GB2435973A

GB2435973A - Assisting movement of a user of a mobile station in a low visibility environment

Info

Publication number: GB2435973A
Application number: GB0604534A
Authority: GB
Inventors: Nanna Svane Theisen; Mark Edwards
Original assignee: Motorola Inc
Current assignee: Motorola Solutions Inc
Priority date: 2006-03-07
Filing date: 2006-03-07
Publication date: 2007-09-12
Anticipated expiration: 2026-03-07
Also published as: WO2007103903A3; WO2007103903A2; GB2435973B; EP1997327A2; GB0604534D0; EP1997327A4

Abstract

A mobile station 101 is disclosed for use in a radio communications system (100, Fig 1) and includes a means 208,216 for determining a current location of the mobile station, a direction signal receiver 215 for receiving a signal indicating a current direction faced by a user of the mobile station, a transceiver 203 operable to send to another communication terminal (113, Fig 1) radio signals including current location data and to receive from the other terminal selected direction data relating to a selected direction required to be taken by the user from the current location to proceed to a target destination, and a processor 216 for comparing the current direction faced by the user with the selected direction. The mobile station is particularly suited for assisting the movement of a user such as a fire fighter through a smoke filled building.

Description

1 2435973 TITLE: MOBILE STATION, A COMBINATION INCLUDING THE MOBILE

STATION, AND A COMMUNICATION SYSTEM AND METHOD

FIELD OF THE INVENTION

The present invention relates to a mobile station, a combination including the mobile station, and a communication system and a method. In particular, the invention relates to assisting movement of a user of a mobile station, particularly in an environment in which visibility is low or zero.

BACKGROUND OF THE INVENTION

Technologies for determining location or position of a mobile communication station, e.g. a mobile radio unit or a telephone unit, carried by a user are now well developed in outdoor applications particularly by use of the Global Positioning System (GPS) . There is a current demand for a technology for corresponding use inside a building or other enclosure. Such technology could for example be especially useful to emergency services such as the fire service and the police to be able to locate personnel accurately within a building, particularly a multistorey building or a large underground facility such as a mine and to assist personnel to move about within the building.

Various techniques have been developed to locate and track personnel working in hazardous environments in which there is low or zero visibility. For example, it is known to determine electronically the location of a person such as a firefighter in a smoke-filled building and to relay a wireless signal giving the person's location from a mobile station carried by the person to a control station outside the building. The location may be tracked at the control station using a console which includes a display which shows a map of the building with the current location, as sent by the wireless signal, indicated on the map. Another person at the control station operating the console can observe the indicated location and can give the person whose location is being indicated oral directions over a wireless link back to the mobile station carried by that person. Such directions can be used for example to guide that person through the smoke to a particular door or other target destination.

SU)ARY OF THE INVENTION According to the present invention in a first aspect there is provided a mobile station as defined in claim 1 of the accompanying claims.

According to the present invention in a second aspect there is provided a combination as defined in claim 9 of the accompanying claims.

According to the present invention in a third aspect there is provided a system as defined in claim 13 of the accompanying claims.

According to the present invention in a fourth aspect there is provided a method as defined in claim 18 of the accompanying claims.

Further features of the invention are as defined in the accompanying dependent claims and are disclosed in the description of embodiments of the invention which follow.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a schematic layout of a system embodying the invention for assisting movement of a person having a mobile station of the system.

FIG. 2 is a block schematic diagram showing more detail of a mobile station of the system of FIG. 1.

FIG. 3 is a block schematic diagram of functional components of an electronic compass useful in association with the mobile station of FIG. 2.

FIG. 4 is a front view of a firefighter's helmet incorporating an electronic compass such as that of FIG. 3.

FIG. 5 is a perspective view of an electronic compass such as that of FIG. 3 having a gimbal mounting.

FIG. 6 is a block schematic diagram of an example of a form of control station for use in the system of FIG. 1.

FIG. 7 is a flowsheet illustrating operation of a method to assist movement of a person in the system of FIG. 1.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The inventors have recognised in connection with the present invention that the data, which may be delivered by wireless communication to or from a mobile station carried by a user in a hazardous environment particularly one in which visibility is low or zero, such as a building or other enclosure filled with smoke, may beneficially include data relating to a measured direction which the user of the mobile station is currently facing and/or to a selected direction which the user should face to proceed to a target destination.

The signals from the mobile station may be sent from the mobile station to a remote terminal such as a control station. A person who is monitoring received data at the remote terminal may relate the received data to a map or plan of the building or environment in which the user of the MS is located to assist the user of the MS to select an appropriate direction in which to face and in which to proceed to a target destination.

Alternatively, or in addition, the data received at the remote terminal may be related automatically to such a map or plan to select an appropriate direction to be used by the MS user.

FIG. 1 is a diagram showing a schematic layout of an illustrative communication system 100 embodying the invention for assisting movement in three dimensions of a user of a MS (mobile station) 101 within a large building 103. Beacons 105(1) to 105(9) are fixed in the building 103 in locations of known pre-recorded latitude, longitude and elevation or altitude (e.g. indicating storey number of a multi-storey building) Using nine beacons as in the system 100 shown in FIG. 1 is illustrative only. In principle, any number of beacons may be used, depending on required accuracy of location, practicality of deployment, cost and other factors. In particular, in a very large building or other enclosure the number of beacons could be much greater than nine.

The beacons 105(1) to 105(9) may be radio beacons which transmit radio signals in a manner to be described later. The signals transmitted by the beacons 105(1) to 105(9) can be picked up and processed by the MS 101 inside the building 103 in a manner to be described later. A ET (base transceiver) 107 is fixed to the outside of the building 103 and is able to communicate by radio with mobile stations including the MS 101 inside the building 103 and is also able to communicate by radio with other terminals outside the building 103, particularly with a BTS (base transceiver station) 111 which is included in a system infrastructure 109. The BT 107 is an optional component and could for example be replaced by a mobile station or could be dispensed with.

The system infrastructure 109 routes and manages radio communications sent to and from mobile stations operating within the system 100, including the MS 101 inside the building 103 and other mobile stations 102, 104 and 106 outside the building 103. The communication system 100 comprising the infrastructure 109 and the mobile stations 101, 102, 104 and 106 may operate as a trunked communication system according to a known industry protocol standard, e.g. APCO 25 or TETRA. A control station 113 is linked to the system infrastructure 109 by a link 112, which may be a RF link or a hardwired cable link or other known form of link.

The control station 113 is an operational control centre attended by one or more operational control personnel who provide operational instructions to users of mobile stations operating within the system 100, e.g. the MS5 101, 102, 104 and 106. For example, the users of these MS5 may be firefighters (fire service personnel) and the control station 113 may be a fire service operations control centre. Radio communications between the control station 113 and the NS5 101, 102, 104 and 106 are sent via the system infrastructure 109 including the BTS 111.

The control station 113 includes an operations server which receives and sends via the system infrastructure 109 data relating to the MSs of users whose operations are controlled from the control station 113. The operations server 115 processes, manages and stores such data as well as programs needed to process such data. The data stored may for example include the current location of the relevant MSs, including the MS5 101, 102, 104 and 106, and where appropriate, data relating to the current direction a user of one of those NS5 is facing. The operations server 115 may also process, manage and store related location data and programs such as data describing the known locations of the beacons 105(1) to 105(9) in the building 103 (and of other similar beacons within other buildings, not shown) and data and a program which provides a map or plan of the building 103 (and of other buildings, not shown) The operations server 115 may act as a correlator to correlate identities of the beacons 105(1) to 105(9), which may be picked up by the MS 101 in signals from those beacons, with pre-recorded data relating to known locations of the beacons 105(1) to 105(9) inside the building 103.

FIG. 2 is a block schematic diagram showing more detail of the MS 101. The MSs 102, 104 and 106 are constructed and operate in a similar manner. The operational functions of the MS 101 are controlled by a controller 201 which operates in conjunction with a timer 209 which synchronises operations within the MS 101 and a memory 210 which stores data and programs used within the MS 101. A processor 202 processes information included in RF signals sent and received by a transceiver 203. The processor 202 extracts information from a received RF signal detected by the transceiver 203 and passes the information to an appropriate output transducer. Similarly, the processor 202 receives input information for transmission from an appropriate input transducer and delivers the information to the transceiver 203 for transmission in the form of an RF signal by the transceiver 203. The MS 101 includes an audio output 204 which is an output transducer, e.g. a speaker, which converts signals received which represent speech information to an output audible form for delivery to a user. The MS 101 also includes an audio input 205 which is an input transducer, e.g. a microphone, which converts an input audio signal, e.g. in the form of speech, into an electrical form in a well known manner. The electrical signal is delivered to the processor 202 described above.

A data connector 213 provides an output for data received in an RF signal at the transceiver 203 and extracted by the processor 202. The data connector 213 also provides an input for delivery of data to the processor 202 for sending as an RF transmission by the transceiver 203. The data connector 213 may comprise a connection, e.g. a USB data connection, to one or more peripheral devices (not shown) . A keypad 212 serves as a user interface and allows a user to enter control signals for delivery to the controller 201 to operate functions of the MS 101. The keypad 212 also acts as another input transducer allowing entry of alphanumeric data for delivery to the processor 202 for processing to send in radio communications by the transceiver 203. A display 207 operated by a display driver 206 under control of the controller 201 provides displayed information to a user of the MS 101 in a known manner.

A location signal receiver 208 receives RF signals from location system transmitters. The location system transmitters from which the RF signals are received by the location signal receiver 208 may for example be GPS (Global Positioning System) satellite transmitters when the MS 101 is operating in an outdoors environment or the location beacons 105(1) to 105 (9) shown in FIG. 1 when the MS 101 is operating inside the building 103 as illustrated in FIG. 1. The location signal receiver 208 passes information extracted by the location signal receiver 208 to a mobility processor 216 which is able to estimate in a known manner a current location of the MS 109 using the information received from the location signal receiver 208. Location data relating to the estimated current location may be delivered from the mobility processor 216 to the processor 202 for use in one or more ways to be described later and recorded in the memory 210.

The MS 101 also includes a direction signal receiver 214. The direction signal receiver 214 receives signals from a direction measuring device 215 operating in combination with the MS 101. The direction measuring device 215 may be incorporated in the MS 101 or, as illustrated by a dashed line in FIG. 2, may be external to the MS 101 but nevertheless carried by a user who is also carrying the MS 101. The direction measuring device 215 measures a direction in which a person carrying the mobile station 101 is currently facing, e.g. in a manner described later, and provides a direction indicating signal to the direction signal receiver 214 including direction data relating to the current measured direction. The direction signal receiver 214 passes the current direction data it receives in the direction indicating signal to the mobility processor 216 for use in one of the ways to be described later. The current direction data may also be recorded by the mobility processor 216 in the memory 210.

A battery 211 provides electrical power to all operational components of the MS 101.

The transceiver 203 provides RF communications to and from the transceivers of other terminals operating within the system 100 such as the BT 107 and the BTS 111 and, when able to operate in a direct communication mode with the MS 101, the MSs 102, 104 and 106.

When the MS 101 is being used in an outdoors environment and is able to receive GPS signals normally, the location signal receiver 208 picks up the GPS signals and the mobility processor 216 uses data extracted from the signals to compute the current location of the MS 101 in a known manner. When, as shown in FIG. 1, the MS 101 is being used in the building 103, which is an example of a known enclosure having location beacons (the beacons 105(1) to 105(9)) provided in known locations within the enclosure, the mobility processor 216 detects that the signals are from such location beacons in a pseudo GPS system rather than real GPS transmitters.

The beacons 105(1) to 105(9) shown in FIG. 1 may serve as partially coded pseudo GPS transmitters in the manner described in Applicant's copending UK patent application number GB 0510050.8. The signal transmitted by each of the beacons 105(1) to 105(9) may be at the known GPS Li carrier frequency and may be modulated with an identity code in a manner similar to the inclusion of the known PRN satellite identifier in a normal GPS signal. The three dimensional location (latitude, longitude and altitude) of each of the beacons 105(1) to 105(9) may be, as noted earlier, already known in the system 100 and may for example be stored in the operations server 115 or even in the memory 210 of the MS 101. This pre-recorded location data for any of the beacons 105(1) to 105(9) can easily be retrieved if the identity code of the beacon in question is obtained from the coded signal transmitted by the beacon. The MS 101 can obtain this identity code by receiving the signal from a given beacon 105(1) to 105(9) at the location signal receiver 208 (FIG. 2) . Thus, when in the building 103, the mobility processor 216 uses data extracted from signals from the beacons 105(1) to 105(9), instead of data extracted from signals from real GPS satellites, and computes location of the MS 101 inside the building 103 accordingly in the manner described in copending UK patent application number GB 0510050.8.

The location data relating to current location computed by the mobility processor 216 in one of the ways described above may be sent by the MS 101 to the operations server 115. Such data may be sent in signals transmitted via the route described above which extends between the transceiver 203, the BT 107, the BTS 111, the system infrastructure 109 and the link 112. The location data may also be used by the MS 101 in any of the known ways in which current location information (e.g. obtained using location data from real GPS satellites) is used by a mobile station. Thus, the information may be displayed to the user of the MS 101 on the display 207 in the form of text or graphical information, and/or may be transmitted by a radio signal sent by the transceiver 203, e.g. via the BT 107 to one or more other MSs, e.g. the MSs 102, 104 and 106.

The direction data obtained by the mobility processor 216 may be used in a manner similar to the location data. Thus, the direction data may be sent to the operations server 115 and/or may displayed to the user of the MS 101 on the display 207 and/or may be transmitted to one or more other MSs, e.g. the MSs 102, 104 and 106.

Where the location data and the direction information are displayed on the display 207, the information may be displayed in the form of text or graphical information. Where the displayed data is graphical, it may for example be in the form of a map or plan showing a layout of the building 103 with the position of fixed reference points in the building 103 and with the current location and direction indicated.

The current direction may for example be indicated by an arrow. However, if the visibility in the building 103 is very poor, the user of the MS may not be able to read the information displayed on the display 207 and may have to rely on assistance received online' from the control station 113 in one of the ways to be described later.

The direction measuring device 215 may comprise a known device. It may comprise a magnetic compass having an electronic output, in particular a compass providing a digital output of a direction measured by the compass.

Alternatively, it may be a device in which direction is indicated by received polarized radiation, e.g. light, in which for example a vertically polarized radiation component is obtained from a wall of a first set of walls inside the building, e.g. North facing walls, and a horizontally polarized radiation component is obtained from a wall of a second set of walls facing in a direction perpendicular to the first set, the combination of components indicating direction.

Where the direction measuring device 215 comprises an electronic compass it may comprise a known electronic compass. Electronic compasses are well known per se.

Examples of such electronic compasses are described for example in US-A-6817106, US-A--6084406, US-A-6014025 and US-A-5600611. The compass may be mounted in a manner to retain stability to face a given direction even when the user moves body position. For example, it may be gimbal mounted or mounted in a thick, viscous liquid in a known manner.

In FIG. 3, an electronic compass 300 of known form which is suitable for use in or as the direction measuring device 215 is shown. The electronic compass 300 includes a battery 313 providing a source of electrical energy for components of the compass 300. A magnetometer 301 senses local components of the earth's magnetic field along orthogonal reference axes fixed internally in the electronic compass 300. The magnetometer 301 may for example employ magnetoresistive elements in Wheatstone bridge circuits to measure the magnetic field components. A control circuit 303 is operably connected to the magnetometer 301 to control operation of the magnetometer 301. The magnetometer 301 may for example be operated periodically according to an operation program controlled by an electronic processor 307 to which the control circuit 303 is connected.

Individual components of the local magnetic field along the pre-defined reference axes may be measured consecutively by the magnetometer 301. The magnetometer 301 when operated produces an analog electrical signal representing the measured magnetic field components. An A/D (analog to digital) converter 305 is operably connected to the magnetometer 301 to convert the analog electrical signal produced by the magnetometer 301 into a digital number representing the measured component magnetic field values. The A/D converter 305 is operably connected to the electronic processor 307 which computes from the digital number provided by the A/D converter 305 a digital direction value which is equal to a bearing which the electronic compass 300 is facing. An output 309 from the electronic compass 300 delivers a signal which includes the digital direction value computed by the electronic processor 307.

The output 309 may be connected directly to the direction signal receiver 214 shown in FIG. 2.

Alternatively, the output 309 may be connected to a radio transmitter unit 311 (indicated as an optional component by a dashed line) which communicates with a corresponding radio receiver (not shown) incorporated in the direction signal receiver 214. In both cases, the computed digital direction value produced by the electronic processor 307 is received in an input signal at the direction signal receiver 214 and the value is extracted by the mobility processor 216.

The electronic compass 300 may operate constantly or only during selected periods when direction indication is needed by the user of the MS 101. For example, electrical energy from the battery 309 may be supplied only when a switch (not shown) is closed by operation of the user or by a command signal from the MS 101 when a direction seeking mode is selected in the MS 101.

The electronic compass 300 may be fitted in clothing or headgear, e.g. a helmet, worn by a user. The actual location of the electronic compass 300 is not C. important. However, it is important that the electronic compass is fitted in a manner so that it gives an indication of the direction faced by the user independent of the work position of the user (e.g. standing, lying, bending etc.). In other words, the electronic compass 300 as an example of the direction measuring device 215 is incorporated in the clothing or headgear in such a way that the direction measured is known and fixed with reference to a direction the user is facing.

FIG. 4 is a front view of an illustrative helmet 400 to be worn by a user who is a firefighter. The helmet 400 includes in its front surface a module 401 in which is fitted a miniature electronic compass which operates in the manner of the electronic compass 300 described with reference to FIG. 3 to measure a directon or bearing which the firefighter and therefore the module 401 is facing. The electronic compass employed in the module 401 is desirably mounted in a manner such as to provide stability even when the user's head moves relative to the user's body. This is illustrated in FIG. in which the electronic compass is gimbal mounted. The electronic compass is housed in a case indicated in FIG. by a reference numeral 501. An outer ring 503 is attached by rods 505 to inner side walls (not shown) of the module 401. The outer ring 503 is able to swing about a horizontal axis defined by the rods 505. An inner ring 507 is attached to the outer ring by joints 509 one of which is shown in FIG. 5. The inner ring 507 is able to swing about a vertical axis defined by the joints 509 inside the outer ring 503. The case 501 of the electronic compass is attached to the inner ring 507 by joints 511 one of which is shown in FIG. 5. The case 501 enclosing the electronic compass is able to swing about a horizontal axis defined by the joints 511. The gimbal mounting of the case 501 of the electronic compass as shown in FIG. 5 allows the electronic compass to remain substantially stationary in a horizontal plane when the helmet 400 is moved as a result of a movement of the attitude of the head of the firefighter wearing the helmet 400. This allows the electronic compass always to face forward in the same horizontal plane when taking a bearing in the manner described with reference to FIG. 3.

FIG. 6 is a block schematic diagram of an example of a form 600 which may be taken by the control station 113 shown in FIG. 1. In the form 600 illustrated, the control station 113 includes a transceiver 601 which receives and sends signals via the link 112 (FIG. 1) and the system infrastructure 109 (FIG. 1) . The form 600 of the control station 113 includes the operations server already shown in FIG. 1. The transceiver 601 is connected to the operations server 115 and allows data to be communicated between the operations server 115 and MS5 and other terminals operating in the system 100. For example, the transceiver 601 is able to receive and pass to the operations server 115 signals sent by the MS 101 including location and direction data in the manner and via the path described earlier. A control console 603 is operably connected to the transceiver 601 and the operations server 115. The control console 603 includes a keyboard 604 for data entry by a user, a display screen 605 to display information relevant to control of operations using the system 100 and a radio dispatcher unit 606 to allow speech communications to be made to MSs via the link 112 and the system infrastructure 109 and the radio link from the BTS 111 of the system infrastructure 109 to the appropriate MS. The control console 603 also includes as an optional component a telephone 607 to allow standard landline telephone communications to be made to and from a person operating the control console 603.

The display screen 605 may for example display information illustrating the mobility of a selected MS in the system 100. For example, the display screen 605 may display using data and a program obtained from the operations server 115, including current location data and optionally current direction data received from the MS 101, a map of the building 103 indicating a current location of the user of the MS 101 and optionally a current direction in which the user of the MS 101 is facing. The person operating the console 603 may employ information displayed on the display screen 605 to assist a user of the MS 101 in real time to reach a target destination inside the building 103, e.g. a door leading to a point of safety, during an operation carried out by the user. Examples of ways in which such assistance may be provided are as follows.

In a first way in which the operator of the console 603, the console operator', may provide assistance to the person carrying the MS 101, the MS user', inside the building 103, the console operator monitors on the display screen 605 the current location of and direction faced by the MS user. The console operator also notes from the display screen 605 any target destination inside the building 103 to be reached by the MS user and any obstacles that need to be avoided. The console operator may speak to the MS user via the radio dispatcher unit 606 (and the communication route between that and the MS 101 as described above) to give oral instructions to the MS user. The console operator may instruct the MS user to turn slowly on the spot. The console operator may monitor the MS user's change in direction on the display screen 503 until the MS user faces in a correct or selected direction or bearing. At this point, the console operator tells the MS user to stop turning. The console operator may then instruct the MS user to proceed slowly in the direction the MS user is facing until the MS user reaches a target destination. If movement in more than one direction, e.g. to avoid obstacles, is needed along a selected movement route, to reach the target destination, the console operator may instruct the MS user to change direction at one or more particular points along the route to the target destination.

In a second way in which the console operator may assist the MS user, the console operator may send to the MS 101 using an instruction at the keyboard 504 a required bearing selected by the console operator of a route to a target destination to be reached by the MS user. Theinstruction is in the form of a data message communicated via the transceiver 601 and the MS 101 via the communication route between the transceiver 601 and the MS 101 described above. The required bearing included in the data message may be passed in the MS 101 to the mobility processor 216. The required bearing may be compared in the mobility processor 216 with the actual current direction faced as measured by the direction measuring device 215 and a difference angle between the required bearing and the current direction faced may be calculated by the mobility processor 216.

For example, an audible, vibratory or visible output may be provided by the MS 101 to indicate to the MS user a magnitude of the difference angle between the required bearing and the current direction faced.

In a first example of such an indication, the mobility processor 216 may pass to the audio output 204 a signal which causes the audio output 204 to emit an output audio signal which indicates the difference angle. For example the pitch or repetition frequency of the output audio signal emitted by the audio output 204 may increase as the difference angle becomes smaller. So the MS user may slowly turn the direction measuring device 215, e.g. the electronic compass in the module 401 of the helmet 400, by a turn of the head, until the pitch or repetition frequency of the emitted output audio signal reaches a maximum.

In a second example of such an indication, the mobility processor 216 may pass an output signal to a vibrator or buzzer (not shown) which may provide a vibrating/buzzing output with a variation in intensity or frequency to indicate the measured difference angle.

In a third example of such an indication, a light indicator, which may be part of the display 207 or another light indicator of the MS (not shown), increases in brightness or flashes with an increased repetition frequency to indicate that the measured difference angle is becoming smaller.

In a third way in which the console operator may provide assistance to the MS user, the console operator may trace on the display 604 a displayed route to be followed by the MS user to a target destination. The displayed route may for example be traced by the console operator by use of a cursor of a mouse which is part of the equipment of the control console. This action records, e.g. by the operations server 115, data defining the route to be taken by the MS user including one or more selected bearings to be followed by the MS user along the route. The data is sent to the MS 101, received by the mobility processor 216 of the MS 101 and used by the mobility processor 216 in the manner described above to calculate a difference angle between the required bearing and the current direction faced and to provide an output signal indicating the calculated difference.

In a further method in which the console operator is not involved, the location data, and optionally the direction data, sent by the MS 101 to the operations server 115 is automatically fitted to an electronic map of the building 103 stored by the operations server 115.

The operations server 115 thereby calculates a required bearing that needs to be taken by the MS user and sends a data message to the MS 101 giving the required bearing. The required bearing received by the MS 101 is used by the MS user to adjust a direction faced in one the ways described above.

FIG. 7 is a flowsheet of a method 700 which summarises the various ways which have been described in which the user of the MS 101 may be guided to a target destination in the building 103. In a step 701, the MS 101 obtains location data and direction data relating respectively to the current measured location of the MS 101 as computed by the mobility processor 216 and the direction faced by the user of the MS 101 as obtained by the mobility processor 216 from the direction measuring device 215 via the direction signal receiver 214. In a step 703, the MS 101 sends the current location data and the current direction data to the control station 113 via the communication route described above. The data is received and stored by the operations server 115. In a step 705, the received location data and direction data is fitted to a previously recorded map of the building 103. Data relating to the map may be stored by the operations server 115. In a step 707, a bearing required to be taken by the user of the MS 101 to a target destination in the building 103 is sent from the control station 113 to the MS 101. The required bearing may be observed or traced by a console operator from a map or plan displayed on the display screen 605 and may be communicated to the MS 101 orally or as a data message by the console operator. Alternatively, the required bearing may be generated by automatic reading of a map or plan of the building 103, e.g. by the operations server 115 and may be communicated to the MS 101 as a data message from the operations server 115. In a step 709, the MS user adjusts a direction faced using the required bearing provided in step 706 until the direction faced matches that of the required bearing. In a step 711 the MS user proceeds along the required bearing toward the target destination.

In the embodiments of the invention described above, the current location of the MS 101 is found by a pseudo GPS system operating inside a building. It will be apparent to those skilled in the art that other known location technologies, such as triangulation using signals from at least three different transmitters, could be used to provide an estimation of current location of the MS 101. Furthermore, use of the invention is not limited to use inside a building. In some embodiments of the invention, the hazardous environment in which the user of the MS 101 has to navigate may be outdoors, in which case the GPS system or any other outdoor location technology may be used.

Use of the invention is not limited to use by emergency services personnel fulfilling a special task such as by firefighters moving in a smoke filled building. In some applications, embodiments of the invention may be employed to guide members of the public, e.g. people who are blind in a shopping mall or other congested area. Of course, in such embodiments, information provided to the user is not in visual form but in another form such as audio or vibratory form as described earlier.

In the above described embodiments of the invention, measurement of the direction in which the user of the MS 101 is currently facing as well as the location of the MS 101, and communication of related data between the MS 101 and the control station 113, beneficially allows more accurate and efficient movement assistance to be provided from the control station 113 to the user of the MS 101 when operating in a hazardous environment, particularly where visibility is low.

Claims

CLAIMS

1. A mobile station for use in radio communications in a mobile communication system including means for determining a current location of the mobile station, a direction signal receiver for receiving a signal indicating a current direction faced by a user of the mobile station, a transceiver operable to send to another communication terminal radio signals including current location data relating to the current location of the mobile station and to receive from another communication terminal selected direction data relating to a selected direction required to be taken by the user from the current location to proceed to a target destination, and a processor for comparing the current direction faced by the user with the selected direction.

2. A mobile station according to claim 1 wherein the processor is operable to produce a signal indicating a difference angle between the current direction faced and the selected direction.

3. A mobile station according to claim 2 including means for providing to a user of the mobile station an indication signal indicating the difference angle.

4. A mobile station according to claim 3 including an audio output operable to provide an indication audio signal having a pitch or repetition frequency which varies dependent on variations in the difference angle.

5. A mobile station according to claim 3 or claim 4 including an output comprising a vibrator or buzzer operable to provide a vibrating or buzzing indication

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signal having a variable intensity or frequency to indicate the measured difference angle.

6. A mobile station according to claim 4 or claim 5 including a visual indicator operable to provide an indication light signal having a brightness or repetition frequency which varies dependent on variations in the difference angle.

7. A mobile station according to any one of the preceding claims wherein the transceiver is operable to send to another terminal radio signals including current direction data relating to the current direction faced by the user of the mobile station.

8. A mobile station according to any one of the preceding claims including a display operable to display information including the current location of the mobile station and optionally the current direction faced by a user of the mobile station.

9. A combination of a mobile station according to any one of the preceding claims and, operably coupled to the direction signal receiver of the mobile station, a direction measuring device for determining a direction faced by a user of the mobile station.

10. A combination according to claim 9 wherein the direction measuring device comprises an electronic compass.

11. A combination according to claim 9 or claim 10 wherein the direction measuring device has a mounting providing stability of the means for determining a direction.

12. A combination according to any one of claims 9 to 11 wherein the direction measuring device is incorporated in or fitted to clothing or a helmet or other headgear to be worn by a user in such a way that the direction measured is known and fixed with reference to a direction the user is facing.

13. A mobile communication system including a mobile station or a combination according to any one of the preceding claims and a further communication terminal operable to receive the current location data.

14. A system according to claim 13 including a display associated with the further terminal operable to display a map or plan showing a current location of the mobile station.

15. A system according to claim 14 wherein the display is operable to display a map or plan of a building or enclosure in which the mobile station is currently located.

16. A system according to claim 14 or claim 15 wherein the display is operable to indicate the current direction faced by a user of the mobile station.

17. A system according to any one of claims 13 to 16 wherein the mobile station is operable to receive from the further terminal selected direction data relating to a selected direction required to be taken by the user from the current location to proceed to a target destination, wherein the system includes a control station which includes the further terminal, the display and an operational server operable to store and process data relating to location of mobile stations.

18. A method of operation in a system according to any one of claims 13 to 17 including a mobile station obtaining current location data relating to its current location and current direction data relating to a current direction faced by a user of the mobile station, sending the current location data and optionally the current direction data to a control station, comparing at the control station the current location data and optionally the current direction data with a map or plan of an environment in which the mobile station is located, sending to the mobile station a selected direction required to be taken by a user of the mobile station to reach a target destination, comparing in the mobile station the current direction faced by the user with the selected direction, and adjusting the current direction faced by the user to match the selected direction.

19. A mobile station according to claim 1, a combination according to claim 9, a system according to claim 13 or a method according to claim 18 substantially as described herein with reference to one or more of the accompanying drawings.