receiver by the described equipment of claim 16.

18., it is characterized in that clock signal receiver comprises GPS equipment by the described equipment of claim 13.

19. an equipment that time information is input to communication controler in wireless communication system comprises:

Device from the clock source information time of reception; And

Open to the device of the data call of communication controler by system, make it a message transmission thereunto.

20., it is characterized in that the device of the information time of reception comprises GPS equipment by the described equipment of claim 19.