MXPA98010794A - Automatic localization of individuals using the combination of media inalambri - Google Patents

Abstract

Transmit identification codes of fixed units by wireless phones to a central computer via a wireless switching system. The central computer uses identification codes to locate cordless telephones. Since a cordless telephone already has the ability to communicate using a wireless protocol, the only additional cost to the cordless telephone is the ability to receive the transmission of the physical units. Cordless telephones use first wireless means for transmission, and fixed units use second wireless means for transmission. In addition, each fixed unit consists only of one transmitter. The second means can be infrared or ultrasonic transmission. If the cordless telephone fails to detect a fixed unit, the cordless telephone transmits this fact back to the central computer. This is done to determine the locations that are not served by a fixed unit and also to detect the failed fixed units. The central computer maintains a record of fixed units with a wireless telephone that has been previously identified. This allows the central computer to determine if there is a need for a fixed unit or that a fixed unit has failed. The fixed units can be operated with batteries. When the controller controlling the fixed unit determines that the battery is reaching a low state in the fixed unit, the controller transmits this information along with the identification code, so that the low battery indication can be delivered to the central computer.

Description

AUTOMATIC LOCATION OF INDIVLS USING A COMBINATION OF WIRELESS MEDIA Technical Field This invention relates to communication systems, and in particular, with the ability to locate people automatically.

BACKGROUND OF THE INVENTION Within the prior art, systems for locating indivls automatically are known. One such system is disclosed in U.S. Patent No. 4,275,385. The system described in this patent uses fixed units each of which have an infrared transmitter and receiver which are connected via wired links to a central control computer. Each indivl carries a mobile unit that has a transmitter and a receiver. Fixed transmitters are constantly transmitting a signal to indicate the presence of a fixed unit. When the mobile unit receives transmission from a fixed transmitter, the mobile unit transmits its identification to the fixed receiver. The fixed receiver responds to the identification of the mobile unit to transmit this identification via the wired link to the central computer. The central computer stores the position of the REF: 28802 different mobile units. This stored information can be retrieved to determine the position of any of the mobile units. The problems with the solution of the prior art are the following. First, the fixed unit has to be strongly connected back to the central computer. In general, the cost of making the connection will greatly exceed the fixed unit itself. Due to this cost, only a limited number of fixed units can be deployed; thus reducing the location accuracy of a mobile unit. In addition, each mobile unit must have a transmitter and a receiver operating in the infrared spectrum.

BRIEF DESCRIPTION OF THE INVENTION A technical advance was achieved by means of an apparatus and a method using fixed units consisting solely of a transmitter transmitting the identification code of the fixed unit using a first wireless means. A mobile unit receives the transmitted identification from the fixed unit and uses a second wireless means to directly transmit this information back to a central computer. Advantageously, the mobile unit is a wireless telephone that uses standard wireless communication channels to report back the identification received from the fixed unit. Since the cordless telephone already has the ability to communicate using a wireless protocol, the only additional cost to the cordless telephone is the ability to receive the transmission from the fixed unit. Advantageously, the first means is an infrared or ultrasonic transmission. Advantageously, if the wireless telephone fails to detect a fixed unit, the wireless telephone transmits this fact back to the central computer. This is done to determine places that are not served by a fixed unit and also to detect failed fixed units. The central computer keeps a record of fixed units with which the wireless telephone has been previously identified. This allows the central computer to determine where there is a need for a fixed unit or which fixed unit has failed. Advantageously, the fixed units can be operated with batteries. When the controller controlling the fixed unit determines that the battery is reaching a low state in the fixed unit, the controller transmits this information along with the identification code, so that the low battery indication can be delivered to the central computer. These and other features and advantages of the present invention will become more apparent from the following description of an illustrative embodiment of the invention considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 illustrates, in the form of a block diagram, a system according to the invention; FIGURE 2 illustrates, in the form of a block diagram, a fixed unit according to the invention; FIGURE 3 illustrates, in the form of a block diagram, a wireless telephone according to the invention; FIGURE 4 illustrates, in the form of a flowchart, the steps performed by a wireless terminal according to the invention; FIGURE 5 illustrates, in the form of a flowchart, the steps performed by a fixed unit according to the invention; and FIGURE 6 illustrates, in the form of a flowchart, the steps performed by a central computer according to the invention.

Detailed Description FIGURE 1 illustrates a system according to the invention. The system controller 111 via the base stations 121-122 provides the wireless communication service to the wireless telephone sets 112-114. In addition, each of the fixed units 102-109 have an identification code that is periodically transmitted using infrared or ultrasonic transmission means. One skilled in the art could easily devise other types of transmission means including a high or low frequency transmission network. Each fixed unit is transmitting within a defined physical area. In the system illustrated in FIGURE 1, the fixed unit 101 is located in a vestibule which provides access to rooms in which the fixed units 102-108 are located. To understand the system operation illustrated in FIGURE 1, consider the following example. Initially, the wireless telephone handset 113 is in the room served by the fixed unit 107. When the wireless telephone handset 113 is moved from the room served by the fixed unit 107 to the lobby served by the fixed unit 101, the wireless telephone handset 113 recognizes that the identification code being received does not belong to that of the fixed unit 107 but that it is the identification code of the fixed unit 101. The wireless telephone apparatus 113 then establishes a logical data channel via a base station to the controller system 111. The system monitor 111 responds to this logical channel by establishing a logical data connection with the central computer 119. The wireless telephone apparatus 113 then transmits to the central computer 119 the fact that it is now receiving the identification code of the the fixed unit 101. The central computer 119 in response to this infor This update updates the database defining the location of the wireless telephone set to reflect the fact that the wireless telephone set 113 is now in the lobby served by the fixed unit 101. Alternatively, the wireless telephone set 113 could establish a telephone call to either the system controller 111 or the central computer 119 and to use multiple frequency tones to transmit the identification code of the fixed unit 101. If the fixed unit 101 has failed or did not exist, when the wireless telephone set 113 moved from the room served by the fixed unit 107 to the lobby, the wireless telephone apparatus 113 informs the central computer 119 that it was not receiving an identification code from a fixed unit. The central computer 119 responds to this information to analyze the possible locations of the wireless telephone handset 113. If the vestibule were the only exit from the room, the central computer 119 initiates a maintenance procedure to repair the fixed unit 101. In addition, each of the fixed units 101-108 can be operated with batteries. If a fixed unit is operated with batteries and detects that the power output of the battery is low, this low energy information is also transmitted in the identification code. A wireless telephone device receiving the low energy identification code transmits the information along with the identification code of the fixed unit to the central computer 119 via the system controller 111. In addition, the central computer 119 maintains a frequency rate for each fixed unit that defines the speed at which the cordless telephone handset comes into contact with one of the fixed units. If the speed at which the contact with a particular fixed unit falls below the normal statistical frequency rate for that fixed unit, the central computer 119 initiates the maintenance procedures to determine whether the fixed unit has failed. FIGURE 2 illustrates a fixed unit in the form of a block diagram. The fixed unit of FIGURE 2 is powered by a battery 201. However,, one skilled in the art could easily observe that normal AC power could also be used to power the fixed unit. The controller 203 periodically transmits the identification code for the fixed unit of the transmitter 204. Advantageously, the transmitter 204 may transmit using an infrared transmission or an ultrasonic transmission. Transmitters for transmitting in infrared or ultrasonic form are well known in the art. If the controller 203 detects that the battery 201 is at a low energy level via the conductor 207, the battery verifier 2Q2, and the driver 208, the controller 203 activates the alarm indicator 205 and transmits the low energy indication together with the identification code via transmitter 204. Wireless telephone apparatus 112 is illustrated in greater detail in FIGURE 3. Wireless telephone apparatus 112 implements a wireless protocol that allows wireless telephone apparatus 112 to maintain a wireless signal link with the wireless telecommunication system controller 111 via the base stations 121-122. An aerial interconnection that can be used is the Japanese PHS protocol as set forth in "User-Network Interface and Inter-Network Interface Standards for PHS", the Telecommunications Technology Committee, 1995, and "Personal Handy Phone System RCR Standard", Version 1 , RCR STD-28, December 20, 1993. The message set of the PHS protocol is similar to the set of ISDN messages. The total control of the wireless telephone apparatus is provided by the control unit 201. The units 302, 303, 306, 307, 308 and 309 provide the RF communication capabilities to the wireless telephone handset. Elements 304, 310 and 311-314 provide the audio information received and transmitted to the user; while elements 316-318 and 305 provide basic user interconnection. The PHS protocol allows the control unit 301 to establish a logical data channel with the system controller 111. The control unit 301 uses this logical data channel to transmit the identification information of the fixed units to the system controller 111 on the which in turn transfers this information to the central computer 119 of FIGURE 1 using well-known methods. The receiver of the fixed unit 321 receives the identification code of a fixed unit and transfers this identification code to the control unit 301 for transmission to the central computer 119. The receiver of the fixed unit 321 is of a well-known design in the art for any infrared or ultrasonic transmission medium. One skilled in the art could easily observe the receiver of the fixed unit 321 which could provide the control unit 301 with the strength of the received signal. In addition, the control unit 301 could also tune the receiver of the fixed unit 321 to receive different frequencies or other variations of the transmission means using techniques well known in the art.

FIGURE 4 illustrates the steps performed by a wireless terminal such as a wireless telephone handset 113. Decision block 401 determines whether the time to verify a fixed unit has elapsed. Advantageously, every second of the wireless telephone apparatus is checked to determine whether the transmission signal of a fixed unit is being received. If the answer in decision block 401 is no, normal processing is effected by block 402 before the control returns back to decision block 401. If the answer in decision block 401 is yes, control is transferred to decision block 403 which determines whether a transmission signal is being detected. If the response in decision block 403 is no, the control is transferred to block 404 which establishes a logical channel to the central computer 119 through a base station of the system controller 111. After the establishment of the logical channel, the The wireless telephone handset transmits a "no fixed unit" message to the host computer before transferring control back to decision block 401. Returning to decision block 403, if the answer is yes, the control is transferred to block 408 which establishes a logical channel with the central computer 119. The block 409 determines the identification code of the fixed unit whose transmission signal is being received, and the block 411 transmits the identification code received in the central computer 119 before transferring the control to decision block 412. Decision block 412 determines whether a low battery indication was included in the signal of transmission of the fixed unit. If the answer is no, the control is transferred back to the decision block 401. If the answer in the decision block 402 is yes, the block 413 transmits a low battery indication message to the central computer 119 for the identified fixed unit . FIGURE 5 illustrates the steps performed by a fixed unit. Decision block 501 determines if this is the time to transmit the identification code of the fixed unit. Advantageously, the identification code is transmitted every tenth of a second. If the answer is no, the control is transferred back to the decision block 501. If the answer is yes, the decision block 503 determines whether the battery checker of 202 of FIGURE 2 is indicating a low battery. If the answer is no, block 504 simply transmits the identification code of the fixed unit before transferring the control back to decision block 501. If the answer in decision block 503 is yes, block 506 transmits a message that it includes the identification code and a low battery indication before transferring the control block to the decision block 501. FIGURE 6 illustrates the steps performed by the central computer 119 in the implementation of the invention. Decision block 601 determines whether there is a message from the wireless telephone set. If the answer is no, the control is transferred to block 602 which performs normal processing before returning the control back to decision block 601. If the answer in decision block 601 is yes, decision block 607 determines whether a "no fixed unit" message from a wireless telephone device is being received. Such message indicates that the cordless telephone is not receiving the transmission signal from any fixed unit. If the answer is yes in decision block 607, the control is transferred to control 604 which determines the last known location. The central computer 119 keeps a list of the last known locations of each of the wireless terminals. Block 606 then indicates that the cordless telephone can not receive a fixed unit around the last place listed for the cordless telephone. This signaling can be in the form of a message displayed or presented to an operator of the central computer 119 or simply be a message that is included in a maintenance record of the central computer 119. After the execution of block 606, Control is transferred back to decision block 601. Returning to decision block 607, if the answer is no, decision block 608 determines whether a low battery indication is included in the message that identifies the unit fixed phone wireless If the answer is no in decision block 608, block 609 determines the location based on the identification code of the fixed unit of the cordless telephone and stores this location in a database maintained by central computer 119. The base of The data is used by the central computer 119 to determine the location of the wireless telephones after requesting it. Such operations are well known in the art. If the answer in decision block 608 is yes, the low battery indication for the identified fixed unit is placed in the database, and message maintenance indicating low battery is generated before transferring control to block 612. Block 612 performs the same operations as block 609 before transferring control back to decision block 601.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following:

Claims (8)

1. A method for indicating the location by means of a wireless telephone interconnected to a wireless switching system and using a plurality of fixed units each of which transmits a unique identification code, characterized in that it comprises the steps of: receiving an identification code of a plurality of fixed units; and establishing a data communication path via the wireless switching system to a central computer; transmit the received identification code to the central computer via the data communication path.

2. The method of compliance with the claim 1, characterized in that the reception of the identification code of each of a plurality of fixed units is effected using a first transmission means and the transmission by the cordless telephone is effected using a second transmission means.

3. The method of compliance with the claim 2, characterized in that it also comprises the step of transmitting a first message to the central computer after an identification code has not been received. The method according to claim 3, characterized in that it comprises the step of transmitting an alarm condition with the identification code to the central computer after an alarm condition exists and which is transmitted by one of the plurality of units fixed. 5. A wireless telephone interconnected to a wireless switching system using a first transmission means and a plurality of fixed units each of which transmits a unique identification code using a second transmission means, characterized in that the wireless telephone comprises the steps of: a transmitter to establish a data communication path via the wireless switching system to a central computer by one of the wireless telephones; a receiver for receiving an identification code of one of the plurality of fixed units by the wireless telephone; - the transmitter also transmits the received identification code to the central computer via the established data communication path; and the central computer determines the location of the wireless telephone using the received identification code. The wireless telephone according to claim 5, characterized in that the transmitter also transmits a first message to the central computer by means of the wireless telephone after not receiving the identification code. The wireless telephone according to claim 6, characterized in that the transmitter further transmits an alarm condition with the identification code to the central computer after an alarm condition exists and which is transmitted by one of the plurality of units. fixed. The wireless telephone according to claim 7, characterized in that the data communication path is a logical channel of the signal channel that lies between the wireless telephone and the wireless switching system for the processing of calls. SUMMARY OF THE INVENTION Transmit identification codes of fixed units by wireless phones to a central computer via a wireless switching system. The central computer uses identification codes to locate cordless telephones. Since a cordless telephone already has the ability to communicate using a wireless protocol, the only additional cost to the cordless telephone is the ability to receive the transmission of the physical units. Cordless telephones use first wireless means for transmission, and fixed units use second wireless means for transmission. In addition, each fixed unit consists of only one transmitter. The second means can be infrared or ultrasonic transmission. If the cordless phone fails to detect a fixed unit, the wireless phone transmits this fact back to the central computer. This is done to determine the locations that are not served by a fixed unit and also to detect the failed fixed units. The central computer maintains a record of fixed units with a wireless telephone that has been previously identified. This allows the central computer to determine if there is a need for a fixed unit or that a fixed unit has failed. The fixed units can be operated with batteries. When the controller 'controlling the fixed unit determines that the battery is reaching a low state in the fixed unit, the controller transmits this information along with the identification code, so that the low battery indication can be delivered to the central computer .