The invention concerns a method for the pric- ing of connections in a telecommunication system com- prising means for generating a connection record from a connection, and a billing system comprising a set of rules describing different communication events. In the method, the price of a connection is determined responsively to said connection record.

BACKGROUND OF THE INVENTION When one of the parties to a connection ter- minates the connection or the connection is broken off for some other reason, a connection record is gener- ated from the communication event in question. The connection record contains information relating to the communication event, such as the caller's number, i. e. the A-number, connection start time, i. e. date and time, and the number dialled by the caller, i. e. the B-number.

The connection record thus created is util- ized in generating a connection bill, such as a tele- phone bill. The connection record is transmitted to a billing system, which, based on the record, produces price data for the subscriber's connections and trans- mits these data further to an invoicing system.

In prior art, connection events are identi- fied on the basis of rules incorporated in the program code of the billing system.'Rule'means a logic rule whereby a field in a connection record can be compared with a predetermined value. The rule is e. g. of the

form"Starting date = 19982002"or"Ending date <> 19982002".

Rules embedded in program code become a prob- lem when the rules need to be altered. When changes are made in the connection pricing profile, the rules are written directly in the program code, whereupon the entire program code or the software module respon- sible for the pricing of connections has to be trans- lated again into a form understandable to the central processing unit. A drawback with this procedure repre- senting the state of prior art is that particularly laborious operations are needed every time when the rules are changed as it is necessary to perform a spe- cial process comprising various steps, such as trans- lation and saving. The complexity of the process con- tributes towards increasing the probability of mal- functions.

The object of the present invention is to eliminate or at least to significantly alleviate the problems described above. A specific object of the in- vention is to disclose a new type of method and system that allows flexible modification of connection pric- ing principles.

BRIEF DESCRIPTION OF THE INVENTION The invention identifies connections associ- ated with certain communication services on the basis of communication events and rules concerning them. The invention makes use of a special database in which the rules and communication events are stored. The data- base can be easily modified through a separate user interface.

The invention concerns a method for the pric- ing of connections in a telecommunication system as described above. In the method of the invention, a da- tabase is created from a set of rules describing com- munication events. Communication event'is a descrip-

tion of communication related to a communication event type, taking place in the network and associated with a service or client. Communication event type is a de- scription of who is the payer of the connection and what is the pricing principle applied to the connec- tion. The pricing principle may be based e. g. on the A-number and the connection start time. In addition, pricing modules are formed by means of which the price of a connection is determined from the connection rec- ord. Further, in the method of the invention, to de- termine the price of a connection, the connection rec- ords are compared with the database and the price of the connection is determined in a pricing module indi- cated by the database.

In an embodiment of the invention, the price and/or price components of a connection are stored in the database. If price determination has failed, then in one embodiment an error code is generated from the unsuccessful event and stored in the database.

In an embodiment of the invention, a set of rules is created in the database via a user interface provided in the billing system.

In an embodiment of the invention, before the connection record is compared with the database, the connection record is analyzed and fields giving a more detailed description of the connection record and/or content of the connection are added to the connection record.

In an embodiment of the invention, the rules of the pricing module are manipulated via the user in- terface. This allows the pricing modules to be modi- fied dynamically without having to be separately translated by the end user.

The invention also concerns a system for the pricing of connections in a telecommunication system comprising a communication system provided with means for generating a connection record from a connection

and a billing system connected to the communication system and comprising a set of rules describing commu- nication cases. In addition, the telecommunication system comprises means for transmitting the connection record to the billing system, and means for determin- ing the price on the basis of the connection record in the billing system. The billing system of the inven- tion comprises a database which comprises a set of rules describing communication cases, pricing modules, means for comparing the connection records with the database and means for determining the price of a con- nection in a pricing module indicated by the database.

In an embodiment, the billing system com- prises means for saving the price and/or component prices of a connection to the database. In an embodi- ment, the billing system comprises means for generat- ing an error code if pricing has failed and means for saving the error code to the database.

In an embodiment, the billing system is pro- vided with a user interface for creating a set of rules in the database. In an embodiment, the billing system comprises means for analyzing the connection record and means for adding to the connection record fields giving a more detailed description of the con- nection record and/or content of the connection.

As compared with prior art, the invention has the advantage that it allows various communication events to be defined for the pricing modules without any software changes made separately. The invention makes it possible to parametrize the pricing of con- nections so as to allow the users themselves to define different communication event types. The invention makes it possible to implement a faster pricing change which can also be managed by the end user, i. e. the user of the billing system.

LIST OF ILLUSTRATIONS In the following, the invention will be de- scribed by the aid of a few examples of its embodi- ments with reference to the attached drawing, wherein: Fig. 1 presents a diagram representing an em- bodiment of the system of the invention, Fig. 2 presents a flow diagram representing a method according to the invention, Fig. 3 presents an example illustrating the addition of fields to the connection records; and Fig. 4 presents an example of matching of the rules.

DETAILED DESCRIPTION OF THE INVENTION Fig. 1 presents an embodiment of the system of the invention. The communication system 1 comprises telecommunication terminals TE1, TE2, at least one telephone switching center 14 and a telephone network 17. The communication system 1 may be based on a wired network or a mobile communication network and on digi- tal or analog, narrow-band or wide-band, circuit- switched or packet-switched operation. The switching center 14 comprises means 2 for generating a connec- tion record 5 from a connection between telecommunica- tion terminals TE1 and TE2. The connection record 5 is generated when either one of the parties TE1, TE2 to the connection terminates the connection or when the connection is broken off for some other reason. The connection records 5 are saved to the switching center 14.

Connected via a telecommunication connection 16 to the communication system 1 is a billing system 3. In an embodiment, the billing system is part of the functionality of the switching center 14, in another embodiment the billing system 3 is a separate computer system, based e. g. on UNIX. The telecommunication con-

nection 16 is connected to the systems via means 4 which serve to implement compatibility between the systems. The telecommunication connection 16 may be a telephone or other connection capable of transmitting MMI (Man-Machine Interface) commands between the bill- ing system 3 and the communication system 1.

Using means 15, the price of a connection is determined on the basis of the connection record 5.

The connection records 5 are transmitted to the bill- ing system 3 e. g. by executing a batch run at prede- termined intervals. The invention can also be applied in systems in which the data are transmitted to the billing system in real time in conjunction with bill- ing essentially based on price determination taking place during the call or immediately in conjunction with it, e. g. in connection with Prepaid or Hotbilling type billing.

In the billing system 3, the connection rec- ord 5 is analyzed using means 13. As a result of the analysis, fields giving a more detailed description of the connection record and the content of the connec- tion are added to the connection record using means 13. Fig. 3 illustrates the principle of expanding the connection record 5 into a larger connection record 5'. The practical aim is to increase the number of fields K1... K5 in use and to get new, previously un- known information to the connection record so that a larger number of fields K1... K5, L1... L4 can be re- ferred to by the set of rules describing communication events. In this way, a larger variety of pricing prin- ciples can be applied. The fields L1... L4 to be added may comprise e. g. the area code for the connection, which may be e. g. a free number type code or a na- tional area code. In other words, connections can be grouped by the area code. In another embodiment, the field to be added is for the name of the owner of an extension, e. g. the name of an enterprise having a

plurality of parallel extensions. Instead of billing each extension separately, the connections of all ex- tensions can be collected into a single invoice al- ready at the time of price determination. Furthermore, the field to be added may depend on the route via which an incoming connection is established, in which case the value of the field is dependent e. g. on an- other operator.

The billing system 3 further comprises a da- tabase 6 which contains a set of rules describing dif- ferent communication events. The billing system 3 re- trieves the data relating to pricing from the database 6 and compares the data with the expanded connection record 5'. The matching of the rules is illustrated by an example presented in Fig. 4. Having established which sets of rules apply to the connection record, the system determines the communication events and communication event types in question.

Using means 9, the price of the connection is determined in a pricing module 7 indicated by the da- tabase. The pricing modules 7 may be located either in the same software aggregate with the billing system 3 of the invention or they may be distributed in differ- ent parts of the network. Connection tariffs corre- sponding to different situations are presented in the pricing modules 7, and these return to the system the price and price types they have computed for the con- nection. This makes it possible to compute all desired prices in a concentrated manner and to process them to the invoice for the client, which may be an operator, an enterprise or a private home. The price thus deter- mined for the connection is saved to the database 6 using means 10. If an error occurs at any point of the price determination procedure, then the billing system 3 will generate an error code concerning the event us- ing means 11, which pass the error code further to the database 6.

Connected to the billing system 3 is a user interface 12, by means of which a set of rules is cre- ated in the database 6. The user interface is used e. g. by a switching system specialist who knows the structure of the telecommunication network or a person familiar with the operator's pricing policy. Via the user identifier, it is also possible to modify the rules of the pricing module 7. The rules can be modi- fied dynamically while the billing system 3 is in op- eration.

The means 4... 11 used in the billing system 3 can be implemented in several different ways. In one embodiment, the means 4... 11 are implemented in the memory of a computer as a software aggregate connected to the automated billing system 3. The means 4... 11 can also be implemented using discrete components, a suitable port logic or ASIC circuit (ASIC, Application Specific Integrated Circuit).

Fig. 2 presents an example of the system of the invention as a flow diagram. In step 20, the pa- rameter data, i. e. the required communication event types, communication events and rules, are loaded. In step 21, the connection records 5 are checked. In step 22, the connection record 5 is checked against the first rule to establish whether the rule applies to it. There may be more than one rule applying to the connection record; in step 23, a check is carried out to see if any other rule applies. If there are more than one rule applying to the connection record, then, based on these rules, price components are determined, which can be added together in the invoice or charged separately for different services. If none of the rules applies, then the procedure goes on to step 24 and an error message is given to the billing system 3 and saved to the database 6. In this example, only one possible error situation is presented; in a practical

implementation, there may occur several error situa- tions.

In step 25, the pricing module 7 correspond- ing to each rule applying to the connection record 5 is called. Different pricing modules 7 may also be used to determine different component prices. The rules are interpreted by matching the field and field value described in the database to those in the con- nection record in accordance with desired logical op- erators. The database may contain e. g. a rule stating that the B-number area code = 09. In step 26, the sys- tem retrieves the payer data and pricing principles corresponding to the rule, which have also been de- fined dynamically. In step 27, the price corresponding to the connection record is computed. In step 28, the price data is saved to the database 6.

The invention is not restricted to the exam- ples of its embodiments described above, but many variations are possible within the scope of the inven- tive idea defined in the claims.