HK1093129B

HK1093129B - Method and system for controlling prepaid data services

Info

Publication number: HK1093129B
Application number: HK06113760.5A
Authority: HK
Inventors: 加里．塔卡拉
Original assignee: Nokia Technologies Oy
Priority date: 2003-05-28
Filing date: 2004-04-19
Publication date: 2012-10-12

Description

Method and system for controlling prepaid data services

Technical Field

The present invention relates to controlling prepaid data services. In particular, the invention relates to a method of controlling prepaid data services of at least two service groups providing different charging criteria in a network. The invention also relates to a system for controlling prepaid data services and a communication system for providing prepaid services.

Background

Various types of services may be provided to users through a communication system. The communication system can be seen as a facility that allows communication between two or more entities such as user equipment and/or network entities or other nodes associated with the communication system. The communication may include, for example, communication of various types of data, such as voice data, electronic mail (email), text messages, content data, multimedia, and so forth. In many cases, the service may be charged in advance. This is called prepaid.

In voice data communications, prepaid services have been successfully used. Such pre-payment may also be applied to other communication services than voice services. However, when not strictly applied to voice services, there are some problems due to data complexity. There may be a large number of different tariffs and the consumption of different services may vary widely. For example, data sessions over the internet may typically be charged on a byte-by-byte basis. The connection may remain online, although the use of the connection may not be activated for a long period of time. Thus, it is possible that a sudden consumption of many megabytes may occur instantaneously. The consumption of resources can be substantially diversified. For example, a user may wish to use text messaging and/or multimedia and/or any other service. Therefore, it may be desirable to apply different tariffs to services of different characteristics. It is also possible that a terminal consumes several services at the same time, compared to only one telephone call at a time, which is typical.

Such prepaid charging is conventionally implemented to reserve a certain amount of funds in advance for each service individually. Such reservations are then committed or denied based on the user's behavior. The network element measuring such consumption (chargeable traffic) does not have to know anything about the actual price of the service. Typically, there are charging devices that reserve funds from a prepaid system and rating devices that convert the amount of reserved funds into measurable units (e.g., minutes) that a user may consume. When the service has consumed the reserved amount, this is reported to the charging device. A new amount of funds for the service may then be requested from the prepaid system. This operation is repeated as long as necessary.

Packet data services may have widely differing prices and charging standards. For example, the user may be charged based on at least one of the following different criteria:

can be in HTTP (hyper text transfer protocol)www.news.com$ 0.20 per news page visited (click-to-charge),

can be in HTTPwww.rumours.com$ 0.10 per news page visited (click-to-charge),

with $ 1 per megabyte as the base charge (volume charge) for any unlisted traffic, for HTTP accesswww.guides.operator.comThe service of (a) is free of charge,

send e-mail at mail. operator. com using SMTP (simple mail transfer protocol) at $ 1 per 10 kilobyte (volume charge),

operator.com for sending e-mails at mail.operator.com using SMTP for $ 1 per message (transaction charge), the unit price may depend, for example, on the size of the message, and

fromwww.movie.com$ 1 per 10 minutes (time charge).

This list may continue.

New services are always being introduced for the operator network. The new service may typically be a packet data service. They may often be adapted to prepaid ideas. To avoid more complex network architectures, operators may wish to interface the charging of new services with existing prepaid systems.

A traditional solution for integrating new services with existing prepaid systems is to have a dedicated charging session for each charging standard for each user. However, there are a number of problems with using dedicated charging sessions. For example, if the funds are reserved when using services, the prepaid system becomes easily overloaded due to the huge amount of signaling that would be present. This occurs particularly when the service is used with advanced devices, such as laptop computers, rather than simple devices such as telephones.

With advanced equipment it is possible to use many charging criteria simultaneously. If funds are reserved in advance for each service, the user may not have sufficient resources reserved for all services. It is also possible that the user may not reserve in advance sufficient funds for using all services. However, with total funds, if each service is used separately, the user may have sufficient funds for each service. If the measuring device knows the actual price, it will assign intelligence to the network. This can lead to administrative complexities and challenges when pricing changes.

Therefore, there is a need for an improved system for controlling prepaid data services in a network. In particular, it may be advantageous to try to minimize signaling between the prepaid system and the device that measures and reports usage. It is also desirable to be able to consume all of the allocated funds even if the device does not know anything about the actual price.

Disclosure of Invention

Embodiments of the present invention aim to address one or several of the above problems or issues.

According to an embodiment of the present invention, there is provided a method for controlling prepaid data services, which are divided into at least two service groups of different charging standards in a network, the method comprising the steps of: reserving resources from a prepaid system, setting initial data transfer limits for each service group by a rating device based on the resources and information about charging criteria, sending a message containing information about the initial data transfer limits from the rating device to a measuring device, allocating in the measuring device a proportional data transfer limit for each service group separately, and reallocating in the measuring device the remaining resources to the service groups based on pricing weights of the service groups to obtain separately a new proportional data transfer limit for each service group, the new proportional data transfer limit being used to transfer data after the service group has exceeded its proportional data transfer limit.

In a more specific embodiment, the method further comprises the steps of: the proportional data transfer limit for each service group is defined as a proportion of the initial data transfer limit.

In a more specific embodiment, the method further comprises the steps of: the pricing weight for each service group is defined as the ratio of the sum of the proportional data transfer limits to the initial data transfer limit of the group.

In a particular embodiment of the invention, the method further comprises the steps of: after all reserved resources have been used, a report is sent from the measurement device to the quorum device.

In a particular embodiment of the invention, the method further comprises the steps of: the initial data transfer limit is defined as the amount of service with the same amount of funds worth for each service group.

According to still another embodiment of the present invention, there is provided a system for controlling prepaid data services, the system having: a prepaid system hosting prepaid resources; a rating device for obtaining information of prepaid resources and service group charging criteria and setting an initial data transfer limit for the service group based on the obtained information; and a measuring device for individually assigning the scaled data delivery limit for each service group, measuring the usage of the service groups, and reallocating remaining available resources to the service groups based on pricing weights of the service groups when the service groups exceed their scaled data delivery limits to individually obtain new scaled data delivery limits for each service group for delivering data.

According to yet another embodiment of the present invention, there is provided a communication system for providing prepaid service to its subscribers, the communication system having: at least one data communication network; a prepaid system hosting prepaid resources; a rating device for obtaining information of prepaid resources and service group charging criteria and setting an initial data transfer limit for the service group based on the obtained information; and a measuring device for individually assigning the scaled data delivery limit for each service group, measuring the usage of the service groups, and reallocating remaining available resources to the service groups based on pricing weights of the service groups when the service groups exceed their scaled data delivery limits to individually obtain new scaled data delivery limits for each service group for delivering data.

Drawings

The invention will now be described in more detail, by way of example only, with reference to the following examples and the accompanying drawings, in which:

fig. 1 shows an example of a configuration in which an embodiment of the present invention can be implemented.

Fig. 2 shows a flow chart of an embodiment of the invention.

Fig. 3 shows a flow diagram of the measurement device functionality according to one embodiment of the invention.

Detailed Description

Fig. 1 shows an example of a communication system for providing services to users via a data communication network. The communication system of fig. 1 is shown to include communication networks 10 and 11, a plurality of Service Providers (SPs) 12, 14 and 16, and an end user 18.

In the example of fig. 1, the service providers offer different data services such as voice 12, multimedia 14, and email 16. In connection with the present invention, service providers typically provide services by transmitting data such as voice, images, moving images, or a combination thereof, or provide any other form of service that may occur via a communication network.

The communication networks 10 and 11 may be any suitable data communication networks. For example, the communication network 10 may be the core network of an operator. The communication network 11 may be a public network, such as the internet, or the operator's backbone network. It should be understood that although the networks 10 and 11 are provided in the preferred embodiment shown in fig. 1 by two different networks, the data communication facility may be provided by one data communication network. For example, all communication may occur via the public data network 10.

The term user, end user, refers to an object, such as an individual, company, system, or device, that uses a service provided by a service provider. It should be understood that fig. 1 is merely an example showing three service providers and one end user, and that the number of these entities may differ significantly from that shown.

The configuration of fig. 1 also illustrates a prepaid system 24, a rating device 26 and a measuring device 28 for operation in accordance with certain embodiments of the present invention. The operation of the prepaid system 24, the rating device 26 and the measuring device 28 as exemplified in accordance with the following description will become clear. The rating device 26 may also be referred to as a charging and rating device.

Prepaid system 24 typically includes a database that hosts a prepaid account for a user. The prepaid system 24 may also track the balance of the prepaid account. A prepaid account is typically a contract between a user and an operator. The user may place an amount of resources, typically funds, into his prepaid account. The prepaid system 24 then releases the resources 30 in some manner to pay for the services requested by the user and provided by the service provider that requires prepaid.

In a preferred embodiment, the user may consume the service according to several charging categories simultaneously or in succession. The charging categories may be defined in different units, e.g. one category may be charged by time, another category may be charged by quantity like bytes etc., and yet another category may be charged by click, like URL (uniform resource locator) click or TCP (transmission control protocol) connection establishment. Different charging criteria may exist even if the units being measured are the same, e.g. bytes. In the case of the present embodiment, these services of different charging standards form each service group.

The rating device 26 may reserve resources, such as funds, from the prepaid system 24. The rating device 26 receives the charging criteria 32 for the service providers 12, 14 and 16. The information may come from a service provider or from other sources, such as an operator or local configuration. The rating device 26 then sets the initial data transfer limit 34 for each service group separately. The maximum consumable amount in appropriate units such as minutes, kilobytes, clicks, and the like is notified to the measurement device 28. Preferably, the respective maximum consumable amounts for all services are sent in one message. The measurement device 28 may then take care to redistribute units between service groups when needed. In this manner, it is possible to use all funds reserved from the prepaid system 24 regardless of the initial data transfer limit 34. The measurement device 28 may also be able to report the consumption for all service groups. There is no communication between the measuring device 28 and the rating device 26 and therefore the prepaid system 24 is needed before the full reserved resources 30 are used.

The above-described process is shown in the flowchart of fig. 2. Resources are reserved from the prepaid system in step 100. In step 102, an initial data transfer limit is set in the rating device for each group based on the resource and information about charging criteria. In step 104 a message containing information about the initial data transfer limit is sent from the rating device to the measuring device. In step 106, proportional data transfer limits are individually assigned in the measurement device for each service group. At step 108, the remaining resources are reallocated in the measurement device to the service groups based on their pricing weights to obtain a new proportional data transfer limit for each service group individually for transferring data after the service group exceeds its proportional data transfer limit.

When at least one service group uses the maximum consumable amount of a service, the measurement device 28 reallocates the remaining resources between the service groups. This reallocation may be accomplished through the use of quota equalization 38. This quota equalization enables assurance that all of the funds allocated by the quota device 26 may be consumed before a new limit is required. The purpose of quota balancing is to minimize the amount of traffic from the measuring device 28 to the rating device 26 and the actual prepaid system 24. The quota balancing is a process of repartitioning the remaining resources. It is an iterative process and can continue as long as any resources remain. Fig. 3 shows a possible equalization process taking place in the measuring device.

The rating device 26 is a system that interfaces with the actual prepaid system 24. The rating device 26 may reserve a certain amount of resources 30, typically funds, from the prepaid system 24. The rating device 26 may be in contact with the service providers 12, 14 and 16. The rating device 26 is thus aware of the charging criteria 32 and can assign initial data transfer limits 34 to service groups based on, for example, the unit price of each group. In quota balancing 38, the funds are advantageously evenly divided among the groups. This means that each service group in quota balancing is preferably allocated an amount of service worth the same amount of funds, so that expensive groups get less restrictions than cheaper groups. The measuring device 28 does not need to know any information about the price.

After the measuring device 28 has received the list of initial data transfer limits 34 for the service groups at step 200, it may calculate proportional data transfer limits and pricing weights for each group at step 202. If the resources are divided into groups before the limit is calculated, the proportional limit may be the amount of resources belonging to the group in the simplest form. This limit for each group can be given as the total amount of resources that each group may consume. The proportional limit is useful because it defines the amount of security of the service that can be delivered to each group before further checks are needed, even if the communication would spread over multiple groups. Pricing weights show the importance of a certain set of limits compared to the total data transfer limit.

In step 204, measurement device 28 measures the consumption 36 of each service set while the service or data transfer is in progress. At step 206, the consumption is compared to the data transfer limit proportional to each group. At step 208, when the service set exceeds its proportional data transfer limit, the remaining total available limit is calculated. This remaining total available limit corresponds to the amount of resources that have not been consumed from the resources reserved by the rating device 26 from the prepaid system 24.

The measuring device reallocates the remaining resources between the service groups in step 210. This reallocation is based on pricing weights previously calculated by measurement device 28 for each service group. If no resources remain within the total available limit, no equalization is performed.

The rating device 26 and the measuring device 28 may communicate using any suitable protocol. In the following, certain variables used in the communication between the rating device 26 and the measuring device 28 according to certain embodiments of the present invention are defined. The examples given below are merely examples, and any suitable device or protocol may be used.

An appropriate variable may be used to inform the measurement device what service groups can be balanced together. This functionality reduces the amount of accounting packets that need to be transferred between the measuring device and the rating device. Based on this variable, the rating device is able to reserve funds to be used among several service groups without explicitly specifying the exact number limit on each group. Thus, the amount of the representative funds can be repartitioned among the groups as long as any unused quota remains. If the funds for a particular group are from a different source, such as from a sponsor, it may be excluded from the balance.

In the following example, the equalization variable is provided by the variable "eg". By default, i.e., when no "eg" variable is provided, no equalization is performed. The clear code "eg" can be used to refer to equalizing all groups. The groups can be marked as belonging to the equalization. For example, symbol (+) may refer to a group belonging to equalization. Then the symbol (-) may mean that the group does not belong to equalization. As an example, the parameter "eg" may have the form "eg ═ + + - -". If there are fewer groups than the limit in the "eg" list, the rule may be to exclude additional groups from the balance. Thus, "eg" - + - - "and" eg "- + -" may refer to the same in certain embodiments. Similarly, the absence of "eg" and "eg ═ may mean that any group will be unbalanced.

Groups that share the same resource source and belong to the equalization process may each be given a maximum number limit. This would mean that each group could consume all of the funds individually if only that group were used.

The equalization may obtain proportional weights for the groups based on a number assignment, as described below.

One or more equalization groups may be used simultaneously.

The variable "ru" is used to indicate reporting limits for several service groups for the measurement device. These limits may be separated by a slash (/) and the value may represent the total traffic (═ inbound + outbound). The variable "ru" can also represent a quantity, time, click amount, etc., as long as only one criterion is used as a limiting criterion. If a group is a balanced part (see "eg"), the reporting limit may be the maximum number that may belong to the group. In some embodiments, communications to certain groups may be free and therefore not limited. This may be indicated to the measuring device, for example by a plus sign ("+") or any other suitable means. Thus, the variable "ru" may, for example, have a value of "ru +/10/50" to indicate that group 0 is free and therefore no reporting restrictions apply, that group 1 may have a reporting restriction of 10kB, and that group 2 may have a restriction of 50 kB.

The equalization can be controlled by the rating device using the "eg" variable. A null value "eg ═ prohibits this equalization. When the rating device knows (or assumes) that there is a possibility that the user will run out of funds when a given limit has been reached, it may send a communication pause variable to the measuring device indicating to the measuring device that no chargeable communication should be allowed to pass after the measuring device sends the next report. This can be used by the rating device when a limit is assigned indicating the last money of the user. Such an indication is preferably sent together with the data transfer restriction.

When the measuring device receives the communication pause variable, it can calculate the traffic and perform quota equalization as usual. When the usage limit is reached, the measuring device sends an update message to the quorum device and begins to block the user's communication until a reply has been received.

This blocking may be applied only to groups that have reached the limit. If equalization is disabled globally or only for depleted groups, traffic may be allowed to the group that has not reached the limit. By means of the communication pause variable, the rating device can ensure that the user will not get any available traffic that may flow through before the response is processed by the measuring device.

In the following, a preferred quota balancing mechanism is explained with reference to a mathematical representation.

For simplicity of presentation, it is assumed that the variable "eg" is filled with "+" symbols, and therefore all service groups are included in the equalization process.

When receiving q from the rating device_i1When (i ═ 1.. n), let q_i1Is the restriction for group i in the first round. The measuring device therefore receives the information packet ru ═ q in the first message₁₁/q₂₁/.../q_n1. In general, the restriction for group i over test interval j (j 1.) is passed through q_ijAnd (4) showing. l_ijThe proportional limit for group i at wheel j is indicated and defined as:

total limit L for quantity over reporting interval j_jIs defined as:

since the prices for these groups can be different, the total price for all groups can beThe following pricing weight p is defined for each group i (i 1.. n) of the wheel j (j 1.. n)_ijTo calculate.

In addition, when redistributing, a multiplier for adjusting the limit is required. The weight at each set of the round j is

And it is well selected because of

Let v_ijThe number of measurements for group i at round j. When in use

Group i has exceeded its limit for wheel j. Limits for each i on wheel j +1 (l)_ij+1) Constraint L based on residual_j+1And (3) calculating:

if L is_j+1< 0, the equalization has failed and the measurement device can report the consumption to the rating device.

Examples of the invention

Example 1

There are 3 different price groups, the first group being $ 1 unit, the second group being $ 1 unit and $ 2 and the third group being $ 1 unit and $ 4. The rating device reserves $ 36 and calculates the amount of value equivalent to the funds for all groups that belong to the balance. The rating device therefore responds to the measuring device with "eg ═ + + +" and "ru ═ 36/18/9". If the traffic consists of only 3 units for the last group, the user has consumed an amount worth $ 12 ($ 3 units x $ 4).

If the remaining $ 24 is repartitioned, it means that each group gets a proportional limit worth $ 8, which results in new limits of 8, 4, and 2 units, respectively.

If these numbers are used in the above formula, we will see how quota balancing handles the same situation without knowing anything about the actual price. In this case n is 3 andandthereby to obtain

The communication consumes only the third group, which has an amount of 3 units. Thus v₃₁Is increased and(because of). In fact, according to the formula, it should be > rather than ≧ but for ease of representation, let equal trigger the process. So that now equalization is performed:

now, we can calculate the value for the second round when j is 2. First, we calculate L2:

according to the formulaWe thus get:

thus, the formula gives the desired result without using the price.

Example 2

In some embodiments, the pricing may be different for different times of day or week, for example. Such pricing can also be easily achieved in a measuring device constructed according to the above principles by dividing the services into several service groups based on the time. When the tariff time changes, the communication is considered to belong to a different service group. This is described in the following example.

We define 2 different services: service a is free and service B costs $ 1/MB at office hours (8 am-5 pm) and $ 0.50 at other times. Any service may have a validity interval in the measurement device and therefore we need to define an additional service group to be able to implement both tariffs for the same service (service B in this case). Therefore, we end up with the following service set: 0 for free communication of service a, service group 1 for "service B having a price of $ 1 at business hours" and service group 2 for "service B having a price of $ 0.50 at non-business hours".

We can easily see that at any time the user's communication will belong to service classes 0 and 1 or 0 and 2, but not to their three at the same time.

When the rating device reserves $ 2 from the prepaid system, it will give a quota to the measuring device with the "ru" variable ru +/2048/4096. This means that category 0 is free of charge, category 1 can use 2MB and category 2 can use 4 MB.

It is assumed that there is no tariff change and that it is daytime. Thus, the communications belong to classes 0 and 1. Proportional Limit for Category 1 (l)₁₁) Is 2048/2-1024. 1MB traffic belonging to class 1 has been generated at the userThereafter, the proportional limits for Category 1 have been expendedAnd has consumed the fund $ 1.

The measuring device performs an equalization if the rating device allows, which results in a proportional limitationAnd(the remaining $ 1 is repartitioned to 2 billable categories using the original scale). This continues until the user has generated traffic worth all $ 2, i.e., 2MB for service class 1. The measuring device then asks the quorum device for more quota.

The same pattern applies at night.

Then, assuming a clock of 5pm, the original quota is similar to (ru +/2048/4096) above, and the user has generated 512kB traffic for category 1From now on, chargeable communications belong to category 2. Thus, in appending 2MB to Category 2Afterwards-and a total of 2.5MB of traffic-this situation isThe equalization is therefore performed by the following values:

remaining proportional limit (l)₁₂And l₂₂) Indicating how to classify the remaining $ 0.50 into the following categories: 512kB at office time and 1024kB at other times through $ 0.50, and thusAndthe next equalization starts after 512kB and continues as such. At the end, the user has consumed 512MB for category 1 and 3MB for category 2, which is $ 0.50+1.5 to $ 2 in total.

While the invention has been described in terms of specific embodiments, various modifications are possible without departing from the scope and spirit of the invention as defined by the appended claims. For example, the rating device and the measurement device may be any suitable devices using any suitable protocol, as will be appreciated by those of ordinary skill in the art. In a particular embodiment, it is also possible to actually provide the rating device and the measuring device in one device. Even in this case, the simplified effect of the invention allows for an efficient data transfer with minimal signaling between different network entities.

Claims

1. A method for controlling prepaid data services, said prepaid data services being divided into at least two service groups of different charging criteria in a network, the method comprising the steps of:

the resources are reserved from the pre-paid system,

setting initial data transfer limits for each service group by the rating device based on said resources and information about charging criteria,

sending a message containing information about initial data transfer limitations from the rating device to a measurement device,

in the measuring device, proportional data transfer limits are allocated individually for each service group, an

Reallocating remaining resources to the service groups in the measuring device based on pricing weights of the service groups to obtain new proportional data transfer limits for each service group individually, the new proportional data transfer limits being used to transfer data after a service group has exceeded its proportional data transfer limit.

2. The method of claim 1, further comprising the step of: a proportional data transfer limit for each service group is defined as a proportion of the initial data transfer limit.

3. The method according to claim 1 or 2, further comprising the step of: a pricing weight for each service group is defined as a ratio of a sum of the proportional data transfer limits to an initial data transfer limit for the service group.

4. The method according to claim 1 or 2, further comprising the step of: sending a report from the measurement device to the quorum device after all reserved resources have been used.

5. The method of claim 3, further comprising the step of: sending a report from the measurement device to the quorum device after all reserved resources have been used.

6. The method according to claim 1 or 2, further comprising the step of: the initial data transfer limit is defined as an amount equivalent to the same amount of funds for each service group.

7. The method of claim 3, further comprising the step of: the initial data transfer limit is defined as an amount equivalent to the same amount of funds for each service group.

8. A system for controlling prepaid data services, comprising:

a prepaid system hosting prepaid resources;

a rating device for obtaining information of prepaid resources and charging standards for each service group and setting an initial data transfer limit for each service group based on the obtained information; and

a measuring device for individually assigning a proportional data transfer limit for each service group, measuring usage of each service group, and reallocating remaining available resources to service groups based on pricing weights of the service groups when a service group exceeds its proportional data transfer limit to individually obtain a new proportional data transfer limit for each service group for transferring data.

9. A communication system for providing prepaid services to subscribers thereof, the communication system comprising:

at least one data communication network;

a prepaid system hosting prepaid resources;

a measuring device for individually assigning a proportional data transfer limit for each service group, measuring usage of the service groups, and reallocating remaining available resources to the service groups based on pricing weights of the service groups when a service group exceeds its proportional data transfer limit to individually obtain a new proportional data transfer limit for each service group for transferring data.

10. A communication system according to claim 9, wherein the at least one data communication network comprises a packet core communication network for data communication between a user and the metering device, and a public data network for data communication between the metering device and a prepaid service provider.

11. A controller for controlling prepaid data services, said prepaid data services being divided into at least two service groups of different charging criteria in a network, the controller comprising:

a reservation means for reserving resources from the prepaid system;

setting means for setting initial data transfer limit for each service group by rating means based on the resource and information on charging standard;

sending means for sending a message containing information about initial data transfer limitations from the rating device to a measurement device;

allocating means for allocating in the measuring apparatus a proportional data transfer limit individually for each service group; and

reallocating, in the measuring device, remaining resources to the service groups based on their pricing weights to obtain individually a new proportional data transfer limit for each service group, the new proportional data transfer limit being used to transfer data after a service group has exceeded its proportional data transfer limit.

12. The controller of claim 11, further comprising defining means for defining a proportional data transfer limit for each service group as a proportion of the initial data transfer limit.

13. The controller of claim 12, further comprising second defining means for defining a pricing weight for each service group as a ratio of a sum of the proportional data transfer limits to an initial data transfer limit for the service group.

14. A controller according to any of claims 11-13, further comprising second transmitting means for transmitting a report from the measuring device to the rating device after all reserved resources have been used.

15. The controller according to claim 11, further comprising defining means for defining the initial data transfer limit as an amount equivalent to the same amount of funds for each service group.

16. The controller according to claim 12, further comprising second defining means for defining the initial data transfer limit as an amount equivalent to the same amount of funds for each service group.

17. The controller according to claim 13, further comprising third defining means for defining the initial data transfer limit as an amount equivalent to the same amount of funds for each service group.

18. A rating device for controlling prepaid data services to at least two service groups of different charging criteria in a network, the rating device comprising:

means for obtaining information on prepaid resources reserved from the prepaid system and charging criteria for each service group of prepaid data services,

means for setting initial data transfer restrictions for the service groups based on the obtained information, and

means for sending a message to the measurement device containing information about the initial data transfer limit.

19. A metering apparatus for controlling prepaid data services divided into at least two service groups of different charging criteria in a network, the metering apparatus comprising:

means for assigning a proportional data transfer limit individually for each service group,

means for measuring the usage of each service group, an

Means for reallocating remaining available resources to the service groups based on pricing weights of the service groups when one service group exceeds its proportional data transfer limit to individually obtain a new proportional data transfer limit for each service group for transferring data.