The present invention pertains to the management of changes in
conditions for delivering a service associated with a current communication
established by a user terminal and, more specifically, the management of changes
in conditions for delivering a service that cause a change in billing conditions for
delivering the service.
The document 3GPP TS32.299 defines a Ro interface for real-time
charging between a Charging Trigger Function (CTF) module and an Online
Charging System (OCS) module.
Trigger and re-authorization functions define events that the CTF module
must monitor while delivering a service. Whenever such an event takes place—for
example, a change of location or a change in quality of service—the CTF module
must trigger a reauthorization for the OCS module in order to adapt the service's
charging.
The OCS module monitors the delivery of a service by means of a
Diameter session, during which charging is performed by reserving units. If, during
the delivery of a service, a change takes place that may influence rates, the CTF
module must produce a message to reserve new units with updated conditions.
For example, a change may be a modification of the number of participants
in a conference, or a modification of a type of media in a multimedia call, or a
change in quality of service.
Subsequent to that change, the OCS module may reject a reservation of
new units made with the updated conditions for a user who has requested and is
paying for the service. For example, the service with the updated conditions may be
billed to a specific sub-account that has no credit.
Currently, the Diameter Ro protocol does not allow conditional changes
while delivering a service. If the OCS module is not capable of delivering the service
with the amended charging conditions, the OCS module transmits a reply with a
Result-Code that contains a field filled by an Attribute–Value Pair (AVP) that
corresponds to a failure, with this reply ending the Diameter session and the
delivery of the service.
3
One objective of the invention is to remedy the aforementioned
shortcomings by ensuring continuity of service whenever the charging conditions
associated with the service happen to change.
To achieve this goal, a method for managing a change in a usage condition
of a service associated with a current communication established by a user terminal
within a telecommunications network comprises the following steps for a server
included within the telecommunications network:
after receiving a first request coming from a network element capable of
generating charging events while monitoring the communication's use of the
network's resources, said request comprising a service identifier related to the
communication and a parameter defining a service usage condition change,
determining that the user's account does not allow the delivery of the
service with the change in a service's usage conditions and transmitting to the
network element a reply containing a code indicating that the delivery of the service
is authorized only with other conditions for using the service, in order for the
network element to transmit a second request to the server, the second request
containing another parameter defining a service usage condition change different
from the one contained in the first request.
Advantageously, the invention offers an additional feature to the
telecommunication network, allowing a conditional change in charging conditions. In
other words, if the conditions for delivering a service happen to change, and the
server that comprises an OCS module is no longer able to deliver and bill the
service under the altered conditions, the OCS module allows the network element
that comprises a CTF module to continue delivering the service under other
conditions rather than terminating the service.
The invention also pertains to a method for managing a change in a usage
condition of a service associated with a current communication established by a
user terminal within a telecommunications network, comprising the following steps
in a network element capable of generating charging events while monitoring the
communication's use of the network's resources:
transmitting a first request to a server, said request comprising an identifier
of the service related to the communication and a parameter defining a service
usage condition change, in order for the server to determine that the user's account
4
does not allow the delivery of the service with the service usage condition change,
and to transmit to the network element a reply containing a code indicating that the
delivery of the service is authorized only with other conditions for using the service,
and
transmitting a second request to the server, the second request containing
another parameter defining a service usage condition change different from the one
contained within the first request.
According to other characteristics of the invention, the parameter contained
within the second request may define a new service usage condition change
different from the requested condition change contained within the first request,
which does not match the old service usage conditions prior to the transmission of
the first request, or the parameter contained within the second request may define a
new service usage condition change that matches the old service usage conditions
prior to the transmission of the first request.
According to another characteristic of the invention, the reply may contain a
validity time defining a period during which the network element may transmit
another request to the server; upon the expiration of that period, the session shall
terminate if no request has been transmitted.
The invention also pertains to a server for managing a change in a usage
condition of a service associated with a current communication established by a
user terminal within a telecommunications network, comprising:
means for determining that the user's account does not allow the delivery
of the service with a change in the conditions for using a service, after the receipt of
a first request coming from a network element capable of generating charging
events while monitoring the communication's use of the network's resources, said
request comprising a service identifier related to the communication and a
parameter defining the service's usage condition change,
means for transmitting to the network element a reply containing a code
indicating that the delivery of the service is authorized only with other conditions for
using the service, in order for the network element to transmit a second request to
the server, the second request containing another parameter defining a service
usage condition change different from the one contained in the first request.
5
The invention also pertains to a network element for managing a change in
a usage condition of a service associated with a current communication established
by a user terminal within a telecommunications network, the network element being
capable of generating charging events while monitoring the communication's use of
the network's resources and comprising:
means for transmitting a first request to a server, said request comprising
an identifier of the service related to the communication and a parameter defining a
service usage condition change, in order for the server to determine that the user's
account does not allow the delivery of the service with the service usage condition
change, and to transmit to the network element a reply containing a code indicating
that the delivery of the service is authorized only with other conditions for using the
service, and
means for transmitting a second request to the server, the second request
containing another parameter defining a service usage condition change different
from the one contained within the first request.
The invention also pertains to computer programs capable of being
implemented within a server and within a network element, said programs
comprising instructions which, when the programs are executed within said server
and said communication device, carry out steps according to the inventive method.
The present invention and the benefits thereof shall be better understood
upon examining the description below, which makes reference to the attached
figures, in which:
- Figure 1 is a schematic block diagram of a communication system
according to one embodiment of the invention for managing changes in conditions
for delivering a service; and
- Figure 2 is an algorithm of a method for managing changes in conditions
for delivering a service according to one embodiment of the invention.
With reference to Figure 1, a communication system according to the
invention comprises a telecommunications network RT, a user terminal TU, a
charging trigger module MDT and a charging control module MCT.
6
In the remainder of the description, the term module may designate a
device, a software program, or a combination of computer hardware and software,
configured to execute at least one particular task.
The telecommunication network RT may be a wired or wireless network, or
a combination of wired and wireless networks.
The user terminal TU is capable of establishing a communication within a
telecommunications network RT, for example with another user terminal. A user
terminal TU may, for instance, be a landline or mobile telephone, an electronic
telecommunication device or object that is personal to the user and which may be a
personal digital assistant (PDA) or a smartphone, capable of being connected to an
access terminal of a public wireless local area network (WLAN), or a wireless local
area network that complies with one of the 802.1x standards, or a medium-range
network using the Worldwide Interoperability for Microwave Access (WiMAX)
protocol.
The charging trigger module MDT and the charging control module MCT
communicate with one other over the telecommunications network RT, of the
Internet type. In one variant, the charging trigger module MDT and the charging
control module MCT communicate with one other over a local area network or over
specialized lines through the network RT.
The charging trigger module MDT and the charging control module MCT
may respectively be implemented in different servers, such as application servers.
A particular functionality of the charging trigger module MDT is to ensure
that the service is delivered with the assistance of service units authorized by the
charging control module MCT, which it regularly triggers in order to do so.
A particular functionality of the charging control module MCT is to
determine an authorized number of service units for delivering the service, and to
transmit a reply containing that authorized number of service units to the charging
trigger module MDT. To that end, the module MCT may determine a rate associated
with the account or sub-account to be used to charge the service, and may
determine the authorized number of service units based on the rate and on the
number of service units remaining in the account or sub-account.
Furthermore, whenever the charging control module MCT receives a
number of units that are actually being used for the service, transmitted by the
7
charging trigger module MDT, the module MCT decrements the corresponding
account or sub-account.
According to one embodiment of the invention that will be referred to
throughout the remainder of the description, the telecommunication network RT is a
packet network connected to an IP Multimedia Subsystem (IMS) network.
It is assumed that the user terminal is capable of communicating through
the telecommunications network RT connected to the IMS network, for example
with another terminal, using communication compliant with the Session Initiation
Protocol (SIP). For example, the communication corresponds to an exchange of
multimedia flows regarding audio and/or video content, or instant messages. The
communication established by the user terminal may also be a communication with
a service server, such as a web server or multimedia content server.
The user's profile, containing the services to which that user has
subscribed, is saved in a Home Subscriber Server (HSS) server that manages a
database particularly containing users' identities, registration information, access
parameters, and information needed to invoke the services that the users have
subscribed to. In one implementation, the HSS server interacts with other entities of
the IMS network using the Diameter protocol.
The control of a communication initiated by the terminal is performed within
the IMS network, particularly by three Call State Control Function (CSCF) control
entities: the entities Proxy CSCF (P-CSCF), Interrogating CSCF (I-CSCF), and
Serving-CSCF (S-CSCF).
The entity P-CSCF is the first point of contact in the IMS network, and its
address is discovered by the user terminal when a Packet Data Protocol (PDP)
context is activated to exchange SIP messages.
The entity I-CSCF communicates with the entity P-CSCF and with the HSS
server to assign the entity S-CSCF to the user based on the user's profile saved in
the HSS server.
The entity S-CSCF is in charge of controlling the communication session
established by the user terminal and invoking the services to which the user is
subscribed.
The charging trigger module MDT monitors the context of the
communication established by the user terminal, checking whether the value of at
8
least one piece of data among a predefined context data set has changed. This
context data is provided by the telecommunication network and related to the
communication. This context data corresponds, for example, to the
communication's bit rate, or to the communication's quality of service, or to the type
of media used in the communication.
Whenever the charging trigger module MDT detects the expiration of a
given period, or a context data value change, the module MDT queries the charging
control module MCT so that it can provide the module MDT with information about a
change in the communication's charge. The charging trigger module MDT and the
charging control module MCT communicate with one another, for example, by
means of the Diameter Ro protocol.
The charging control module MCT may be included in an online charging
system (OCS), which may be a server located elsewhere in the IMS network.
The charging trigger module MDT may be included in a network element,
such as an application server or Gateway GPRS Support Node (GGSN) gateway.
For example, the charging trigger module MDT implements a Charging Trigger
Function (CTF), which is a central point for collecting relevant information about
charging events in the network and monitoring the communication's use of network
resources.
The network element, in which is included the charging trigger module
MDT, capable of generating charging events while monitoring the communication's
use of network resources.
The charging control module MCT determines the present price of a
current communication based on a set of parameters and the values of those
parameters associated with the price. The parameters are related to the
communication, and may partly correspond to context data provided by the network
or be based on context data sets.
In one example, there is a parameter for the type of media used in the
communication whose value may be either "video" or "audio." The value of this
parameter may be equal to the value of a piece of context data that corresponds to
the type of media used in the communication. In another example, a parameter is
the resolution type of a video used in the communication; its value may be "high" or
"low." The value of that parameter may be deduced from the context data values
that correspond to the communication's bit rate and the communication's quality of
9
service. In yet another example, a parameter is the number of participants in an
audio conference, and its value may be comprised between "3" and "5".
With reference to Figure 2, a method for managing changes in conditions
for delivering a service according to one embodiment of the invention comprises
steps E1 to E6 executed within the communication system.
The method is described below with reference to a telecommunication
network RT connected to an IMS network as an example.
In step E1, the terminal TU establishes a communication within the network
RT, for example with a media server. The terminal transmits a communication
session initiation message to the charging trigger module MDT. This message is,
for example, an "INVITE" message, and particularly contains an identifier of the type
of communication requested by the user, which corresponds, for example, to a
session or a video session. The charging trigger module MDT identifies the user's
profile and the type of service related to the communication. The module MDT
transmits a Credit Control Request (CCR) to the charging control module MCT to
request authorization to use the service related to the communication established
by the terminal TU.
The request CCR particularly contains an identifier IdS of the service and a
number of requested service units (RSUs). The service units may correspond to
monetary units or telephone credit units. The request CCR further contains at least
one communication parameter ParI that defines an initial condition for using the
service, the parameter ParI potentially being a number of participants in a telephone
conference, equal to "3" for example, or a resolution of a video, equal to "low" for
example.
In step E2, the charging control module MCT determines the
communication's initial price, based on a set of parameter values related to the
communication and the type of service by means of the identifier IdS. The charging
control module MCT verifies that the service can be delivered based on the user's
account, meaning if the account contains enough units to authorize the delivery of
the service.
The charging control module MCT generates a Credit Control Answer
(CCA) containing, in particular, the number of granted service units (GSUs).
10
The number of GSUs corresponds to a maximum number of units that are
debited over the course of the communication, and once all the units have been
debited, the charging trigger module MDT must automatically query the charging
control module MCT again in order to request a number of RSUs.
The charging control module MCT transmits the reply CCA to the charging
trigger module MDT.
In step E3, preferences for using the service are changed, for instance by
the user, for instance by increasing the number of participants in a telephone
conference, or by increasing the resolution of a video.
The charging trigger module MDT again transmits a request CCR to the
charging control module MCT. The request CCR particularly contains the identifier
IdS of the service, another number of RSUs and a number of used service units
(USUs). If all the GSUs have been debited, the number GSU is equal to the number
USU.
The request CCR further contains a communication parameter ParC
defining a condition for using the service, the parameter potentially being a number
of participants in a telephone conference, equal to "4" for instance, or a video
resolution, equal to "high" for instance.
In step E4, the charging control module MCT checks whether the
requested change in conditions for using the service allows the delivery of the
service based on the pricing conditions and on the user's account.
The charging control module MCT determines that the user's account does
not allow the delivery of the service with the service usage condition change. The
charging control module MCT produces a message with a Result Code (RC), equal
to 4020 for example, indicating that delivery of the service is authorized only with
other conditions for using the service, meaning that the service cannot be delivered
with the condition change, but may be delivered with the old conditions or potentially
other conditions.
The charging control module MCT transmits the reply CCA to the charging
trigger module MDT containing the code RC and a validity time VT. The validity time
VT defines a period during which the charging trigger module MDT may again
request authorization to use the service related to the communication established
11
by the terminal TU, and upon whose expiration the session terminates if no request
has been made.
In step E5, the charging trigger module MDT may decide to reject the
changed conditions for using the service and to continue delivering the service with
the old conditions, or potentially with other conditions.
The charging trigger module MDT again produces a request CCR.
The request CCR particularly contains the identifier IdS of the service and
another number of RSUs. The request CCR further contains a communication
parameter ParC2 defining a service usage change condition, the parameter
potentially being a number of participants in a telephone conference, equal to "3"
again for instance, or a video resolution, equal to "low" again for instance,
corresponding to the old conditions for using the service. The old conditions
therefore correspond to the last conditions with which the delivery of the service has
been accepted, meaning the conditions for using the service prior to the
transmission of the request CCR in step E1.
The charging trigger module MDT transmits the request CCR with RSU.
In one variant, the request CCR contains a communication parameter
ParC2 defining a new service usage condition change different from the condition
change requested in step E3 and which does not correspond to the old conditions
for using the service, the parameter potentially being a video resolution equal to
"medium", for instance.
In step E6, the charging control module MCT determines the current price
of the communication based on the conditions for using the service and checks that
the service can be delivered based on the user's account, i.e. that the account
contains enough units to authorize the delivery of the service.
The charging control module MCT transmits a reply CCA to the charging
trigger module MDT, the reply containing, in particular, a number of GSUs.
The invention described here relates to a method, a service, and a network
element for managing a communication's pricing changes. According to one
implementation of the invention, the steps of the invention are determined by the
instructions of computer programs incorporated into the server or network element.
12
The programs comprise program instructions which, when said programs are
loaded and executed within the server and network element respectively, carry out
the steps of the inventive method.
Consequently, the invention also applies to a computer program,
particularly a computer program on or within an information medium, suitable to
implement the invention. This program may use any programming language, and be
in the form of source code, object code, or intermediate code between source code
and object code, such as in a partially compiled form, or in any other form desirable
for implementing the inventive method.
13

I/We Claim:
1. A method for managing a change in a usage condition of a service
associated with a current communication established by a user terminal (TU) within
a telecommunications network (RT), comprising the following steps in a server
included within the telecommunications network:
after receiving a first request (CCR) coming from a network element
capable of generating charging events while monitoring the communication's use of
the network's resources, said request comprising an identifier (IdS) of the service
related to the communication and a parameter (ParC) defining a service usage
condition change,
determining (E4) that the user's account does not allow the delivery of the
service with a change in the conditions for using a service and transmitting to the
network element a reply (CCA) containing a code (RC) indicating that the delivery of
the service is authorized only with other conditions for using the service, in order for
the network element to transmit (E5) a second request (CCR) to the server, the
second request (CCR) containing another parameter (ParC2) defining a service
usage condition change different from the one contained in the first request.
2. A method according to claim 1, whereby the parameter (ParC2) contained
within the second request defines a new service usage condition change, which
matches the old service usage conditions prior to the transmission of the first
request.
3. A method according to claim 1, whereby the parameter (ParC2) contained
within the second request defines a new service usage condition change different
from the requested condition change contained within the first request, and which
does not match the old service usage conditions prior to the transmission of the first
request.
4. A method according to one of the claims 1 to 3, whereby the reply (CCA)
contains a validity time defining a period during which the network element may
14
transmit another request to the server, upon whose expiration the session shall
terminate if no request has been transmitted.
5. A method for managing a change in a usage condition of a service
associated with a current communication established by a user terminal (TU) within
a telecommunications network (RT), comprising the following steps in a network
element capable of generating charging events while monitoring the
communication's use of the network's resources:
transmitting (E3) a first request (CCR) to a server, said request comprising
an identifier (IdS) of the service related to the communication and a parameter
(ParC) defining a service usage condition change, in order for the server (E3) to
determine that the user's account does not allow the delivery of the service with the
service usage condition change, and to transmit to the network element a reply
(CCA) containing a code (RC) indicating that the delivery of the service is
authorized only with other conditions for using the service, and
transmitting (E5) a second request (CCR) to the server, the second request
(CCR) containing another parameter (ParC2) defining a service usage condition
change different from the one contained in the first request.
6. A server for managing a change in a usage condition of a service
associated with a current communication established by a user terminal (TU) within
a telecommunications network (RT), comprising:
means (MDT) for determining that the user's account does not allow the
delivery of the service with a change in the conditions for using a service, after the
receipt of a first request (CCR) coming from a network element capable of
generating charging events while monitoring the communication's use of the
network's resources, said request comprising an identifier (IdS) of the service
related to the communication and a parameter (ParC) defining the service's usage
condition change,
means (MDT) for transmitting to the network element a reply (CCA)
containing a code (RC) indicating that the delivery of the service is authorized only
with other conditions for using the service, in order for the network element to
transmit (E5) a second request (CCR) to the server, the second request (CCR)
15
containing another parameter (ParC2) defining a service usage condition change
different from the one contained in the first request.
7. A network element for managing a change in a usage condition of a
service associated with a current communication established by a user terminal
(TU) within a telecommunications network (RT), the network element being capable
of generating charging events while monitoring the communication's use of the
network's resources and comprising:
means (MCT) for transmitting a first request (CCR) to a server, said
request comprising an identifier (IdS) of the service related to the communication
and a parameter (ParC) defining a service usage condition change, in order for the
server (E3) to determine that the user's account does not allow the delivery of the
service with the service usage condition change, and to transmit to the network
element a reply (CCA) containing a code (RC) indicating that the delivery of the
service is authorized only with other conditions for using the service, and
means (MCT) for transmitting a second request (CCR) to the server, the
second request (CCR) containing another parameter (ParC2) defining a service
usage condition change different from the one contained in the first request.
8. A computer program capable of being implemented within a server for
managing a change in a usage condition of a service associated with a current
communication established by a user terminal (TU) within a telecommunications
network (RT), said program comprising instructions which, when the program is
loaded and executed within said server, carry out the following steps:
after receiving a first request (CCR) coming from a network element
capable of generating charging events while monitoring the communication's use of
the network's resources, said request comprising an identifier (IdS) of the service
related to the communication and a parameter (ParC) defining a service usage
condition change,
determining (E4) that the user's account does not allow the delivery of the
service with a change in the conditions for using a service and transmitting to the
network element a reply (CCA) containing a code (RC) indicating that the delivery of
the service is authorized only with other conditions for using the service, in order for
the network element to transmit (E5) a second request (CCR) to the server, the
16
second request (CCR) containing another parameter (ParC2) defining a service
usage condition change different from the one contained in the first request.
9. A computer program capable of being implemented within a network
element for managing a change in a usage condition of a service associated with a
current communication established by a user terminal (TU) within a
telecommunications network (RT), the network element being capable of generating
charging events while monitoring the communication's use of the network's
resources and comprising, said program comprising instructions which, when the
program is loaded and executed within said server, carry out the following steps:
transmitting (E3) a first request (CCR) to a server, said request comprising
an identifier (IdS) of the service related to the communication and a parameter
(ParC) defining a service usage condition change, in order for the server (E3) to
determine that the user's account does not allow the delivery of the service with the
service usage condition change, and to transmit to the network element a reply
(CCA) containing a code (RC) indicating that the delivery of the service is
authorized only with other conditions for using the service, and
transmitting (E5) a second request (CCR) to the server, the second request
(CCR) containing another parameter (ParC2) defining a service usage condition
change different from the one contained in the first request.