METHOD IN ANALYSIS OF DIALLING

Abstract: The present invention concerns a method intended for use in a telecommunications network comprising at least one switching centre (SSP), an inbound interface (20) in the switching centre (SSP), at least one terminal device (10) communicating with the inbound interface (20), and at least one control logic (SCP) communicating with the switching centre (SSP). According to the method, dialling is received at the inbound interface (20), whereby an intelligent network triggering (11) occurs, and, possibly, one or more additional characters dialable from the terminal device (10) received at the inbound interface (20) are complementarily collected via the switching centre (SSP) to the control logic SCP. Further, the dialling received at the inbound interface (20) is monitored by a dialling timer so that, if the inbound interface (20) does not receive digits within a predetermined dialling timer time-out, the timer time-out expires triggering a predetermined function. According to the invention, this function is implemented using a special dialling time-out and, if the special dialling time-out expires, the switching centre (SSP) sends the control logic (SCP) such a predetermined dialling sequence end character that cannot be produced from a conventional subscriber terminal device.

Description: Method in analysis of dialling The invention relates to a method for intelligent network dialling analysis. A portion of services in intelligent networks are implemented so that the service will already be triggered by the first digits dialled by the subscriber or simply by lifting the receiver. Typically in these cases, the control logic of the service must collect the remaining digits dialled by the subscriber during the later steps of the service. By conventional techniques and operation based on standardised procedures, generally the completion of the number must be performed digit by digit, because there are no practicable means (due to continuously changing information and enormous memory requirements) to provide the control logic with fresh data about all the routing analyses employed in the entire telecommunications network, in order to know in each specific case how many digits there still remains to be collected. Moreover, the call quite frequently ends in a situation where the subscriber must be requested to dial more digits, but the request evokes no response and, according to standard routines, the switching centre can only react by issuing a fault announcement, leading to unsuccessful completion and disconnection of the service. In conventional embodiments, the triggering of the intelligent network, which takes place prior to the receipt of the entire number (that is, whilst picking up the receiver or after receiving from 1 to n dialled digits, where n is smaller than the overall quantity of digits required to complete the service), it is necessary in most cases to "query" the number from the switching centre in a digit by digit manner, using a sequence to be described later in the text. A straightforward approach to solve the problems hampering conventional techniques would be to provide the data base of the control logic (SCP) with a complete copy of the numbering scheme of the telecommunications network, whereby in each specific case the correct quantity of remaining digits could be requested in a single operation. However, such a copy of the numbering scheme would consume an undue amount of the system memory capacity and, moreover, its updating would cause an enormous administrative and other overhead load. In practice, this kind of an all-encompassing embodiment is not economically nor technically viable to implement. Hence, services must today be accomplished in the conventional manner to be described in more detail later in the text, which means collecting the remaining digits of a number one by one. If the service level experienced by the subscriber is considered, carrying out the above-described procedure without a prior knowledge of the numbering scheme in some cases leads the system to request one too many of the additional digits, resulting in a failure of the control logic and thereby in an unsuccessful call. One of the technical problems of the prior art leading to the invention was that triggering the control logic of an intelligent network on the basis of a number dialling sequence, which is not sufficiently complete for decision-making on executing further steps in the control logic, does not generally give the control logic sufficient information on the quantity of remaining digits to be dialled by the subscriber. The technique of the prior art is hampered by the following disadvantages: An improper design of the analysis results in a situation in which the quantity of requested numbers is one too many, resulting in a failure of the entire call attempt. An undue increase in the message traffic between the service control point/control logic (SCP) and the service switching point (SSP) occurs when the digits must be requested one by one. However, without having this additional message traffic of digit-by-digit requests and a copy of the numbering scheme, it is impossible at the service control point to achieve a dialling analysis, which guarantees that an extra digit will not be requested after the actual "last dialled" digit. If this situation is to be circumvented by not even attempting to collect all digits (assuming that the service allows for this), the control logic of the intelligent network would not have access to all digits dialled by the subscriber. Since the charging relating to the services in many cases are transmitted to the external equipment from the control logic of the intelligent network, these charging data thus remain deficient as regards the full sequence of digits dialled by the subscriber, because the sequence was not (could not) be requested at full length from the switching centre. The control program portion containing the dialling analysis must be compiled in a very complicated manner with a facility to control all the possible number sequences as to their length, where 09-6061, for instance, is a number of 4 digits, whereas number sequences starting with 09-6062-9 have (or may have) up to 8 digits. The goal of the invention is achieved by programming the switching centre (SSP) to always add a terminating character (e.g., hexadecimal value F) to the end of the sequence of digits collected from the subscriber, when the subscriber does not continue dialling more digits to the sequence (or does not even start dialling) and the dialling time-out is triggered. Herein, a command can be given in conjunction with the collection to collect digits well in excess of what is expected in reality, whereby the approach described above is capable of preventing a fault condition in the procedure, that is, an unsuccessful call attempt, if the requested number of digits is not dialled before the dialling timer time-out. Typically, the number collection routine uses dialling timer time-out times (typically in the order of 3 to 7 seconds) shorter than those programmed for switching centres. Later in the text, this dialling timer time-out of shorter duration than that normally applied is referred to as special dialling timeout. More specifically, the method according to the invention is characterised by what is stated in the characterising part of claim 1. The invention offers significant benefits. The dialling analysis in the control logic (SCP) of the intelligent network or an equivalent external control logic operating on the basis of information collected by a switching centre is substantially simplified, con- tains a smaller amount of program code, thus reserving a lesser amount of memory capacity, and, due to its straightforward structure, is less sensitive to human (programming) errors. The message traffic between the control logic (SCP) and the switching centre (SSP) is reduced substantially when the triggering of the intelligent network (e.g., in INAP at trigger points "Origination_Attempt", "Origination_Attempt_Authorized" (TDP1), "Collectedjnformation" (TDP2) and "Analyzedjnformation" (TDP3)) occurs in the beginning of an uncompleted dialling sequence (not yet addressing the destination of the call). As all control logic units can be set to request a number of digits which is always in excess of those to be dialled by the subscriber, the control logic (SCP) of the intelligent network is at all times provided with information on the full number dialled by the subscriber as required, e.g., for transmitting this information to external devices for charging and similar operations. The invention makes it possible to without problems allow the control logic to request a sufficiently large quantity of remaining digits at a time, without causing a call attempt failure (as occurs with conventional techniques) even if all the requested digits are never received. Savings in the installed capacity of the switching centre and control logic equipment are achieved, because there is no need to repeatedly request the remaining digits one by one and, furthermore, because the reduced quantity of unsuccessful call attempts also reduces the quantity of new call attempts made by subscribers, thus obviously also lowering the traffic load imposed on switching centres. In the following, the invention is described in more detail with reference to exempli- fying embodiments illustrated in appended drawings in which Fig. 1 is a flow diagram illustrating a conventional method, suitable for dialling analysis in an intelligent network; Fig. 2 is a flow diagram illustrating a method according to the invention, suitable for dialling analysis in an intelligent network; Fig. 3 is a flow diagram illustrating a method based on the invention, suitable for dialling analysis in an intelligent network; and Fig. 4 is a block diagram illustrating an application of the method according to the invention. The method according to the invention is capable of compensating for the shortcomings of conventional techniques. By virtue of the invention, the message traffic between the switching centre (SSP) and the control point/control logic (SCP) is reduced to a minimum and the dialling analysis is simplified. According to the invention, this takes place in the following fashion: The software of the switching centres is modified so that triggering the event "Collect more numbers" between the control logic (SCP) and the switching centre (SSP) (e.g., in INAP by triggering the RequestReportBCSMEvent [Event Detection Point 2 (EDP2)] + Collect Information operation) does not cause the switching centre to terminate the call attempt even when the subscriber does not dial the requested quantity of digits, but instead the so-called timer time-out function (Inter digit timer time-out) is triggered (Fig. 1: prior-art function, step xiii). Instead of considering the call attempt a failure, the switching centre inserts a character, that cannot be dialled from a conventional subscriber set, at the end of the dialled sequence of digits or, if no digits are dialled, as the only digit. Characters of this category are, e.g., supra-decadic characters, such as hexadecimal F (hex F), for instance (Fig. 2: novel function, step iv). Rather than requesting the remaining digits one by one (Fig. 1 : prior-art function, steps ii - xi), the SCP uses the command "Collect more numbers" either, and as a general rule, only once, by requesting the collection of a number of digits, which with certainty is sufficient (Fig. 2: novel function, step ii), or, possibly, several times in accordance with Example 2 of the novel function (Fig. 3 : novel function, step v), if the hex F character has not yet been received in step iv. The SSP reports the dialling operation made by the subscriber to SCP (e.g., in INAP by triggering the EventReportBCSM operation), either because the subscriber dialled the quantity of digits ordered in step 2 (according to the function of the prior art) or because the subscriber dialled from 0 to n digits, after which the dialling time-out was triggered, whereby according to step 1 the dialled sequence is complemented with a terminating character hex F (new procedure) (Fig. 2: novel function, step iv). In the new procedure, the dialling time-out of the SSP is automatically set to be shorter (typically by half or thereabouts) than for normal calls (special dialling time-out) on the basis that an EDP2 triggering is detected. Thus a special dialling time-out in accordance with the invention is applied. The SCP analyses the last digit of the dialled sequence as follows: If the digit is hex F, there is no need to request additional digits, as all digits have been received (conclusion made possible by the new procedure). If the digit is not hex F, steps 2-4 must be repeated until hex F is detected or the total capacity of digits has been selected. In Fig. 1 an embodiment according to the prior art: is shown: i) the service is started by a trigger (e.g., in INAP by triggering the InitialDP operation) (e.g., at Trigger Detection Point 3); ii) one more digit is requested by triggering EventDetectionPoint 2 (e.g., in INAP by triggering the RequestReportBCSMEvent [Event Detection Point 2 (EDP2)] + Collect Information operation) and by using the normal dialling time-out function of the switching centre; iii) the dialling timer time-out is started; iv) one new digit is reported to have been requested (+ all previously received digits) (e.g., in INAP by triggering the EventReportBCSM operation); v) the control logic software analyses the received quantity of digits, compares it with information stored in the memory on different prefix digits and thereupon decides to request a next digit. Herein, one more digit is requested by triggering EventDetectionPoint 2 (e.g., in INAP by triggering the RequestReportBCSMEvent [Event Detection Point 2 (EDP2)] + Collect Information operation) and using the normal dialling time-out function of the switching centre. vi) the dialling time-out timer is started; vii) one newly requested digit is reported (+ all previously received numbers) (e.g., in INAP by triggering the EventReportBCSM operation); viii) the control logic software analyses the quantity received of digits, compares it with information on different prefix digits stored in the memory and thereupon decides to request a next digit. Herein, one more digit is requested by triggering EventDetectionPoint 2 (e.g., in INAP by triggering the RequestReportBCSMEvent [Event Detection Point 2 (EDP2)] + Collect Information operation) and using the normal dialling time-out function of the switching centre ix) the dialling time-out timer is started, x) one newly requested digit is reported (+ all previously received numbers) (e.g , in INAP by triggering the EventReportBCSM operation), xi) the control logic software analyses the quantity of digits received, compares it with information on different prefix digits stored in the memory and thereupon decides to request new digits Herein, one more digit is requested by triggering EventDetectionPoint 2 (e g , in INAP by triggering the RequestReportBCSMEvent [Event Detection Point 2 (EDP2)] + Collect Information operation) and using the normal dialling time-out function of the switching centre xii) the dialling time-out timer is started, xiii) when no more dialled digits are received from the subscriber, the normal dialling timer time-out is triggered at the switching centre, a call attempt failure situation occurs, the call attempt is terminated and the service fails llustrates the method according to the invention in more detail i) the service is started by a trigger (e g , in INAP by triggering the InitialDP operation) (e g , at Trigger Detection Point 3), ii) a quantity of remaining digits estimated to be sufficiently high (e g 8 digits) is requested by triggering EventDetectionPoint 2 (e g , in INAP by triggering the RequestReportBCSMEvent [Event Detection Point 2 (EDP2)] + Collect Information operation). Simultaneously, the SSP initiates the special dialling time-out for the reception of dialled digits. iii) the special dialling time-out is started; iv) after the subscriber has dialled, e.g., five more digits and then stopped dialling, the special dialling time-out is triggered and the switching centre confirms that the dialling has ended, whereby the switching centre reports the new digits plus all the other digits previously received in conjunction with the triggering of the service and adds the hex F character to the end of the dialled sequence (e.g., in INAP by triggering the EventReportBCSM operation); v) the operation continues in accordance with the service software. rnative procedure according to the invention illustrated in Fig. 3 is carried out ws: i) the service is started by a trigger (e.g., in INAP by triggering the InitialDP operation) (e.g., at Trigger Detection Point 3); ii) a quantity of remaining digits, estimated to be sufficiently high (e.g., 4 digits), is requested by triggering EventDetectionPoint 2 (e.g., in INAP by triggering the RequestReportBCSMEvent [Event Detection Point 2 (EDP2)] + Collect Information operation). Simultaneously, the SSP continues to apply the special dialling time-out for the reception of dialled digits. iii) the special dialling time-out is started; iv) the new digits (4 pcs.) obtained as requested plus all other digits, previously received in conjunction with the triggering of the service, are reported, however, without adding the hex F character at this stage (e.g., in INAP this can be implemented by triggering the EventReportBCSM operation); v) a new quantity of remaining digits estimated to be sufficiently high (e.g. 4 digits) is requested by triggering EventDetectionPoint 2 (e.g., in INAP by triggering the RequestReportBCSMEvent [Event Detection Point 2 (EDP2)] + Collect Information operation). Simultaneously, the SSP continues to the special dialling time-out for the reception of dialled digits. vi) the special dialling time-out is started; vii) after the subscriber has dialled, e.g., two more digits and then stopped dialling, the special dialling time-out is triggered and the switching centre confirms that the dialling has ended, whereby the switching centre reports the new digits plus all the other digits previously received in conjunction with the triggering of the service and adds the hex F character to the end of the dialled sequence (e.g., in INAP by triggering the EventReportBCSM operation); viii) the operation continues in accordance with the service software. As shown in Fig. 4, the method according to the invention is intended for use in a telecommunications network comprising at least one inbound interface 20 in a switching centre (SSP), at least one terminal device 10 communicating with the inbound interface 20, at least one switching centre (SSP) communicating with the terminal device and at least one control logic SCP communicating with the switching centre. According to the method, dialling is received at the inbound interface 20 as digits dialled by the subscriber from terminal device 10, whereby an intelligent network triggering 11 occurs. In addition, the subscriber may, possibly, set one or more characters dialable from the terminal device 10 to be sent via the inbound interface 20 of the switching centre (SSP) to the control logic SCP. Furthermore, the dialling received at the inbound interface 20 of the switching centre is monitored by a dialling timer, so that if the inbound interface 20 of the switching centre does not receive digits within a predetermined timer time-out time, the timer time-out expires, triggering a predetermined function. The function according to the invention is implemented using a special dialling time-out having a time-out time different from that of a normal dialling time-out and, if the special dialling time-out expires, the switching centre (SSP) sends the control logic SCP a predetermined dialling sequence end character that cannot be selected from a conventional subscriber terminal device 10. According to a preferred embodiment of the invention, the addition of the dialling sequence end character is performed after the last digit sent from the terminal device 10 and received at the inbound interface 20 of the switching centre. The inbound interface 20 may, for instance, be an incoming trunk line, an ISDN exchange, a radio network or a terminal device.

Claims: What is claimed is: 1. Method for intelligent network dialling analysis in a telecommunications network comprising at least one switching centre (SSP), an inbound interface (20) in the switching centre (SSP), at least one terminal device (10) communicating with the inbound interface (20) at least one control logic (SCP) communicating with the switching centre (SSP), in which method - dialling is received at the inbound interface (20) of the switching centre, whereupon an intelligent network triggering (11) occurs at dialling, and, possibly, one or more additional characters dialable from the terminal device (10) are complementarily received via the switching centre (SSP) to the control logic (SCP), and - the dialling received at the inbound interface (20) of the switching centre is monitored by a dialling timer so that if the inbound interface (20) does not receive digits within a predetermined timer time-out time, the timer time-out expires triggering a predetermined function, c h a r a c t e r i z e d in that - a special dialling time-out different from normal dialling time-out is used having a preset time-out setting different from that of the preset normal dialling time-out and, - if the special dialling time-out expires, the switching centre (SSP) sends the control logic (SCP) such a predetermined dialling sequence end character that cannot be produced from a conventional subscriber terminal device (10). 2. Method according to claim 1, c h a r a c t e r i z e d in that the addition of the dialling sequence end character is performed after the last digit sent from the terminal device (10) and received at the inbound interface (20) of the switching centre. 3. Method according to claim 1 or 2, characteri sed in that the dialling sequence end character is a supradecadic character such as hex D, E or F. 4. Method according to claim 1 or 2, characterised in that the intelligent network triggering (11) is started when the terminal (10) goes off-hook. 5. Method according to claim 1 or 2, characterised in that the intelligent network triggering (11) is performed on the basis of first digits dialled from the terminal device. 6. Method according to claim 1 or 2, characterised in that the intelligent network triggering (11) is implemented by means of dialling analysis imposed on the digits dialled from the terminal device (10). 7. Method according to claim 1, characterised in that a predetermined quantity of digits is requested after the intelligent network triggering (11). 8. Method according to claim 1, characterised in that the time-out of the special dialling time-out timer is set to half the normal dialling timer time-out.

Inventors: FILS HENRY, HALME MARKO, JAUHIAINEN RAISA, FILS, HENRY, HALME, MARKO, JAUHIAINEN, RAISA
Applicants: HELSINGIN PUHELIN OYJ, HELSINGIN PUHELIN OYJ - HELSINGFORS TELEFON ABP
Application year: 1999
Main classification: H04Q3
IPC codes: H04Q3