KR20070022852A - System and method for tracking assets using an ad-hoc peer-to-peer wireless network - Google Patents

Abstract

By placing a network of wireless devices, including mobile terminals, wireless routers and at least one control console, within a three-dimensional deployment area, such as a building, communication, identification and location calculation of people, such as firefighters, can be made using the wireless terminals. Can be made regardless of the structure, and determines whether the target asset, such as a firefighter in a fire and rescue scenario, has stayed within a given user indication area for longer than desired periods, and the target asset, and the building in which the target asset is located A system and method are disclosed that can generate an alarm that identifies a location, such as a floor number of.

Network Deployment, Wireless Devices, Mobile Terminals, Asset Tracking, Firefighters

Description

SYSTEM AND METHOD FOR TRACKING ASSETS USING AN AD-HOC PEER-TO-PEER WIRELESS NETWORK}

This application claims the benefit of US Provisional Application No. 60 / 585,920, filed July 8, 2004, the entire contents of which are incorporated herein by reference.

<Cross Reference of Related Application>

United States of America, including John M. Belcea, entitled "System and Method for Identifying the Floor Number Where a Firefighter in Need of Help is Located Using Received Signal Strength Indicator and Signal Propagation Time," filed June 4, 2004. US Patent Application No. 10 / 861,557 to John M. Belcea entitled "System and Method for Accurately Computing the Position of Wireless Devices Inside High-Rise Buildings", filed June 6, 2004 And US Patent Application No. 10 / 861,668 to John M. Belcea, entitled "MAC Protocol for Accurately Computing the Position of Wireless Devices Inside Buildings," filed June 4, 2004, each of which is incorporated herein by reference in its entirety. The entire contents of the application are incorporated herein by reference.

The present invention utilizes ad hoc peer-to-peer wireless mobile communications network technology to accurately determine whether a target asset, such as a firefighter in a fire and rescue scenario, is staying in a given area for a longer time period than desired. And a system and method capable of generating an alarm that identifies a location, such as the number of floors of a building where the target asset is located.

Recently, a kind of mobile communication network known as "temporary multi-hop" network has been developed. In this type of network, each mobile node can act as a router to other mobile nodes that provide most of the functionality of the base station, thereby extending coverage area at a very low cost. Details of the ad hoc network are described in Mayer's US Pat. No. 5,943,322, the entire contents of which are incorporated herein by reference. As will be appreciated by those skilled in the art, a network node is a time division multiple access (TDMA) format, code division multiple access (CDMA) format, which allows a single transceiver at a base station node to simultaneously communicate with multiple mobile nodes within its coverage area. Or transmit and receive data packet communications in a multiplexed format, such as a frequency division multiple access (FDMA) format.

In addition to allowing mobile nodes to communicate with each other as in a typical ad hoc network, other fixed or mobile nodes, such as nodes on a public switched telephone network (PSTN) and other networks, such as the Internet, may be connected to fixed nodes by More sophisticated ad hoc networks are also being developed that allow communication with the public. Details of these advanced types of ad hoc multi-hop networks are described in US Patent Application No. 09 / entitled "Ad Hoc Peer-to-Peer Mobile Radio Access System Interfaced to the PSTN and Cellular Networks," filed June 29, 2001. 897,790, filed March 22, 2001, entitled "Time Division Protocol for an Ad-Hoc, Peer-to-Peer Radio Network Having Coordinating Channel Access to Shared Parallel Data Channels with Separate Reservation Channel." 09 / 815,157, and US Patent Application No. 09 / 815,164 entitled "Prioritized-Routing for an Ad-Hoc, Peer-to-Peer, Mobile Radio Access System," filed March 22, 2001. The entire contents of each of these applications are incorporated herein by reference.

In a typical wireless communication network, or in a temporary wireless communication network, it may be necessary or desirable for a mobile node to know or determine a relative or absolute geographical location or location. As is known to those skilled in the art, this can be achieved through the use of several techniques. These techniques include round trip time (RTT), timing advance (TA) and measurement signal level (RX level), time difference of arrival (TDOA), and angle of arrival (A0A) techniques that can be understood by those skilled in the art. Requires combined cell identification. Another available technique uses cellular signal timing based methods for CDMA and Wideband CDMA (WCDMA). Another technique uses Global Positioning System (GPS) technology, which generally appears to be more accurate than all the other methods listed.

Despite the fact that GPS technology has been in use for a considerable period of time, and most of the world's navigation relies on it, GPS technology is likely to produce large measurement errors under some specific conditions. This technique can provide positioning results with very high accuracy only after performing a relatively large number of measurements involving multiple satellites to eliminate propagation and method errors. A description of the disadvantages of GPS is in a document by Institute for Mathematics and its Applications (IMA) entitled "Mathematical Challenges in Global Positioning Systems (GPS)", the entire contents of which are incorporated herein by reference. Some other tests also include land-based networks where GPS technology operates in an environment where the number of visible satellites is too small to provide good accuracy, such as in underground tunnels, inside buildings, under heavy foliage, or in “deep canyons” in urban areas. It is proved unsuitable for the field.

To solve the above problem associated with determining location information, new technologies are being developed that do not require the use of satellites or a central computing facility to determine location information. Further details of the new techniques for computing the location of a mobile terminal in an ad hoc multi-hop network are entitled, "System and Method for Computing the Location of a Mobile Terminal in a Wireless Communications Network," the entire contents of which are incorporated herein by reference. US Pat. No. 6,728,545. In addition, ad hoc networks can be developed using unfixed or movable base components. Further details of networks using mobile access points and repeaters for optimal coverage and capacity limitations are described in "Movable Access Points and Repeaters for Minimizing Coverage and Capacity Constraints in a Wireless Communications Network and a Method, filed August 15, 2001." for US Patent Application No. 09 / 929,030 entitled "For Using the Same", the entire contents of which are incorporated herein by reference.

The foregoing patents and patent applications generally relate to mobile networks that connect to a permanent fixed network where location information is indicated as an absolute location. However, as can be seen from the foregoing patent applications, temporary temporary multi-hop networks do not necessarily have the same requirements. Thus, there is a need for portable, easily deployed, self-contained temporary multi-hop network systems where relative position detection is required, such as where the location of people working in emergency situations is very important. Relative locations may be provided in addition to or instead of absolute geographic locations and should be able to communicate easily between the various transmission obstructions generally present at such locations.

Thus, improved systems and methods for easily determining and communicating the absolute and / or relative position of mobile nodes within a deployed wireless communication network, and specifically using such systems, such as firefighters with mobile nodes in fire and rescue scenarios. There is a need for a system and method that can identify whether an asset has been in a given area for longer than a desired time period, thereby generating an alarm that identifies the target asset and its location, such as the number of floors of the building where the target asset is located. do.

The above and other objects, advantages and novel features of the present invention will be more readily understood when reading the following detailed description in conjunction with the accompanying drawings.

1 is a conceptual diagram of a building in which wireless routers of a system according to an embodiment of the present invention are disposed therein.

FIG. 2 is a block diagram illustrating an example of components of a wireless router used in the system shown in FIG. 1.

3 is a block diagram illustrating examples of components of a mobile terminal that can be used by firefighters in the building shown in FIG.

4 is a flowchart illustrating an example of an initialization operation performed to identify locations of mobile terminals in the system shown in FIG. 1 according to an embodiment of the present invention.

5 is a flowchart illustrating an example of a data collection operation performed to identify the location of mobile terminals in the system shown in FIG. 1 according to an embodiment of the present invention.

6 is a flowchart illustrating an example of a floor counting operation performed to identify locations of mobile terminals in the system shown in FIG. 1 according to an embodiment of the present invention.

7 is a flowchart illustrating an example of a floor number score recording operation performed to identify locations of mobile terminals in the system shown in FIG. 1 according to an embodiment of the present invention.

8-19 are diagrams showing an example of a display screen generated by an Incident Commander Console (ICC) based on the positions of firefighters determined according to the embodiment of the present invention described in FIGS. 1-7.

FIG. 20 shows one floor of a building being displayed on the screens shown in FIGS. 8-19, and a number of regions of interest on the floor indicated by the user, so that the system is described in FIGS. In accordance with an embodiment a diagram illustrating an example of a display screen generated by an ICC to allow determining whether any firefighters are staying in any of the areas for a period longer than a desired period.

As mentioned above, the location of people working in emergency situations is very important for many reasons. There are instances where people like firefighters get lost in smoke and confuse themselves about the actual location of themselves or others on the current or previous floors they were working on. The system and method described below is provided as an embodiment configured to ensure the safety of firefighters. In another embodiment of the present invention, the systems and methods may be configured to support the activity of any number of other emergency or special forces deployments.

Specifically, the present invention places a network of wireless devices comprising mobile terminals, wireless routers and at least one controller, specifically a mobile wireless temporary peer-to-peer network, within a three-dimensional deployment area, such as a building, to communicate Identification and location calculations can be made regardless of the building structure, and determine whether the target asset, such as a firefighter in a fire and rescue scenario, remains within a given user indication area for a longer time period than desired. And a system and method capable of generating an alarm that identifies a location, such as the number of floors of a building where the target asset is located. The incident and person management system according to one embodiment of the present invention described herein is designed to provide a means for tracking emergency people in an incident area, such as a building in which a fire occurred. People's locations are reported by building floors and / or zones. The system also provides access to real-time person location information and alert status indicators. Ancillary personnel data managed by the system includes attributes including unit numbers, names, assignments, and radio frequency assignments.

This type of system can be enabled using MEA ^™ radio technology. This technique uses a plurality of wireless transceivers, such as the MeshNetworks ^™ WMC6300 wireless transceiver, and wireless ad hoc, scalable routing techniques. In this example, the transceiver uses a modem, such as a MeshNetworks ^™ QDMA modem, to facilitate robust over-the-air data transmission even in inadequate RF environments. This transceiver, combined with the MeshNetworks ^™ Scalable Routing (MSR) protocol and geolocation solution, allows users to deploy dense, scalable, ad hoc multi-hopping networks on the fly without a single point of failure. In sum, the system includes a temporary, wireless, multi-hop communication structure capable of transmitting voice, video and data, and also computing the relative position of certain elements residing within the network boundary. The temporary nature of this system makes it simple to deploy and provides complete connectivity between all network nodes to ensure timely delivery of critical information to the Incident Command Console (ICC) even when faced with harsh or constantly changing physical conditions. It is one of several properties that make it possible to form.

As described in more detail below, the system further includes, in particular, a MEA ^™ ICC, a plurality of Floor Indicating Routers (FIRs), and at least one MeshTracker ^™ (MT) device. The MEA ^™ ICC includes a Windows-based PC with a touch screen display, thus providing a simple user interface. Event management application is executing on the PC, is connected to the network structure through the MEA MEA ^{TM TM} wireless network card. The command console is completely self-contained and is intended to be monitored by people who manage the event site, such as the leader of the Rapid Intervention Crew. The event management application is intended to provide a graphical representation of real time person location and identification information. Specifically, the data reported by the event command console may include the location, unit number, name, radio frequency assignments of everyone in the event area; The FIR (generally the ingress / egress point) and range closest to each individual; Ability to mark people as squads (via captain / squad leader) or as individuals; Failure of network communication with an individual or failure of communication with an FIR, as well as alarm status of each individual is included.

Floor Indication Routers (FIRs) are small portable devices that use FCC / UL certified MEA ^™ wireless transceiver cards as described above. These devices are placed as static reference points around the event area. These devices are typically deployed by field people, such as the RIC, after they reach the event site. The FIR is placed close to the elevator shaft, i.e. at the entry and exit points, on the column in the stairwells. Multiple FIR pillars can be placed as needed to increase the wireless coverage area and reliability of the system. In this example, the FIR device is portable, weighs less than 12 ounces and has a battery life of 5 hours. The device operates in the second ISM band (range 2.40-2.48 GHz) and has a transmit power of +25 dbm.

MeshTracker ^™ (MT) devices are morphologically similar to FIR, except that they are intended to be used as mobile devices, i.e. mobile terminals, owned by field people responsible for tracking and accounting for locations. MeshTracker uses MEA ^™ location technology to calculate the relative location within the event scene, which is accomplished by wireless interaction with FIR devices placed within the event area as described below. The MTs use deployed FIRs and other MTs as a temporary wireless communication structure to relay important information to the command console.

As mentioned above, the underlying technology that serves as the backbone and data delivery mechanism in this system is MEA ^™ , a MeshNetwork ^™ temporary multi-hop networking solution that allows deployment to be performed quickly without significant dependencies using simple deployment guidelines. The network is deployed in one of two ways: network-based components (FIRs) are pre-deployed as part of the building management and safety system (eg, combined with the "Exit" marking on each floor) or It can be deployed when an event occurs. Regardless of when the network is deployed, the deployment guidelines are the same as will now be described.

First, a command post is established, a place where events are managed through the ICC. This location should allow radio access to at least two FIRs in the incident area. Connectivity between the command console and the FIR network can be achieved in the range of hundreds to thousands of feet.

The FIRs are arranged at the poles outside the entry and exit points (generally in or near the stairwell and / or elevator shaft). FIRs are placed on and around the layers and areas where the asset is tracked, typically the fire floor and staging area. Each FIR is logically connected to layers and columns. Floor and column information for each FIR may be preloaded in the command console or configured in real time via the GUI by the event commander. The system can provide positional information when only one FIR column is placed, but the placement of a larger number of FIR columns improves position accuracy, increases the area of oversight, and any device is caused by thermal or falling debris. It guarantees the necessary redundancy in the event of a failure. A single FIR column generally provides about 200,000 square feet of coverage per floor, or provides a precise location in more than 95% of cases while providing a coverage radius of 250 feet in a high rise structure. The size of the coverage area and the accuracy of the location found are greatly influenced by the division method and material used for each layer. After the network of FIRs is deployed, location updates from people are automatically reported to the ICC using MeshTracker ^™ in the event area.

1 is a conceptual block diagram illustrating a building 100 with a staircase 102 and an elevator shaft 104 in which the FIRs 106 are disposed in the manner described above. The legend of FIG. 1 shows the symbols for the firefighter 108, the location reference FIRs 106, the data link, and the event conductor (dispatcher) 110 where the aforementioned ICC 111 is located. In addition to providing location criteria, the FIRs 106 also ensure network connectivity across the layers and network connections between the layers. If the event conductor is located too far from the event area, secondary wireless routers (not shown in this figure) must be deployed to connect all the wireless components into one network. Since they provide dual functionality, FIRs are often referred to as a wireless router (WR).

2 is a block diagram illustrating an example of components within FIR 106. As shown, each FIR 106 includes at least one modem 112 and a controller 114 for controlling the transmission and reception operations of the modem 112 as well as data storage and retrieval for the memory. In this example, the modem 112 is a modem using a MeshNetworks ^TM QDMA MeshNetworks ^TM WMC6300 wireless transceiver. FIR 106 acts as a wireless node in a temporary wireless communication network as described, for example, in the patent applications referenced above. Each FIR 106, or selected FIRs 106, may include sensors, such as thermal sensors, CO sensors, and the like, to provide the command console with information about the environment in which the FIR 106 is located. Accordingly, firefighters may be advised to avoid areas that require sensors in the FIRs 106 to be particularly dangerous due to, for example, extreme heat or to require extreme boundaries in those areas.

3 allows each firefighter 108 to use his mobile terminal 116 to communicate with other firefighters within the transmission range of the mobile terminal 116, and tracking all firefighter movements as described below. Is a block diagram illustrating an example of a MeshTracker ^™ Mobile Terminal (MT) 116 that may be issued to each firefighter 108 in order to be able to do so. The mobile terminal 116 may include a headset provided with a microphone and earphones to ensure hand-free operation. A digital compass may also be included to provide direction, and a motion sensor may report when the fireman is motionless. All these devices can be connected to a battery that is part of the general operator's belongings.

The microphone and earphone of the mobile terminal 116 may be connected to a small transceiver having three main components, including the modem 118, the controller 120, and the voice processor 122. Program code and software stored as controller parameters in the controller memory control the operation of all components of the mobile terminal.

The modem 118 uses a transmitter and a receiver to provide wireless communication with other components of the network. The operation of the transmitter and receiver is controlled by storing appropriate data and codes in a memory configured as a set of registers. The receiver and transmitter use memory registers to provide feedback about the modem status and the results of the functions performed. Controller 120 is coupled to modem 118 via a memory bus. The controller 120 includes a CPU and a memory for storing code of a program for controlling data and modem functions. This controls the operation of the modem 118 by writing data to the modem registers through the memory bus and reading the modem registers to discover the modem status. In this example, the modem 118 is a modem using a MeshNetworks ^TM QDMA MeshNetworks ^TM WMC6300 wireless transceiver. Mobile terminal 116 acts as a mobile wireless node in a temporary wireless communication network as described, for example, in the patent applications referenced above.

The voice processor 122 of the mobile terminal 116 is also coupled to the controller 120 and includes at least two independent components, an encoder and a decoder. The encoder converts the sound received by the microphone into a string of numbers, and the decoder converts the string of numbers back into sound, which is sent to the speaker or earphone. In the embodiment shown in FIG. 3, voice processor 122 further includes access to controller memory via a memory bus. A digital compass may also be included in the headset, which, when properly positioned, indicates the orientation of the operator's head and thus identifies the orientation using an angle relative to the operator's current position (i.e. 20 to 20 feet). can do. Motion sensors (not shown) may also be included in the transceiver. This can be reported automatically if the fireman has not moved for a period of time. A push button having the same effect as a motion sensor may also be included. Firefighters can press a button if they need assistance. The push of the button is sent to the transceiver software which generates a set of data messages for the main control, for example ICC 111. When the main control receives these messages, it alerts the incident commander which firefighters need assistance and where their current location is.

An example of the operation of the system described above in an emergency scenario is now described.

Rapid Intervention Crew (RIC) is assigned to each firefighting task. While firefighters are battling the fire, the RIC team is waiting for someone in need of rescue. If any firefighters or groups do not respond to the call, or if they call for help, the RIC enters the action and proceeds with rescue operations. First, they must identify where the firefighters are to rescue now and proceed with their rescue. Currently implemented procedures require the RIC to proceed from the beginning of the search to the last known location of firefighters in need of rescue. In the event of a fire in a multi-storey building, one important success factor is the ability to quickly identify the exact floor where the search should begin.

As is known in building construction, modern multi-storey buildings have concrete layers reinforced with steel, while older buildings may have layers of another material, such as wood. The absorption of radio energy is greater when radio waves pass through concrete, and not so much when passing through wooden boards. As a result, in buildings with concrete floors, radio waves can only pass through several floors, while in buildings with wooden floors, radio waves can pass through many floors.

As briefly described above, FIG. 1 shows the rescue operation progressed by RIC people proceeding on stairwell 102 (right) and elevator 104 (left). Depending on the situation, the RIC can access the building from many floors using stairs and elevators. As shown, there is a wireless floor-indicating router (FIR) 106 in the stairwell 102 and next to the elevator shaft 104 of each floor. Since the signals lose energy as they pass through the floor and wall, the FIR 106 may not be able to communicate with a firefighter not on the same floor as the FIR 106.

The RIC rescue team will place one router on each floor when the RIC first arrives at the fire site, allowing the RIC to find the number of floors in which a particular firefighter is located within seconds of the emergency declared. All FIRs 106 should be placed as close to the vertical line as possible, either by placing routers at the same corner of the stairwell in buildings with wooden floors or on stair rails in buildings with metal or concrete floors. It can be realized by resembling routers. In higher buildings with one or more elevator shafts, FIRs 106 may be placed from the elevators as they move upwards. That is, when the elevator stops on each floor, the FIR 106 can be placed close to the elevator doors to ensure that all of the FIR 106 are as vertical as possible.

As will now be described, the number of floors is found using time of flight (TOF) and received signal strength indicator (RSSI) data in accordance with one embodiment of the present invention.

The propagation of wireless signals in buildings is subject to a number of reflections that make it impossible to determine the exact distance between the wireless FIR 106 and the firefighter using the MT. The propagation of radio signals in buildings is also affected by high energy absorption as radio waves pass through layers and walls. The level of absorption depends on the thickness and composition of the obstruction. Concrete walls and layers reinforced with steel have elevated absorption levels, while wood or dry walls have less effect on radio wave energy. Since the medium is not uniform, it is almost impossible to calculate the exact distance between the fireman and the wireless router based on RSSI.

Systems and methods in accordance with embodiments of the invention described herein utilize both TOF and RSSI to identify the floor on which the firefighter is located. RSSI and TOF values received from all routers are filtered before they are used for the assessment of floor numbers. The RSSI and TOF data may not represent the exact distance to the firefighter, but the filtered data may be compared to find the floor where the FIR is located that simultaneously provides the minimum TOF and the best RSSI to the target mobile device.

The operations shown in the flow charts illustrated in FIGS. 4-7 provide a technique for setting scores in each layer and selecting the layer with the best score. The same technique is used to set the score according to the TOF and RSSI data. In other words, this technique first determines the minimum value of the TOF (or minimum absolute value of the RSSI) divided by the number of measurements performed between the mobile terminal 116 and the FIRs 106 having a signal that the mobile terminal 116 can receive. Find it. The FIR 106, which provides the minimum value of the weighted TOF, represents the floor where the MT 116 is most likely to be located, and the score is set to the maximum value. The next most likely layer is found by retrieving from the remaining layers the minimum value of TOF divided by the number of measurements. This method is applied until all layers have been retrieved and a score is assigned to each layer. If the search values found for the two layers are about the same (eg, the values are within 5% of each other), the scores of the two layers are set equal. After calculating the score of each layer based on RSSI and TOF, a general score is calculated by adding both RSSI and TOF scores. The floor that matches the maximum score is designated as the floor where the firefighter is located.

The layer identification shown in the algorithm of FIGS. 4-7 is made in real time. As mentioned above, each firefighter has a subscriber device (ie MT 116) as part of his belongings. The event commander, for example, a senior fire chief or superior, may use a computer such as the MEA ^™ event command console 111 that displays the location of each firefighter in a row as described above, for example, as shown in FIGS. 8-19. Have

Note that each MT 116 exchanges range messages with all wireless routers (ie FIRs 106) with which it can communicate. When MT 116 determines the list of FIRs 106 in its transmission range, MT 116 receives a list of FIRs 106, a TOF for each of them, and each FIR 106 in its propagation range. Information (ie, data packets) including the RSSI of the received signal is transmitted to the Incident Commander Computer (ICC) 111. The ICC 111 may be located in the command console 110 described above. The ICC 111 receives data from the FIR 106 and the MT 116 via the multi-hop capabilities of the ad hoc network, performs floor counting, and displays the floor number at which each firefighter is located. Real-time processes using the GUI outputs require computation with three different components: initialization, data collection, and GUI update.

The initialization operation is executed when the ICC 111 starts up. An example of the initialization operation is shown in FIG.

As part of the initialization, in step 1000, the number of floors (nFloors) and the number of stairs (nStairs) in the building 100 are set as well as other information not strictly related to the calculation of the number of floors and not provided herein. In steps 1010, 1020, 1030, and 1040, the values of the variables Count, TOF, RSSI, and FIRID are all erased (i.e., set to 0, but FIRID is a text variable, so it is set to blank). The initialization process ends at step 1050.

When the MTs 116 have data available, they send a data packet to the ICC 111. Thus, the data collection job shown in FIG. 5 is activated when data is received. The ICC GUI should be updated periodically to keep the ICC informed of the progress of the operations. Therefore, the update of the GUI to which the calculation of the number of floors should be preceded is activated by a periodic timer. The application maintains its own data structure. This data structure has four components, each with as many lines as nFloors and as many columns as nStairs.

Now, the variables and arrays shown in FIGS. 4-7 are briefly described.

FIRID (which represents the FIR identifier) is an array with the identifiers of each FIR 106. Each FIR identifier is associated with the number of floors in which the FIR is placed. This means that all FIRs placed on the same layer are on the same line of the matrix, regardless of their position on the layer. Since the MT 116 may not be able to communicate with all FIRs on the same floor due to wireless energy absorption, some of the locations in the FIRID table may remain unused. When the firefighter moves around the building, new FIR identifiers are added to the table, but old FIR identifiers are not removed.

The Count matrix contains a count of the number of range messages that the SD reports for each FIR.

The RSSI and TOF tables have the same structure as the FIRID. These include the filtered values of RSSI and TOF recorded for each FIR.

5 shows a data collection function. The name of the function is NewData, which is activated and started in step 1100 whenever a new data set is received from the MT. The NewData function has four parameters, which represent the FIR representing the identifier of the FIR from which the data was collected, the FIR_TOF representing the final TOF for the FIR, the FIR_RSSI representing the absolute value of the RSSI for the last received message, and the number of layers on which the FIR is placed. It is FLOOR.

The data collection function finds the location of the FIR identifier in the FLOOR line of the FIRID table. If this is a new identifier, as determined at step 1110, then at step 1120 a new FIR identifier is added to the first empty position of the table. As indicated in step 1130, FIRj is a column of FIR identifiers on the FLOOR line.

TOF and RSSI values are initially filtered using a variable size window of size Count as indicated in steps 1140 and 1150. When the number of messages exchanged between MT and FIR is greater than the predetermined value MAX_IT, the filter is changed to an infinite input filter with a rate of 1 / (MAX_IT + 1). The effect is achieved by limiting the values in the Count table greater than MAX_IT by steps 1160 and 1170 as indicated.

Step 1180 of the flowchart ensures that the algorithm “forgets” the data collected too long ago. "Forgetfulness" is necessary because the fireman can move away from one FIR to access the other FIR, so that the values of the collected TOF and RSSI change according to the new location of the fireman. The algorithm forgets faster or slower depending on the value of the FORGET argument, which is always a number between 0 and 1. If the argument is zero, the algorithm does not remember anything. If the argument is 1, the algorithm remembers everything. For this application, the most common value is .99 or .999 depending on how often data is collected from the FIRs. The data collection process then ends at step 1190.

6 shows a function GetFloorNumber for calculating the number of floors of firefighters. This function starts at step 1200 and uses two local integer arrays with as many elements as the number nFloors of layers. This function calls the GetScore function twice to calculate RSSIscore in step 1210 and TOFscore in step 1220. The combined scores provide a more accurate estimate of the possible layers than each independent criterion. Due to reflections in the building, the TOF was measured to be affected by errors as large as 30 meters. Considering that the distance between the layers is 3-6 meters, an error of 30 meters means an error in the estimate of the number of layers in the 5-10 layers. RSSI indicates the strength of the signal that the MT receives from the FIR. All FIRs transmit at the same power, but the path length of each signal is different due to the different division of each layer and the fact that the absorption of the layers is very different from the absorption of the walls. Moreover, the number of walls between the MTs and the FIRs with which the MT communicates depends on the partitioning method of each layer, and therefore it differs from one FIR to another. Because of this, RSSI information by itself cannot be used to find the number of floors. Thus, the algorithm calculates the score for each layer and then uses both criteria to select the layer that provides the best additional score. The tests showed that the results were very accurate. Step 1230 of the flowchart finds the floor count based on the maximum score calculated by adding the TOFscore and RSSIscore for each floor. The process ends at step 1240.

7 shows an example of a flow chart of the GetScore function. This function is called by steps 1210 and 1220 described above in FIG. 6 with RSSI and RSSIscore as parameters, followed by TOF and TOFscore as parameters. This function calculates the score of each layer according to each criterion.

The function starts at step 1300 and then starts by setting all score values to zero at step 1310 and then makes a copy of the data (RSSI or TOF) within the temporary storage temp at step 1320. lastVal and Level are also initialized in step 1330. The value of the Level variable is not important but should be the same for both RSSI and TOF.

This function has a loop that identifies the layer whose reference (RSSI or TOF) has the best value. If a layer is found in step 1340, all other data from the same layer is ignored and the next layer is identified. This function continues as long as the layer requiring identification remains as determined in step 1350. However, if there is no such layer, the function ends at step 1360.

During execution of the algorithm, the contents of temp are removed at step 1370. For this reason, the contents of the data were copied to temp in step 1320.

If the two layers have values with a difference less than 5% of the values, they receive the same score by keeping the same value for the Level variable as indicated in steps 1380, 1390, and 1400. If the values are different, the score for each layer is different because in step 1420 the value of Level decreases with each found layer. In step 1410, lastVal represents the previous value of minVal, which is the minimum value of the reference. If a minimum value is found for each layer and the score is set according to the result of classifying these minimum values, the same result can be obtained.

As mentioned above, FIGS. 8-19 show examples of display screens generated by the ICC based on the location of firefighters determined in the manner described above. For example, FIG. 8 shows an initial display window before firefighters enter a building, and FIG. 9 has a “legend tab” expanded to show symbols that can be displayed on a display window representing different types of people and conditions. One initial display window is shown. FIG. 10 shows a display of four floors of a building with FIRs placed on each floor, and FIG. 11 shows a symbol indicating that the battalion conductor entered the floor or “staging 0” floor of the building using the European numbering convention. Rods). FIG. 12 shows a ladder unit entered into the second floor of the building, and FIG. 13 shows details of three people (ie one captain and two firefighters) of the ladder unit on the second floor. 14 shows an expanded display view of layer 2. FIG. 15 shows the alarm state of layer 2, and FIG. 16 shows that the alarm has been acknowledged. 17 shows details of the selected person (large in this example) and the distance from the large intestine to the closest FIR 106. In this example, the large intestine is 2.9 feet from the FIR 206 labeled "A". FIG. 18 shows an example of a display when the FIR (in this case, FIR labeled 2C) lost a signal, meaning that the FIR may be damaged or destroyed. 19 shows an example of a multilayer display and people in each layer. Of course, the system can be modified to display the information in any desired format.

In addition, FIG. 20 illustrates a floor of a building being displayed on the screens shown in FIGS. 8-19, and for a period in which any asset (eg, firefighters) is longer than a desired period in accordance with one embodiment of the present invention. Multiple areas 202-1, 202-2 instructed by the user of the ICC 111 to allow the system to determine whether any of the multiple areas of interest 202-1, 202-2 on the floor are staying. An example of a display screen generated by the ICC, showing a plan view 200 of Fig. 1), is shown. Specifically, the graphical user interface and the ActiveX control associated with the ICC 111 to generate an indication may include a set of polylines in which the user defines, for example, a finite region (eg, region 202-1 or 202-2), respectively. It is possible to define an area or regions 202-1 or 202-2 on the display using a mouse and / or keypad or other controls to draw them. Although only two regions 202-1 and 202-2 are shown, the user can specify any desired number of regions, each having any desired size. ActiveX control associates the location of the assets 204-1 through 204-5 (eg, firefighters described above) displayed on the display with the location of the designated area or regions 202-1, 202-2. Let's do it.

When the target asset (eg, asset 204-1) enters the designated area (eg, 202-1), the controller of ICC 111 starts a timer. Controller of ICC 111 when asset 204-1 stays in region 202-1 for a period longer than a predetermined threshold time (e.g., minutes or any desired period) that may be set by the user. Generates an alarm that identifies the target asset 204-1 and / or any attributes associated with asset 204-1, and also the location of asset 204-1 within region 202-1. The controller of the ICC 111 maintains a track of the respective times in which the respective assets 204-1 through 204-5 are staying in any of the respective designated areas 202-1 and 202-2. Please note. Also note that regions 202-1 and 202-2 can overlap, and a user can set each time threshold equal or different for each of regions 202-1 and 202-2.

In short, according to this aspect of the invention, the timer is started when the target asset enters the designated area. This timer is related to assets and areas. If the asset is in an area and a timeout of the timer is detected, an alarm is generated. When an asset comes out of the zone, each timer associated with this asset and zone is reset to its initial value. As noted above, this aspect of the present invention may be used in conjunction with the location system features described above in fire fighting operations or in any other type of scenario where asset tracking within a designated area is desired for a desired period of time.

In the above-described embodiments of the present invention, the system and method provide accurate location of mobile network members and enable voice exchange between members of a team involved in the task. Although only a few embodiments of the invention have been described in detail above, those skilled in the art will appreciate that many modifications are possible in the exemplary embodiments without substantially departing from the novel teachings and advantages of the invention. Accordingly, all such modifications are intended to be included within the scope of this invention.

Claims (20)

As a method of monitoring movement in a three-dimensional multilevel structure, Placing a plurality of mobile wireless remote terminals within the three-dimensional structure; Determining respective positions of the mobile wireless terminals in the three-dimensional structure; Generating an indicator indicative of respective positions of the mobile wireless terminals in the three-dimensional structure; Modifying the indicator to indicate at least one area of the three-dimensional structure; And Monitoring if any of the mobile wireless terminals have been in the area for longer than a desired period, in which case generating an alarm How to include. The method of claim 1, wherein the indicator comprises a display indicating respective positions of the mobile wireless terminals within the three-dimensional structure. The method of claim 2, The modifying step includes allowing a user to modify the display to indicate a plurality of the areas, The monitoring step monitors whether any one of the mobile wireless terminals is staying in any one of the respective areas for a period longer than each desired period as instructed by the user, in which case an alarm How to produce. The method of claim 3, wherein some of the respective regions overlap. 4. The method of claim 3, wherein at least some of the respective desired periods are different for each of the different regions. The mobile terminal of claim 1, wherein each of the mobile wireless remote terminals is suitable for communicating in a wireless ad-hoc peer-to-peer communication network, The method, Deploying a plurality of wireless routers within the three-dimensional structure, each of the wireless routers configured to communicate in the wireless temporary peer-to-peer communication network; And Controlling each of the mobile wireless remote terminals to exchange signals with any of the routers within their broadcast range and determining their position within the three-dimensional structure based on the signals How to include more. The method of claim 1, further comprising operating at least some of the mobile wireless remote terminals to communicate at least voice data with each other. A system for monitoring movement in a three-dimensional multilevel structure, A plurality of mobile wireless remote terminals configured to be disposed within the three-dimensional structure; And Determine locations of each of the mobile wireless terminals in the three-dimensional structure, generate an indicator indicating the location of each of the mobile wireless terminals in the three-dimensional structure, and indicate the at least one region of the three-dimensional structure; A monitoring unit configured to modify the indicator, monitor whether any of the mobile wireless terminals have been in the area for longer than a desired period, and in that case generate an alarm System comprising. 9. The system of claim 8, wherein the indicator comprises a display indicative of respective positions of the mobile wireless terminals within the three-dimensional structure. 10. The apparatus of claim 9, wherein the monitoring unit also enables a user to modify the display to indicate a plurality of the regions, and wherein the respective regions for a period longer than each desired period as indicated by the user. A system configured to monitor whether any of the mobile wireless terminals are staying in any of the areas, and in such a case generate an alarm. The system of claim 10, wherein some of the respective regions overlap. The system of claim 10, wherein at least some of the respective desired time periods are different for each of the different areas. 9. The mobile station of claim 8, wherein each of the mobile wireless remote terminals is configured to communicate in a wireless temporary peer-to-peer communication network, The system, A plurality of wireless routers configured to be disposed within the three-dimensional structure, each of the wireless routers being configured to communicate in the wireless temporary peer-to-peer communication network; Each of the mobile wireless remote terminals exchange signals with any of the routers within its transmission range and determine its position within the three-dimensional structure based on the signals. 10. The system of claim 8, wherein at least some of the mobile wireless remote terminals comprise a transceiver configured to communicate at least voice with another of the mobile wireless remote terminals. A monitoring unit for monitoring movement of at least one mobile wireless remote terminal in a three-dimensional multi-level structure, A controller configured to determine a location of each of the mobile wireless terminals within the three-dimensional structure; And Location indicator-under the control of the controller, the location indicator indicates the location of the mobile wireless terminal within the three-dimensional structure, modifies the indicator to indicate at least one area of the three-dimensional structure, and a desired period of time. Monitor whether the mobile wireless terminal is staying within the area for a longer period of time, and in such a case generate an alarm. Monitoring unit comprising a. 16. The monitoring unit of claim 15, wherein said indicator comprises a display indicative of the location of said mobile wireless terminal within said three-dimensional structure. 17. The apparatus of claim 16, wherein the position indicator also enables, under the control of the controller, a user to modify the display to indicate a plurality of the regions, and longer than each desired period as indicated by the user. A monitoring unit, configured to monitor whether any mobile wireless terminal is staying in any of each of the areas for a period of time, and in such a case generate an alarm. 18. The monitoring unit of claim 17, wherein some of the respective regions overlap. 18. The monitoring unit of claim 17, wherein at least some of each desired periods are different for each of the different areas. The method of claim 15, The monitoring unit monitors movement of a plurality of wireless terminals, The controller is configured to determine respective positions of the mobile wireless terminals within the three-dimensional structure, The position indicator, under the control of the controller, indicates the positions of each of the mobile wireless terminals in the three-dimensional structure, modifies the indicator to indicate at least one area of the three-dimensional structure, and is longer than a desired period. A monitoring unit, configured to monitor whether any of the mobile wireless terminals are staying in the area for a period of time, in which case generate an alarm.

Images