WO2003039183A1

WO2003039183A1 - Methods, systems and computer program products for dividing a physical domain

Info

Publication number: WO2003039183A1
Application number: PCT/DK2002/000725
Authority: WO
Inventors: Jens Gottfredsen
Original assignee: Unwiredfactory A/S
Priority date: 2001-11-01
Filing date: 2002-10-31
Publication date: 2003-05-08

Abstract

The present invention relates to a method, system and computer program product for dividing a physical domain into a plurality of virtual cells, and to a method, system and computer program product for tracking a plurality of portable communication units, such as mobile telephones, in the domain.

Description

METHODS, SYSTEMS AND COMPUTER PROGRAM PRODUCTS FOR DIVIDING A PHYSICAL DOMAIN

Technical field

The present invention relates to a method, system and computer program product for dividing a physical domain into a plurality of virtual cells, and to a method, system and computer program product for tracking a plurality of portable communication units, such as mobile telephones, in the domain. The invention further relates to the use of a system according to the invention in a game, and to a game system. The invention generates and utilises one or more virtual cells or grids into which the physical domain is divided.

Background of the invention

The prior art has suggested various systems and methods for locating mobile communications units in a physical domain. 099/55133 discloses a method and a system for generating location dependent information in a gallery or a shopping mall. An area of coverage is divided into one or more logical zones, and information related to the zone is transmitted to the user when the user appears in the zone, whereby the user may e.g. receive information concerning the piece of art nearest to the user. EP 0 856 746 describes a method and a system for locating a mobile station, such as a mobile phone, wherein the mobile phone is located within a specific cell of a grid, whereby the position .is determined as an area and not a specific point. US 5,732,354 and US 5,293,645 disclose various systems for determining the location of a mobile telephone within a serving area of a mobile telephone system. US 5,732,354 describes an algorithm which reduces the error component in the calculated distances by taking a propagation slope, i.e. signal strength variation, into account. In US 5,293,645, propagation delays are used to determine the position of the movable terminal.

Description of the invention

It is an object of the invention to provide a method and a system in which cells or grids may be used to adapt information transmitted to and/or from portable communication units, such as mobile telephones, to meet specific user needs or requirements. It is a further object of the invention to provide an entertaining game system which utilises the advantages of the cell or grid technology.

Thus, in a first aspect the invention provides a method of dividing a physical domain into a plurality of virtual cells, the physical domain comprising a plurality of portable communication units, each portable communication unit being adapted to communicate,^' through wireless transmission, with another of said portable units and/or with a stationary communication device, the method comprising:

- dividing, in response to user input information, the physical domain into said- plurality of cells, the user input information comprising information about:

- the number of cells into which the physical domain is to be divided, and/or

- the extent and/or location of the physical domain,

- storing, in a memory of a computer system, data representing each cell, said data including at least an identification and/or location of each cell. The computer system may comprise or be comprised in the portable communication units, which may constitute a mobile telephone system. Thus, said memory may be the memory of a mobile telephone, or a memory a server system of a telecommunication provider.

The virtual cells preferably constitute a virtual domain, whereby the physical domain is represented by the virtual domain in the memory of the computer system. In the virtual domain, one or more users may send and receive specific information, whereby the information may vary in dependence from the physical location of the user and his/her portable communication device. Thus, a user may for example choose to receive information concerning local bus or train departure times within each cell of the virtual domain. Other kinds of information may be transmitted, such as theatre show information, local news, special offers by local shops, etc. In certain embodiments of the invention, each user may select which kind of information he/she will receive. Alternatively or additionally, various types of information may be transmitted from each portable communication unit. Optionally, the information may be transmitted to various persons, the persons to whom the information is transmitted being dependent from the location of the user in relation to the virtual domain. For example, when a user is in a cell close to his/her home, information revealing the location of the user may be sent to a cohabitant of the user, e.g. a family member, whereas when the user is close to his/her place of business, location information may be sent to the user's employee.

In other appliances, the invention may be used in games played by a plurality of users by means of the portable communication devices, such as mobile telephones. For example, the users may play a treasure _ιhunt or mine sweeper game, wherein a physical domain, e.g. an area of a city, is divided into a grid of cells. The location of each user in the grid may be visualised on a display of the portable units, whereby the users may tracks each other's movements.

The cells need not represent a continuous, unbroken physical domain. For example, certain cells of the virtual domain may represent a first area of a city, whereas other cells of the same domain may represent another area of the city which is remote from the first area of the city.

By allowing a user, through user input, to define the number of cells, the extent and/or location of the virtual domain, a very flexible system is achieved, in the sense that the user may choose a fine-meshed virtual domain for certain purposes and a coarse-meshed grid for other purposes. Further, the size of cells and the extent of the domain may depend from exterior conditions, such as distance between stationary transmitters in a mobile telephone network or signal propagation properties. Alternatively, a fine-meshed grid would be needed ^• for local bus and train departure information, whereas a coarse-meshed grid would be need for airport information services. A user may define a plurality of overlapping or non-overlapping virtual domains, so that one or more physical domains may be covered both by a fine-meshed and by a coarse-meshed virtual domain. In certain appliances, a virtual cell in a first virtual domain may completely comprise a second virtual domain.

The cells may be grouped in several groups with common properties, such as, in a game appliance, properties relating to owners, names, sizes of cells,- etc. In respect of appliances for playing games, the user-specified definition of number of cells and/or extent of a domain allows for an entertaining and exciting variation in games played with portable communication devices, such as mobile telephones.

The user input information may be entered on one or more of the portable communication units or by a system administrator administrating and representing a plurality of users. However, the user input information may also be entered on a computer, e.g. a personal computer, connected to a network, such as the Internet, whereby the- user may define the virtual domain^' at a location remote from the physical domain. A plurality of users may communicate via the Internet or directly via wireless communication between the portable units when defining the virtual domain, whereby a plurality of users may agree on the extent and number of cells of the domain.

In other words the term user should in this context be construed as an user of a portable communication unit such as cellular or mobile phone, as a network administrator administrating a network of interconnected portable communication units in a network, or as a super user administrating a plurality of selective portable communication units. Hence the user input information may be input directly on a portable communication unit by the user, be performed from a client station such as a personal computer interconnected with a telecommunication network operator server through a computer network such as wired or wireless dedicated lines, local area network, wide area network, metropolitan area network, internetwork, or any combination thereof. The virtual domain may have a centre area or a centre point which is derived from a location at which the user input is given. The geographical location of the user may be found by performing a positioning on the user' s portable communication unit which may be achieved by a positioning system known per se . In case of the portable communication unit being a mobile telephone, the positioning is preferably performed by receiving and processing data from a telecommunication operator. For example, data relating to precision and antenna coordinates in longitude and/or latitude may be provided.

The user input information may comprise number of rows and number of cells in the grid, and/or at least one dimension of the virtual domain. In the memory of the computer system, the grid is preferably represented by its height, width, centre location, number of rows, and number of columns. Though a grid may have any size and dimension, limits for a minimum cell size and possibly also a maximum number of cells may given. The minimum cell size may for example be determined by the precision of the positioning data provided by a telecommunications operator, so that reliable location data of a e.g. a mobile telephone in relation to the virtual domain may be provided, whereas the number cells may be limited by the space available on a display of a mobile telephone. Whereas grids, comprising 1000 or more rows and columns may be provided^' for, the number of rows and columns may be in the order of 10x10, such as 5x5, or 5x2, or in the order of 50x10, 50x20 or 25x25. The extent of the physical domain which also governs the extent of the virtual domain may be as large as 1000 km xlOOO km, but more often it will be in the order of 100 km x 50 km or smaller, such as 50 km x 5 km, ore 5 km x 5km, 2 km x 2 km or 1 km x 1 km. Once generated, multiple virtual domains may be joined. In appliances, where the portable units communicate with stationary transmitters, i.e. in a mobile telephone network, the sizes of the cells and the extent of the virtual domain may depend from the physical distance between the transmitters and/or signal propagation properties. The definition of the sizes of the cells, their number and/or the extent of the virtual domain may be determined in an iterative process during which conditions, such as signal propagation properties, are taken into account.

An area of a cell may be defined by an arc section, whereby a minimum cell size may be determined based on an arc centre, arc radius and angular span.

Various properties may be assigned to the virtual domain, preferably to each cell of the domain. Properties may be shared between two or more virtual domains. In the present context, the term "properties" should be construed as comprising any . kind of information relevant to a specific user of a specific appliance, such as the possible presence of other users or players in a specific cell and their number, bus or train departure information, etc. In a game appliance, the properties may comprise information related to a proprietor of a cell, or to a score of a user, or properties or tools granted to the user, such as a sword, additional lives, or penalty points.

In a second aspect which may comprise any feature or functionality described above in connection with the first aspect, the invention relates to a method of tracking a plurality of portable communication units in a physical domain, the method comprising: - dividing the physical domain into a plurality of virtual cells by the method of the first aspect of the invention,

- transmitting data from at least one of the portable units to another one of the portable units and/or to a stationary communication device, said data comprising information from which a physical position of said at least one portable unit may be derived,

- deriving, by means of a computer system, the position of said at least one portable unit,

- determining in which one of said cells the portable unit is located.

The physical location may be an absolute position expressed as longitude and latitude,, or it may be position relative to a predetermined location.

As described above in connection with the first aspect of the invention, the virtual cells may constitute a virtual domain. A plurality of virtual domains may be generated at the step of dividing, and properties may be assigned to the domain or domains, preferably to each cell within each domain. In the case of a plurality of domains, properties may be shared between the domains. A plurality of properties may be assigned to each virtual cell. The properties may be visualised on a display of one or more of the portable units.

The number of cells may be automatically changed when the dimensions of the virtual domain are changed, e.g. by user input .

In a third aspect, the invention provides a computer system for dividing a physical domain into a plurality of virtual cells in a memory of the computer system, the system comprising, in the physical domain, a plurality of portable communication units, each portable communication unit being adapted to communicate, through wireless transmission, with another of said portable units and/or with a stationary communication device, the computer system further comprising:

- a data input device for receiving information derived from a user input, the user input information comprising information about:

- the number of cells into which the physical domain is to be divided, and/or

- the extent and/or location of the physical domain,

- a processor being programmed to divide, in response to the user input information, the physical domain into said plurality of cells and to store, in the memory, data representing each cell, said data including at least an identification and/or location of each cell.

The input device may be provided at or comprised in the portable communication units, and it may for example be constituted by a keypad of a mobile telephone.

It should be understood that the system according to the third aspect of the invention may be adapted to perform or comprise any feature and functionality described above in connection with the methods of the first and second aspects of the invention.

In a fourth aspect, the invention provides a computer system for tracking a plurality of portable communication units in a physical domain, the system comprising said plurality of portable communication units and:

- a computer system according to the third aspect of the invention, - at least one transmitter for transmitting data from at least one of the portable units to another one of the portable units and/or to a stationary communication device, said data comprising information from which a physical position of said at least one portable unit may be derived,

- a processor being programmed to derive the position of said at least one portable unit and to determine in which one of said cells the portable unit is located.

It should be understood that the system according to the fourth aspect of the invention may be adapted to perform or comprise any feature and functionality described above in connection with the methods of the first and second aspects of the invention and the system of the third aspect of the invention.

As mentioned above, the methods and systems of the invention are applicable to games, and accordingly the invention relates to, in a fifth aspect, the use of a system according to the fourth aspect for a game in which scores and/or properties are assigned to a plurality of players, each player carrying a portable communication unit, the score or property assigned to each player being dependent from the location of the player's portable units in relation to the cells. The invention further provides, in a sixth aspect, a game system comprising a computer system according to the fourth aspect, wherein the processor of the computer system is adapted to assign scores and/or properties to a plurality of players, each player carrying a portable communication unit, the score or property assigned to each player being dependent from the location of the player's portable units in relation to the cells.

In a seventh and eighth aspect, the invention provides computer program products allowing for the above-mentioned features and functionalities. In the seventh aspect, the invention provides a computer program product for dividing a physical domain into a plurality of virtual cells, the physical domain comprising a plurality of portable communication units, each portable communication unit being adapted to communicate, through wireless transmission, with another of said portable units and/or with a stationary communication device, the computer program product comprising:

- a first computer program segment for receiving user input information comprising information about:

- the number of cells into which the physical domain is to be divided, and/or

- the extent and/or location of the physical domain,

- a second computer program segment for dividing, in response to user input information, the physical domain into said plurality of cells,

- a third computer program segment for storing, in a memory of a computer system, data representing each cell, said data including at least an identification and/or location of each cell.

In the eighth aspect, the invention provides a computer program system for tracking a plurality of portable communication units in a physical domain, the computer program product comprising:

- a computer program product according to the seventh aspect of the invention for dividing the physical domain into a plurality of virtual cells,

- first algorithms for transmitting data from at least one of the portable units to another one of the portable units and/or to a stationary communication device, said data comprising information from which a physical position of said at least one portable unit may be derived, - second algorithms for deriving, by means of a computer system, the position of said at least one portable unit, third algorithms for determining in which one of said cells the portable unit is located.

In any aspect of the invention, the term "computer system" should be construed as any system comprising a programmable processor and a memory, such as a personal computer, a computer network, a mobile telephone, a network of a plurality of mobile telephones or other electronic devices.

In a ninth aspect, the present invention provides a communication system for providing an alarm to a portable communication unit in accordance with position of said portable communication units in a grid, and comprising: a wireless communication network for interconnecting said portable communication units;

- a communication server for generating said alarm and adapted to monitor position of said portable communication units in said grid; a gateway connecting to said wireless communication network and adapted to communicate with said portable communication units through said wireless communication network;

- a computer network for interconnecting said gateway and said communication server so as to enable said communication server to communicate with said gateway and transmit said alarm to said gateway; and wherein said communication server is adapted to establish said grid by dividing, in response to input information, a physical domain into a plurality of cells, and to establish said grid by storing, in a memory of said communication server, properties data representing each cell, and adapted to forward said alarm to said portable communication in accordance with specific data representing a cell in which said portable communication unit is positioned.

The properties data may comprise a plurality of values for each cell. The values may comprise user or mobile telephone specific preferences for a cell.

The alarm according to the ninth aspect of the present invention may comprise a text, a series of texts, a picture, a series of pictures, a video sequence, a series of video sequences, an audio track, a series of audio tracks, or any combination thereof. The alarm may be internally or externally generated. When the alarm is externally generated by a connecting mobile telephone or service provider, such as another mobile telephone, a telecommunication network operator or gateway, the alarm may be forwarded as a short messaging service (SMS) , an unstructured supplementary service data (USSD) message, a multimedia messing service (MMS) message, an e-mail message, or any combination thereof.

An internally generated alarm may be generated when a user of a mobile telephone has assigned particular values to the cell and the mobile telephone is positioned in the cell, which values determine that the user of the mobile telephone should receive a predefined notification.

The communication system according to the ninth aspect of the present invention may incorporate any features according to the first through eighth aspect of the invention.

In a tenth aspect, the present invention provides a communication server for providing an alarm to a portable communication units in accordance with position of said portable communication unit in a grid, and comprising:

- a processor adapted to divide said grid, in response to input information, a physical domain into a plurality of cells,

- a memory adapted to store properties data representing each cell, and wherein said communication server is adapted to forward said alarm to said portable communication in accordance to specific properties data representing a cell in which said portable communication unit is positioned through a wireless communication network connecting to said portable communication unit; a gateway connecting to said wireless communication network; and a computer network for interconnecting said gateway and said communication server.

The communication server according to the tenth aspect of the present invention may incorporate any features according to the first through ninth aspect of the invention.

In a eleventh aspect, the present invention provides a method for providing an alarm to a portable communication units in accordance with position of said portable communication unit in a grid, and comprising: connecting a said portable communication unit with a communication server by means of a wireless communication network, a gateway, and a computer network; establishing said grid by dividing, in response to input information, a physical domain into a plurality of cells, and by storing properties data representing each cell of said plurality of cells; and forwarding said alarm to said portable communication unit in accordance to specific properties data associated with a cell in which said portable communication unit is positioned.

The method according to the eleventh aspect of the present invention may incorporate any features according to the first through tenth aspect of the invention.

Brief description of the drawings

The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawing, wherein:

figure 1 shows a users position if different grids and mobile telephone showing a users position is a grid,

figure 2 shows a user located in a grid according to the present invention,

figure 3 shows a grid according to the present invention,

figure 4 shows a hierarchical representation of the virtual domain,

figure 5 shows a representation of the virtual domain,

figure 6 shows an embodiment of a virtual cell,

figure 7 shows a geographical area comprising one or more grids, figure 8 shows a detailed view of a single grid of the geographical area,

figure 9 shows a virtual grid defined by a network administrator,

figure 10 shows a road map overlaid with a grid, and

figure 11 shows a communication system according to one embodiment of the present invention.

Detailed description of the drawings

In the following description of the various embodiments, reference is made to the accompanying drawing which form a part hereof, and in which is shown by way of illustration various embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention.

Figure 1 shows a plurality of grids 101, 102, 103, wherein a user of a mobile telephone 107 is located. The position or the mobile telephone 107 in relation to each grid 101, 102, 103 is illustrated with the bar 104. Each grid is divided into a plurality of columns 105 and a plurality of rows 106. The display 108 of the mobile telephone 107 shows one grid 109. The position 110 of the mobile telephone 107 is shown in the display 108, which furthermore shows the position 111, 112, 113 of other mobile telephones in relation to the- grid 109.

The plurality of grids 101, 102 and 103 each representing an area in which the mobile telephone is located. The plurality of grids 101, 102 and 103 may in a first embodiment of the present invention be defined by separate users of mobile telephones, in a second embodiment of the present invention be defined by the user for a single mobile telephone i.e. the plurality of grids 101, 102 and 103 are defined in one mobile telephone and a user of said phone may toggle between various grids, in a third embodiment of the present invention be defined by a network administrator defining grids for a plurality of mobile phones, and in a fourth embodiment of the present invention be defined by a super user of a selected group of mobile telephones.

The bar 104, as described above, illustrates the mobile telephone 107'^' s position in each of the plurality of grids 101, 102 and 103. Hence in the first embodiment of the present invention each grid 101, 102 and 103 belongs to a specific user of a mobile telephone and the location of the mobile telephone 107 in the grids 101, 102 and 103 is shown as the bar. The users of the grids 101, 102 and 103 continuously may identify the position of the mobile telephone 107 in their respective grids. Similarly, the user of the mobile telephone 107 on the display 108 may identify the position of other mobile telephones on the positions 111, 112 and 113.

This feature is particularly advantageous since this enables a plurality of mobile telephones to identify relative position of one another. The relative position should in this construed in terms of both a geographical position in for example a map and a virtual position i.e. a non-geographical position but entirely a position in a grid.

A user for a single mobile telephone according to the second embodiment of the present invention is able to generate the plurality of grids 101, 102 and 103 for personal user. For example the user might define a first grid for a first area, a second grid for a second area, .and a third grid for a third area. The first, second and third areas may be fully or partly overlapping geographical areas or non-overlapping separate geographical areas. In addition, the first, second and third areas may be virtual areas such as used in games or "treasure hunts". Hence, the user may participate in a plurality of grid configurations simultaneously.

A network administrator according to the third embodiment of the present invention is adapted to generate a virtual grid for a plurality of mobile telephones in a telecommunication network. The mobile telephones may be positioned continents apart physically, however, in the virtual grid they may be next to each other. This facilitates the plurality of mobile telephones to perform "treasure hunts" or searches entirely in a virtual plane.

Obviously, the network administrator according to the third embodiment of the present invention is further adapted to generate a grid relating to a geographical area for a plurality of mobile telephones in a telecommunication network. Each of the mobile telephones may thereby monitor the position of one another so as to for example effectively position personal in accordance to a geographical demand for services.

A user of a single mobile telephone according to the fourth embodiment of the present invention is enable to define a plurality of grids 101, 102 and 103. The user e.g. a taxi service owner may continuously monitor the position of his employers positioned in an area and thereby provide a fast service for clients. Figure 2 shows a detailed view of a grid 101 according to the present invention. In the grid 101 the position 110 of the mobile telephone 107 is shown. Furthermore figure 2 shows the horizontal distance 114 and the vertical distance 115 of the mobile telephone 107 from the centre 116 of the grid 101. The grid 101 comprises a plurality of columns 105 and a plurality of rows 106 and has a grid height 117 and a grid width 118.

The grid height 117 and the grid width 118 are defined by the user of a mobile telephone according to the first and second embodiment of the present invention, by the network administrator according to the third embodiment of the present invention, and by the user/super user of the mobile telephone according to the fourth embodiment of the present invention. The grid height 117 and grid width 118 'define the size of a grid, which size may have symmetric or asymmetric dimension in the range from a few metres to several thousands of kilometres so as to enable a generation of a grid covering a supermarket to a grid covering continents, or even several continents.

The grid 101 in figure 2 is shown as a rectangular grid, however, an alternative embodiment may define any other polygonal area, or even a substantially circular, oval or elliptical shaped area. The presentation of the grid in the alternative embodiment may, obviously, be rectangular as shown in figure 2.

Figure 3 shows a grid 101 according to the present invention, having a plurality of columns 105 and a plurality of rows 106. Furthermore the figure shows the height 131 and the width 119 of a cell 120. As describe above with reference to figure 2, height 131 ^'and width 119 of the cell 120 are defined by the user of a mobile telephone according to the first and second embodiment of the present invention, by the network administrator according to the third embodiment of the present invention, and by the user/super user of the mobile telephone according to the fourth embodiment of the present invention. The height 131 and width 119 define the size of the cell 120, which size may have dimension in the range from a few centimetres to several kilometres so as to enable a generation of a cell covering a supermarket to a cell covering a part of a street or city.

The cell size may in an alternative embodiment be determined in accordance with the quality and coverage of the wireless network such as a telecommunication network or a global positioning system network.

In some less populated areas a wireless telecommunication network generally comprises fewer transmission stations compared to highly populated areas such as cities or towns comprising a significant number of transmission stations. The denser populated areas thus enables a cell definition which is smaller thereby providing a grid which has a higher accuracy in positioning of mobile telephones. The smaller the grid the higher an accuracy of determining position is achieved.

Figure 4 shows a hierarchical representation 121 of the virtual domains e.g. grids 101 of the present invention. Each grid 101 comprises a plurality of cells 120 each having a plurality of properties 122. The properties may be assigned a value 123. The properties 122 of one of the cells 120 according to the first through fourth embodiment of the present invention comprises a value or a plurality of values 123 for a particular cell. The properties 122 comprises user or mobile telephone specific preference for a cell. For instance, the specific preference may limit the types of alarms generated thereby enabling a user, a super user, or a network administrator to define what types of alarms are generated for a grid in any cell.

For example, a user according to the first and second embodiment of the present invention assigns values to cell in a grid, which values determine an alarm to be generated on the user's mobile telephone when the mobile telephone is positioned in the associated cell. The user may establish reminders to a particular cell so as to generated an alarm for the reminder when the user is in the cell: "When in Paris remember to buy red wine".

In a second example, a network administrator according to the third embodiment of the present invention assigns values to cells in a grid, which values determine when an alarm is to be generated in mobile telephones or forwarded to mobile telephones in the associated cell. The alarm may be a "treasure" message.

In a third example, similarly to the second example, a super user according to the fourth embodiment of the present invention assigns values to cells in a grid, which values determine when an alarm is to be generated in mobile telephones or forwarded to mobile telephones in the associated cell. The super user may generate alarms containing messages informing the receiving mobile telephones in the grid prior to leaving or entering a grid. For instance a route for a car might be defined by a grid and the driver is notified whenever the car is deviating from said route.

The alarm according to the first through the fourth embodiment of the present invention is a text, a series of texts, a picture, a series of pictures, a video sequence, a series of video sequences, an audio track, a series of audio tracks, or any combination thereof.

The alarm is internally or externally generated. When the alarm is externally generated by a connecting mobile telephone or service provider, such as another mobile telephone, a telecommunication network operator or gateway, the alarm may be forwarded as a short messaging service (SMS) , an unstructured supplementary service data (USSD) message, a multimedia messing service (MMS) message, an e-mail message, or any combination thereof.

An internally generated alarm is generated when a user of a mobile telephone has assigned particular values to the cell 120 and the mobile telephone is positioned in the cell 120, which values determine that the user of the mobile telephone should receive a predefined notification.

Figure 5 shows a hierarchical representation 124 of the first through fourth embodiment of the present invention. A set of co-ordinates 125 are assigned to a plurality of grids 101 each comprises a plurality of cells 120. Each cell 120 is assigned to properties 122, which have one or more of values 123 assigned thereto.

In figure 6, the determination of the position of the mobile telephone 107 is illustrated in relation to an area 126 in which the mobile telephone is located. A cell, such as cell 120, comprises at least one area 126 given a transmission and/or reception value in accordance with signal strength of the wireless telecommunication network in said area 126. The area 126 is only located in one cell thus cannot spread between two cells.

The area 126 comprise any polygonal shape which is determined on the basis of placements and signal strengths of antennas in the telecommunication network. The signal strength of an antenna diminishes with increasing radial distance from the antenna. An arc segment 127 defining a specific radial distance from an antenna is used to determine the area 126 in which the mobile telephone 107 is located. Each arc segment 127 has an origin 128 being the position of the antenna. The position of the mobile telephone is determined by using the co-ordinates of the origin 128 of the antenna and a start angle 129 and a stop angle 130 defining the arc segment 127 and an inner and an outer radius to the arc segment. When two arc segments are established the accuracy of the determination of the position of the mobile telephone is significantly increased.

Figure 7 shows a geographical area 200 comprising one or more grids 202 defined by a network administrator according to the third embodiment of the present invention. A plurality of mobile telephones may utilises the administrator defined areas to participated in a battle game. The mobile telephones receive instructions according to position in the one or more grids 202. When a mobile telephone enters a cell 203 the presentation of the cell 203 changes e.g. as hatched in black or alternatively, as shown in cell 201 as hatched in white. The colour of the hatched effect may in an alternative embodiment comprises any colour or grey scale so that the cells 201 or 203 are hatched in a scale which has a specific meaning to the user of the mobile telephone. Figure 8 shows a detailed view of a single grid 204 in the one or more grids shown in figure 8. The network administrator assigns properties to each cell in the grid 204, such as cell 206.

The presentation of the grid 204 to the mobile telephones positioned in the grid 204 is not necessarily identical for all mobile telephones. The plurality of mobile telephones in the grid 204 may be assigned to teams of mobile telephones receiving only team specific information regarding position of team mobile telephones.

The mobile telephone operating in the grid 204 may have effect on the properties .of a cell 208 when the mobile telephone enters the cell 208. For example, if the grid 204 is utilised for determining the progress of a postal service employee' s progress through a postal district the cell 208 is marked when the postal service employee has left the area.

Figure 9 shows a virtual grid 210 defined by a network administrator according to the third embodiment of the present invention. The mobile telephones utilise the grid 210 for establishing a virtual area in which particular operations are to be performed. The operations may be solved by transporting a mobile telephone to a cell 212 of the virtual grid 210. Any participating mobile telephone, obviously, physically moves within surroundings of the mobile telephone in order to move in the virtual grid 210.

Figure 10 shows a road map designated in entirety by reference numeral 220 and being overlaid with a grid 222. The network administrator according to the third embodiment of the present invention and/or the super user according to the fourth embodiment of the present invention may define properties of cells in the grid 222. A plurality of cells 224 are marked by the super user or network administrator so as to indicate a change of properties. The super user and/or the network administrator may for example define a specific route for a chauffeur and the ensure that an alarm is generated whenever the chauffeur deviates from the required route.

Figure 11 shows a communication system designated in entirety by reference numeral 300 and according to one embodiment of the present invention. The communication system 300 comprise one or more portable communication units 302 such as a cellular or mobile telephone, a global positioning device, or a bluetooth device .

The portable communication units 302 are connected to a wireless communication network 304, which comprises a wireless telecommunication network utilising an antenna system 308, a bluetooth identification device utilising an antenna system 310, a satellite communication system 306, or any combination thereof.

The communication system 300 further comprise a gateway 312 connecting to the wireless communication network 304. The gateway 312 communicates with the portable communication units 302 and in one embodiment of the present invention comprises a positioning procedure for determining the position of the portable communication units 302. Alternatively, the positioning procedure is implemented in an application server 314 connected to the gateway 312 through a computer network 316 such as a wired or wireless dedicated lines, a local area network, a wide area network, a metropolitan area network, an internetwork (e.g. the Internet), or any combinations thereof. The application server 314 correlates position of the portable communication units 302 with internally or externally stored grids as described with reference to the previous figures. In case the one of the portable communication units 302 enters a cell of a grid having a specific property for said one of the portable communication units 302, then the application server 314 initiates the transmission of an alarm to said portable communication unit. The alarm may as described above relate to a reminder for performing certain acts in the area of the cell.

The communication system 300 further comprises an administrator 318 for administrating the grid or grids stored in the application server 314 and connected to the application server 314 through the computer network 316.

The users of the portable communication units 302 and the administrator may define a grid for any number of portable communication units 302. That is the users and/or the administrator defines grid dimensions and defines properties of individual cells in the grid.

Claims

1. A method of dividing a physical domain into a plurality of virtual cells, the physical domain comprising a plurality of portable communication units, each portable communication unit being adapted to communicate, through wireless transmission, with another of said portable units and/or with a stationary communication device, the method comprising:

- dividing, in response to user input information, the physical domain into said plurality of cells, the user input information comprising information about:

- the number of cells into which the physical domain is to be divided, and/or

- the extent and/or location of the physical domain,

— storing, in a memory of a computer system, data representing each cell, said data including at least an identification and/or location of each cell.

2. A method according to claim 1, wherein the virtual cells constitute a virtual domain.

3. A method according to claim 1 or 2, wherein the user input information is entered on one or more of the portable communication units.

4. A method according to claim 3, wherein the virtual domain comprises a grid of said virtual cells.

5. A method according to claim 3 or 4, wherein the virtual domain has a centre area or a centre point which is derived from a location at which the user input is given.

6. A method according to claim 4 or 5, wherein the user input information comprises number of rows and number of cells in the grid.

7. A method according to any of claims 2-6, wherein the user input information comprises at least one dimension of the virtual domain.

8. A method according to any of claims 2-7, further comprising the step of joining multiple virtual domains.

9. A method according to any of claims 4-8, wherein the grid is represented by its height, width, centre location, number of rows, and number of columns.

10. A method according to any of the preceding claims, wherein the virtual cells are generated by taking into account positioning data provided by a telecommunication operator, the positioning data representing a location of one of said portable units.

11. A method according to claim 10, wherein the positioning data define an area in which said portable unit is located.

12. A method according to claim 11, wherein said area is defined by an arc section.

13. A method according to claim 12, further comprising the step of determining a minimum cell size based on an arc centre, arc radius and angular span.

14. A method according to any of the preceding claims, wherein properties are assigned to the virtual domain.

15. A method according to claim 14, wherein at least one property is assigned to each virtual cell.

16. A method according to claim 14 or 15, wherein properties are shared between two or more virtual domains .

17. A method of tracking a plurality of portable communication units in a physical domain, the method comprising:

- dividing the physical domain into a plurality of virtual cells by the method of any of claims 1-16,

- determining in which one of said cells the portable unit is located.

18. A method according to claim 1, wherein the virtual cells constitute a virtual domain.

19. A method according to claim 18 a plurality of virtual domains are generated at said step of dividing.

20. A method according to claim 18 or 19, wherein properties are assigned to the virtual domain or domains.

21. A method according to claim 20, wherein, in the case of a plurality of domains, properties are shared between the domains .

22. A method according to claim 20 or 21, wherein a plurality of properties is assigned to each virtual cell.

23. A method according to any of claims 18-22, wherein grid properties are visualised on a display of one. or more of said portable units.

24. A method according to any of claims 18-23, wherein one or more of said properties is/are shown on a display of one or more of said portable units.

25. A method according to any of claims 18-24, wherein the number of cells is changed when the dimensions of the virtual • domain are changed.

26. A computer system for dividing a physical domain into a plurality of virtual cells in a memory of the computer system, the system comprising, in the physical domain, a plurality of portable communication units, each portable communication unit being adapted to communicate, through wireless transmission, with another of said portable units and/or with a stationary communication device, the computer system further comprising:

- the number of cells into which the physical domain is to be divided, and/or

- the extent and/or location of the physical domain,

— a processor being programmed to divide, in response to the user input information, the physical domain into said plurality of cells and to store, in the memory, data representing each cell, said data including at least an identification and/or location of each cell.

27. A computer system for tracking a plurality of portable communication units in a physical domain, the system comprising said plurality of portable communication units and:

- a computer system according to claim 27,

- at least one transmitter for transmitting data from at least one of the portable units to another one of the portable units and/or to a stationary communication device, said data comprising information from which a physical position of said at least one portable unit may be derived,

- a^' processor being programmed to derive the position of said at least one portable unit and to determine in which one of said cells the portable unit is located.

28. Use of a system according to claim 28 for a game in which scores and/or properties are assigned to a plurality of players, each player carrying a portable communication unit, the score or property assigned to each player being dependent from the location of the player's portable units in relation to the cells.

29. A game system comprising a computer system according to claim 28, wherein the processor of the computer system is adapted to assign scores and/or properties to a plurality of players, each player carrying a portable communication unit, the score or property assigned to each player being dependent from the location of the player's portable units in relation to the cells.

30. A computer program product for dividing a physical domain into a plurality of virtual cells, the physical domain comprising a plurality of portable communication units, each portable communication unit being adapted to communicate, through wireless transmission, with another of said portable units and/or with a stationary communication device, the computer program product comprising:

- a first computer program segment for receiving user input .information comprising information about:

- the number of cells into which the physical domain is to be divided, and/or

- the extent and/or location of the physical domain,

31. A computer program system for tracking a plurality of portable communication units in a physical domain, the computer program product comprising:

- a computer program product according to claim 31 for dividing the physical domain into a plurality of virtual cells,

- first algorithms for transmitting data from at least one of the portable units to another one of the portable units and/or to a stationary communication device, said data comprising information from which a physical position of said at least one portable unit may be derived,

- second algorithms for deriving, by means of a computer system, the position of said at least one portable unit,

- third algorithms for determining in which one of said cells the portable unit is located.

32. A communication system for providing an alarm to a portable communication unit in accordance with position of said portable communication units in a grid, and comprising: a wireless communication network for interconnecting said portable communication units; a communication server for generating said alarm and adapted to monitor position of said portable communication units in said grid;

- a gateway connecting to said wireless communication network and adapted to communicate with said portable communication . units through said wireless communication network;

- a computer network for interconnecting said gateway and said communication server so as to enable said communication server to communicate with said gateway and transmit said alarm to said gateway; and wherein said communication server is adapted to establish said grid by dividing, in response to input information, a physical domain into a plurality of cells, and to establish said grid by storing, in a memory of said communication server, properties data representing each cell, and adapted to forward said alarm to said portable communication in accordance to specific data representing a cell in which said portable communication unit is positioned.

33. A communication server for providing an alarm to a portable communication unit in accordance with position of said portable communication unit in a grid, and comprising:

- a processor adapted to divide said grid, in response to input information, a physical domain into a plurality of cells;

- a memory adapted to store properties data representing each cell; and wherein said communication server is adapted to forward said alarm to said portable communication in accordance to specific properties data representing a cell in which said portable communication unit is positioned through a wireless communication network connecting to said portable communication unit, a gateway connecting to said wireless communication network, and a computer network for interconnecting said gateway and said communication server.

34. A method for providing an alarm to a portable communication units in accordance with position of said portable communication unit in a grid, and comprising:

- connecting a said portable communication unit with a communication server by means of a wireless communication network, a gateway, and a computer network; establishing said grid by dividing, in response to input information, a physical domain into a plurality of cells, and by storing properties data representing each cell of said plurality of cells; and

- forwarding said alarm to said portable communication unit in accordance to specific properties data associated with a cell in which said portable communication unit is positioned.