AUTOMATED MOBILE CREW TRACKING SYSTEM WITH REMOTE ACCESS
FIELD OF THE INVENTION The present invention relates in general to information management systems and in particular to automated systems and to methods for the location and planning of field crew routes.
BACKGROUND OF THE INVENTION Businesses such as utility companies, which deploy numerous employees in a wide geographical area to service a dispersed infrastructure or customer base, are faced with the particularly uncomfortable work of communicating the work assignment and the data related to the personnel that is dispersed in the field. For example, a utility company faces the daunting task of maintaining an infrastructure that encompasses a potentially large geographic area. When interruptions occur in a public service network, field personnel must be sent to solve the problem. Generally, field personnel are already in the field at the time new service tasks or work orders are generated. In this way, utility companies are faced with the complex task of receiving work orders, identifying the field staff that is most suitable for the job, and communicating to field staff that a particular work order has been assigned to them. assigned. Generally, work orders are assigned to field crews based on training and experience. However, another important consideration when assigning work orders is the proximity of the field crew to the work area. Generally, a central dispatcher or an operations manager does not have automatic means to locate the field crew. Instead, an operations manager must rely on voice communication from the field crew for their location. The location data collected from the field crew may not always be accurate or useful descriptions of the position of the field crew. In addition, manual maintenance of field location data for multiple field crews can be a difficult task to manage; performing this for a large number of field crews could be excessively heavy, if not impossible. Additionally, even if the field location data is available, it must be applied to a map in such a way that it is useful to calculate the proximity to the work locations and also to make decisions about the assignment of work orders. So far this task is also done manually. In this way, there is a need for automated systems and more advanced two-way data communication methods between field staff and the central office. In particular, there is a need for a system by which the precise field location is gathered and the position data for a field crew is automatically communicated to a central position directly to other field crews deployed in the field.
SUMMARY OF THE INVENTION In summary, the present invention is intended to provide an automated system for the gathering of data related to the position of a field crew, the communication of requests for the position data and the communication of the desired position in response to the request. . The system consists of a computer system of the company, at least one mobile field unit, a wireless communication network that supports the protocol of transmission control / Internet protocol (TCP / IP). A mobile field unit consists of a receiver to receive the position data from a positioning service, or processor having instructions therein to process the position data, and a radio modem to communicate the position data through the wireless network to the computer system of the company or another mobile field unit. The company's computer network consists of application programs through which you can view request position data, several server machines for the storage and reception of position data, a local area network (LAN) that connects the server machines to a gateway to the wireless TCP / IP network. Each mobile field and machine unit in the company's computer system has a unique IP address assigned to it. In accordance with this, commands and position data can be communicated freely among all machines. In accordance with another aspect of the invention, a method for distributing position data is provided. Additionally, a method for the processing of the position data is disclosed. According to another aspect of the invention, a method for formatting the position data is provided.
BRIEF DESCRIPTION OF THE DRAWINGS Other features of the invention are further apparent from the following detailed description of the currently preferred example embodiments of the invention, taken in conjunction with the accompanying drawings, of which: Figure 1 is a schematic diagram of a system according to the present invention. Figure 2 is a diagram of the software components of a system according to the present invention. Figure 3 is a diagram of the software components of a system according to the present invention. Figure 4 is a diagram of a system according to the present invention, where the data flow shows directly between two mobile field units as well as between the mobile field units and the computer system of the company. Figure 5 is a flow diagram of the process according to the present invention for the distribution of the position data of the mobile field units. Figure 6 is an illustration of an example screen for the selection of a mobile field unit whose position data we wish to know. Figure 7 is an illustration of an example screen for displaying the position data of a field mobile unit. Figure 8 is a flow diagram for a process according to the present invention for the processing of position data requests. Figure 9 is a flow chart for a process according to the present invention for processing the position data. Figure 10 is a flow diagram for a process according to the present invention for formatting the position data. Figure 11 is a diagram of software components and data flows in a system according to the present invention. Figure 12 is a diagram of the software components and data flows in a system according to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED MODALITY The present invention provides the systems methods for locating field crews and assigning tasks. In particular, the invention consists of an automated system for distributing the position data of the field crew to a central position as well as to the camp personnel scattered over a large geographical area. In a system according to the present invention, the position data, which can be any type of data related to the position of the mobile field units, are gathered in a mobile field unit. In an embodiment of the invention, the data is received from a global positioning system (GPS). For example, a Trimble Inc. system can be used to supply the data in both standard and proprietary formats. Mobile camp units receive the request from other mobile field units of the company's computer system to transmit their position data. In response, the mobile camp unit transmits the requested position data. The mobile field unit may also send the position data intervals in response to the request. In this case, a single request results in multiple cases of transmission of position data. In the event that position data is transmitted to the company's computer system, mobile camp units can request position data from the company's computer system. Note that the present invention can be performed in a system that is used to distribute work orders and related data in addition to the position data of the field crew. These systems are described in the pending TCP Patent Application with serial number (still unassigned) (case number ABME-0538), filed on the same date as this, entitled "Mobile Crew Management System", whose content is incorporated to the present in its entirety as a reference. Figure 1 graphically describes a system according to the invention. As shown, the inventive system consists of the computer system of the company 50, the mobile field units 52 and 53, and a wireless communication network 54. The computer system of the enterprise 50 can contain the database servers 56 for the field requests for the purpose of storing the data in a database 58, the protocol servers ^ hypertext transfer (HTTP) 60 for the field requests for the data of web pages, the monitoring server 62 to accept and provide data related to the status of the work orders, the file servers 64, and the UPS servers 65 for the reception of the position data of the mobile field units and the distribution of requests for the field position data. While each of the servers 56, 60, 62, 64 and 65 are represented by means of a separate machine in Figure 1, in some embodiments of the company's system a single machine can be configured to perform all these operations. A company's computer system can also contain work stations 66 from which various application programs can be accessed. The servers 56, 60, 62, 64 and 65 and the workstations 66 are interconnected through an Ethernet local area network (LAN) 68. The local area network 68 supports TCP / IP and each of the machines 56 , 60, 62, 64, 65 and 6 are uniquely identified with an IP address. Gate 70 provides a communication connection between LAN 68 and the wireless network TCP / IP 54. In one. Typical application of the invention system, the computer system of the company 50 is located in a central office, operations center, dispatch center. As described in more detail below in relation to Figures 2 and 3, the position data for the mobile field units 52 can be requested using an application program in the company system 50. Once received from the unit mobile field, the position data is stored in the company's 50 system. The position data can be displayed in the company's computer system 50 can also be transmitted responding to the request of the mobile field units 52. The mobile field units 52 and 53 comprise the position data unit 73. The position data unit 73 comprises the position data receiver 75 having a reception antenna 77 operatively connected to the position data unit.
• same. The position data receiver 75 operates to receive position data from the global positioning system.
Generally, the position data receiver 75 stores data of latitude, longitude, speed and direction from the global positioning system. The receiving antenna 7 generally operates to receive signals from satellites, and therefore, may require satellite site access lines. Thus, when a field mobile unit 52 s located within a vehicle, the antenna 77 can be mounted on the outside of the vehicle. The position data unit 73 also comprises a wireless radio modem 74. The wireless radio modem provides the means for communicating via a wireless network 54 with the company's computer system 50 and other field units. The wireless radio modem 74 supports a point-by-point protocol (PPP) a TCP / IP protocol through a wireless radio network 54. The position data unit 73 further comprises a processor 78 which has stored itself same computer-readable instructions for processing the position data received in the receiver 75. The processor 78 is operable to communicate with the radio modem 74 and is, therefore, capable of communicating the processed position data to the computer system of the company 50 or other mobile field units by means of the wireless network 54. It should be noted that, while the components of the position data unit 73, for example, the receiver 75, the radio modem 74, and the processor 78, s shown separately in Figure 1, these components can be incorporated into a single physical device. The mobile field units 52 and 53 can optionally consist of a computing device 72, and which could be a portable computer, an asistent personal digital (PDA), or a similar device. Generally, the computing device 7 consists of a processor, a random access memory (RAM), a network search software for internet communication and intranet, and an interactive mechanism of visual representation. The computing device 72 may also include: storage capacity (electromechanical flash), a serial interface, an audio reproduction device, and software to support a TCP / IP stack protocol and a PPP protocol. It should be noted that any or all of the components of the position data unit 73, i.e., the processor 78, the radio modem 74, the receiver 75, can be incorporated into a computing device 72. The mobile field units 52 and 53 may also optionally comprise a wireless two-way voice communication device 76. The device 7 may be integrated with a computing device 72 may be a separate radio device, a cell phone or a digital cell phone. Each field crew is assigned a mobile field unit. Thus, although only two are shown in Figur 1, numerous mobile field units can be deployed and operated at the same time. Each mobile field unit 5 has an IP address assigned to it. In addition, the computer system of the company 50 comprises a database of input data indicating for each field unit, the field crew having the unit. Thus, when the position data of the field unit is required to assign a work order to a particular field crew, the inventive system automatically routes the appropriate commands and data, as described below and in accordance with the Patent Application of the pending TC, serial number (still unassigned) (case number ABME-538) entitled "Mobile Crew Management System", to the appropriate mobile field unit. Field crews are free to access the computer system of company 50 to gather position data for other field crews or to gather data that may be useful to carry out the assigned work order. In addition, the position data of the field units can be accessed in a first mobile field unit 5 directly from another mobile field unit 52, without access to the company's computer system 50.
The wireless radio network 54 provides TCP / IP communication between the computer system of the company 50 and the mobile computer devices 52 and 53.
As noted above, the mobile field unit 52 is assigned a unique IP address. Similarly, the machines in the computer network of the 50th enterprise are assigned a unique IP. Like the radio network
Wireless 54 supports TCP / IP, the routing of data and commands between field mobile units 52 and 53 and the company's 50 computer system can be achieved by existing network techniques. In addition, the mobile field units 52 and 53 can be accommodated in various network configurations such as subnets, intranets and, theoretically, if appropriate gates are accommodated, they can be accessed through the Internet. IP addressing allows commands to route to, and data to be accessed from, any network machine. Thus, the data and / or commands can be transmitted via gate 70 to the wireless radio network 54 and distributed to any mobile unit in field 52 in particular. Similarly, the data and / or commands can be transmitted from the mobile computing device 52 via the modem 74 to the wireless router 54 that distributes the data and / or commands to a particular machine designated by a unique I address in the the company's computer system 50. Preferably, the wireless network 50 employs native TCP / I. In any case, any type of network can be used, trying to adapt it to support TCP / IP. Accordingly, the wireless network 54 may be any of the following network types: a public network CDP (packet switching); a packet-switching radio network (adapted for TCP / IP); a network based on rate / n rate; or a network of Personal Communication Systems (circuit switching). A system according to the invention can be implemented at any location where one of these types of network exists. These alternative communication networks are discussed in more detail in the pending Patent Application "Mobile Crew Management System". Two alternative modalities of the software components of the present invention are described below. A first mode uses a UDP client servers in the company's computer system 50 mobile field units 52 to communicate the position data of the field crew. A second modality employs an HTTP server in the mobile field unit 52 and an HTTP client in the computer system of the company 50. Both modes can be operated to pass data from field units to the computer system of the company 50 or other field units 53.
Figure 2 is a diagram of software components comprising, in a first embodiment, a system according to the present invention, where UDP technology is used to communicate the position data of the field units. As shown, in the computer system of company 50, there may be numerous components of application programs or clients 80. Preferably, these are written using the JAVA programming language in such a way that they can be operated on platforms running various operating systems. . Each application 80 can serve a particular purpose with respect to the management of work orders to monitor the progress of these work orders. The system operators use the UDP 83 position tracking application to manage the position data of several mobile field units. In particular, the UDP tracking application 83 can be used to request the position data of a particular mobile field unit 52. It should be noted that there may be multiple examples of the same application 80, 83 running at any time. Additionally, remote applications 81 from external system 50 may occasionally access system resources. The company's computer system 50 also includes a server 'UDP 87. The UDP server 87 operates to receive and store position data received from the mobile field units 52 and 53. The common gate (CGI) 89 interface is employed. to retrieve the position data and to format the position data in response to the request for said data. According to one embodiment of the invention, CGI 89 is written in PERL script language. The company's computer system 5 also comprises software for database server 8 which may be, for example, an Oracle database server. Actually, there may be multiple data bases 82 in a system 50. The data base server software 82 manages position data of field units, work order data, as well as other data related to the business. For example, in the case of a public service company, the databases 82 may comprise detailed data of equipment and map data. The company's computer system also includes HTTP servers 84, which can be, for example, a Netscape or Apache HTTP server. The HTTP 84 s servers can operate for field requests from all the machines, but particularly from the re searchers located in the mobile field unit 52. The monitor server software 85 accepts updates from the applications 80 indicating that an order of work has been assigned. The monitor server software 85 also accepts updates, such as if a work order has been successfully transmitted to field unit 52 and if it was accepted by the field crew. The monitor server 85 also provides a report generation feature. The field mobile units 52 and 53 comprise several software components associated with the position data unit 73. It should be noted that, while the mobile field units 53 comprise 73- position data units, the software specific components of the data units 73 are shown only in field units 52 for the sake of brevity. The position data units 73 consist of a UDP server 95 for receiving position data requests. Preferably, the UDP 95 server is multi-wired, it being understood that it handles requests and, once received, causes the UDP client 96 to gather the requested position data and transmit them back to the UDP server 87 in the system 50. In this way, the UDP server 96 can continuously handle additional requests. The position data unit 73 also comprises the GPS interface 97 for interconnecting with the receiver 75. The GPS processing software 98 processes the data received from the receiver 75 to obtain an internally recognizable format. The TCP / IP stack 99 is used to communicate with the radio modem 74. The PPP server 100 can be used to interconnect with other devices in the mobile field unit 52, such as the mobile computing device 72. The field unit mobile 52 may also comprise a mobile server application 86. Mobile server application 86 caters for requests from the company's computer system 50 to field mobile unit 52. In a preferred embodiment, mobile server 86 is written to JAVA programming language, which allows the mobile server 86 to run on various hardware platforms running different operating systems, such as Windows, Mac OS or Unix. The mobile server 86 is multi-wired, meaning that it handles requests and once an entry is received, it causes the process 88 to react with respect to the entry. In this way, the mobile server 86 can continue to handle additional requests. The field mobile unit 52 also comprises a network browser 90, which may be loaded with files 92, which are downloaded by the company's computer system 50. The network browser 90 loads the network browser enhancer 94 in order to show maps and related data. The network finder enhancer 94 may be an outlet that is initially stored in the field mobile unit 52. Alternatively, the network fetcher 94 may be an Applet, which is downloaded by the company's computer system 50. Figure 3 provides a view of the software components of an alternative software modality -in accordance with the present invention, which employs HTTP communications for the distribution of data from Positioned field units. As can be seen, most of the software components are identical to the software of the UDP mode described above in relation to Figure 2. However, as regards the system of computer processing of company 50, in which , in the previous modality, the UDP server 87 and the UDP position tracking application 83 were used to retrieve the data from the field unit position, in the mode of Figure 3, the HTTP client application 110 both requests and receives the field position data from the camp 52 mobile unit. As regards the camp mobile units
52 and 53, the position data unit 73 comprises the HTTP server 112 to receive and respond to requests for position data from the field unit. The HTTP server 112 interacts with a common interface program. Compuert (CGI) 114 in order to retrieve the position data.
Other components of the position data unit 73 include the receiver interface software 97, the position processing software 98, and the TCP / IP 99 interface software, all of which operate in an identical manner to those shown in Figure 2 above. . The mobile field units 52 and 53 may also comprise other different components, including a mobile server 86, the process 88, the network browser 90, the network browser enhancer 94. These also operate as described above in connection with the Figure 2. In general, the field mobile unit 52 collects position data from a positioning system and transmits the position data to the machines when requested. The requesting machine can be another mobile field unit 53 or a machine in the computer system of company 50. Where the data is transmitted to the computer system of company 50, the position data is stored and distributed according to request to other mobile field units 53 or customer applications 80 and 83. Where the position data is provided directly from one mobile unit from field to another, i.e., peer-to-peer, a mobile field unit 53 can operate as mobile command center. As such, the movement of the mobile file units can be tracked in a mobile field unit. Also, by providing position data to both the computer system 50 and the mobile unit d field 53, the location of a mobile field unit 52 s can track simultaneously in both locations. In theory, several mobile field units can track position data for one or more mobile field units. With the advent of offers of unlimited use of CDPD, the previous scenarios turn out to be very attractive. The above is due in particular to the relatively low surplus associated with UDP packets. Fig. 4 illustrates the direct connections between mobile units of field 52 as well as between mobile field units 52 and computer system of enterprise 50. A mobile unit d field can be configured as a mobile control center to receive position data that they are transmitted simultaneously to the company's computer system 50. Figure 5 provides a flow chart of the process of distributing position data from a field mobile unit 52 or 53. As can be seen, in step 120 they meet the position data of the field unit 52. In step 122, in the field mobile unit 52 s receives a request for transmission of position data to a particular machine, preferably identified by an IP address. In detail with regard to Figure 8 below, the request can be either for an immediate transmission of the position data or for the transmission of post data. icion specific intervals. In Figure 6, a screen is shown by way of example, for the specification of a particular machine for which position data is desired. Referring again to Figure 5, in step 124, depending on the IP address specified in the request, the position data is routed through a wireless network 54 to either another mobile field unit 53 or to the system company computation 50. If the data is routed to the company's computer system 50, in step 126 the position data is processed and stored in the company system 50. Next, in step 128, the computer system of company 50, in response to a request for position data by a mobile field unit 52, retrieves the stored position data. In step 130, the position data is formatted to obtain a format that can be easily processed by the mobile field unit requesting them. As will be described later, normally this step of formatting brings with it the generation of a file with a MIME type with the position data located in it, as well as an HTML file with a reference to the integrated MIME file. In step 132, the formatted position data is transmitted to the mobile field unit. In step 134, the requesting mobile field unit 53 loads the position data in the network browser 90. Figure 7 is an exemplary screen showing the plotted position data d. If in step 124 the position data s routed directly to a mobile field unit 53, in step 136 the field unit 53 formats the position data. In this, the transmission scenario of equal equal of the position data, the position, the speed, the address data is extracted from the packets received from the data connection. Normally, in the peer-to-peer scenario, no history records of the position data are kept, that is, the previous position data is deleted. In this way, the formatting of the position data upon receipt in the mobile camp unit directly from another mobile field unit may involve the replacement of the previous position data with the new position data. In step 138, the renewed position data are uploaded and displayed in the re 90 search engine with the help of a 94 network browser enhancer. S should note that, because the history records are not normally retained in the peer-to-peer scenario, if a crew wants to show more than the current position of the mobile field unit 52, that is, the route, it is necessary to obtain this information from the coy's computer system 50. In step 122 in Figure 5, a request for position data is processed in the mobile field unit 52. Figure 8 provides a detailed flow chart of a process for processing a data request. As seen in Figure 8, in step 142, in the field mobile unit 52 a request for position data is received. The request may vary as to exactly what is requested. The request can be to immediately send the position data. Alternatively, the request may indicate that the position data must be transmitted periodically at specific intervals. The interval can be defined in terms of time or distance traveled by the mobile field unit 52. Also, the request can define a primary device and a secondary device to which to transmit the position data. The communication of the position data to a primary and a secondary machine allows the coy's computer system 50 and another mobile field unit 53 to simultaneously monitor the field locations of the field unit 52. If in step 144 the request is for an immediate transmission, in step 146 the position data a is immediately transmitted. the requesting machine. In an embodiment of the present invention, such as that shown in Figure 2, where a UDP server 95 is used in the position data unit 73, the IP address and the port number of the requesting machine can be extracted. of the UDP packet of the request and the position data can be transmitted immediately to the address and port number. If in step 144, the request is for sending the position data at specific intervals, in step 148 the position data is transmitted to the primary machine and, eventually, to the secondary machine as specified in the request. Next, in step 150, it is determined whether the specified interval has been reached, for example, time or path traveled. If so, in step 148, updated position data is transmitted. If the interval has not been reached in step 150, the process is still waiting in step 152. In Figure 5, in step 126, the company's computer system 50 processes the position data received from the mobile unit of the company. field 52. The steps of the process that can be used in the format operation are shown in Figure 9. In step 160, the position data received from the mobile computing unit 52 is analyzed. In step 162, from from the analyzed position data, the latitude and longitude coordinates are calculated. The GPS system takes these coordinates of latitude and longitude relative to the curved surface of the earth. A two-dimensional map like the one that exists in the mobile field unit 53 does not take into account the curvature of the earth. In this way, when mapping the GPS coordinates to two-dimensional planar coordinates, it is necessary to adjust the coordinates. The above takes place in step 164, e where the coordinates of latitude and longitude are converted to two-dimensional planar coordinates, usually for the state or region in which the field unit 52 is located. In step 166, from the data of analyzed position statistics of speed and direction are extracted. In step 168, the formatted position data is stored for later retrieval. As will be described in more detail below, the position data can be stored either in a file or in a system database. In Figure 5, in step 130, at the request of a mobile field unit, the company's computer system 50 formats the position data when preparing them for transmission to a field unit. Figure 10 provides a detailed flow chart of the formatting process. In step 180, the formatted position data is stored in a first file. This first file is preferably a MIME file type and has a file name that ends with an ".mpx" extension. The formatting of the .mpx file is analogous to that described in the TCP Patent Application pending serial number (even if assigned) (case number ABME-0538), presented on the same date as the present one and entitled "Mobile Crew Management System. " However, entering in said request the data in the .mpx file represent map objects, in this case the data represent a series of data points of position for a mobile unit of field at various points of time. The series of position data points t can be connected to display as marks on a map in order to represent the route that a mobile field unit 52 has followed. Each mark represents a real measure. Different brands can be used to represent various mobile field units. In step 182 a second file is generated. This second file is preferably an HTML file that can be loaded by the network browser 90. The HTML file comprises an integrated reference to the .mpx file. When loading the HTML file, the network browser 90 detects the reference to the first file, that is, the ".mpx" file and loads the network browser enhancer 94, which is specifically developed to display the contents of the .mpx file. . In addition to carrying out other functions, the network enhancer 94 overlays the route with land-based maps and network maps. Thus, the network browser can display the location data in the field. As indicated above, the present invention can be implemented using UDP technology or HTTP technology in order to transmit the position data. Figure 11 shows various commands and data flows associated with the transfer of position data that can be implemented in a mode of the invention using UDP technology. The distribution of position data can be started with the UD 83 position tracking application in the company's 50 computer system requesting, as indicated by the arrow 200, which is transmitted back to the computer system of the company 50 the data d position of the field mobile unit 52. In the field mobile unit 52, the request is received on the UDP server 95 (arrow 200). The UDP 95 server causes the UDP client 96 to respond to the request (arrow 202). After recovering the position data, the UDP client 96 transmits the requested position data to the UDP server 95 in the computer system of company 50 (arrow 204). The UDP 95 server analyzes the position data, retrieves the latitude and longitude coordinates as well as the address speed statistics, and converts the latitude and longitute coordinates to flat state coordinates. The UDP server 87 stores the processed position data with an indication of the IP address of the mobile field unit 52. In general, the processed position data is stored (arrow 206) in a system log file, referred to as gps .log 210
The position data is normally also stored in the database 82 (arrow 208). Then, the position data can be retrieved from any location. It should be noted that flows 204 to 208 may be repeated on an interval basis, if initially it was requested that the position data be delivered in that manner. Where the updated position data is repeatedly delivered at intervals for a certain time, the file gps.log database 82 is attached to the updated position data. In general, when a field crew or individuals in the computer system of company 50 want to see the position data of a mobile field unit
52 can do so by accessing through the network interface, the position data stored in the computer system of the company 50. In Figure 11, this process of accessing the stored position data is illustrated by a access from a mobile field unit
53. It should be noted, however, that this same process could be initiated from another location, including clients in the company's computer system 50. Normally, a user can specify the particular machine on which they wish to have position data, using a web page as shown in Figure 6. As can be seen in Figure 6, a user can select a field unit 52 by selecting the IP address of the desired machine. Of course, other means could alternatively be used to designate a particular mobile field unit 52, as long as they uniquely identify the unit. For the purposes of this illustration by way of example, it can be assumed that in the field unit 53 a position data request of the field unit 52 is made. In the field unit 53, the position data request is transmits, as represented by arrow 212, to HTTP server 84 in the company's computer system 50. The request identifies position data of field unit 52 including the IP address of field unit 52 is desired. In one embodiment of the invention, the stream 212 refers to an HTTP CGI post-connection between the network browser 90 and the HTTP server 84. In response to the request, the HTTP server 84 launches a CGI 89, which is implemented preferably as a PERL script (arrow 214). Using the IP address that was transmitted along with the request, the PERL 89 script searches the stored position data. The position data can be stored both in a log file, gps.log 210, and in database 82. Position data can be retrieved from the two locations using the IP address. For example, the PERL 89 script can search the gps.log 210 file for all position data related to the designated IP address. In general, the position data that has been stored in the company's computer system has gathered at intervals and may contain some inaccuracies in the position data. In this way, the PERL 89 script may have to process the position data to take these inaccuracies into account. In general, the PERL script 89 analyzes each line of the gps.log 210 file or each database record 82 by extracting the planar state coordinates related to the field unit 52. The PERL 89 script stores the previous and current coordinates and detects sudden changes in the value. If the values are negative, they ignore. Normally, the negative values are an indication that the positioning system has not yet reached a stop in the particular field unit when the position data was generated. The PERL 89 script can also ignore the values of position data if the value represents a sudden change in the position of the field unit that can not be justified. The PERL 89 script can differentiate between values of false abrupt changes and valid position data when evaluating values in relation to those that come before and after. According to this sliding window algorithm, if a value represents a sudden change in position, but the subsequent values of the position are consistent with that value, that is, within a reasonable proximity, the value is considered valid. A sudden change like this can occur, for example, when the field unit was turned off later it was turned on while being in a completely new location. However, if the change can not be justified, it is discarded. All the values of the position data that are considered valid are inscribed in a first file 21
(arrow 218). In one mode, the first file 216 is a MIME type file and has a file name ending with ".mpx". Next, the PERL script 89 generates a second file 220, preferably an HTML file (flech 222). The HTML file 220 comprises a reference or tag integrated into the ".mpx" file 216. The HTML file 220 and the ".mpx" file 216 are transmitted via the HTTP server 84 to the field unit 53 (arrow 224). Once received, the HTML file 220 is loaded into the network browser 90. The browser network 90 recognizes the reference to the file ".mpx" 216 and, in response, loads the browser finder network 94, which can be operate to display the position data stored in the ".mpx" file 216 (arrow 226). Figure 7 shows an example screen, which can be displayed after loading the position data in the search engine 90. It should be indicated that the screen preferably graphically presents the speed and direction to a location for each mobile unit countryside. For example, you can draw a vector attached to each icon or mark on the map. The vector indicates the direction of the displacement and the length of the vector is an indication of the speed of the mobile field unit. Of course, the speed can also be displayed as text on the screen. It should also be noted that the ".mpx" file 216 may include land-based data representing a sub-map that includes the coordinates of the route of the mobile field unit. In this way, the finder enhancer 94 can cover the route of the mobile field unit in a land-based map display. The file ".mpx" 216 and the HTML file 218 should normally have unique names. Otherwise, with subsequent requests for position data for the same field unit, the network browser 90 could present old map data in place of the newly downloaded data. The mechanisms for assigning unique file names may include, for example, assigning file names according to the time and date when a file was generated or assigning unique random numbers. A complete description of the contents and uses of the file ".mpx" 216 and of the HTML file 218, is provided in the Patent Application of the pending TCP with serial number (still not assigned) (case number ABME-0538), filed e the same date as this, and entitled "Mobile Crew Managemen System", whose content is incorporated into this com reference. As indicated above, position data can be transmitted directly from one field mobile unit to another mobile field unit without first being stored in the company's computer system 50. Thus, for purposes of illustration, one user in the unit Field 5 may want to retrieve position data directly from field unit 52. Accordingly, a request is made from network browser 90 of field unit 53 to server UDP 95 of field unit 5
(arrow 230). The UDP 95 server causes the UDP 9 client to gather the requested position data (arrow 232). The UDP client 96 gathers the data and transmits it back to the field unit 53 (arrow 234). The network browser 90 of the field unit 53 receives the position and load datds and network finder enhancer 94 in order to display the new position data (arrow 236). It should be noted that, normally, the position data requests can designate first a primary and a secondary machine by means of the IP address and the location of the port that should receive position data. Then, in response to these requests, UDP packets containing position data are transmitted to the primary and secondary machine. The position data can be transmitted at intervals if specified in the request. Of course, if no secondary n primary addresses are specified, position data is not sent. Thus, the first embodiment of the invention allows two or more machines to simultaneously receive position data from the same field mobile unit. As stated above, this makes it possible for a mobile field unit to receive position data and operate as a mobile control center while the position data is simultaneously provided to the company's computer system 50. A second system modality for the data distribution of position employs HTT communications to distribute position data from a mobile unit d field. Figure 12 shows the data and command flows for a modality like this. Typically, a position data request is made via the HTTP position tracking application 110 and includes making an HTTP client connection with the selected field mobile unit 52 (flech 300). Once received, the HTTP server 112 requests the CGI program 114 to gather the requested position data (arrow 302). The CGI program 114 requests position data from the position processing application 98 (flech 304). The position processing application 98 returned the requested position data to the CGI 114 program (flech 306). The CGI program 114 returns the position data to the HTTP application 110 (arrow 308). The HTTP application 11 stores the position data in the gps.log 210 file and the database 82 (arrow 310). The process of retrieving data from the computer system position of the company 50 to a field mobile unit 53 in the system of Figure 12, is generally identical to that described above in relation to Figure 11. As such, the numbering of the corresponding flow (arrows 212 to 226) remained the same. In case of retrieving position data from the field unit 52 directly to a field unit 53, the process is only slightly different from that described above in connection with Figure 10. Accordingly, a request from the network browser is sent. 90 of the field unit 53 to the HTTP server 112 of the field unit 52 (arrow 330). The HTTP server 112 launches the CG 114 program to gather the requested position data (flech 332). The CGI 114 program collects the data and transmits it back to field unit 53 (arrow 334). The network browser 90 of the field unit 53 receives the data and loads and improves the network browser 94 in order to show the new position data (arrow 336). Although the flow is generally the same for the UDP and HTTP implementations of the present invention, there are some slight differences in the capabilities of the systems. The present implementation does not allow position data to be transmitted at intervals as a result of a single request. Rather, a request is usually sent whenever position data is required, even for updates. Of course, it is possible and surely conceivable that an HTTP mode allows the transmission of position data intervals. Also, the HTTP modality does not currently provide an individual request that results in the designation of a primary and a secondary machine and, simultaneously, receives position data. However, this functionality can be duplicated in the HTTP mode by generating a list of machines to which to transmit position data, and each time position data is requested, a request is made for each machine in the list. Thus, as described above, the present invention provides systems and methods for the timely and economical communication of position data of field units between a field unit, a central enterprise system and secondary field units. The system comprises a computer system of the company, a wireless network and multiple mobile field units. Communications are made based on TCP / IP and can be done through a public or private network using a variety of communication technologies. While the invention was described and illustrated with reference to specific embodiments, those skilled in the art will recognize that modifications and variations can be made without departing from the principles of the invention as described above and further in the claims. In particular, the present invention has been explained with reference to a means of application as an example, but can be used in other media such as maintenance service companies, ambulatory services, public safety systems or any other operation that communicates work orders to field staff. Also, it should be noted that the position data can be displayed according to the methods and systems of the present invention in an application that is not a network browser. In accordance with the foregoing, reference should be made to the appended claims as an indication of the scope of the invention.