Method and arrangement as well as terminal for indicating a calling subscriber, or an A-subscriber, in the telecommunications connection setup phase
The present invention relates to telecommunication and it can be used in the telecommunications connection establishing phase, i.e. in the SETUP phase. More specifi- cally, the present invention relates to a method according to claim 1, to an arrangement according to claim 6, and to a terminal according to claim 13 for indicating a calling subscriber, or an A-subscriber, to the user of a called subscription, or a B- subscription, in the telecommunications connection setup phase.
Several existing digital public land mobile network terminals, such as GSM telephones and future so-called third generation mobile stations, i.e. UMTS telephones, include a function in which, in connection with storing a number in memory, a selectable identifying ringing tone is chosen for calls coming from the number in question from a group of available ringing tones. However, since the number of ringing tones is limited and since the ringing tone is usually stored as such in the memory of the telephone, it is not necessarily possible to choose a fully distinctive ringing tone for all the numbers to be stored. Moreover, the choosing of a ringing tone is made difficult by the fact that one cannot know for sure that the same ringing tone will not be unintentionally chosen for two or more callers. Hence, calls with the same ringing tone may come even from several A-subscribers, which is not the intention when the ringing tones intended to be distinctive are stored.
Previously there is also known a function in which, in connection with storing a number in memory, the calls coming from said number are stored as calls of a certain group, and a selectable ringing tone identifying the group is chosen for each group from a number of available ringing tones. Thus, the calls placed from certain groups ring differently, thereby allowing the user to identify with certainty from the
ringing tone a call as belonging to a certain group. A problem with the group- specific ringing tone is that the callers within a group cannot be distinguished from one another at the B-subscriber' s based on the ringing tone.
Moreover, storing of different ringing tones intended to be number-specific and/or group-specific in connection with number storage is complicated and requires that the telephone numbers are stored in the telephone's own memory, because the number record of a SIM (Subscriber Identity Module) card required in a mobile station has no place for information about the ringing tone.
It is also previously known to display the number of the calling subscriber, or the A- subscriber, at the called subscription, i.e. at the B-subscriber 's. This function known by the name of CLIP (Calling Line Identity Presentation) is a standardized feature known per se of both a digital public land mobile network (PLMN), such as, for example, a GSM/UMTS network and a fixed network, such as an ISDN network, and available only if the terminal used supports said feature. This kind of feature is also available to subscribers of a conventional analog network, such as a public switched telephone network (PSTN) network, as a network service, but the utilization of the service usually requires an agreement with a network operator and the connecting of a special display to a telephone line and/or a terminal supporting the function. Thus, this kind of number display identifying the calling party, or the A- subscriber, is based on a CLIP signal, i.e. A-Id, which is sent, for example, as a code in binary form to a B-subscriber from a local exchange of an analog network as DTMF signals and from a mobile switching centre or from a local exchange of an ISDN network as part of ACCESS signalling between a terminal and a network element.
The aim of the present invention is to provide a new method for generating at the B- subscriber's a ringing tone which identifies the caller, thus substantially facilitating and speeding up the identification of A-subscribers at the B-subscriber' s.
This aim is achieved by means of a method, an arrangement and a terminal of the kind mentioned at the beginning, the characteristic special features of them being set forth in the accompanying set of claims.
Thus, the present invention is based on the new and inventive basic idea that a ringing at the B-subscriber' s, for example, an acoustic signal which is given to the called subscriber, or the B-subscriber or user, to indicate that a call is coming, such as a telephone call, a fax message, a data message or a text message, is determined individually or substantially individually based on the subscriber number, or the telephone number, of the calling subscriber, or the A-subscriber. This is achieved, for example, such that each digit 0-9 is assigned a distinctive pitch and/or a tone length of its own which is/are stored as a coding table in the program memory of the telephone, which can be used for generating a ringing tone whenever a telephone call is coming. Thus, in the generation of a ringing tone it is possible to use any number series, which can thus be the subscriber number of the calling subscriber, or the A- subscriber, which can be signalled to the B-subscription, for example, in an OPC (Originating Point Code) field.
According to one preferred embodiment of the invention, the ringing tone is a series of acoustic signals which have been generated according to CLI (Calling Line Identification) data, i.e. according to A-Id (Caller Identification), for example, in accordance with a postfix of a subscriber number or in accordance with a selectable number of the last digits in a subscriber number. Regardless of the type of the telecommunications network to which a calling subscriber, or an A-subscriber, is connected, information about the calling subscriber, or the A-subscriber, in a SETUP message formed as a result of dialling a B-number is signalled to the exchange of a telecommunications network which serves said A-subscriber, after which the telecommunications network routes the call setup further by utilizing the TUP/ISUP (ITU-T series of Recommendations Q.700) signalling protocol, in which connection information about the calling subscriber, or the A-subscriber, is transferred in an OPC field in a message signalling unit MSU to the mobile switching centre or to the local exchange which is serving the called subscriber, or the B-
subscriber. Information about the calling subscriber, or the A-subscriber, is sent from the local exchange of an analog network to the B-subscriber as DTMF signals, and from a mobile switching centre of a public land mobile network or from a local exchange of an ISDN network as part of ACCESS signalling between a terminal and a network element, which signalling is based on the BSSAP signalling protocol in public land mobile networks and on the DSS1 (ITU-T Recommendation Q.931) signalling protocol in an ISDN network, advantageously the information about the A- subscriber is transferred through a D-channel to the B-subscriber. In this way, information about the calling subscriber, or the A-subscriber, can be transferred through the telecommunications network to the called subscriber, or the B-subscriber, and arranged to control the generation of a ringing, for example, by means of a ringing tone generator, at the B-subscriber 's.
With regard to the advantages of the invention, it may be mentioned that the telephone calls placed by calling subscribers, or A-subscribers, to a single called subscriber, or a B-subscriber, ring at the B-subscriber 's each in their own specific way and, in a corresponding manner, the telephone calls placed by a single A- subscriber always ring at all B-subscribers in their own specific way. Thus, the B- subscribers can immediately identify an A-subscriber from the ringing tone without any ambiguity, and since the identification can be made without looking at the user interface, a visually handicapped person can also fully benefit from the present invention.
Hereafter, the calling subscriber is referred to by the term 'A-subscriber' and the called subscriber is referred to by the term 'B-subscriber' .
In the following, the invention will be described by way of example in more detail by means of some of its preferred embodiments with reference to the accompanying patent drawings in which
FIG. 1 schematically shows a telecommunications network which includes an analog, fixed PSTN network, a fixed digital ISDN network, and a digital PLMN mobile network,
FIG. 2 shows signalling in a telecommunications network for signalling information about a caller, i.e. information about a calling subscriber, or an A-subscriber, from an A-subscriber of a fixed network to a B-subscriber,
FIG. 3 shows signalling in a telecommunications network for signalling information about a caller, i.e. information about an A-subscriber, from an A-subscriber of a public land mobile network to a B-subscriber of a public land mobile network,
FIG. 4 schematically shows a mobile station according to the invention,
FIG. 5 shows one advantageous coding table for A-Id information at a B-subscription according to the invention,
FIGs. 6a and 6b illustrate ringing tones generated by means of the coding table of FIG. 5 based on one piece of A-Id information received from a telecommunications network,
FIG. 7 illustrates another advantageous coding table for A-Id information at a B- subscription according to the invention, and
FIG. 8 illustrates a ringing tone generated by means of the coding table of FIG. 7 based on one piece of A-Id information received from a telecommunications network.
The telecommunications network shown in FIG. 1 includes as parts an analog fixed PSTN network, a fixed digital ISDN network, and a digital mobile PLMN network.
The network elements of the PSTN network include: local exchanges LX-A and LX- B, regional exchanges RX, one of which is in telecommunication and data transmission connection with a number of local exchanges LX-A or LX-B, and a national exchange NX, with which the regional exchanges RX are in telecommunication and data transmission connection; and in which terminals NT-A and NT-B are in telecommunication and data transmission connection with the local exchanges LX-A and LX-B, respectively.
The network elements of the ISDN network include: local exchanges LX-A and LX- B, regional exchanges RX, with one of which a number of local exchanges LX-A or LX-B are in telecommunication and data transmission connection, and a national exchange NX, with which the regional exchanges RX are in telecommunication and data transmission connection; and in which terminals NT-A and NT-B are in telecommunication and data transmission connection with the local exchanges LX-A and LX-B, respectively.
The network elements of the PLMN mobile network include: base station controllers BSC, mobile switching centres MSC-A and MSC-B with a number of base station controllers BSC connected thereto, and a gateway mobile switching centre GMSC, to which the mobile switching centres MSC-A and MSC-B are connected and through which the mobile network PLMN communicates with the fixed telecommunications network or fixed telecommunications networks PSTN/ISDN. The network elements of the public land mobile network also include a home location register HLR, which is in data transmission connection with the gateway mobile switching centre and with the mobile switching centre/centres MSC-A and MSC-B and in which subscriber data have been stored permanently, and a visitor location register VLR in which information about those mobile stations has been stored which are at a given point in time in the service area of the mobile switching centre MSC- A, MSC-B. In other words, the VLR keeps track of the service area cells of the mobile switching centre MSC-A, MSC-B within which the mobile station may move, and the VLR is immediately informed if a mobile station is turned off or on in the service area.
In this kind of telecommunications network comprising a fixed PSTN and/or a fixed ISDN telecommunications network/networks and a PLMN mobile network, setting up a connection is substantially similar regardless of whether the type of the telecommunications network is PSTN or ISDN, and setting up a connection is based on the TUP and/ or ISUP network signalling protocol (Interexchange Signalling). However, it has been found in tests that have been carried out that there are less problems when the signalling protocol of a telecommunications network is ISUP. To establish a connection from a fixed network to a GSM mobile network PLMN, ISUP is the network signalling protocol between the fixed network PSTN/ISDN and the gateway mobile switching centre GMSC. In addition, the ISUP network signalling protocol is used in the public land mobile network between the gateway mobile switching centre GMSC and the other mobile switching centres MSC-A, MSC-B. The network signalling protocol used between the mobile switching centres MSC-A, MSC-B and the base station controllers BSC is in turn BSSAP. Further, in the mobile network PLMN, the interface between the base station controller BSC and base transceiver stations BTS is called Abis, and LAPD links according to the GSM: 08.56 standard are used for Access signalling. Finally, the air interface between mobile stations MS-A, MS-B and the base transceiver stations BTS is a Um interface in accordance with the GSM standard, and the Access protocol LAPDm (Link Access Protocol Dm-channel) according to the GSM:04.06 standard is used over this air interface.
FIG. 2 shows, in a simplified manner, different ways of signalling in setting up a connection in a telecommunications network in order to signal information about a caller, i.e. information about an A-subscriber, from an A-subscriber of a fixed network to a B-subscriber to control the generation of a ringing tone dependent on the A-subscriber at the B-subscriber' s according to the invention. The upper part of FIG. 2 illustrates signalling in a fixed telecommunications network and the lower part of FIG. 2 illustrates signalling from a fixed telecommunications network to a public land mobile network.
Reference is made to the upper part of FIG. 2 which illustrates in a highly simplified manner setting up of a telephone call based on the TUP or ISUP network signalling protocol (Interexchange Signalling) in a fixed network PSTN or ISDN.
In the following, the setting up of a connection in the PSTN network based on the TUP network signalling protocol is described. After an A-subscriber NT-A of the PSTN network has lifted the handset and received a dial tone and started dialling a B-number, analysis of the B-number is initiated in the local exchange LX-A in the area of which the A-subscriber NT-A is located. If the analysis shows that the call is to be connected to another exchange, an outgoing trunk line is selected. In that connection, an initial address message IAM (Initial Address Message) is generated which usually contains the complete B-subscriber number, the A-subscriber category, and the identity of the voice channel to be used. The IAM message is sent from the sending local exchange LX-A through the necessary regional exchanges RX and/or national exchanges NX to a receiving local exchange LX-B, which acknowledges the transmission by sending an ACM (Address Complete Message) message after the B- subscriber NT-B has been identified and can receive the incoming call. After that, the local exchange LX-A signals to the B-subscriber a ringing setup message which includes CLI or A-Id information for the B-subscriber NT-B, at which a ringing tone is generated which is dependent on the calling subscriber NT-A in accordance with the invention. When the B-subscriber NT-B answers, a connection has been established and communication between the subscribers NT-A and NT-B can begin.
In the ISDN network, the setting up of a connection is based on ISUP signalling, and the setting up of a connection differs in its details to some extent from the setting up of a connection based on the TUP signalling protocol in the PSTN network. Thus, in the following, there is a more detailed description of setting up a connection through the ISDN network from an A-subscriber NT-A, which is an ISDN subscription, to a B-subscriber NT-B, which is another ISDN subscription and which belongs to another local exchange LX-B. After the A-subscriber NT-A has dialled the number of the B-subscriber NT-B and pressed the send key, a SETUP message is sent through a D-channel to a local exchange LX-A. If the message is
found to contain enough information upon analysis thereof, a CALL PROCEED signal is sent to the A-subscriber NT-A, which means that no more SETUP information can be given. When the local exchange LX-A has selected an outgoing circuit, an ISUP message - IAM (Initial Address Message) - is sent from the sending local exchange LX-A through the necessary regional exchanges RX and/or national exchanges NX to the local exchange LX-B of the receiving B-subscriber NT-B. This message contains all the initial data for a connection. After the IAM message has been analysed, a ringing setup message containing CLI or A-Id information is signalled from the local exchange LX-B through a D-channel to the ISDN terminal of the B-subscriber NT-B. If this ringing setup message is correct and complete, the ISDN terminal of the B-subscriber NT-B activates a ringing. In accordance with the invention, the ringing tone is dependent on the calling subscriber NT-A. When the B-subscriber NT-B answers, a connection has been established and communication between the subscribers NT-A and NT-B can begin.
The lower part of FIG. 2 illustrates, in a simplified manner, setting up of a telephone connection from a PSTN or ISDN network to a mobile network PLMN and further to a B-subscriber MS-B of the mobile network PLMN based on the above- mentioned ISUP, BSSAP network signalling protocols and on network signalling according to the standard GSM: 08.56 as well as on Access signalling according to the standard GSM: 04.06. Setting up a connection from an A-subscriber NT-A of the fixed network PSTN/ISDN to the B-subscriber of the public land mobile network comprises two phases so that in the first phase, a connection is set up from the A- subscriber of the fixed network PSTN or ISDN to a gateway mobile switching centre GMSC of the mobile network PLMN, which switching centre connects the mobile network PLMN to the fixed PSTN or ISDN network. The setting up of the connection itself begins, as above, with the dialling of the B-number accomplished at the A- subscriber's NT-A, as a result of which a SETUP message containing, among other things, B-subscriber data and IAM data, is sent from the A-subscriber, for example, through a D-channel to the network by means of Access signalling compatible with the fixed PSTN or ISDN network. If the message is found to contain enough information upon analysis thereof and when the local exchange LX-A has chosen an
outgoing circuit, the IAM message is signalled from the sending local exchange LX- A through the necessary regional exchanges RX and/or national exchanges NX to the gateway mobile switching centre GMSC. When the gateway mobile switching centre GMSC has found that the IAM message contains the necessary initial data for setting up a connection, the service area where the called mobile station is situated is located in the public land mobile network, and a CPG (Call ProGress) message is signalled to the mobile switching centre MSC-B taking care of this service area. After that, the called mobile station MS-B is located and it is sent a ringing setup message containing CLI or A-Id data through a base station controller BSC and a base station BTS-B. If this ringing setup message is correct and complete, the mobile station MS-B activates a ringing. In accordance with the invention, the ringing tone is dependent on the calling subscriber NT-A. When the B-subscriber MS-B answers, a connection has been established and communication between the subscribers MS-A and MS-B can begin.
FIG. 3 illustrates, in a simplified manner, setting up of a telephone connection from an A-subscriber MS-A to a B-subscriber MS-B in a mobile network PLMN based on the above-mentioned ISUP, BSSAP network signalling protocols as well as on network signalling according to the standard GSM: 08.56 and on Access signalling according to the standard GSM: 04.06. The setting up of a connection begins as above by dialling the B-number at the A-subscriber' s MS-A, as a result of which a SETUP message containing, among other things, B-subscriber data and IAM data, is sent from the A-subscriber by means of Access signalling compatible with the fixed PLMN network. When a mobile switching centre MSC-A finds that the IAM message contains the necessary initial data for establishing a connection, the service area where the called mobile station MS-B is situated is located in the public land mobile network, and a CPG (Call ProGress) message is signalled to the mobile switching centre MSC-B taking care of this service area. After that, the called mobile station MS-B is located more exactly, i.e. with an accuracy of one cell, and it is sent a ringing setup message containing CLI or A-Id data through a base station controller BSC and a base station BTS. If this ringing setup message is correct and complete, the mobile station MS-B activates a ringing. In accordance with the
invention, the ringing tone is dependent on the calling subscriber NT-A. When the B-subscriber MS-B answers, a connection has been established and communication between the subscribers MS-A and MS-B can begin.
As is clear from the foregoing, data about the calling subscriber, or the A-subscriber, regardless of the type of telecommunications network, can be signalled through to the called subscriber, or the B-subscriber, in which the information about the A-subscriber can be arranged to control the generation of a ringing tone, for example, by means of a ringing tone generator, in accordance with the invention. In this connection, it shall be noted that in order to utilize the A-subscriber data if the transmitting telecommunications network is an analog PSTN network, if signalling of the A-subscriber data to the B-subscriber demands a separate service agreement with a network operator, and if the terminal does not in itself support this additional service, a special accessory is needed which must usually be disposed in the customer line parallel with the terminal or in series before the terminal. A digital PLMN or ISDN network does not involve such general limitations associated with the terminal, because in them ACCESS signalling in itself supports the signalling of the A- subscriber data, i.e. CLI data, to the B-subscriber.
FIG. 4 schematically illustrates a mobile station which is connected to a digital PLMN mobile network, such as a GSM network, according to the invention and in which ringing is based on CLI/A-Id data received from a local exchange LX-B / mobile switching centre MSC-B serving a B-subscriber NT-B, MS-B according to the invention. This mobile station includes a transmitter part 1 which connects to a base transceiver station of the PLMN network through a Um interface 9, a receiver part 2 which connects to the base transceiver station of the PLMN network through the Um interface 9, - a switch part 3 and a controller part 10 which control the mobile station so as to activate a ringing in the connection setup phase and to operate in a send and/or receive state,
input parts 4, such as a microphone and a keyboard to operate the mobile telephone, such as, for example, to dial a B-number, a program memory 5 and/or a SIM memory 6 of the telephone, which memory can be used, when a call is coming, for coding incoming A-Id/CLI data in order to generate an A-Id/CLI-based ringing tone. Advantageously, a pitch, duration of a tone or another acoustic indicator distinguishable with the ears corresponding to each digit from 0 to 9, for example, in the form of a coding table, is stored in the program memory or in the SIM memory, and can be used whenever a call is coming for generating a ringing tone. In that connection, in accordance with the invention, at the B-subscriber' s, advantageously in the switch and controller parts 3, 10, the CLI/ A-Id data is coded into a number series consisting of individual digit values, and each individual digit value included in the CLI/A-Id identifier or at least some of the digit values of the CLI/ A-Id identifier, advantageously the last five digit values, is/are assigned by means of the coding table a control signal for a pitch of a tone, for duration of a tone, for an acoustic signal like Morse Code, or another control signal for an acoustic indicator distinguishable with the ears, which control signal corresponds to the digit value, and a ringing tone generator 7 which generates an audible ringing tone through a ringing tone speaker 8 from the signals for control of the pitch of a tone, from the signals for control of the duration of a tone, from the signals for control of acoustic signals which are like Morse Code, or from the signals for control of other acoustic signals distinguishable with the ears, which control signals are received by the ringing tone generator 7 and which correspond to the digit values of the CLI/ A-Id identifier.
FIG. 5 shows one advantageous coding table for A-Id/CLI data at the B-subscription according to the invention. The coding table is preferably located in the program memory 5 of a mobile telephone. Of course, and especially when the SIM memory has a sufficient capacity, such a coding table may be located in the SIM memory 6. The A-Id/CLI digits to be coded are situated in the left-hand column of the coding
table, and from the horizontal line a selection can be made according to whether the terminal is desired to ring
1) based on differences in the pitches of tones, or
2) based on differences in lengths of continuous tones. The signals for control of the pitch of a tone or for the duration of a tone produced by means of the coding table are passed to the tone generator 7 and a corresponding ringing tone is heard through the ringing tone speaker 8 of the ringing tone. FIG. 6a shows a melody produced by the method according to the alternative 1) from the A- subscriber number 6153500, and FIG. 6b shows a ringing tone based on the A- subscriber number 6153500 and composed of sounds of different lengths produced by the method according to the alternative 2).
FIG. 7 shows one advantageous coding table for A-Id/CLI data at the B-subscription in accordance with the invention. The coding table is preferably located in the program memory 5 of the mobile telephone. Of course, and especially when the SIM memory has a sufficient capacity, such a coding table may be located in the SIM memory 6. In the coding table, the A-Id/CLI digits to be coded are located in a matrix in which, in the direction from left to right, the first field in each row in the vertical direction always represents a short tone and after that the fields alternately represent a long tone and a short tone. Such a matrix register is read from above vertically downwards, in which connection the coding table codes the A-Id/CLI digits into different series of short/long acoustic signals which are like Morse Code and different in length. The control signals for acoustic signals similar to Morse Code produced by means of the coding table are passed to the tone generator 7, and a corresponding ringing tone is heard through the ringing tone speaker 8 of the ringing tone. FIG. 8 shows a sequence of acoustic signals generated based on the A- subscriber number 6153500.
Above, in connection with FIGs. 5—8, the generation of a ringing tone at the B- subscriber's has been described directly on the basis of individual A-subscriber digits so that one and only one kind of ringing signal corresponds to each digit. It shall be noted that, as a variation of this in generating a ringing tone, it is possible to use
predictive generation of the ringing tone to provide a more melodious ringing tone. In that connection, in a ringing tone formed of successive ringing signals, such as musical notes, successive ringing signals, preferably their pitch, are determined on the basis of at least one preceding ringing signal, such as the pitch of a musical note, Advantageously, this can be accomplished such that the binary code of each digit to be converted is assigned three possible pitches instead of one, and the option which is the most suitable in terms of melody is determined based on the preceding signal/signals. In that connection, it is advantageous that the program or SIM memory of the mobile station contains a selection algorithm suitable for the purpose.
Above, the invention has been described only by way of example. This is, of course, not intended to limit the invention by any means and, as is clear to a person skilled in the art, alternative arrangements and variations are feasible within the inventive idea and its scope of protection defined in the accompanying claims.