GB2389004A - A mobile electronic device having a rechargeable power source and means for disabling the device if placed in an alien recharger as it determines its location - Google Patents

Abstract

The present invention relates to a method of selectively disabling the operation of a mobile electronic device such as a mobile telephone, which has a rechargeable power source and a location determination system. The method comprises the steps of selectively identifying at least one home location of the electronic device and then activating the location determination system during a recharging operation of the device to determine a charging location, which charging location to be compared with the preferred home location and in the event that the charging location is different from the home location disabling the electronic device until such time that a deactivation code is inputted into the device. There is also provided a mobile electronic device, usually a mobile phone, having a rechargeable power source such as a battery, a location determination system and a memory for retaining a code indicative of the preferred home location of the device and further comprising a security mechanism which is activated to disable the electronic device in the event that the determined location of charging of that device is different from the home location.

Description

( 1 2389004

Security System for Mobile Electronic Equipment :, The present invention relates to mobile electronic devices having a rechargeable power source and means for determining location ot that device, and more particularly to a method and device for selectively disabling such equipment it its use is unauthorised thereby providing a theft deterrent device for mobile communications equipment.

1() The onset of mobile communication development, and in particular the increase in lightweight portable devices, particularly mobile phones, GPS (Global Positioning Satellite) systems, portable and laptop computers and a host of other electronic devices, has not only improved communications but created a number of 1: expensive articles which, due to their compact and lightweight design, are highly desirable lo thieves due to their ease of concealment and disposal. The subsequent increase in theft of such devices has now prompted both manufacturers and government bodies to seek improved means of preventing and deterring the theft of such portable equipment.

in the case of portable and laptop computers, such devices can be provided with appropriate password locks but quite often these must be manually input each time the computer is set down, hi order to "lock" the computer - an operation which is oltcn overlooked (either inadvertently or deliberately), by the user thereby making

the deterrent factor dependent on the actual owner of the device. By providing systems that automatically activate a password lock then this problem can be overcome but at the inconvenience of the user who may become frustrated at the continuous need to unlock their equipment, often voluntarily disabling this automatic lock function. The use of such password locks are thus ineffective as a theft deterrent system due to the inconvenience to the user often resulting in such systems being deactivated The mobile communications manufacturers have historically addressed the problem by attempting to render their phones and other devices useless to a thief or unauthorized user. Current systems involve locking such phones to their removable SIM card (Subscriber Identity Module) whereby the SIM card Pled number (Personal Identification Number also referred to as CHV1 - Card Holder Verification 1) can be enabled so that a particular phone with a predetermined 1. SIM card can be activated by the appropriate code. However, again many users are reluctant to be inconvenienced by the need of entering a Ply code each time they power up their mobile communication device, thereby negating the etfcctiveness of this security feature. Thus, whilst security systems are currently available for such electronic devices, they usually require a high intensity user 9() interaction making them undesirable and often unused thus rendering the security systems impotent as a large scale theft deterrent for this type of equipment.

( Therefore an object ot the present invention is to provide a method and device tor selectively disabling operation ot such mobile electronic devices which alleviates the atoren1entioned problems in a comparatively unobtrusive manner.

According to the present invention there is provided a method of selectively disabling operation or a mobile electronic device of the type having a rechargeable power source and a location determination system, such method comprising the steps of: selectively identifying at least one preferred home location of the electronic 1 0 crevice, activating the location determination system when a recharging operation of the device is being undertaken and determining the charging location, comparing the charging location with the preferred home location, and disabling the device if the determined location is different to the at least one 1: preferred home location.

In this manner, when the device is being recharged' the act of recharging can be used to automatically activate an appropriate system and/or software feature of the device for determine the relative location of the electronic device and, if it is 9() determined that such device is not in a pre-selected area, the device can be electronically or mechanically disabled until such time as the authorised user is able to override the disabling feature. This provides that should a mobile communication device be stolen it will be usable until such time that the device

! needs to he recharged whereby the act of recharging the device will automatically engage the security feature subsequently rendering the device worthless to an unauthorized user. This system will only require operator input in the event the security feature is invoked rattler than continuously being required to unlocl; the :' system by input ot an appropriate code.

Preterably, the step of identifying the at least one preferred home location will comprise allocating a first electronic code indicative of that at least one home location, wherein the step of determining the current charging; location will 1() comprise allocating a second electronic code indicative of the charging location, wherein these two electronic codes are subsequently compared. These electronic codes may be binary or alphanumeric or may be of other electronic form.

Usually, the recharging operation comprises recharging a power source, such as a 15 battery, as it remains attached to the device, thereby allowing the method to be initiated as the electronic device detects a gradual increase in its popover source.

Alternatively, the recharging operation may comprise removing and replacing the power source, for example in the event of the device using non rechargeable batteries or rechargeable batteries that must be recharged remote from the device 2() itself. As such, the term recharging is intended to cover all aspects of increasing' the power source available to the device inclusive of simply changing discharged batteries with fully charged or partialiv charged batteries, or even connecting the

device to a power source such as a mains aclaptor. Devices employing this method will thus be configured to detect an increase in their power source.

In one embodiment of the present invention, the step of disabling the device comprises preventing the recharging operation itself, thus eventually rendering the device inoperable as having no power. Such a system, however, is only feasible in devices where it is not possible to replace the power source or where replacement power sources are not readily find inexpensively available' or for devices where the removable power source is not capable of being readily recharged remote from 10 the device.

Alternatively, the step of disabling the device may comprise electronically or mechanically locking Operation of the device, either by utilising a conventional security programme embedded in the devices electronic memory which will I À prevent its operation until an override code is entered, or alternatively by activating a mechanical lock preventing operation of some or all of the mechanical input means (such as switches) on these types of devices. Electronically locking the device includes the use of software to restrict all or some functions of the dev ice.

_() Preferably. where the method employs the step of electronically locking the device, such a process may be reversible by input of a preselected cancel instruction, usually be in the form of an input code entered through a device

keypad. However, the cancel instruction may also or alternatively comprise a mechanical operation such as the insertion of a mechanical l; ey into the device and operation thereof.

Furthermore, the input of such cancel instructions may also,.selectively, be employed to reallocate the determined charging location as either the or one of the preferred home locations. This allows for the recharging operation to be carried out by the authorized user in alternative locations upon entry of appropriate authorization and to selectively determine whether that alternative charging 1() location is to become a regular location, for example if the user wishes to have the option of recharging the device at both a residential home and their place of employment. To this end, it is envisaged that the method may further employ the allocation of several pre-selected home locations, each of which would then be compared to the detected charging location.

Preferably, the location determination system will use existing mobile communications technology of at least one ot Cell Identity, Location Area Code.

Mobile Country G'dc Mobile Network Code or Network Measurement to identify the determined charging location. Such systems and technology are readily 9() available and currently employed in the majority of mobile telecommunications devices, being able to determine their location relative to an array of appropriate transmitters to identify the device location as being within a pre-determined area determined by the mobile communications companies and often referred to as

( cells. Advantageously, the location determination system will use a combination I ot two or more of these existing location determination systems in identifying the determined char=,h, location.

Alternatively, the method is equally employable whereby the location determination system determines the charging location by the detection and analysis ot signals from global position satellites, by use of conventional GPS systems. 1() Furthermore. this method itself may be selectively deactivated by an authorised user upon appropriate operation ot a pre-selected key which key may comprise input of a pre-determined electronic deactivation code or, alternatively, a mechanical key. In this manner should the operator wish to recharge the device I at a plurality of locations, he may temporarily or permanently disable the optional 1: security system according to the present invention.

In addition, whilst it is possible that the selective disabling of the device could disable all functions of the device? it is often desirable that the disabling functions arc selective so that only a pre-selected series of functions of the device are 2t) actually disabled. This would be beneficial in at least allowing override codes to be continued to be input into the device or, in the event of a mobile communications device, communication to be retained for emergency use such as calling conventional emergency numbers.

I Preferably, this method is intended for use on mobile communications devices such as motile phones, as they already incorporate appropriate location determination systems.

- According to a further aspect of the present invention, there ix also provided a mobile electronic device having a rechargeable power source, a location determination system, a memory system for retaining a code indicative of a preferred home location for the device and a security mechanism for selectively 1() disabling the device upon detemmination of a pre-selected signal, wherein the location determination system is activated during a recharging operation of the power.source to produce a charging location code indicative of the device charging location, wherein the security mechanism comprises a comparator circuit tor comparing the charging location code with the home location code and issuing 1> the pre-selected signal in the event that the charging location code is different to the home location code.

Preferably the location determination system will comprise at least one of a Cell Identity system, a Location Area Code identification system, a Mobile Country 2() Code identification system, a Mobile Network Code identification system or a Network Measurement system to identify the determined location.

Advantageously, the location detemnination system will employ a combination of

it) two or more ot such existing identification systems. Alternatively, the location determination system may comprise a GPS System.

The device will also usually comprise a keypad and a security mechanism override circuit responsive to a predetermined code entered on the keypad to reset the security mechanism by the authorized user.

Preferably such a device will comprises a mobile phone.

1() There w ill now be described, by way of example only, a preferred embodiment of the present invention with reference to the accompanying drawing: Figure I is a flow chart illustrating a method of selectively disabling a mobile phone according to the present invention.

Mobile phones, being, lightweight and compact, are highly susceptible to theft. To address this problem in the past such phones were originally provided with Securilv software allowing, the authorised user to input a password code which would activate or deactivate the phone. Additionally, with the introduction of

9() removable SIM cards and the ability for a user to transfer their SIM card from one phone to another phone (the SIM card identifying the user and their particular system requirements) appropriate security systems were developed to provide each SIM card with a unique PIN number (CHVlCard Holder Verification I

I() number) which was embedded in the card itself. Mobile phones, each time when powered up, are pre-programmed to prompt the user to enter the correct PIN (CHV I) number to be verified against the SIM. The drawback of such a simple system is, firstly, the inconvenience to the authorized user who is repeatedly required to enter their authorization code (and subsequently is enticed to disable such a security feature) and, secondly, since the required PIN number is simply to provicie authorized access to the SIM card, in stolen phones the SIM card is simply rcmovel and rephaced with a new, legally purchased SIM card with a new CHV1 PIN number.

1() Additional developments have attempted to address this problem by subsequently introducing software developments allowing the phones themselves to be selectively locked to appropriate SIM cards whereby the user (or manufacturer) is able, upon insertion of the appropriate SIM card into an appropriate phone, to 1: activate appropriate code recognition software within the phone so that phone is only operable with that appropriate SIM carci. Whilst this feature is of considerable use as a deterrent to theft, it still requires that the primary operation ol the CHVI recognition software remain active so as to continually require (on powering up) the authoriseci user to input the CHV I PIN number to ensure that the 9() phone has not been stolen. If the CHVI recognition feature is disabled and the phone subsequently stolen, the phone remains operable with the original SIM

t 1 Thcretore. in order tat he used effectively existing security systems will still require the user to input the appropriate CHV1 Pli\' number each time the mobile phone is powered up, which, as previously described, most end users are reluctant to do and thus the security system tends to be ignored (and deactivated) thereby lailin=, to provide a universal deterrent to theft Theretore, as with the majority of existing security systems adopted by the mobile phone manufacturers. these systems all involve a high degree of interaction and password input by the end user who is reluctant to do so, often deliberately 1() choosing lo de-activ. ite such security systems thereby negating their efficiency as a theft deterrent The current invention overcomes the problems of existing security systems tor mobile communication devices by providing a semiautomated security feature 1: which is capable of partialiv or wholly disabling the mobile phone without the need for interaction and continuous re-setting of the security system by the authorized user It is well recognized that conventional mobile phones comprise a rechargeable (1 power source in the form of a rechargeable battery. As an alternative to rechargeable batteries, some mobile phones use and provide for the replacement ot conventional batteries

( In the event of rechargeable batteries the recharging operation can occur with the b,Jttcrv maintained in engagement with the phone or with the battery remote from the phone ie. with a dual battery system one battery can be recharged whilst a secon;i ballerv is in use anti the b, altcry is then simply swapped over when the phone requires recharging.

In addition, battery life technology for mobile phones, whilst having increased signit'icantly over the last few years, still even for the best commercially available rechargeable batteries necessitates recharging within a maximum period of 1() approximately two weeks, the majority of batteries requiring recharging within at least seven days. Thus7 the recharging operation is a highly cyclic procedure which the authorised user must undertake on a regular basis. Furthermore, the increase in charge in the battery, either by in-situ recharging or by replacing the discharged battery \\,ith a t'reshly charged battery, is readily detectable by the 1: mobile phone itself' which is pre-programmed to monitor and display battery charge. The current invention therefore utilises this cyclic procedure to automatically activate a security mechanism within the phone itself to determine whether or not 7() the phone is retained by the authorised user.

In particular, mobile phones are often referred to as cellular phones due to the t'act that the mobile communication networks operate on a cell basis. Each service

1' provider has developed J nctworl; of appropriate communication base stations and transmitters around their particular territory dividing the territory into a number of areas serviced by each particular base station which are referred to as cells (hence adoption of the term "cellular network". The cells vary in size and shape and are dependent on the envisaged users within a particular area and the number ot base stations and transmitters that are therefore allocated to a particular area. For example in a major city or town a high concentration ot transmitters and base stations are employed due to the high intensity of use ot the mobile communication network. thereby creating relatively small cells as compared to i 1) rural areas whereby the users requiring operation of that mobile communication network are considerably reduced thus reducing the intensity of use on each base station. It is well understood within the field ot mobile communications, that the

1: authorised user uses these devices whilst mobile, and often whilst moving; from one particular cell to another. Therefore, in order for the mobile phone to operate correctly and efficiently, it is important that the phone understands where it currently is in relation to the array of cells and thus periodically, and automatically, operates appropriate software to detect and communicate with the 2() nearest base station and transmitter in order to identify which particular cell the user is currently in. Thus when the user wishes to operate the phone, the phone knows which transmitter it is trying to connect with. Each particular cell is allocated an appropriate identification code recognised by the phone.

Conventionally, mobile phones are able to identify their locations within one or more ccilular networks by using one or more of the standard location icicntitication systems which are able to determine and identity trom the array of local transmitters one of a number ot cell identification codes (Cell Identity Codes), in particular these include Cell Identity, Location Area Code, Mobile Country Code and Mobile Network Code. The exact electronic systems and software conventionally employed in mobile phones, and the methods employed to letcrminc these cell identification codes are well understood within the mobile 1() phone industry and are standard features employed in all mobile phones (due to the need for the phones themselves to continually monitor their cell location for efficient operation). As such operation of such systems and use of these identification codes will not be described in detail herein but is considered to be common practice within the mobile phone industry and readily incorporated into 1: the current invention The important feature is that the phones are able to automatically determine their relevant location within one or more cell networl;s lay reference to and identification ot one or more such codes. It is also important to note that operation of the current invention is not dependent on identification of a geographical location but is able to operate by determination of a location within a 2() ceil nctworl;.

The present invention now marries the two procedures of recharging the power source of the mobile phone and its continuous automatic location determination to

( provide security crevice which is automatically activated without the need of operator input In particular. a mobile phone is provided with appropriate circuitry to detect an increase ha charge in its power source or battery either by determining a recharging operation of the battery when connected to the mobile phone or detecting when a battery has been replaced with an alternative battery having a higher energy content On detection of this increase in power, the phone then automatically detects its particular cell location by determining one or more of the Cell Identity Codes using one or more conventional systems as discussed above Whilst only one Cell Identity Code would be sufficient for use in the 1() current hvenlion' the current invention may advantageously detect two dit't'erent Cell Identits Codes to operate a cross reference" to correctly determine its

location The mobile phone, having determined this charging location within the cell network, is also provided with a comparator circuit ot'conventional design and/or appropriate software which will then compare the charging location against one or a plurality of pre- determined acceptable charging locations for the mobile phone In the event that the current charging location is determined not to be comparable with a pre-selected acceptable charging location, the comparator circuit (or 9(] appropriate software) can then activate a disabling device, which can be either electronic, sot'tware or mechanical, to prevent further operation of the phone. In the pret'erred embodiment ot'the current invention this disabling device will utilise standard password lock technology, automatically activating a software lock in the

phone preventing some or all communication operations of the phone until the correct password code is entered. Such disabling systems usually disable all communications except connection to the emergency services. However, the throne could simply be barred lrom allowing outgoing calls or any one of a :' plurality of selective disabling operations.

In particular, the phone is pre-pro;,rammed so that during the first recharging operation the phone will detect the charging operation location, as described above, and the authorised user will be prompted to acknowledge whether that 1() particular charging location is to be entered as the or one of the preferred home locations of the phone. This charging location will usually either be a place of residence or a place of work of the phone owner and can, in fact, be set for both.

Once the user identifies the home location to the mobile phone, the mobile phone I then electronically records the appropriate Cell Identity Code (or codes) of the particular cell location in which it is being charged as the (or one of the) home location. Each time the mobile phone is then subsequently recharged it will automatically determine its charging location and compare that charging location against the home charging location to determine whether this is an acceptable 2() charging location.

In the event that the mobile phone is being charged in a different cell to that of the home location, the disabling system will be engaged preventing full or partial

( operation of the mobile phone. In particular the disabling system will also prevent continued recharging of the phone once activated.

In addition to disabling the mobile phone, the user is also al:fordetl the opportunity to enter an appropriate override code to re-enable the phone operation. Since it is cc,mmonplace tor mobile phone users to re- charge their phone at a base station at a pre-determined location (normally their home address) it is also commonplace to require recharging at Iternative locations outside of their particular home cell (for example when travelling on business or on holiday). In this case, the mobile 1() phone will notify the user of the need to enter an appropriate override code in order to be reactivated and to allow continuation of the recharging operation. The phone is also programmed to allow the authofised user to alternatively input the effective override code prior to the charging operation, thereby selectively deactivating this described security feature in order to prevent its disabling the 1: phone during the subsequent recharting operation. This override feature is particulariv beneficial whereby the mobile was being recharged in a motor vehicle which subsequentiv travels through a plurality or different cells.

It will be appreciated that an enhanced variation of this security system provides 2() for the selective de-activation of this security feature to be limited to one recharging cycle. Once de-activated the security system will not be invoked by the; phone during the next re-charging operation. Subsequently, on detecting of the next plus one recharging; operation, the programmed system will then,

automatically, again determine the charging location and compare such charging location with the home charging location.s as previously described. This again obviates user input to reactivate the security feature when they return to their normal recharging cell.

- To prevent an unauthorised user or thief from getting around this security system by simply detaching the battery and charging it separately, the mobile phone will be set to simply detect an increase in battery charge with or without a charger connected and to activate the disabling mechanism in either scenario.

1() In its most basic form, operation of the security system of the current invention is shown in Figure 1, whereUv the mobile phone itself continuously monitors its power source by use ot'a conventional charge detection system to determine whether or not there is an increase in charge at any time (1()). If no charge is 1 detected then the charging detection system 1() simply resets. However, it an increase in charge is detected, the system then initiates a charging location determination step 2() to identify the particular cell in which charging is occurring, each cell having a unique cell identification number. This unique cell identification number is then compared by conventional comparator circuit 3t] 2() with at least one pre-selected home location cell identification number and, if these are the same, the security system simply resets and continues to monitor whether the mobile phone is being recharged in the home cell. In the event, at step 3(), that the charging location has been determined to be different from the (or

one of a plurality) ot home location then the phone is disabled in a manner pre-

selccted by the manufacturer- step 4() (to be either completely or partially disabled). :> 11 the mobile phone is being recharged in a vehicle travelling from one cell to another then the chartYin, location code determined at step 90 may change during the whole charging operation and thus it is beneficial to continuously monitor the charging location during the recharging operation as shown in Figure l.

1() The major benefits of the current invention is that the legitimate user will not be Obliged to undertake and additional interactive operation whatsoever in the event that charging occurs at the home location. The only active user input that is required is to de-activate the disabling of the mobile phone in the event that char ring occurs outside of the normal home location, either prior to the recharging l: or during the recharging operation. However, user input is considerably reduced and this security system does not need to be actively set when the user is not using thephone. Also, since recharging is a regular activity, should a phone be stolen it will only be a matter of days before the security system is activated. It is also highly unlikely that a thief will be able to determine the exact cell location ot the 9() home location with no means ol determination from the phone itself where such home location is, thus matting the system relatively foolproof.

2() In addition in the event that the thief happens to live within the same cell location equating to the home location, it is likely that at least one recharging operation will eventually occur at a clit'ferent cell location (t'or the same reason as a Ic=,itimatc user will have requirements to recharge away from his home location) Since the security system is continuously activated it will only require one attempt to recharge the mobile phone remote from the home location to activate the security system to disable the phone Once the phone has been disabled the thief' will be then be unable to override the security feature, rendering the phone useless. It) Additional benefits of the current invention is that there is no requirement for modification whatsoever to either the charger or the batteries and the invention can be simply implemented by appropriate software modifications in the phone itsel t Furthermore. since the phone itself' is disabled, even should a thief try to replace the SIM card aficr the phone has been disabled, the addition of a new SIM card will not serve to override the security system integrated in the phone software itselt'and the phone will remain disabled Whilst it is possible that the thief could 2() then attempt to use the SIM card in a different phone, the mobile phone service providers are then able to blocl; operation of that SIM card and associated number, thus rendering the SIM card unusable

Thc foregoing description provides for the basic concept of the current invention

which is a means, determined by a recharging operation of a mobile phone, to automatically determine the charging location ot the phone and to selectively disalllc it if.such phone is not in a pre-selected location.

- However'there are many variants to this basic embodiment that are readily employable and further enhance the security benefits of this new invention. In particular, since the security system is simply effected by appropriate software additions to conventional mobile phones. it is not only relatively inexpensive to implement, but it is very.straightforwarcl to activate by the authorised user, whereby upon the first charging operation the user is able to identify that charging location as the home location. Alternatively, in the event that the first charging location is not the home location (cg. first charged in a shop), further software provisions may be employed to provide the user with the option to delay recording 1:, a first determined charging location as the home location as appropriate.

Software nodifications can also be provided to allow the authorised user, on input ol appropriate authorization codes, to add and/or change preferred home location settings within the phone to accommodate variations in lifestyle, such as the need A) to recharge at several different locations (particularly beneficial if the user were located near a cell boundary). Additionally,.since it is possible to determine more than one Cell Identity Code, it may be possible to set the security system to activate only if more than one of a plurality of determined codes do not match the

?Q - - homc location codes. This could then compensate for difficulties and fluctuation ot cell determin.,tion at or near cell boundaries.

Further modit'ications to the invention that are readily envisaged would be that should the user be recharging the mobile phone remote from his home location the phone may then prompt the entry of an appropriate authorization code to allow charging to continue without disabling the phone, and could also be used to request that the authorised user, again on appropriate entry of an authorization code, confirm whether the currently detected charging location is to be added to 1() the preferred home charging, location directory for future reference.

Additionally, whilst the pret'erred invention described above resulted in an electronic disabling of a mobile phone, which would employ appropriate software, a mechanical restraint could also be engaged to prevent physical activation of the 1:, keys on the mobile phone if so required. Alternatively, once the disabling feature has been activated, the mobile phone may require a mechanical key to override this disabled function. Again, this override 'Key could be used at any time to disable the security t'eature during, for example, use and recharging Blithe phone he a car.

_ () Still further, whilst the preferred invention discusses the use of conventional location determination systems used in mobile phones, it is also possible that conventional GPS (Global Positioning Satellite) systems could also be used to

identify both the home location and the charging location. This would obviously allow t'or a much more specitic utilization ot'the present invention whereby use of GPS systems enable the home location to be restricted to within several yards of an ideal recharging position as opposed to the home location being restricted (o a relatively large single communication cell in the preferred embodiment.

However, the use of a GPS system would require additional hardware as well as software modifications to the mobile communications devices. Nevertheless, use ot'GPS systems would be attractive for very expensive electronic portable; 1() equipment and again would be activated during the recharging operation thereof.

One of the major benefits of this particular type of system is its deterrent "'actor. If a thiet'were to be believe that a mobile phone would be rendered useless within t several days once its current battery charge expired. then the desire to steal such a 1: product is greatly diminished. i However, in order to prevent the thief from physically threatening the authorized user to input the overricte code during the actual theft itself, the system could he further modified so that the override code could only be entered on during or 3() tallowing detection of a charging operation in an location different to a home charging location. In this way' in order for the thief to force the authorized user to deactivate the security system. the thief would actually require a charger to be connected to the phone at that time ot'the theft, which is highly unlikely in the r T

?4 - event that most ot these thefts occur remote from the home location. In this manner, the system provides a security device of which the thief will be unaware of until such time as he tries to recharge it.

:, One further alternative to the present invention is that instead of the mobile phone teeing disabled as a result ot this security system, it may simply require that the recharging operation its prevented, which may have particular benefit in the event that the rechargeable battery is not replaceable..

1() Finally, whilst the preferred embodiment has been described with reference to mobile telephones, it will be appreciated that any form of mobile electronic equipment having a rechargeable power source could benefit from the security system described herein by the provision of appropriate hardware and software to provide for location determination either through use of conventional mobile 1:' phone technology or through taking advantage of the GPS systems commercially avai table.

Claims (1)

1. - Minims A method of selectively disabling operation of a mobile

   electronic device having a rechargeable power source and a location determination system comprising the steps of a) selectively identifying at least one preferred home location of.said electronic device; b) activating said location determination system when a recharging operation of the device is being undertaken and determining said 1() charting location; c) comparing said charging location with said preferred home location; and d) disabling said device if said detemmined location is different to said at least one preferred home location.

   A method as claimed in claim I wherein the step of identifying said at least one home location comprises allocating a first electronic code indicative of Saifi at least one home location and said step of determining said charging location comprises allocating a second electronic code 2() indicative of said charging location, with said comparing step comprising comparison of said two electronic codes.

   ( Aft 2. A method as claimed in claim 2 wherein said electronic codes are binary or alphanumeric. 4. A method as claimed in any one of the preceding claims wherein said recharging operation comprises recharging a power source attached to said device. I. A method as claimed in any one of claims 1 to 3 wherein said recharging operation comprises removing and replacing the power source.

   1() (. A method as claimed in any one of claims 1 or claim 4 wherein the step of disabling the device comprises preventing said recharging operation.

   7. A method as claimed in any one of the preceding claims wherein the step 1: of disabling said device comprises electronically locking the operation of the device.

   8. A method as claimed in any one of the preceding claims wherein the step ot disabling said device comprises mechanically preventing operation ot 2() the dev ice.

   9. A method as claimed in claim 7 wherein the step of electronically locking the device is reversible by input of a pre-selected cancel instruction.

   A method as claimed in claim 9 wherein input of said cancel instruction reallocates said one charging location as said at least one preferred home location. - 11. A method as claimed in any one of the preceding claims having a plurality of preferred home locations and said charging location is compared with each of.said plurality of home locations.

   I2. A method as claimed in any one of the preceding claims wherein the location determination system uses mobile communications technology to determine at least one of Cell Identity, Location Area Code, Mobile Country Code Mobile Networl; Code or Network Measurement results to identify the determined charging location.

   13. A method as claimed in any one of claims I to 9 wherein the location determination system determines said charging location by the detection and analysis of signals trom Global Positioning Satellites. i 0() 14. A method as claimed in any one of the preceding claims which is selectively deactivated by operation of a pre-selected key.

   15. A method as claimed in claim 19 wherein operation of a pre-selected key comprises input of a predetermined electronic deactivation code.

   I6. A method as claimed in any one of the preceding claims wherein the step 5 ol selectively disabling said device comprises partial disabling of pre selected functions of said device.

   17. A method of selectively disabling operation of a mobile phone according to any one of the preceding claims.

   1() IS. A mobile electronic device having a rechargeable power source, a location determination system, a memory system for retaining a code indicative of a preferred home location for said device and a security mechanism for selectively disabling, said device upon determination of pre-selectec3 signal, l: wherein said location determination system is activated during a recharging operation of said power source to produce a charging location code indicative ot said device charging location, wherein said security mechanism comprises a comparator circuit for comparing said charging location code with said home location code and issuing said pre-selected 90 signal in the event that the charging location code is different to said home location code.

   19. A device as claimed in claim 18 wherein said location determination system will comprise at least one of a Cell Identity system, a Location Area Code identification system, a Mobile Country Code identification system, a Mobile Network Code identification system or a Network Measurement system to identify the determined 3(). A device as claimed in claim 18 or claim 19 further comprising a keypad and a security mechanism override circuit responsive to a predetermined code entered on said keypad to reset said security mechanism.

   1() 21. A device as claimed in any one of claims 18 to 20 comprising a mobile phone. 2. A method of selectively disabling operation of a mobile electronic device 1> substantially as herein described with reference to the accompanying figures. 93. A mobile electronic device substantially as herein described with reference to the accompanying fixtures.

   _()