GB2361150A

GB2361150A - Management of communications for a dual mode mobile telephone

Info

Publication number: GB2361150A
Application number: GB0025768A
Authority: GB
Inventors: Laurent Lejay
Original assignee: Sagem SA
Current assignee: Sagem SA
Priority date: 1999-10-21
Filing date: 2000-10-20
Publication date: 2001-10-10
Also published as: FR2800226A1; FR2800226B1; DE10051876A1; GB0025768D0

Abstract

Managing calls by a dual mode mobile/cordless phone, wherein the presence of the phone within a determined area is detected, respective links are set up between the cordless base and the mobile network, and the mobile network and the mobile phone whereby the presence of the phone in the area is confirmed, a database is updated to indicate the presence of the phone and calls are managed according to the content of the database. The dual modes are cordless DECT and GSM cellular. When the cordless base station detects the presence of the mobile phone within its area, a siganlling call is sent over the fixed line network, to the cellular provider, then an RF link is set up between the cellular base station and the mobile phone which confirms the location of the mobile phone. A database in the cellular system is updated to indicate the location, such that cellular calls to the mobile phone can be redirected to the cordless base, as long as the mobile is within the cordless base area.

Description

1 2361150 METHOD TO DETECT THE POSITION OF A MOBILE TELEPHONE An object of

the invention is a method to detect the position of a

mobile telephone. The field of the invention is that of mobile telephony.

Through its implementation, the field of the invention is also that of cordless domestic telephony. The aim of the invention is to provide information to an operator about the presence of a subscriber in possession of a mobile telephone in a place which he designates as his. home when taking out his phone subscription. His domestic is located at the centre of an area known as a domestic area. With this information, the operator can adapt the subscription of the subscriber. This adaptation Tay consist either of a modification ofthe connection fee rates or a re-directing of his mobile telephone line. It is therefore important that this localisation should be reliable.

In the prior art, there are several known systems for the localising of a mobile telephone. A first technique for localising a mobile telephone uses radio direction-finding or radiogoniometry. Indeed a mobile telephone, when it is in a given place, picks up signals from several base stations. These base stations are at fixed locations and af^e.. capable of measuring the power of the signal that they receive from the mobile telephone. From this power, they can deduce the distance at which the mobile telephone is located.

Thus, three base stations that are not aligned can be used to locate a mobile telephone by triangulation. However, this method is imprecise because it does not take account of the obstacles that lie between the mobile telephone and a base station. Indeed, a wall for example may significantly reduce the power of the signal received even if the telephone is not physically distant from the base station. The localisation thus obtained is therefore not sufficiently precise for the a pplications envisaged.

In a second approach, the mobile telephone is provided with a small radio device. The centre of the domestic area is then equipped with another radio device. The two radio devices thus installed can therefore communicate with each other and identify themselves to each other. The two radio devices have an identical transmission range. This range defines the size of the domestic area which is then approximately a circle with a radius equal to the range of the radio devices. In this approach, as soon as one radio device detects the presence of the other, the mobile telephone 1 2 informs the operator that it is in his domestic area. This approach has the advantage of being very precise but it is not reliable at all. Indeed, it is quite possible to simulate the working of this second radio device or quite simply moe it to another place and thus seek to derive benefit from several domestic areas. In this case unfortunately, the advantages. attributed to the domestic area, and even the re-directing of the line, will be achieved in a configuration corresponding to the subscription but not corresponding to the other place in which the radio device is located. Furthermore, there is a problem of cost related to the implementation of this approach. Indeed, it is necessary to manufacture two radios that have no use other than to localise the mobile telephone.

A third approach consists of the detection' of the presence of the mobile telephone when this mobile telephone is placed on its battery support. This means that the mobility of the mobile telephone is highly reduced or even eliminated, if it is an office battery-charger. This approach can be envisaged only in the context of a re-directing of the mobile telephone to the domestic line. Here again, the problem of reliability arises. For, it is quite possible to move the recharging devide of the mobile telephone.

In a fourth approach, the domestic area by means of a base station with a limited range. This approach runs up against problems of deployment which lead to absolutely over-priced solutions.

The invention resolves these problems by making use, for detection or validation, of a cabled domestic line that can be neither moved nor simulated. For the localising, the invention makes use of a cordless domestic telephony base, of the DECT type especially, and a mobile telephone provided with a module communicating with a public base and with this cordless domestic telephony base, which therefore is of the DECT type in this case. Thus a dialogue may be set up between the mobile telephone and the cordless telephony base, between the cordless telephony base and a public telephone operator and between the mobile telephone and this operator. According to the invention, the cordless telephony base is capable of detecting the presence of a two-mode mobile telephone and of calling the operator through the domestic cabled line. The operator can then identify the origin and nature of the call and make sure that the mobile telephone is actually in the place where it should be, namely in a stated 3 domestic area. As a security measure, the operator can then get connected with the mobile telephone so that it confirms that he is really connected to the right cordless telephony base. In this configuration, the mobile telephone can'then be used either as a mobile telephone or as a cordless telephone depending especially on the predefined configuration, An object of the invention therefore is a method for the management of communications exchanged with a two-mo ' de telephone capable of working as a mobile telephone, especially of the GSM type and as a cordless domestic telephone especially of the DECT type, wherein:

- the presence of the two-mode telephone is detected when the two mode telephone has sufficiently approached a cordless domestic telephony base whose range defines a domestic area, characterised in that:

- from the cordless domestic telephony base, through a fixed telephony link, a signalling call is sent to a central circuit of a mobile telephony operator with whom a user of the two-mode telephone is a subscriber, to report that the two-mode telephone is in the domestic area, an RF link is set up between the'iQvo-mode telephone and a mobile telephony base station and in confirmation, between this central circuit and this two-mode telephone, a transmission is made of an identification of this domestic area, resulting from a signalling communication on this RF link, - a database, indicating the confirmed presence or absence of the two-mode telephone in the domestic area, is updated, - the communications exchanged are managed as a function of this updated database.

The invention will be understood more clearly from the following description and the appended figures. These figures are given purely by way of an indication and in no way restrict the scope of the invention. Of these figures:

- Figure 1 illustrates means useful for the implementation of the method according to the invention; - Figure 2 illustrates steps of the method according to the invention.

Figure 1 shows a mobile telephone 100 located in a room 101 of a dwelling 102. The telephone 100 is a two-mode telephone. In other words it can communicate according to two standards. The main difference between is the two standards is that one of them is for public use and the other for domestic use. Figure 1, to this end, shows that the telephone 100 can be connected by an RF link to a public mobile telephony base station 103. In the ' example of Figure 1, this station 103 is a GSM type station but it could equally well be a station using the DCS or PCS standard or any other standard of public mobile telephony existing anywhere in the world. The base station 103 can be connected with any user who has subscribed to a mobile telephony contract with the operator managing the station 103. The station 103 is a public station.

Furthermore, the telephone 100 can be connected to a cordless domestic telephony base 104. The base 104 is! for example located in another room of the dwelling 102. In the example of Figure 1, the base 104 is a base of the DECT type. This is a digital connection standard but analog standards or other digital standards could equally well be used. The base 104 may be capable of managing a certain number of telephone handsets.

In order that it may recognise telephone handsets, they must be matched with the base. In other words, the user of the base 104 should declare his telephone handset or handsets to the baM 104. In the invention, the two mode telephone 100 is herein both a GSM type mobile telephone and a DECT type telephone handset.

Figure 1 shows that the telephone 100 comprises a microprocessor controlled by instruction codes contained in a memory 106. The microprocessor 105 and the memory 106 are connected together by a bus 107. The memory 106 also has areas known as working areas used by the microprocessor to perform its communications activity. This activity incorporates the composition of the messages that the telephone 100 sends either to the station 103 or to the base 104. If the microprocessor 105 seeks to send a message to the base 104, the telephone 100 composes these messages and can store them in the memory 106, and transmit them to a radioelectrical module DECT 108. The module 108 is connected to the bus 107. The module 108 is also connected to an antenna 109. When the module 108 receives information to be transmitted from the microprocessor, it converts them into analog signals that it sends to the antenna 109 which in turn broadcasts them. If the telephone 100 is close enough to the base 104, the base receives these messages. In order that the base 104 may accept 1 the information coming from the telephone 100, this base 104 and the telephone 100 should be matched. The matching procedures are known, especially for DECT type instruments.

1 When the telephone 100 wishes to communicate with the station 103, the microprocessor 105 composes a message that it sends through the bus 107 to a GSM module 110. The GSM module 110 is also connected to an antenna 111. When it receives information elements to be transmitted, the module 110 converts them into analog signals and sends them to the antenna 111 which in turn broadcasts them. These analog and GSM information elements that are broadcast will then be picked up by the station 103.

The connections set up by the telephone 100 respectively with the base 104 and the station 103 are RF connections and are the connections 112 and 113 respectively. The communications from the station 103 to the is telephone 100 and from the base 104 to the telephone 100 are made in known ways and are described by standards implemented for these communications. The communications between the telephone 100 and the base 104 or between the telephone 100"'a'-nd the station 103 are generally encrypted. The aim of this encryption is to reinforce the security and therefore the validity of the localisation. In practice, the encryption takes place when the messages to be transmitted are being encoded. The decryption takes place upon the reception of a message.

The station 103 is connected through a network 114 to another station 115. The nature of the network 114 may be varied and may contain cable and RF connections. This makes no difference to the invention. The station in turn is connected to a central circuit 116. It may be noted that the network 114 may very well be directly connected to the central circuit 116.

The station 115 is therefore connected by an RF link through an antenna 117 to the central circuit 116. The antenna 117 in turn is connected to a GSM module 118 of the central circuit 116. The nature of the module 118 is left to the choice of a public mobile telephony operator who manages the central circuit 116. It may indeed be a DCS module or a module according to any other mobile telephony standard. Should the network 114 be directly connected to the central circuit 116, the module 118 may equallywell be only 6 - 1 6 a simple digital interface between the central circuit 116 and the network 114.

The base 104 is connected to a domestic telephony wall socket 119. The; socket 119 in turn is connected by a cable connection to a branch exchange 120 of a switched telephone network. The branch exchange 120 may be connected through a network 121 to another branch exchange 122. This other branch exchange 122 in turn may be connected to the central circuit 116 through a modem 123. In one variant, it may be envisaged to directly connect the network 121 to the central circuit 116. In this case, the modem module 123 is a simple digital or analog interface with the network 121 and the central circuit 116. As the case may lpe, the modules 123 and 118 are connected to a bus 124 of the central circuit 116.

The central circuit 116 also has, connected to the bus 124, a microprocessor 125, a program memory 126 and a data memory 127. Instruction codes contained in the memory 126 command the microprocessor 125. The data memory 127 is structured as a database in rows and columns. Each row corresponds to a subscriber and each column corresponds for example to a partic ul r type of information on this subscriber. This structure is an example. Indeed, the presently used databases are multitable bases and may be easily used within the context of the invention. Among the information elements contained in the columns, there are, successively, a subscriber cable line identifier called NDECT, a mobile telephony subscription identifier called SIM and an indicator indicating that the mobile telephone is or is not in the domestic area. This indicator is called DOM. In the example, the indicator DOM is at 0 when the mobile telephone is not in its domestic area, and it is at 1 when the mobile telephone is in its domestic area.

The central circuit 116 is controlled by a mobile telephony operator but it could also be controlled by a fixed telephony operator. This operator therefore has access to information contained in the memory 127. Through this access, he can know if the mobile telephone that has taken a subscription with him is in his domestic area or not. If the mobile telephone is located in his domestic area, i.e. if the indicator DOM in the line corresponding to the subscriber is at 1, then the operator may, for example, decide to reduce the cost of the telephone call units for this subscriber. In 7 this case, the operator may for example agree to invoice a call exchanged with a mobile telephone at the cost of a cable communication. Indeed, when the subscriber is at home, it comes to the same for him, financially, to use his ow mobile telephone or his domestic line. With the option chosen, the user will at least have two lines, a mobile telephone line and a domestic telephone line.

Figure 2 shows a preliminary step 201 for the detection of the presence of the mobile telephone in the domestic area. In the step 201, the base 104 sends, for example at regular intervals, a message representing a question to the telephones or telephone handsets that are matched with it.

The purpose of this question is to find out if a 'mobile telephone 100 is i present in the domestic area. This message has an identifier of the telephone or telephone handset. In order that there may be a detection, there should therefore be prior matching. This matching consists of an exchange of information between the telephone 100 and the base 104. The telephone 100 gives the identifier to the base 104 which can then communicate with it. Similarly the base 104 may give the telephone 100 an identifier of itself. These identifiers may'le series numbers, for example, because these. numbers are unique.

When the mobile telephone 100 receives and is capable of recognising the message, it means that it has come sufficiently close to the base 104. In practice, the DECT type bases may have a range of about 300 metres. This range, which herein has a radius of 300 metres, defines the domestic area. When the mobile telephone 100 receives the question, it responds positively to the base 104. If it does not receive the question, a sequence of programmes provides for the message to be sent to it periodically.

In a first variant of the invention, and in the event of reception, the invention passes to the step 202 where the base 104 calls the mobile jo telephony operator. In the step 202, the base 104 sends a call to the central circuit 116. This call is conveyed by the switched telephone network 121.

The call is conveyed to a particular number that is known to the base 104. In a preferred example, the central circuit 116 receives the call from the base 104 and recognises the number of the base 104 that has called it. This occurs especially in the case of an option, commonly offered by fixed 8 telephone operators, known as a "caller identification" option. The person called, before picking up the telephone, receives a piece of information in the transmitted signal. This piece of information represents the telephone number of the person calling him. On receiving this number, the operator 116 therefore knows who is the sender of the call. Since this reception takes place in a period of time that is known to be short, all that the base 104 needs to do is to maintain its call for a sufficient determined duration. The central circuit 116 does not need pick up the line and take it upon reception of this call. Thus, the cost of a call is saved while, at the same time, the identity of the person who has called the central circuit 116 is known. The particular number called corresponds to a declaration of presence in or starting from the domestic area. in this example, the information elements contained in the column NDECT in the memory 127 are therefore domestic numbers of subscribers who have taken out a subscription with the operator controlling the central circuit 116. It is the operator who activates or deactivates the caller identification option. He can therefore ensure that the caller identification is active during a call from a particular number to the central circuit 116.

In one variant, the central circuit 116 may pick up the line at the step 202. Thus, there may be an exchange of information between the base 104 and the central circuit 116, in order to secure the exchange of data or to obtain greater certitude of the presence of the telephone 100 in its domestic area.

After the step 102 has been accomplished, the method comprises a step 203 of dialogue between the operator and the mobile telephone 100. In the step 203, the base 116 uses the microprocessor 125 to make a search in the memory 127 for the identifier NDECT corresponding to the base 104 that has just called. Facing this identifier, in a row recording of the database, there is the identifier SIM of the mobile telephone matched with the base 104. The central circuit can therefore start communicating with the mobile telephone 100. If several mobile telephones 100 are matched with the base 104, during the phase 201, the detected mobile telephone 100 informs the base 104 about its identification. In this case, during the step 202, the base 104 provides an indication of that mobile telephone 100, among all those that are matched with it, that have effectively entered a domestic area. In this 9 case, the phase 202 may comprise a line-taking operation to transmit this identification, unless the signalling before the connection is taken provides for the transmission of this identification. The central circuit 116 therefore ask's the telephone 100, this time through the network 114, to confirm that it is truly in the domestic area. This confirmation can. be given by the mobile telephone 100 inasmuch as, during the step 201, it has responded affirmatively to the question that it has been asked about its presence.

In one variant of the invention, it is possible to go from the step 201 to a step 204 where the mobile telephone 100 gets connected to the operator especially the central circuit 111 in a signalling type link. In getting connected to the central circuit 116, the mobile telephone therefore indicates its subscriber number or its SIM identifier. This indication enables the microprocessor 125 to recover the cable telephone or domestic telephone NDECT number of the subscriber in the memory 127. There is then a passage to the step 205 where the central circuit 116 of the operator calls the base 104. In the step 205, the central circuit 116 calls the base 104 through the switched telephone network 120-122. The base 104 then has to indicate the number of the entity, in this ca's'-e the central circuit, that is calling it. It is therefore capable of knowing that it is the central circuit of an operator that is calling in order to find out if there is really a mobile telephone in its domestic area. In this case, the number of the central circuit 116 has been recorded in a memory of the base 104.

Whatever the variant of the invention, the method can pass from the step 203 or 205 to a step 206 of dialogue between the mobile telephone 100 and the base 104. In the step 206, if it is first variant, the mobile telephone can send a request to the base 104 to find out if it has just sent a call to the central circuit 116. The base 104 then responds in the affirmative. The invention can then go to the step 207 of dialogue between the mobile telephone and the operator.

In the step 207, the mobile telephone 100 gives the central circuit 116 confirmation of the fact that the base with which it is matched has just sent a call to the central circuit 116. This enables the central circuit 116 to know that the base 104 is truly at the location indicated, as determined by the cable line to which it is connected, and that the mobile telephone 100 is well matched with this base 104. The invention then goes to a step 208 for updating the database. In the step 208, the microprocessor 125 updates the area DOM corresponding to a subscriber whose base has just sent a call to the central circuit 116. The area DOM is therefore set at 1 for this subcriber.

If there is a passage to the step 206 in the variant 2 of the invention, it is a base 104 that calls the mobile telephone 100 to inform it that it has just been called by the central circuit 116. The steps 207 and 208 then take place as above.

Whatever the variant and the modes of confirmation, the principle of the invention is to form a signalling loop between, the telephone 100, the base 104 and the central circuit 116. There are also three arms in this loop.

A first arm connects the telephone 100 to the base 104, a second arm connects the base 104 to the central circuit 116, and a third arm connects the central circuit 116 to the telephone 100. The three arms may be crossed by information in one direction, in the other direction or in both directions. In order that the loop may be set up, it is not necessary however that all the arms should be put into service. For example, in the first variant, the confirming interrogation coming from the Central circuit 116 to the telephone may go through the first and second arm without necessarily taking the third arm.

The operation then passes from the step 208, to a step 209 where tests are periodically conducted to find out if the mobile telephone 100 is always in its domestic area determined by the range of the base 104. In the step 209, the base 104 interrogates the mobile telephone 100 at regular intervals to find out if it still within its range of communication. During this interrogation, the telephone and the base identify themselves to each other.

The periodicity of this interrogation 209 is preferably parametrisable.

When the mobile telephone is powered off, in the same way as when it moves to a distance from its base 104, it is put out of the domestic area by the operator. Indeed, if it turns out that the mobile telephone 100 does not respond to an interrogation 209, the operation passes to the step 210 of dialogue between the mobile telephone and the operator. Indeed, once it is in a domestic area, the mobile telephone 100 expects to receive calls at a certain frequency from the base 100. If these calls do not reach it, it may decide that it is no longer in a domestic area and it will set up a 11 communication with the central circuit 116 through the GSM network 114 in order to inform it of this fact.

In one variant of the invention, the call to the central circuit 116 may alsd be initiated by the base 104. In this case, upon reception of the call, the microprocessor 125 tests the DCM area corresponding to the SIM or NDECT number that has just called, and observes that this area is at 1. This means that it is necessary to change the state of this area. Indeed, it cannot be a case of an arrival in a domestic area since, in principle, the mobile telephone 100 was already in a domestic area. There is a passage to a step 211 of updating the database. As soon as the central circuit 116 receives a call informing it that the mobile telephone has come out of its domestic area, it will update the DOM area corresponding to the subscriber. In other words, the area goes back to zero indicating that the mobile telephone has come out of its domestic area. There is an immediate passage to a step 212 in is which the operations of normal mobile telephone are resumed.

..;i t, 12

Claims

CLAIMS is -11r 1. Method for the management of communications exchanged

with a two,mode telephone (100) capable of working as a mobile telephone, especially of the GSM type and as a cordless domestic telephone especially of the DECT type, wherein:

- the presence of the two-mode telephone. is detected when the two mode telephone has sufficiently approached a cordless domestic telephony base (103) whose range defines a domestic area, characterised in that - from the cordless domestic telephony base, through a fixed telephony link (119), a signalling call (NDECT) is sent (202) to a central circuit (116) of a mobile telephony operator with whom a user of the two mode telephone is a subscriber (SIM), to report that the two-mode telephone is in the domestic area, - an RF link (113) is set up (203) between the two-mode telephone and a mobile telephony base station (103) and in confirmation, between this central circuit and this two-mode telephoirthe, a transmission is made of an identification of this domestic area, resulting from a signalling communication on this RF link, - a database (127), indicating the confirmed presence or absence of the two-mode telephone in the domestic area, is updated (208), - and the communications exchanged are managed as a function of this updated database.
2. Method for the management of communications exchanged with a two-mode telephone (100) capable of working as a mobile telephone, especially of the GSM type and as a cordless domestic telephone especially of the DECT type, wherein:

- the presence of the two-mode telephone is detected when the two mode telephone has sufficiently approached a cordless domestic telephony base (103) whose range defines a domestic area, characterised in that:

- an RF link (118) is set up between the two-mode telephone and a base station of an mobile telephony operator (116) with whom a user of the two-mode telephone is a subscriber (SIM), 13 - a signalling call is sent (204) on this RF link to inform a central circuit (116) of this operator that the two-mode telephone is in the domestic area, - a call is sent on a fixed telephony link (11 g), set up between the cordless domestic telephony base and this central circuit, to confirm an identification of the domestic area, - a database (127) is updated (208), indicating the confirmed presence or absence of the two-mode telephone in the domestic area, - the communications exchanged are managed as a function of this updated database.
3. Method according to one of the claims 1 to 2, characterised in that the exchanges of data between the cordless telephony base and the two- mode telephone are encrypted.
4. Method according to one of the claims 1 or 3, characterised in that it is verified (209) at regular intervals that the two-mode telephone is in the domestic area.
5. Method according to one of the claims 1 to 4, characterised in that, during the sending of the call signalling the presence of the two-mode telephone in the domestic area, an idehtlfter (NDECT, SIM) is sent (202, 204) to determine which fixed telephony line is fixed to the cordless domestic telephony base.
6. Method according to one of the claims 1 to 5, characterised in that a caller identifier is used to avoid the taking of a line during the sending of the call signalling the presence of the two-mode telephone in the domestic area.
7. Method according to one of the claims 1 to 6, characterised in that a dialogue is set up (206) between the two-mode telephone and the cordless domestic telephony base, so that this base confirms to the two-mode telephone that it has just called the operator.
8. Method according to one of the claims 1 to 7, characterised in that the presence of the two-mode telephone in the domestic area is disabled as soon as the communication between the two-mode telephone and the cordless telephony base is broken for a duration longer than a given duration that is preferably parametrisable.
9. Method according to one of the claims 1 to 8, characterised in that the mobile telephony base sends the operator an identifier of the two- mode c 14 telephone to which the cordless domestic telephony base is connected, preferably a subscription number (SIM).
10. Method according to one of the claims 1 to 9, characterised in that the two-mode telephone sends the operator a piece of information identifying the cordless domestic telephony base, preferably a subscription number (NDECT).
11. Method substantially as hereinbefore described with reference to the accompanying drawings.

1