MXPA00001378A

MXPA00001378A - Method and system for determining the position of mobile radio terminals

Info

Publication number: MXPA00001378A
Application number: MXPA/A/2000/001378A
Authority: MX
Inventors: Bo Hagerman; Sara Mazur; Walter Ghisler; Ulf Forssen; Janerik Berg
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 1997-08-18
Filing date: 2000-02-08
Publication date: 2001-03-05

Abstract

The disclosure describes a novel Time Difference of Arrival (TDOA) method (500) and system (100, 600 and 700) for determining the position of a first mobile radio terminal (108) within an associated mobile radio system (100, 600 and 700), which is based on Time of Arrival (TOA) measurements, including a plurality of radio base stations (BS1, BS2, BS3), measuring devices (130), network controller (110), and service node (103). The measuring devices are synchronized in otherwise unsynchronized radio base stations (BS1, BS2, BS3). The measuring devices (130) measure TOA on demand and (optionally) Direction of Arrival (DOA), on a digital uplink time slot (301 and 302) or on digital information on an analog uplink traffic channel in one or more radio base stations (BS1, BS2 and BS3). The TOA and DOA information and the traffic channel number are reported to a Mobile Services Switching Center (102), which obtains the first mobile terminal's (108) identity from the traffic channel number and sends the terminal identity and TOA and DOA measurement information to a Service Node (103). The Service Node (103) calculates the position of the first mobile radio terminal (108) using the TOA information (supplemented by the DOA information when available). A second mobile radio terminal (601) is colocated on a mobile platform (auto, emergency vehicle, etc.) with one of the radio base stations (BS1, BS2 or BS3), which can be moved into relatively close proximity with the first mobile radio terminal (103). Consequently, by moving one of the radio base stations (BS1, BS2 or BS3) close to the region of interest (near the first mobile radio terminal (108)), the position determination accuracy is significantly improved.

Description

METHOD AND SYSTEM FOR DETERMINING THE POSITION OF MOBILE RADIO TERMINALS BACKGROUND OF THE INVENTION Technical Field of the Invention The present invention relates, in general terms, to the field of mobile radio communications and, particularly, to a method and system for its use for determine the geographical position of a mobile radio terminal. Description of the Related Art The determination of the position of a mobile radio is an emerging field that has reached a high level of interest lately, and it is now desirable to include a capability of position determination in future cellular mobile radio systems. The method of determining position by Time of Arrival Difference (TDOA), which is known from military applications, has been used successfully to determine the position of mobile radio terminals. A typical TDOA position determination system may be based either on terminals, whereby the Time of Arrival (TOA) measurements are carried out in the "downlink" in the mobile station (MS), or it may be network-based, so the network carries out the TDOA measurements in the "uplink" in the radio base stations (BSs). These TOA measurements are then used to calculate TDOA parameters and estimate the position of the mobile stations. A position determination system, which has been used to determine the cellular mobile radio position, is marketed under the name TruePosition®. This system has been used to determine the position of standard analog mobile radio terminals that operate in accordance with the IS-54 standard. Today, these terminals constitute the vast majority of mobile radio terminals that are being used in the United States of America. The TruePosition system, with its own listening radio base stations, is operable independently of cellular systems and can serve wireline operators (frequency band "A") and non-wireline operators (frequency band "B") within the same geographical area. As such, these operators can share the same TruePosition position determination system. Upon request, the TruePosition system offers position information of individual cellular mobile radio terminals. Otherwise, the position determination system does not normally communicate with cellular mobile radio systems. As mentioned above, the TDOA method of position determination employed by the TruePosition system is based on a known military application. Essentially, with the TDOA method, the absolute TOAs of an uplink message transmitted by a mobile radio terminal are recorded in at least 3 fixed radio base stations. This information is processed in a centrally located processor, which calculates the position of the terminal. The registration of uplink messages in the TruePosition system is primarily directed to uplink control messages on (analog) access channels (ie, "reverse control channels" according to IS-54). Notably, according to IS-54, some of these control messages (e.g., log messages and paging response messages) contain the terminal identity in uncoded code, which allows the TruePosition system to determine the position of a specific terminal without having to obtain any information from the cellular network operator responsible for the terminal in question. The IS-54 standard also facilitates the positioning task because all the access channels are assigned to a few bands of relatively narrow frequency, instead of having these access channels dispersed in a wide frequency band between the traffic channels (by example, as is the case of the IS-136 standard). However, the primary use of access channels means that position determination is most easily carried out for mobile radio terminals in an inactive mode, since the access channels are used only by inactive terminals (for example, when registering or after paging). If the position of a mobile terminal must be determined while in conversation mode, the TruePosition system has the option of using a few traffic channels to track the voice channels. Therefore, for example, if the position of a police officer must be determined during an action while talking on the portable radiotelephone, it is required that the network either transfers or originally assigns the radiophone to a traffic channel monitored by the TruePosition system. U.S. Patent No. 5,327,144 to Stilp, et al. It presents a TDOA cellular phone tracking system (apparently associated with the TruePosition system). According to this patent, periodically transmitted uplink signals (for example, cellular registration messages that may occur every 15 minutes according to the IS-54 protocol) by a mobile radio terminal on a reverse (analog) control channel are received and registered by at least 3 radio base stations. The TOA of each signal is registered in the respective radio base station together with the identity of the transmitting terminal (contained in the uplink message). This information is transferred to a processor using the TDOAs resulting from the 3 TOAs and the known locations of the radio base stations to calculate the position of the mobile radio terminal identified in this way. PCT application No.WO 94/27161 of Stilp et al., (Also apparently associated with the TruePosition system) presents a TDOA system for determining the position of a mobile transmitter. The uplink signals transmitted in response and not periodically (for example, cellular paging acknowledgment message) by a mobile radio terminal are received, marked in time with the TOA, and registered by a plurality of base stations together with the identity of the transmitting terminal contained in the uplink message). This information is transferred to a processor using the TOAs and the known locations of the radio base stations to calculate the position of the mobile radio terminal identified in this way. Even though the documents described above illustrate a considerable advance in the field of cell position determination, there are still a large number of outstanding problems. For example, the TDOA method described above is generally not applicable to analog voice channels in an IS-54 system, because the frequencies of the speech channels are distributed to the radio base stations in accordance with a frequency plan. If predetermined voice channels (frequencies) are used for position determination measurements instead of predetermined access channels, certain radio base stations will not be able to allocate voice channels at these predetermined frequencies because the base station combiners are tuned to specific frequencies of base stations that may not include the predetermined frequencies. Accordingly, the position of the terminals communicating with these radio base stations can not be determined by the method described above when these terminals operate in the talk mode. A further problem with the above described location method in particular, when applied to a mobile radio terminal in the conversation mode in a traffic channel, refers to the power control of the mobile radio terminal. If the mobile radio terminal is near the serving radio base station, the ground system will send power control commands to the mobile radio terminal which requires low uplink transmission power. More distant radio base stations receiving the order to measure TOA will not receive a signal strong enough to perform the TOA measurements and read the terminal identity, if the distance of the mobile radio terminal is such that the interference exceeds a certain limit. Another problem with the mobile terminal location method described above is that it can not be applied in the case of digital voice channels in an IS-54 system, and the mobile terminal must be transferred to a channel among several predetermined analog voice channels before to be able to use the location method. Furthermore, the location method described above is difficult to apply under purely digital standards, such as an IS-136 system (among others), because the control channels can be found at any frequency in the assigned frequency band, and it is impossible to do so. Record all traffic on all channels in advance before receiving a position determination request. In addition, in some cellular mobile radio systems such as the Global Digital System for Mobile Communications (GSM), a frequency hopping mode is used for traffic channels, which makes it virtually impossible to determine the position of a mobile terminal through employment. of the method described above. In conclusion, there is a need for a method for determining the position of any mobile cellular radio terminal in any uplink traffic channel or control channel and in accordance with any current and future mobile communication standard. COMPENDIUM OF THE INVENTION A problem which the present invention focuses on is how to determine the geographical position of a digital or analog mobile radio terminal while applying an uplink TDOA method to digital and analog and ordinary traffic channels (e.g. , voice channels), but recognizing that mobile terminals operating in a conversation mode in the traffic channels does not normally transmit their identities in the uplink, and that the traffic channels may be employed in a frequency hopping mode. Another problem addressed by the present invention is how to determine the geographic position of standard digital and analog mobile radio terminals when directional antennas (eg, antenna arrays) are available for use in radio base stations, and therefore how to complement the uplink TDOA method with direction of arrival measurements (DOA). Another problem addressed by the present invention is how to determine the geographical position of mobile radio terminals operating in a talk mode that employs TDMA time slots on a carrier frequency, where "spikes" in the time slots can merge with those of other time segments when arriving at non-serving radio base stations, because the time alignment system (TA) function is designed to avoid such splices only in the serving radio base station.

Another problem to which the present invention is directed is how to improve the accuracy of measurements in certain geographic locations that require an improved position determination of a mobile radio terminal. For example, the accuracy requirement may vary depending on the environment (outside in the field, inside, in an urban area, etc.) of the mobile terminal that requires position determination. Another problem addressed by the present invention is how to allow radio base stations, in terms of received radio power, to measure the TOA of up-signals transmitted from distant mobile radio stations. Accordingly, it is an object of the present invention to provide an uplink TDOA method and apparatus for determining the position of a mobile radio terminal operating in talk mode directly on an arbitrary digital or analog traffic channel of a system. mobile radio, where traffic channels and frequency hopping are present and where traffic channels with frequency hopping may be present. It is another object of the present invention to provide an uplink TDOA method and apparatus for determining the position of a mobile radio terminal operating in talk mode directly on an arbitrary analog or digital traffic channel of a mobile radio system , where direction measurements are made in the fixed part of the system to complement TDOA measurements. It is another object of the present invention to provide an uplink TDOA method and apparatus for determining the position of a mobile radio terminal operating in talk mode directly on an arbitrary analog or digital traffic channel of a mobile radio system , where the splice of sudden increases received can be avoided. It is another object of the present invention to provide an uplink TDOA method and apparatus for determining the position of a mobile radio terminal operating in talk mode directly on an arbitrary analog or digital traffic channel of a mobile radio system , where a locally improved accuracy can be provided as needed. It is another object of the present invention to provide an uplink TDOA method and apparatus for determining the position of a mobile radio terminal operating in talk mode directly on an arbitrary analog or digital traffic channel of a mobile radio system , wherein base stations (including the case in which distant radio base stations are participating in the determination of the position) are provided with an uplink signal energy received sufficient to determine the TOA of the signals. In accordance with the present invention, the above objects as well as other objects are achieved by integrating the location functions in the terrestrial network of the mobile radio system that handles the mobile radio terminal, particularly, the TOA measurements (and optionally DOA) required for position determinations of mobile terminals are carried out on request at the radio base stations of the mobile radio system employing a Modified Receiver (ModRX) where the usual functions of a transmitter- Receiver (TX-RX) have been complemented by the functions of measuring equipment. In the preferred embodiment, the transmitter part is not used in the modified receiver, and therefore can be excluded. Measurement orders are sent by a network controller, such as a Mobile Service Switching Center (MSC) to one or more base stations, and the orders identify the radio channel in which the measurements are made. The measurements are made and reported to the network controller, and from there (together with the identity of the mobile terminal associated with the radio channel at this particular time) a processor in a Service Node (SN) calculates the position of the mobile radio terminal. In an embodiment of the present invention, the ModRX module in a cellular mobile radio system operating in accordance with the IS-136 standard, receives orders from the MSC to measure the TOA of signals in a traffic channel. of specified uplink, using a number of channels (corresponding to an associated frequency and a specific synchronization word for time segments) for the identification of a traffic channel. When this measurement activity ends, the ModRX transmits its TOA measurements back to the network controller (MSC) along with the traffic channel number (CHN). The network controller uses a look-up table to translate the CHN to the identity (MS-ID) of the mobile terminal operating in the traffic channel at this time. Previously, the MS-ID and CHN information has been copied from a call set-up record available in the cellular system and registered in the search table when the measurement was ordered. The TOA measurements, together with the associated mobile terminal identity provided by the network controller, are offered as input parameters for the position determination calculations, which are performed at the service node in the network making use of at least three simultaneous measurements made on the same terminal on 3 different radio base stations. The ModRX is synchronized with the digital information in the traffic channel in which it makes the measurements, and the TOA measurements are made in relation to an accurate time reference (for example, provided by the Satellite-based Global Positioning System, GPS, or some other type of absolute time reference known). In another version of the first embodiment, improved flexibility accuracy can be achieved by replacing the absolute time reference provided by GPS with a relative time reference provided by at least one mobile reference station. In a second embodiment of the present invention, the mobile terminal position determination method and apparatus described above is complemented by a ModRX carrying out DOA measurements that are reported in the same manner as the TOA measurements described above. The DOA measurements are provided as input parameters to the position determination algorithm at the service node. If both TOA and DOA measurements are available for use in the position determination algorithm, only a radio base station that reports measurements of a radio channel is required to obtain an unambiguous position determination result (e.g., using the intersection of the distance circle of TOA and the line indicated by the DOA). In a third embodiment of the present invention, in circumstances in which distant base stations must be used for position determination measurements, the TOA measurements made in ModRX are made after first carrying out a transfer in such a way that the time segments in the same carrier and adjacent to the measured traffic channel time segment are not used by other mobile connections. As mentioned above, the use of distant base stations is permitted to determine the position in these cases in which there are no nearby alternative base stations available, and the use of a distant base station without first carrying out a transfer would have caused an annoying spike splice. In a fourth embodiment of the present invention, TOA solutions are made through a ModRX located far from its radio base station but still connected to it. In accordance with this modality, the accuracy of the determination of the local position can be improved with low additional cost when required. In a version of the fourth embodiment, improved measurement accuracy can be achieved by a fixed modRX equipment connected to a nearby base station through a fixed connection (e.g., coaxial cable, optical fiberglass cable, or copper wire). In a second version of this mode, which is known as "cascade position determination", improved measurement accuracy can be achieved by arranging mobile modRX equipment in a motor vehicle (eg an ambulance, police patrol) , military vehicle, etc. In accordance with the teachings of the present invention, a method for determining the position of a motor vehicle can be obtained by performing on a fixed base station, TOA / DOA measurements for a mobile station located at The same mobile station is preferably connected via wires to the base station (modRX) also located in the motor vehicle.This mobile station reports TOA / DOA measurements on the mobile cellular radio system performed by the modRX of the base station located in the motor vehicle The modRX can include a GPS receiver that allows the determination of the position of the vehicle or motor either through the cellular system alone or through GPS in cases where better precision is desired. However, the report of the measurement is achieved through the cellular system. An additional possibility is to park the motor vehicle in one of several predetermined parking places with known positions and manually report the position. In a fifth embodiment of the present invention, the service radio base station is very close to the mobile radio terminal (MS). Before ordering the performance of TOA measurements by a modRX at a distant base station, the mobile radio terminal (MS) must increase its transmit power. This increase can be achieved by having the network controller order the mobile radio terminal to transmit with a higher power during the measurements or by transferring the mobile radio terminal to a more distant service base station, which also results in greater transmission power from the mobile radio terminal. In a sixth embodiment of the present invention, the modRX of the radio base station measuring the TOA does not receive sufficient signal energy to be able to perform a reliable measurement in the signal message. However, since no reading of variable information in the traffic channel is related to the TOA measurements made in accordance with the invention, more than one message is received, thus accumulating the energy received from non-variable information (e.g., words synchronization, CDMA code pattern, etc.) in an integration time greater than a message, which improves the signal to noise ratio for the signal in which the TOA measurement is being made. In a seventh embodiment of the present invention, the modRX of the radio base station measuring the TOA does not receive sufficient signal energy above the interference level to make a reliable measurement. Before ordering the RX mode to make the TOA measurements on this distant base station, the mobile radio terminal (MS) is transferred to another traffic channel on the same service base station (intra-base station transfer) , where the new traffic channel is chosen to be less affected by interference at this distant base station that carries out TOA measurements. An important technical advantage of the present invention is that the position determination method can be applied to any analog and digital system, and control channels and circuit switched and packet switched traffic, provided that the mobile radio terminal involved or can cause any digital uplink (or digitized) information to be transported, because the modRX listens to a known digital information in advance (eg, a synchronization word) on any specified uplink radio channel without the need to see terminal identity information or other variable information in the channel. Another important technical advantage of the present invention is that a number of popular mobile combination systems (e.g., the Ericsson CMS88 system) have modules that measure the uplink signal strength in relation to a "verification" before the transfer (ie, uplink signal strength revision in the objective base station), and the measurement module of the present invention can be obtained by modifying such a measurement module by or that the signal protocols and procedures necessary for position determination are readily available from the transfer functions. Another technical advantage of the present invention is that the position termination method applies equally well during a call that when the mobile terminal is in an inactivated mode, because (as mentioned above), a requirement is that the mobile terminal involved can send a uplink of digital information and no variable information is read while the measurements are being carried out. This total capacity may be important for certain critical situations, such as during a police action. Another important technical advantage of the present invention is that it is possible to install modRX measuring modules remotely from a radio base station and consequently improve the local accuracy of the position determination measurements, having exactly the measurement modules available in various different locations without having to have several complete radio base stations. This technical advantage is even more apparent when there are modRX mobile measurement modules located in motor vehicles that participate in a rescue action, police or military, because the accuracy of the measurement is locally improved just during the time in which it is required with more frequent the accuracy of the measurement. A further important technical advantage of the present invention is that it is possible to make measurements in high frequency channels, because the information regarding the jump sequences is readily available in the terrestrial mobile radio network. Another important technical advantage of the present invention is that it allows increasing the signal energy received in the radio base stations when required, integrating the energy in the receiver in more than one message (made possible because the content of the messages does not matter ), by increasing the transmission power in the MS (made possible by the integration of the position termination function in the cellular system), or by transferring the MS through a base intra-station transfer to a traffic channel less affected by interference in a base station that performs TOA measurements (made possible again by integrating the position determination function in the cellular system). A further important technical advantage of the present invention is the option of using at least one mobile reference station instead of absolute time references, eg GPS and national radio transmitters to determine the position of a mobile station. The technical advantage of using reference mobile station (s) instead of the national GPS radio transmitters is even more apparent in the fact that the frequencies between the reference mobile station (s) and The mobile radio terminal to be located are the same or similar, while the frequency associated with the national radio transmitter GPS or the mobile station are obviously different. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the method and apparatus of the present invention can be obtained with reference to the following detailed description when taken in conjunction with the accompanying drawings where: Figure 1 is a schematic block diagram showing a system mobile cellular radio with an integrated position determination function, in accordance with a preferred embodiment of the present invention; Figure 2 is a schematic block diagram showing details of the modified receiver (ModRX) 120 illustrated in Figure 1; Figure 3 is a diagram illustrating a format for a reverse time segment (uplink) according to the standard IS-136 wherein TOA measurements are made, in accordance with the present invention; Figure 4 is a diagram illustrating a format for a reverse voice channel message stream (uplink) according to the IS-54 standard where TOA measurements are made, in accordance with the present invention; Fig. 5 is a flow chart illustrating a method of position determination that can be employed in combination with the system illustrated in Fig. 2, in accordance with the present invention; and Figure 6 is a schematic block diagram showing a cellular mobile radio system with an integrated position determination function in accordance with the preferred embodiment illustrated in Figure 1, but modified to implement the novel concept of "position determination". in cascade ". Figure 7 is a schematic blog diagram showing a cellular mobile radio system in accordance with the preferred embodiment illustrated in Figure 1, but modified to use reference mobile station (s) in place of the GPS and GPS unit. reference time. DETAILED DESCRIPTION OF THE DRAWINGS The preferred embodiment of the present invention and its advantages are better understood with reference to Figures 1-7 of the drawings, similar numbers being used for similar and corresponding parts of the various drawings. Essentially, the present invention offers an uplink TDO method for the determination of mobile radio terminal position, which, in a preferred embodiment, is based on an additional development of a verification procedure applied in combination with transfers in Ericsson systems that operate in accordance with IS-54, IS-136 and Pacific Digital Cellular (PDC) standards. When a transfer request is sent to the MSC, the MSC instructs a specific base station module in the target cell to perform the verification. In an Ericsson system, said module is known as a location and verification module (LMV) according to the IS-136 standard, and a Verification Receiver (VRX), according to the PDC standard. The purpose of this function is to verify the presence of the mobile terminal in the target cell. The verification module is tuned and verifies the presence of the mobile termination in the old channel. The result of the verification is sent to the MSC. In accordance with the present invention, the uplink measurements of position determination performed by the Base Stations may include temporary measurements (for example, TOA) as well as angular measurements. TOA measurements are a preferred method of measurement, however, angular measurements can be used to complement TOA measurements, particularly if a base station is equipped with adaptive antennas (array of antennas) that allow easy estimation of the DOA of signals to from a mobile terminal. The mobile terminal position can be estimated from the TOA and / or DOA measurements made in a base station. The TOA and / or DOA measurements made in a bae station. Alternatively, the TOA and DOA measurements of a plurality of base stations may be combined for the purpose of estimating the position of the mobile terminal. Figure 1 is a schematic block diagram showing a cellular mobile radio system 100 with an integrated position determination function, in accordance with a preferred embodiment of the present invention. A system 100 includes a plurality of radio base stations (exemplified by three such as BS1, BS2, BS3). The radio base stations are located at different sites and are connected to a wired network through communication links 101. The wired network may include, for example, an MSC 102 connected in turn through a Switched Telephone Network. Public or PSTN (not explicitly illustrated) to an SN 103. The connection 104 preferably comprises truncal connections. The MSC 102 includes a look-up table 109 for associating channel numbers (CHNs) with terminal identities (MS-Ids). SN 103 includes a processor 103a that further includes a receiver unit 103b, a storage unit 103c, a delivery unit 103d, and a first calculation unit 103e and a second calculation unit 103f respectively. The first calculation unit 103e calculates the TDOA of the signals received in the uplink by the radio base stations, where the first calculation unit 103e uses reported TOAs. The second calculation unit 103f calculates position of mobile radio terminals using the TDOA information and (optionally) any reported DOA information available. The storage unit 103C maintains the known geographical publications of the radio base stations. The receiving unit 103b and the sending unit 103b provide double communications with clients requesting / receiving position determination information (for example, by using short text messages such as for example known Short Message Service messages). Figure 1 also shows a mobile radio terminal (MS) 108 whose position must be determined. The radio base stations BSl, BS2, and BS3"listen" to the traffic channel of the MS 108 through uplink radio connections 105 received on the two receiving antennas 106 of each base station of this type. This two-antenna capability offers a variety of space for radio traffic and also for position determination measurements that are being made in accordance with the present invention. Each radio base station (BS1, BS2, BS3) includes a control section 110, and several TXRXs 111 connected to the receiver antennas 106 through a splitter 112 and the transmitting antenna 107 through a combiner 113. In addition, each of these base stations includes a time reference unit 114 that receives signals of preference from an accurate time reference such as the GPS passed in space 120. The time reference signal is continuously connected from the unit reference time 114 to the ModRX module. The base station of the present invention (for example BS1) includes a time reference unit 114 and a control section 110 which is capable of serving more units in the base station than only the ModRX. Preferably, the ModRX 130 is located in a base station but said ModRX can also be an independent unit located at a distance from the base station but connected to the control section 110 and the time reference unit 114 of the station of base. If a ModRX is located in a base station, the ModRX can share the base station receiving antennas 106. However, if the ModRX is located away from the base station, the ModRX may include its own receiving antennas 106. .

Figure 2 is a schematic block diagram showing details of the ModRX 130 illustrated in Figure 1. In the preferred embodiment, the ModRX carries out TOA measurements at a radio base station. In certain base stations, the ModRX may also include known DOA measuring equipment 207 to supplement the TOA measurements. The ModRX 130 comprises a measurement section 201 and a radio receiver section 202. The measurement section 201 can be tripled (not illustrated explicitly in Figure 2) for use in the IS-54 system and in the IS-136 system, in order to manage the three time segments of total speed of a frame. Conversely, the radio receiver section 202 may be shared by the tripled measurement sections 201. If the ModRX 130 comprises a version used in a frequency hopping system (eg, GSM), the control section 110 enters preferably, the frequency hopping sequences in the receiver frequency synthesizer 211, which allows the realization of position determinations in traffic channels of frequency jumps. The radio receiver section 202 also includes receivers 212, RF demodulators 213, as well as IF demodulators 214 connected to the two receiver antennas 106. More details are provided regarding the GSM in the GSM technical specification standardized by the European Telecommunication Standards Institute (ETSI) (European Institute of Telecommunications Standards), and in the book entitled: "The GSM System for Mobile Communication", by Michel Mouly and Marie Bernadette Pautet (international standard book number 2-9507190-0- 7).

In Figure 2, the measurement section 201 includes a TOA meter 203 that receives a time reference signal from the time reference unit 114, and the uplink signal in which the TOA measurements are made. from the symbol detector 204. The symbol detector 204 receives the input signal from the equalizer 205 (or a correlator, for analog channels). The synchronization word and the DVCC (Digital Verification Color Code) section 206 receives from the control section 110 a number identifying the radio channel in which the TOA is measured. For example, in an IS-54 or IS-136 system, each base station in a group of base stations has a specific DVCC and 7 different synchronization words that allow synchronization in a particular time segment of a carrier frequency. . This information is recorded in the synchronization word and the DVCC 206 section, which in turn receives the information from the MSC (102). The synchronization word and the DVCC section 06 connect this channel information to the equalizer 205, in order to allow the equalizer to find the time segment (preferably by using known correlation method). Optionally, if the associated radio base station includes an antenna array system (corresponding to more than 2 antennas 106), the measurement section 201 may include a DOA meter 207 connected only to a control section 110. A DOA meter 207 requests and receives from the control section 110 the address information available from the known antenna formation function in a radio base station of this type. Accordingly, the DOA 207 meter is only relieving available information regarding the channel specified for the position determination. When available, the DOA information can be used in the position determination algorithm in the SN to improve the accuracy of the position determination, or to allow position determinations to be carried out with less than 3 base stations involved. For example, when only the TOA and DOA of a single radio base station are available, the position of a mobile terminal can be determined where the straight line provided by the DOA intercepts the circle provided by the TOA measurements (the radius is equal to the speed of light multiplied by the propagation time of the signal from the mobile terminal to the base station). Figure 3 is a diagram illustrating a format 301 for a reverse time segment (uplink) (according to the IS-136 standard) where TOA measurements are made, in accordance with the present invention. A direct time segment format (downlink) 302 is also illustrated, in order to demonstrate the different placement of the 28-bit synchronization word. In the case of the uplink, the synchronization word that is used by the receiver correlator circuit (not explicitly illustrated) to find the time segment is placed far from the beginning or end of the time segment. The reason for this placement is that the uplink timing of successive time segments on a carrier frequency is provided by different mobile radio terminals employing different time slots in the same carrier. Accordingly, there is a risk that uplink time segments may be spliced together when they arrive at the radio base station from different mobile radio terminals. The more or less centralized positioning of the synchronization word minimizes the possibilities of a splice of this type. This problem does not exist for the downlink, however, if a splice of this type occurs in the uplink, it is important to save at least the synchronization word against affectation. Figure 4 is a diagram illustrating a format 401 for a reverse voice channel message stream (uplink) according to the IS-54 standard where TOA measurements are made, in accordance with the present invention. The absolute TOA may refer to any agreed point in a message (for example, the end of the first synchronization word 402). The equalizer 205 can help by time diversity to find the agreed point in a message, searching in several word synchronizations in a message and correcting with the nominal delay 403 in time. For example, this capability is valuable when the agreed point 402 is a message is affected by fading. Analog voice channels do not contain a digital time reference and, therefore, it is necessary to cause the mobile terminal to send an uplink message on the voice channel (eg, in response to an audit order on the downlink) . Fig. 5 is a flow diagram illustrating the position determination method 500 that can be employed in combination with the system 100 illustrated in Fig. 1, in accordance with the present invention. With reference to FIGS. 1 and 5, when a position termination request arrives at SN 103 (step 501), in step 503, a determination is made as to whether the mobile terminal 108 of which the position is in a conversation mode, requesting MSC 102 through trunks 104 to establish a call to the mobile terminal. If the mobile terminal 108 is inactive, the call is established in step 507. If, in step 503, the mobile terminal is already in conversation mode, in step 505, a determination is then made as to whether or not The traffic channel that is being used is a digital traffic channel. If this is not the case (ie, the traffic channel is analog), an audit message is sent from the MSC 102 to the mobile terminal 108 in order that the mobile terminal receives an uplink response in digital form (for example, based on the format illustrated in Figure 4). Otherwise, in step 505, if the traffic channel is digital, an audit message is not required. In step 509, the MSC 102 determines what (eg, 3) base stations should participate in the position determination process and requests TOA measurements from at least 3 specific radio base stations, such as BSl. , BS2 and BS3 through connections 101 and indicating the number of traffic channels in question. The control section 110 in each of the 3 base stations requests that the ModRX 130 determines the position of a mobile radio terminal in the specified channel. In step 511, the 3 base stations perform measurements of compliance with a known TOA measurement method and report the resulting measurement information to the MSC 102 together with the associated channel number (CHN). In step 513, the MSC 102 translates the CHN to a mobile radio terminal identity (MS-ID) using a look-up table 109 in the MSC. In step 515, the MS sends the measurements of the radio base stations BSl, BS2 and BS- together with the MS-ID to the SN 103. In step 515, the SN 103 calculates the position of the mobile terminal 108, in accordance with a known triangulation algorithm. The resulting position information is taken to the position determination system customer who requested the position of the mobile terminal involved. In a different embodiment of the present invention, a slight modification of the flow chart of Figure 5 may include a transfer step before carrying out the TOA measurements in step 509, in order to avoid splicing of time segments neighbors and disorders of TOA measurements when distant radio base stations are participating in control determinations. In another embodiment of the present invention, another slight modification of the flow chart of Figure 5 may include a step to request more than a TOA measurement from a radio base station when this radio base station has a plurality (for example, several) ModRXs connected to it, but these ModRXs are installed in different remote locations. In another embodiment of the present invention, another slight modification of the flow chart of Figure 5 may include the substitution, in step 509, of the method "measuring TOA and DOA in a channel from one BS or more than one BS "instead" TOA measurement on a channel from >3 BS "as shown, when there are base stations that can determine DOA, in the MS radio coverage In this case, steps 511, 517 will also include the handling of DOA measurements. invention, another modification between the flow chart of Figure 5 may include steps to repeat the position determination steps 503-509 if, in step 509, it is determined that the uplink signal in the designated traffic channel is too large. weak to carry out TOA measurements in some base stations In this case, a step is added where the MS transmit power is increased (or the ratio between signal and noise is improved) before repeating step 503, either by making a transfer of base interest to a more distant service base station, or by performing a base intra-station transfer, to a traffic channel less affected by interference in a measurement base station, or preferably by directly indicating to MS to increase its transmission power. Figure 6 is a schematic block diagram showing a cellular mobile radio system 600 with an integrated position determination function in accordance with the preferred embodiment illustrated in Figure 1, but modified to be implemented in the novel concept of "position determination" in cascade ". With reference to Figures 1 and 6, in addition to the elements illustrated and described above in relation to Figure 1, the system 600 includes at least one standard MS 601. An MS 601 is preferably connected by wire through an accessory unit 602 to BSl. The MS (terminal) 601 communicates with the MSC 102 through a radio base station BS4 (603) at a radio air interface 604. In the embodiment illustrated in FIG. 6, the base radio station BS4 ( 603) and the radio air interface 604 (mobile connection) are replaced by the fixed connection (illustrated in figure 1) between the base station 1 and the MSC 102. Accordingly, the use of a mobile connection (eg, BS4 and air interface 604) such as the exemplary mobile connection illustrated in the figure, makes it possible to locate BS1 (or BS2, or BS3) in a moving vehicle (eg, ambulance, police patrol) , military vehicle, etc.) and dynamically improves the accuracy of position determination by moving one or more base stations (for example, BS1, BS2, BS3, etc.), relatively close to the region of interest (for example, relatively close to a person in difficulty and carrying MS 108). If there is only one fixed base station in the region of interest, it may be difficult to determine the position of the motor vehicle and also of MS 108. As shown in Figure 6, in accordance with the present invention, the vehicle may include in a time reference unit 114, a "GPS receiver" in addition to a "time reference" controlled from the GPS. Therefore the vehicle can report its position through MS 601 in cases in which the use of internal GPS receiver is of benefit. In addition, the method illustrated above and described in relation to Figure 5 can also be used to determine and report the position of the mobile station 601 and consequently of the motor vehicle carried by the mobile station (for example, BSl, BS2 or BS3) . Preferably, in order to minimize signal interference for the mode illustrated in FIG. 6, the TOA / DOA measurements made by the mobile radio base station (e.g., BSl, BS2 or BS3) are not spliced in terms of time nor with the TOA / DOA measurements of fixed base station BS4 (603) that is determining the position of the motor vehicle or with the report transmitted in the mobile connection (air interface 604 and BS4 (603) ). Fig. 7 is a schematic block diagram showing a cellular mobile radio system 700 in accordance with the preferred embodiment illustrated in Fig. 1, but modified to use at least one mobile reference station (MSR 709) instead of GPS 120 and time reference 114 (figure 1). With reference to Figures 1 and 7, in addition to the elements illustrated and described above in relation to Figure 1, a system 700 includes the MSR 709 having a known position in relation to the radio base stations BSl, BS2 and BS3 . The base stations BSl, BS2 and BS- are operable to receive uplink radio connections 705 transmitted from MSR 709. More specifically, the MSR 709 transmits a relative time reference or "time indication" to each station of base BS1, BS2 and BS3, where the "time indication" may consist, for example, of the beginning of a particular frame. In response to receiving the relative time reference or "time indication", each ModRX 130 in the base stations BSl, BS2, and BS • determines the corresponding TOA of the "time indication". And, each TOA is then corrected taking into account the known distance between the MSR 709 and the respective base stations, BSl, BS2 or BS3. Then, each ModRX 130 determines a TOA associated with the MS108, where the TOA is measured in relation to the corresponding "time indication". The measured TOAs (e.g., MSRs and MSs) are then transmitted to the service node 103 which implements a known hyperbola position determination algorithm to determine the geographical position of MS 108. In addition, the MSR 709 may also be located within one of the base stations (for example BS2) where the location of the MSR 709 would be known. In a situation of this case, the second MSR (not illustrated) would be required in the system 700 to obtain the required number of TOA measurements that is required to determine the position of MS 108, since each base station BSl, BS2 and BS3 must receive at least one "time indication" from MSRs 709 in order to determine the necessary TOAs. It is possible to locate the second MSR (not illustrated) in one of the other base stations (for example BS1 or BS3) in such a way that the necessary TOAs are measured in order to determine the position of MS 108. Even though it was illustrated in the attached drawings and a preferred embodiment of the method and apparatus of the present invention was described in the above Detailed Description., it will be understood that the invention is not limited to the modality presented, but may present numerous changes, modifications and substitutions without departing from the spirit of the invention proposed and defined in the appended claims.

Claims

CLAIMS A method for determining the geographical position of a mobile radio terminal with a mobile radio system, said mobile radio system includes a network controller and at least 3 radio base stations, each of these at least 3 radio stations. base includes an operable uplink TOA measurement unit for communicating with said network controller, a control unit, and an operable time reference unit for providing timing reference signals to said uplink TOA measurement unit , and an operable service node for storing known positions of said at least 3 radio base stations, the method comprising the steps of: receiving a request in said mobile radio system to determine the position of said mobile radio terminal; if said mobile radio terminal is transmitting either analog signals or no signal, instructing said mobile radio terminal to transmit digital uplink signals in a traffic channel; measuring in said uplink TOA measurement unit an uplink TOA for said at least 3 radio base stations in said traffic channel; receiving in said network controller said uplink TOA measurements from said at least 3 radio base stations and a reference to said traffic channel; translating said reference to said traffic channel into an identity of said mobile radio terminal; bringing said uplink TOA measurements and said mobile radio terminal identity to said service node; and calculating in said service node the position of said mobile radio terminal employing said known positions of said at least 3 radio base stations and said uplink TOA measurements.
The method according to claim 1, further comprising the step of said network controller instructing said mobile radio terminal in the direction of increasing the transmission power during said uplink TOA measurements.
The method according to claim 1, further comprising the step of transferring between said base stations said mobile radio terminal to a more distant service base station.
The method according to claim 2, further comprising the step of transferring within said base station said mobile radio terminal to a second traffic channel if, in a remote base station carrying out a TOA measurement, a ratio between the signal and the noise of said traffic channel is less than a predetermined value, said second traffic channel having a ratio between signal and noise less than said predetermined value.
The method according to claim 1, wherein said ascending TOA measuring unit comprises a ModRX.
The method according to claim 1, wherein said step of giving instructions comprises establishing a call with said mobile radio terminal.
The method according to claim 1, wherein said step of giving instructions comprises activating said mobile radio terminal to transmit if said mobile radio terminal is a discontinuous and inactive type of transmission.
The method according to claim 1, wherein said step of giving instructions comprises taking information to an analog mobile radio terminal, said information instructing said analog mobile radio terminal to respond to the uplink with digital information.
The method according to claim 1, wherein said step of giving instructions comprises the transport of information to a terminal in packets, said information directing said terminal in packets to respond in uplink.
An ammunition equipment for its in a mobile radio system that includes an apparatus for position determination measurements, said measurement equipment is connected to a network controller, a time reference unit, and at least one receiving antenna, which comprises: a first means for measuring TOA, said first means is connected to said time reference; a second means for bringing said digital uplink information from a channel to be measured to said first means and using the correlation with information known in advance to determine the TOA; at least one radio receiver, said at least one radio receiver includes at least one demodulator; and a receiving frequency synthesizer that can operate to connect to said at least one demodulator a frequency that allows measurements of position determination in a specific traffic channel.
The measuring equipment according to claim 10, further comprising a means for receiving and storing frequency hopping sequence in order to allow a TOA measurement in traffic channels of frequency hopping.
12. The measuring equipment according to claims 10 and 11, integrated into a radio base station.
The measuring equipment according to claims 10 and 11, which is located independently and remote in relation to a radio base station to which said measuring equipment is connected.
The measuring equipment according to claim 10, further comprising a first radio base station equipped with at least one TOA meter for measuring the TOA in traffic channels, said at least one TOA meter being operable to communicating with a network controller of said radio base station and for synchronizing with a TOA meter of at least one second radio base station, and where a plurality of transmitters-receivers of said first radio base station are not synchronized with a plurality of transceivers of said at least one second radio base station.
15. A network controller for determining a position a mobile radio terminal comprising: means for instructing at least 3 radio base stations to carry out TOA measurements in a predetermined traffic channel; means for translating a channel idea into an identity of said mobile radio terminal; and means for bringing said TOA munitions and said identity of said mobile radio terminal to a service node for use in calculating said position in said mobile radio terminal.
16. A service node for use in calculating mobile terminal position information in a cellular mobile radio network, comprising: means for receiving requests for position information; means for requesting that a mobile radio terminal transmit digital uplink signals in a traffic channel if said mobile radio terminal is transmitting either analog signals or no signal; means for storing known radio base station position information for use in said calculation of said mobile terminal position information; and means for calculating said mobile terminal position information using TOA information associated with said mobile terminal, and said known radio base station position information.
17. A mobile radio system capable of determining the geographical position of a mobile radio terminal located in said mobile radio system, comprising: a network controller; at least 3 radio base stations, each of said at least 3 radio base stations includes an uplink TOA measuring equipment that can be operated to communicate with said network controller, and a time reference unit which can be operated to provide timing signals to said uplink toe measuring equipment; and a service node that can be operated to store known position information with respect to said at least 3 radio base stations, said mobile radio system can be operated to determine said geographical position of said mobile radio terminal, by means of the receipt of a request to determine said geographical position of said mobile radio terminal, instructing said mobile radio terminal to transmit digital uplink signals in a traffic channel if said mobile radio terminal is transmitting analog signals or no signal, measuring TOA in the uplink TOA measuring equipment in at least 3 uplinks in at least 3 radio base stations in said traffic channel, receiving from said at least 3 radio base stations said TOA measurement information in said network controller and a reference to said traffic channel translating an identity of said traffic channel into an identity of said mobile radio terminal, carrying said information and ascending TOA measurement identity to said service node, and calculating in said service node the geographic position of said terminal mobile radio using said known position information of said at least 3 radio base stations and said information Uplink TOA measurement method.
The mobile radio system according to claim 17, wherein said steering operation comprises establishing a call to said mobile radio terminal.
The mobile radio system according to claim 17, wherein said steering operation comprises activating said mobile radio terminal to transmit if said mobile radio terminal is inactive and a discontinuous transmission type.
The mobile radio system according to claim 17, wherein said instruction-giving operation comprises taking information to an analog mobile radio terminal that directs said mobile radio terminal to respond on said uplink with digital information.
The mobile radio system according to claim 17, wherein said instruction-giving operation comprises taking information to a packet terminal that instructs said packet terminal to respond on said uplink.
The mobile radio system according to claim 17, wherein said uplink TOA measuring equipment includes a DOA meter.
A method for determining the geographic position of the first mobile radio terminal in a mobile radio system, said mobile radio system includes a network controller and at least 3 radio base stations, each of said at least 3 radio base stations includes an uplink TOA measuring unit that can operate to communicate with said controller network, a control unit, and a time reference unit that can operate to provide timing reference signals to said uplink TOA measurement unit, at least one of said at least 3 radio base stations this placed with a second mobile radio terminal and connected to it, said second mobile radio terminal is connected to said network controller through an interface radio, and a service node that can be operated to store known positions of at least 2 of said at least 3 radio base stations, the method comprises the steps of: receiving a request in said mobile radio system to determine the geographical position of said first mobile radio terminal; determining and reporting the position of said second mobile radio terminal to said service node; giving instruction to said mobile radio terminal to transmit digital uplink signals in a traffic channel when said first mobile terminal is not transmitting or is only transmitting analog signals; measuring in said uplink TOA measurement unit an uplink TOA of the digital signals transmitted by the first mobile radio terminal; receiving in said network controller said uplink TOA measurements from said at least 3 radio base stations and a number of traffic channels to said traffic channel; translating said traffic channel number to an identity of said first mobile radio terminal; Transporting said uplink TOA measurements and said first mobile radio terminal identity to said service node; and calculating in said service node the position of said first mobile radio terminal employing said known positions of said at least 3 radio base stations and said uplink TOA measurements.
The method according to claim 23, further comprising the step of said instruction network controller to said first mobile radio terminal to increase the transmit power during said uplink TOA measurements.
The method according to claim 23, further comprising the step of transfers between base stations of said first mobile radio terminal to a more distant service base station.
The method according to claim 23 further comprising 1 step of transferring within a base station, said first mobile radio terminal to a second traffic channel if, in a remote base station carrying out a TOA measurement, a signal to noise ratio of said traffic channel is less than a predetermined value, said second traffic channel has a signal-to-noise ratio greater than said predetermined value.
The method according to claim 1, wherein said uplink TOA measuring unit comprises a modified receiver.
The method according to claim 23, wherein said step of giving instructions comprises establishing a call with said first mobile radio terminal.
The method according to claim 23, wherein said step of giving instructions comprises activating said first mobile radio terminal to transmit if said first mobile radio terminal is of a discontinuous and inactive transmission type.
The method according to claim 23, wherein said step of giving instructions comprises taking information to a first analog mobile radio terminal, said information indicates said first analog mobile radio terminal that responds in uplink with digital information.
The method according to claim 23, wherein said step of giving instructions comprises the fact of carrying information to a first packet terminal, said information indicates said first packet terminal that responds in uplink.
The method according to claim 23, wherein said determining and reporting step comprises determining the position of said second mobile radio terminal using a GPS position information, and reporting said position of said second mobile radio terminal to said service node.
The method according to claim 23, wherein said determining and reporting step comprises determining the position of said second mobile radio terminal employing a predetermined position information, and reporting said position of said second mobile radio terminal to said service node.
34. A mobile radio system capable of determining the geographical position of a first mobile radio terminal located in said mobile radio system, comprising: a network controller; at least 4 radio base stations, each of said at least four radio base stations includes an uplink TOA measuring equipment that can operate to communicate with said network controller, and a radio reference unit. time that can be operated to provide timing signals to said uplink TOA measuring equipment, at least one of said at least 4 radio base stations placed with a second mobile radio terminal and connected thereto, said second terminal mobile radio is connected to said network controller through a radio interface and one of said at least four radio base stations; and a service node that can be operated to store known position information for at least 3 of said at least 4 radio base stations, said mobile radio system can operate to determine said geographical position of said first radio terminal. mobile, by receiving a request to determine said geographical position of said first mobile radio terminal, instructing said first mobile radio terminal and said second mobile radio terminal to transmit digital uplink signals in traffic channels when said first mobile radio terminal or said second mobile radio terminal is not transmitting or is only transmitting analog signals, measuring the TOA of the digital signals transmitted in the uplink TOA measuring equipment in at least 4 base stations of radio, receiving at least 4 radio stations from radio has TOA measurement information in said network controller and numbers of traffic channels to said traffic channels, translating said numbers of traffic channels into identities of said first mobile radio terminal and said second mobile radio terminal, carrying said information TOA uplink measurement and identities to that service node, and calculating in said service node the geographical position of said mobile radio terminal and said second mobile radio terminal by employing said known position information of said at least 3 radio base stations and said TOA measurement information uplink.
35. The mobile radio system according to claim 34, wherein said instruction-giving operation comprises establishing a call with said first mobile radio terminal and said second mobile radio terminal.
36. The mobile radio system according to claim 34, wherein said steering operation comprises activating said first mobile radio terminal to transmit if said first mobile radio terminal is inactive and of a discontinuous transmission type.
37. The mobile radio system according to claim 34, wherein said instruction-giving operation comprises taking information to a first analog mobile radio terminal that instructs said first mobile radio terminal to respond on said link. ascending with digital information.
38. The mobile radio system according to claim 34, wherein said instruction-giving operation comprises transporting information to a first packet terminal that instructs said first packet terminal to respond on said uplink.
39. The mobile radio system according to claim 34, wherein said uplink TOA measuring equipment includes a DOA meter.
40. A mobile unit for use in determining a position of a second mobile radio terminal, comprising: a radio base station connected to a first mobile radio terminal; means for receiving an order for measuring the uplink time of arrival of signals transmitted by said second mobile radio terminal in a specific traffic channel; means for determining and trimming a position of said first mobile radio terminal; and means for measuring and reporting said uplink arrival time of said signals transmitted by said second mobile radio terminal.
41. The mobile unit according to claim 40, wherein said means for determining comprises a GPS receiver.
The mobile unit according to claim 40, wherein said means for determining includes the fact of having a predetermined knowledge of a location of said mobile radio terminal and manually reporting said location.
A method for determining the geographical position of a mobile radio terminal in a mobile radio system, said mobile radio system includes a network controller and at least 3 radio base stations, each of said at least 3 base stations The radio includes an uplink TOA measuring unit that can be used to communicate with said network controller, a control unit, a mobile reference station that can be used to provide timing reference signals relative to said unit of measurement. of TOA uplink, and a service node that can be operated to store known positions of said at least 3 radio base stations and the mobile reference station, the method comprises the steps of: receiving a request in said radio system mobile to determine the position of said mobile radio terminal; if said mobile radio terminal is transmitting either analog signals or no signal, instructing said mobile radio terminal to transmit digital uplink signals in a traffic channel; measuring an uplink TOA for each relative timing reference signal in the uplink TOA measurement units of said at least 3 radio base stations; correcting each uplink TOA measured based on a known distance between the mobile reference station and said at least 3 radio base stations, respectively: receiving and measuring, with respect to the relative timing reference signal, a link TOA ascending from said mobile radio terminal in the uplink TOA measurement units of said at least 3 radio base stations and a reference to said traffic channel; translating said reference to said traffic channel into an identity of said mobile radio terminal; transporting said uplink TOA measurements and said mobile radio terminal identity to said service node; and calculating in said service node the position of said mobile radio terminal by employing said known positions of the mobile reference station and said at least 3 radio base stations and said uplink TOA measurements.
44. The method according to claim 43, wherein the mobile radio terminal and the mobile reference station are operating at similar frequencies.
45. A measurement unit employed in a mobile radio system for determining a TOA measurement of a mobile radio terminal, said measurement unit comprising: at least one radio receiver section which further includes: a receiver for receiving a signal digital uplink from said mobile radio terminal where said mobile radio terminal is receiving instructions to transmit the digital uplink signal in a traffic channel if the mobile radio terminal is transmitting either analog signals or no signal; a demodulator, connected to said receiver, for demodulating the digital uplink signal; and at least one measurement section, connected to said at least one radio receiver section, which further includes: a synchronization word section to receive an identity of the traffic channel; an equalizer, connected to said synchronization word section, for the use of said traffic channel identity to receive the digital uplink signal; a symbol detector for receiving the digital uplink signal from said equalizer; and a TOA meter, connected to said symbol detector, for receiving the digital uplink signal and for making the TOA measurement of the mobile radio terminal employing a time reference signal.
46. The measurement unit of claim 45, wherein said at least one radio receiver further includes a frequency synthesizer, connected to said demodulator, to allow position determination using said traffic channel configured as a frequency hopping traffic channel. -
47. The measurement unit of claim 45, wherein said at least one measurement section further includes a DOA meter.
48. The method according to claim 1, further comprising the step of carrying out a transfer before measuring said uplink TOA measurements.
49. The mobile radio system according to claim 17, further comprising a means for carrying out a transfer before measuring said uplink TOA measurements.
A method for determining a geographical position of a mobile radio terminal in a mobile radio system, said mobile radio system includes a network controller and a radio base station that includes a plurality of uplink TOA measurement units each located in a different place between them and each one that can be used to communicate with said network controller, a control unit, and a time reference unit that can be used to provide timing reference signals to said plurality of Uplink TOA measurement units, and a service node that can be employed to store known positions of said plurality of uplink TOA measurement units, the method comprising the steps of: receiving a request in said radio system mobile to determine the position of said mobile radio terminal; if said mobile radio terminal is transmitting either analog signals or is not transmitting, instructing said mobile radio terminal to transmit digital signals in uplink in the traffic channel; measuring in said uplink TOA measurement unit an uplink TOA measurement in said traffic channel; receiving said uplink TOA measurement from said uplink TOA measurement unit and a reference to said traffic channel in said network controller; translating said reference to said traffic channel into an identity of said mobile radio terminal; bringing said uplink TOA measurements and said mobile radio terminal identity to said service node; and calculating in said service node the position of said mobile radio terminal employing said known positions of said plurality of uplink TOA measurement units and said uplink TOA measurements.
51. A mobile radio system capable of determining a geographical position of a mobile radio terminal located in said mobile radio system, comprising: a network controller; a radio base station that includes a plurality of uplink TOA measurement units, each located at a different location in relation to each other and each used to communicate with said network switch, and a unit reference time that can be used to provide timing signals to each uplink TOA measurement unit; and a service node that can be used to store known positions of said plurality of uplink TOA measurement units, said mobile radio system can be employed to determine said geographical position of said mobile radio terminal, by receiving a request to determine said geographical position of said mobile radio terminal, instructing said mobile radio terminal to transmit digital uplink signals in a traffic channel if said mobile radio terminal is transmitting analog signals or is not transmitting signals, measuring TOA information in said traffic channel in each uplink TOA measurement unit, receiving from said uplink TOA measurement unit said TOA measurement information in said network controller and a reference to said traffic channel, translating an identity of said traffic channel into an identity of said mobile radio terminal, carrying said uplink and identity TOA measurement information to said service node, and calculating in said service node the geographical position of said mobile radio terminal employing said known position information of said plurality of uplink TOA measurement units and said uplink TOA measurement information.
A method for determining the geographical position of a mobile radio terminal in a mobile radio system, said mobile radio system includes a network controller and a radio base station that includes an uplink measurement unit that can be operated to communicate with said network controller, a control unit, and a time reference unit that can be operated to provide timing reference signals to said uplink measurement unit, and a service node that can be used for storing a known position of said radio base station, the method comprising the steps of: receiving a request in said mobile radio system to determine the position of said mobile radio terminal; if said mobile radio terminal is transmitting either analog signals or is not transmitting signals, instructing said mobile radio terminal to transmit digital uplink signals in a traffic channel; measuring in said uplink measurement unit an uplink TOA measurement and a DOA measurement for said base station in said traffic channel; receiving said uplink TOA measurement and said DOA measurement from said radio base station and a reference to said traffic channel in said network controller; translating said reference to said traffic channel into an identity of said mobile radio terminal; bringing said uplink TOA measurement, said DOA measurement and said mobile radio terminal identity to said service node; calculating in said service node the position of said mobile radio terminal employing said known position of said radio base station, said uplink TOA measurement and said DOA measurement.
A mobile radio system capable of determining a geographical position of a mobile radio terminal located in said mobile radio system comprising: a network controller; a radio base station that includes uplink measurement equipment that can be used to communicate with said network controller, and a time reference unit that can be used to provide timing signals to said uplink measurement equipment; and a service node that can be used to store a known position information with respect to said radio base station, said mobile radio system 6i can be used to determine said geographical position of said mobile radio terminal, by receiving a request to determine said geographical position of said mobile radio terminal, instructing said mobile radio terminal to transmit digital uplink signals in a traffic channel if said mobile radio terminal is transmitting analog signals or is not transmitting signals, measuring in said traffic channel a TOA measurement and a DOA measurement in the uplink measurement equipment it receives from said station radio base said TOA measurement and said DOA measurement in said network controller and a reference to said traffic channel that translates an identity of said traffic channel into an identity of said mobile radio terminal, carrying said TOA measurement , said DOA measurement and identity to said service node, and calculating said node the geographical position of said mobile radio terminal employing said known position information of said radio base station, said TOA revision and said DOA measurement.
The method according to claim 23, further comprising the step of carrying out a transfer before the measurement of said uplink TOA measurements of the first mobile radio terminal.
The mobile radio system according to claim 34, further comprising a means for carrying out a transfer before measuring said uplink TOA measurements of the first mobile radio terminal.
A method for determining the geographical position of a first mobile radio terminal in a mobile radio system, said mobile radio system includes a network controller and at least two radio base stations, each including at least one unit of measurement Uplink TOA at a different location in relation to each other and which can be used to communicate with said network controller, a control unit, and a time reference unit that can be used to provide timing reference signals to said uplink TOA measurement units, at least one of said at least two radio base stations is located with a second mobile radio terminal and connected to said second mobile radio terminal, said second mobile radio terminal is connected to said network controller through a radio air interface, and a service node that can be used for storage setting known positions of at least two of said uplink TOA measurement units, the method comprising the steps of: receiving a request in said mobile radio system to determine the geographical position of said first mobile radio terminal; determining and reporting the position of said second mobile radio terminal to said service mode; instructing said first mobile radio terminal to transmit digital uplink signals in the traffic channel when said first mobile terminal is not transmitting or is only transmitting analog signals; measuring in said uplink TOA measurement unit, an uplink TOA measurement of the digital signals transmitted by the first mobile radio terminal; receiving said uplink TOA measurement from said uplink TOA measurement unit and a traffic channel number to said traffic channel in said network controller; translating said traffic channel number into an identity of said first mobile radio terminal; bringing said uplink TOA measurements and said first mobile radio terminal identity to said service node; and calculating in said service node the position of said first mobile radio terminal employing said known positions of said plurality of uplink TOA measurement units and said uplink TOA measurements.
57. A mobile radio system capable of determining the geographical position of a first mobile radio terminal, comprising: a network controller; at least two radio base stations each including at least one uplink TOA measuring unit each located at a different place between them and each one can be used to communicate with said network controller, and a reference unit of time that can be used to provide timing signals to each uplink TOA measurement unit, at least one of said at least two radio base stations is placed with a second mobile radio terminal and is connected to said second terminal mobile radio, said second mobile radio terminal is connected to said network controller through a radio air interface; and a service node which can be used to store known positions of at least two of said uplink TOA measurement units, said mobile radio system can be used to determine said geographical position of said first mobile radio terminal, by receiving of a request to determine the geographical position of said first mobile radio terminal, determining and reporting the position of said second mobile radio terminal to said service mode, instructing said first mobile radio terminal to transmit digital link signals ascending in a traffic channel when said first mobile radio terminal is not transmitting or is only transmitting analog signals, measuring the TOA information of the digital signals transmitted by the first mobile radio terminal in said traffic channel in each unit of TOA measurement Uplink, receiving from each ascending TOA measuring unit said TOA measurement information in said network controller and a traffic channel number to said traffic channel, translating the traffic channel number into an identity of said first mobile radio terminal carrying said uplink and identity TOA measurement information to said service node, and calculating in said service node the geographical position of said first mobile radio terminal employing said known position information of said plurality of measurement units of Uplink TOA and said uplink TOA measurement information. A method for determining the geographical position of a first mobile radio terminal in a mobile radio system, said mobile radio system includes a network controller and a radio base station that includes an uplink measurement unit that can be used to communicate with said network controller, a control unit and a time reference unit that can be used to provide timing reference signals to said uplink measurement unit, said radio base station is placed with a second terminal mobile radio and is connected to said second mobile radio terminal, said second mobile radio terminal is connected to said network controller through a radio air interface, and a service node that can be used to store a known position of said radio base station, the method comprises the steps of: receiving a request in said radio system; l to determine the geographical position of said first mobile radio terminal; determining and reporting the position of said second mobile radio terminal to said service node; instructing said first mobile radio terminal to transmit digital uplink signals in the traffic channel when said first mobile terminal radio is not transmitting or is only transmitting analog signals; measuring in said uplink measurement unit an uplink TOA measurement and a DOA measurement of the digital signals transmitted by the first mobile radio terminal; receiving in said network controller said uplink TOA measurement and said DOA measurement from said radio base station and a traffic channel number to said traffic channel; translating the traffic channel number into an identity of said first mobile radio terminal; bringing said uplink TOA measurement, said DOA measurement and said first mobile radio terminal identity to said service node; and calculating in said service node the position of said first mobile radio terminal employing said known position of said radio base station, said uplink TOA measurement and said measurement of DOA. A mobile radio system capable of determining a geographical position of a first mobile radio terminal, comprising: a network controller; a radio base station that includes uplink measurement equipment that can be used to communicate with said network controller, a control unit and a time reference unit that can be used to provide timing signals to said equipment. uplink measurement, said radio base station is placed with a second mobile radio terminal and connected to said second mobile radio terminal, said second mobile radio terminal is connected to said network controller through a wireless interface. radio air; and a service node that can be used to store a known position information with respect to said radio base station, said mobile radio system can be used to determine said geographical position of said first mobile radio terminal, by receiving a mobile radio station. request in said mobile radio system for determining the geographical position of said first mobile radio terminal, instructing said first mobile radio terminal to transmit digital uplink signals in a traffic channel when said mobile radio terminal is not transmitting or else it is transmitting only analog signals, measuring in the uplink measurement equipment a TOA measurement and a DOA measurement of the digital signals transmitted by the first mobile radio terminal, receiving said measurement from said radio base station of TOA and said DOA measurement in said network controller and a traffic channel number to said traffic channel, translating a traffic channel number into an identity of said first mobile radio terminal, carrying said TOA measurement, said DOA measurement and said first mobile radio terminal identity to said service node, and calculating in said service node the geographical position of said first mobile radio terminal employing said known position information of said radio base station, said TOA measurement and said DOA measurement. SUMMARY OF THE INVENTION The presentation describes a novel method of Differences of Arrival Time (TDOA) (500) and a system (100, 600 and 700) to determine the position of a first mobile radio terminal (108) within an associated mobile radio system (100, 600 and 700), which is based on the Time measurements of Arrival (TOA), which includes a plurality of radio base stations (BSl, BS2, BS3), measuring devices (130), network controller (110) and service node (103). The measuring devices are synchronized in otherwise unsynchronized radio base stations (BSl, BS2, BS3). The measuring devices (130) measure the TOA on request and the Arrival Address (optionally) (DOA), in a digital uplink time segment (301 and 302) or in digital information in a link traffic channel Analog uplink in one or several radio base stations (BS1, BS2 and BS3). The TOA and DOA information as well as the traffic channel number are reported to a Mobile Services Switching Center (102), which obtains the identity of the first mobile terminal (108) from the traffic channel number and sends the terminal identity and measurement information of TOA and DOA to a Service Node (103). The Service Node (103) calculates the position of the first mobile radio terminal (108) using the TOA information (supplemented by the DOA information when available). A second mobile radio terminal (601) is placed on a mobile platform (car, emergency vehicle, etc.), with one of the radio base stations (BSl, BS2, or BS3), which can be moved in a relatively close proximity to the first mobile radio terminal (103). Accordingly, by moving one of the radio base stations (BS1, BS2, or BS3) close to the region of interest (near the first mobile radio terminal (108)), the accuracy of the position determination.