Control decisions in a communication system

Control decisions in a communication system

The present invention relates to communication systems, and in particular to a decision stage of how to control communications through a gateway. The decision may refer to controlling operations such as authorization and control of policies applied to communications routed through a gateway.

A communication system can be seen as an installation that allows communication between two or more entities such as user equipment, servers, gateways and / or other nodes. Communication can comprise, for example, voice, data, multimedia communication and so on. A communication system can allow a user of the same to be provided with different types of services. For example, a user equipment may be in communication with an application server (AS), such as a server of a service provider, through a communication system.

The term "service" used previously and hereafter in this document will be understood, in a general way, that it covers broadly any service that a user may desire, require or provide through the communication system. It will also be understood, in a general manner, that the term covers the provision of complementary services. In particular, but not exclusively, the term "service" shall be understood to include navigation, download, email, continuous transfer services, multimedia (IM) services of the internet protocol, conference, telephony, games, call quality, presence, electronic commerce and messaging, for example, instant messaging.

Signaling between the various entities associated with a communication session is normally required in order to control the communication session. Control is normally required for the establishment of the communication session and also later during the communication of the established session. Signaling can be based on an appropriate protocol or communication protocols.

Communication can be provided through a landline and / or wireless communication interfaces. An example of the landline system is a public switched telephone network (PSTN). Wireless communication can be provided through a mobile communication system. Another example of wireless communication systems is the wireless local area network (WLAN). Mobile communication systems generally refer to any of the communication systems that allow wireless communication to users who can move within the system's service area. An example of a typical mobile communications system is a public land mobile network (PLMN).

A wireless communication system is normally provided with a plurality of access networks. Access networks are to provide a user with wireless access to the central part of the network of the communications network. An access network typically comprises at least one base station system and a radio network controller functionality. The access network can be configured to provide a package of services for the mobile user equipment through the base stations.

The mobile communications network can then be used to access other destinations, such as other networks, central computers, services offered by specific service providers and so on. Such access is provided by nodes that are usually referred to as access points. Normally, an access point or gateway node of the mobile communications network provides additional access to an external network or an external central computer. For example, if the requested service is provided by a service provider located on another network, the service request is routed through a gateway to the other network and to the service provider. The routing can be based on definitions in the mobile subscriber data stored in the mobile network.

A user may need to be a subscriber to the communications system in order to be able to use the services provided through the communications system. Subscriber data is normally stored in a subscriber database for each subscriber. The database is usually controlled by the network operator that provides the access service. The subscriber data may comprise information regarding the quality of service (QoS) the subscriber is entitled to receive, priorities, service restrictions, security, authentication, charging, and so on.

Various different communication standards and protocols have already been developed. Also, new standards and protocols are continually being developed. To distinguish previous developments from the most recent developments, mobile communications standards are divided into different generations. For example, some standards, such as the first digital mobile standards, are referred to as the second generation (2G) standards while the most recent developments in digital mobile telephony are often referred to as the third generation (3G) standards .

The access networks that the user can use to access the services can substantially support different characteristics, depending on the standard used and / or the generation / version of the standard. In addition, the user can use access networks that rely on unlicensed radio or fixed access techniques. Such techniques

Access can substantially support different characteristics, depending on the standard, and the way in which individual access systems are constructed and how these access systems are connected to a backbone network. It will be appreciated that, unlike well-standardized mobile systems, there are no strict and / or commonly accepted standards for unlicensed access systems. For example, the wireless local area network (WLAN), residential WLAN and enterprise WLAN can each technically be considered as being a different type of access network. Also, public WLAN access networks for different wireless access zones can be considered as different types of access networks. For example, different types of WLAN access networks can be provided in hotels in general, in a specific hotel or in a hotel chain, and so on.

A more detailed example of the possible problems that can cause differences between the types of access networks is described below with reference to the general packet radio service (GPRS).

A communications system based on GPRS is an example of wireless communications systems that provide packet switched data transmission to a mobile user equipment. The GPRS functional environment comprises one or more service areas, which are interconnected by a GPRS backbone network. A service area may comprise a number of data packet service nodes (SN). In this specification, service nodes will be referred to as service GPRS support nodes (SGSN). Each of the SGSNs is connected to at least one radio access network. Access networks can be either 2G or 3G access networks.

The data packet service nodes are in turn connected to an external data network, for example, to a public switching data network (PSPDN), through the appropriate gateways, such as the GPRS gateway support nodes (GGSN). Thus, the GPRS allows the transmission of data packets between the mobile user equipment and the external data networks.

An example of the data carriers that can be used to carry traffic flows over the GPRS is a context of the data packet protocol (PDP). A context of the PDP typically includes a radio access bearer provided between the user equipment, the radio network controller and the SGSN, and the switched data packet channels provided between the service GPRS support node (SGSN ) and the GPRS gateway support node (GGSN). A session between the user equipment and another party would then take place in the PDP context. A PDP context may carry more than one traffic flow, but all traffic flows within a specific PDP context are treated in the prior art in the same manner as with respect to their transmission over the network. The requirement for a similar treatment is based on the PDP context processing attributes associated with traffic flows. These attributes may include, for example, service quality and / or charging attributes.

Some features associated with a service flow may need to be controlled by the gateway. The gateway may need to apply control to a traffic flow when a data carrier is established. The control may also need to be applied to a traffic flow in an already established data carrier . The control is based on the political call. In summary, a policy can be seen as a set of rules on how traffic flow should be controlled.

Differences in the type of access networks can cause problems in certain situations. A problem can be caused by the lack of information regarding the access network on the gateway. This may make it impossible for the gateway to adequately provide control of the traffic flows between the different networks with which it interacts. A specific problem revolves around the specific service control of features such as quality of service (QoS), security, charging, access control and so on.

WO 02/052 869 describes a resource allocation system for a network. EP 130 1048 describes a procedure for establishing a connection in a communication system with different traffic carriers.

The embodiments of the present invention are intended to address one or more of the above problems.

In accordance with the invention; a procedure for deciding a policy for controlling communications in a communication system according to claim 1 is provided, and

an apparatus according to claim 25.

The embodiments of the invention may allow specific access control of the provision of services in a communication system. The flexibility of communication systems can be improved. The functional costs of a communication system can be reduced. The embodiments may improve performance during a handover or other change of access network.

For a better understanding of the present invention, reference will now be made, by way of example, to the accompanying drawings, in which

Figure 1 schematically shows a communication system in which the present invention can be realized; Figures 2 and 3 show signaling flow diagrams according to some exemplary embodiments of the present invention; and Figure 4 is a flow chart illustrating the operation of an embodiment of the present invention.

Certain embodiments of the present invention will now be described by way of example with reference to the architecture of a mobile communications system based on GPRS shown in Figure 1. However, it should be understood that the embodiments of the invention can also be applied to any Another suitable form of networks.

A mobile communication system can logically be divided between a radio access network (RAN) and a central network (CN). In the simplified presentation of Figure 1, each base station 31 to 34 and 48 belongs to a radio access network. A radio access network (RAN) can be controlled by a suitable radio network controller (RNC), a base station controller (BSC) or the like. This is not shown in order to increase clarity. A radio access network controller is normally connected to a suitable central network entity or entities such as, but not limited to, a general packet radio service of service support nodes 35 and 45 (SGSN) . It will be appreciated that, although, for clarity, Figure 1 shows only a few base stations, normally the nodes of a central network are connected to a number of base stations through suitable controllers.

A user equipment within a radio access network can communicate with a radio network controller through the channels of the radio network that are normally referred to as radio bearers (RB). These channels of the radio network may be established in a mobile telecommunications network in a known manner. Each user equipment 30 may have one or more radio network channels open at any time with the radio network controller. The relevant radio access network controller is in communication with the service GPRS support node 35 through a suitable interface, for example with a lu interface.

The service GPRS support node 35, in turn, normally communicates with a gateway GPRS support node 40 through the GPRS backbone network at interface 39. This interface is usually a switching interface of data packets The service GPRS support node 35 and / or the gateway GPRS support node 40 are for the provision of support to the GPRS services in the network.

A subscriber database entity 36 is also shown to store information associated with the subscriber of the user equipment 30. The subscriber database may contain various records 38 associated with the subscriber, such as the details of a context subscription PDP of the subscriber of the user equipment.

The basic operating principles of a mobile user equipment, which can also be referred to as a mobile station, are generally known to those skilled in the art. A mobile user equipment is normally configured for wireless communication with other stations, usually with the base stations of a mobile communication system to allow its mobility. A mobile user equipment may include an antenna element for wireless reception and / or the transmission of signals from and / or to the base stations of the mobile communication network. A mobile user equipment may also be provided with a screen for displaying images and / or other graphic information for the user of the mobile user equipment. Speaker means are also normally provided. The operation of the mobile user equipment can be controlled by means of a suitable user interface, such as control buttons, voice commands and so on. Additionally, a mobile station is normally provided with a processor entity and / or memory means. Communication between the mobile user equipment and the entities of the communications network can be based on any suitable communication protocol. A user can use the mobile user equipment for tasks such as, but not limited to, making and receiving telephone calls, receiving and sending data to and from the network and to experience, for example, multimedia content through PDP contexts . For example, a user can access the network through a personal computer (PC), a personal data assistant (PDA), a mobile station (MS) and so on.

It will be appreciated that, although for clarity, only one device is shown in Figure 1, a number of user equipment may be in simultaneous communication with a base station.

Together, communication between the user equipment 30 in an access network and a gateway GPRS support node 40 can be provided by means of a data packet protocol (PDP) context. Each PDP context normally provides a communication path between a specific user equipment and the gateway GPRS support node 40. Once established, a PDP context can normally carry multiple flows. Each flow normally represents, for example, a specific service and / or a media component of a specific service. Therefore, the PDP context often represents a logical communication path for one or more flows through the network. In order to implement the PDP context between the user equipment 30 and the service GPRS support node 35, the radio access bearers (RABs) are normally established that, in a customary manner, allow the transfer of data to the user equipment. The implementation of these logical and physical channels is known to those skilled in the art and, therefore, will not be discussed later in this document.

It will be appreciated that the other access networks, for example non-mobile access networks, can also be used to establish a client access bearer between the user equipment 30 and the gateway GPRS support node 40. Such a client access bearer will be understood as being an equivalent to a PDP context from which a logical communication path is also provided through the network. For example, in a WLAN access or in fixed broadband access networks, a client access bearer can be made through a virtual private network (VPN), a point-to-point protocol (PPP), or IP technology mobile.

The user equipment 30 can connect, through access to the GPRS network, to servers that are generally connected to an external data network, such as, but not limited to, the network 50 of the example internet protocol (IP) .

A policy control entity 52 is also shown that interacts with the gateway 40. The policy controller may be provided by any suitable network entity. For example, the policy control entity may be provided by means of a combined authorization and a policy control node. An IP session control node (IPSC) or a policy decision function (PDF) can also be used for this purpose. The policy control entity 52 may be provided with a database 54 to store the information necessary to create the specific service authorization and policy decisions.

In the embodiment of Figure 1 the gateway 40 is provided with means 41 that determine a type of access network. In the preferred embodiment, the means for determining the type comprise a suitable software code product that is executed on a processor provided on the gateway 40. The possible configurations of the determining means 41 and the function thereof are described in continuation in more detail.

Figure 1 also shows a subscriber management entity 56 connected to the policy control entity 52. ​​The subscriber manager can be provided by means of a directory server or any other suitable database configured to store the information associated with the services available to the subscriber. For example, the subscriber manager may contain information regarding the services that are allowed to a certain subscriber or a group of subscribers. The subscriber manager 56 may store in a database 57 of the same information such as indications of whether a subscriber is authorized to browse the page, send and receive emails, receive content from application servers and so on. As shown in Figure 1, the subscriber manager 56 may be an entity other than the subscriber database 38 associated with the access network.

In the information of the embodiments, with respect to the type of relevant access network is used as a criterion when making authorization and policy decisions. For example, a decision policy may be a QoS policy, a security policy, a pricing policy, a chained service policy, and so on, or a policy that covers an appropriate combination of various policies.

Figure 2 shows a flow chart according to an embodiment of the present invention. In step 100 a node associated with the access network signals the data associated with an access bearer or a service flow to a gateway. The node can be, for example, an SGSN or a user equipment. The data can be signaled in a message from the SGSN or the user equipment to the gateway. The message may be a request from a data bearer or any other message associated with the data bearer control. In step 102 the gateway can determine the type of the node. For example, you may need to determine if the node associated with the access network supports only one of the 2G and 3G standards or a WLAN standard. Once the type of the node is known, the type of access network of the user's equipment is attached so that it can be determined based on this information.

The determination means 41 may be configured to determine the type of access network based on, for example, the information received from a data packet node associated with the access network, such as an SGSN or a wireless access gateway ( WAG) According to one embodiment, the gateway can determine the type of the access network based on the information received from the user equipment. The information may include a type indicator included in a message. Instead of using the information received from the access network, the decision can also be based on the information otherwise available through the gateway.

For example, if it is possible to have an access system well based on 2G or 3G, an SGSN can indicate in a message, for example, a request from a data carrier, if it is a 2S or 3G SGSN. According to one possibility, the gateway can obtain 2G / 3G information from the SGSN address. Similarly, the gateway may obtain that the access network be a WLAN based on the access system based on an indication of the network node sending the message or based on the address of the network node. The gateway can also obtain the type of access network of the characteristics of a message from the network node or the user equipment, for example, the determination of the type of access network can be based on the format or protocol of a message received from The access network. The type of access network can also be obtained based on the information of the physical port through which the gateway received the message. According to one possibility, the user equipment can explicitly indicate the type of gateway access network. The gateway can also obtain the access network type of the user equipment address. These possibilities may, in particular, apply to, but are not limited to, a WLAN based on access.

Once the type is determined, a decision is made in step 104 regarding the specific service policy to be applied to the data and / or the service flow or flows, then in step 106 the gateway applies control to the flow of traffic or flows in the data carrier according to the decision taken in step 104.

It will be appreciated that the decision can be made in relation to a traffic flow in a data carrier that has been established recently. The traffic flow may be a new traffic flow in which the data bearer, or some of the parameters associated with the traffic flow may have changed. For example, the user equipment may have moved to another access network.

Two exemplifying embodiments are described in more detail below with reference to the signaling flow diagrams of Figures 3 and 4.

Figure 3 shows a signaling flow diagram for a possible procedure for establishing an access bearer. In the example, a gateway 40 receives the message 1 requesting an access bearer establishment, for example, for the activation of a PDP context or a client access bearer.

Gateway 40 can determine at this stage if authorization and policy control are needed. This can be based on a list of access points that need / do not need authorization and policy control. If authorization and policy control are considered to be required, the gateway 40 may resolve the address of a suitable policy control entity, for example, based on a predefined policy controller address information. The address of the policy control entity can be stored on the gateway for each access point. Instead of storing this information on the gateway, the address information can be brought from an external database. The address information may be contained in the list or other record used to store an indication of whether authorization and policy control are required first.

Next, the gateway 40 sends a request message 2 to the policy control entity 52. ​​The message may include information such as the identity of the user / subscriber, the access point (AP), the type of the access network , and so on.

As mentioned earlier, the type of access network can be determined based on various information. For example, an SGSN or user equipment may include an indication of the type of access network in the message

1.

Next, the policy control entity 52 may use the information sent by the gateway 40 to obtain information on the decision making of the authorization and the policy control.

If the subscriber profile is not available in the policy control entity 52, the policy control entity can determine whether it is possible that a subscriber profile is available in a subscriber manager 56 that contains a subscriber directory (SD) . In the case of domestic subscribers, the policy control entity 52 may send a search request message 3 to the subscriber manager to retrieve the subscriber profile. If no subscriber profile is available (for example, in the case of visiting subscribers), a predetermined subscriber profile can be used instead.

If the information is requested by the subscriber manager, the request can be answered by a search response message 4 (subscriber profile). The subscriber profile may include specific access attributes for each authorized access point and / or service, for example, a 2G / 3G / WLAN QoS policy, a 2G / 3G / WLAN security policy and / or a charging policy 2G / 3G / WLAN.

The policy control entity 52 may want the subscriber manager to send notifications about changes in the subscriber profile. If this is to be used, the policy control entity may send a "change request" message 5 to the subscriber manager. This message may include information such as the identity of the user equipment, the address of the policy control entity and an "add address" order. Next, the subscriber manager can respond to message 5 by sending a "status modification" message 6 to the policy control entity.

The policy control entity 52 makes an authorization and policy decision using the type of access network as a decision criterion. The policy control entity may send a decision message 7 to the gateway

40.

[0052] Examples of the parameters included in the decision are parameters such as "subscriber identity", "allowed services", "access bearer pricing policy", "access bearer QoS policy", "Services service chained flow "," service chained flow service policies "," service flow charging policy "," service flow QoS policy "and so on. From these parameters the "subscriber identity" can be used to identify the subscriber. "Allowed services" may indicate the services that are allowed on the access bearer. The "access bearer charging policy" may indicate how the access bearer should be charged. The charging policy may be indicated to be, for example , one of “online”, “offline with time reports” and “offline with reports of

volume". The parameter “access bearer QoS policy” can indicate maximum values ​​for quality of service (QoS) and bit rates of the access bearer. The "Service chained flow services" parameter can indicate that the data processing functions will be performed by the service flow and in what sequence. The "service chained flow service policies" parameter can indicate the policies for data processing functions that are performed by the service flow. The "Service flow rate policy" parameter can indicate how the service flow should be charged (for example, online / offline with time reports / offline with volume reports). The "service flow QoS policy" may indicate maximum values ​​for the QoS class and service flow bit rates.

Also, a decision may contain policies for multiple service flows. For example, one set of policies can be for a service flow 1 and another set of policies can be for a service flow 2.

For each access bearer and / or service flow, a specific access QoS policy, a specific access charging policy, the chained services of specific access information and the specific access policies may be included if the policy is customized for the subscriber and if control by the policy control entity is not required. If control by the policy control entity is also required for any of the policies, a control flag of the policy control entity may be included instead of the policy.

It will be appreciated that the policy control entity 52 may well send relevant policies for the type of access network or policies for all types of gateway access network. In the last approach it may not be necessary to indicate the type of access network of the gateway to the policy control entity in message 2. In the last approach, the gateway may use the type of access network to determine the policies They must be executed.

Specific access policies that are not customized by the subscriber can be configured by the gateway. If the gateway does not receive a policy from the policy control entity, then you can apply a default policy that is configured for the gateway.

The policy decision of the policy control entity 52 is sent to the gateway 40 in message 7. The gateway executes the policy decision in the provision of the service.

The gateway can send a "status report" (status) message 8 to the policy control entity. This may simply be an indication of whether the policy has been executed successfully.

Next, the gateway can recognize the establishment of the access bearer in message 9 for the SGSN, thus completing the procedure for establishing the access bearer from its name.

It will be appreciated that although Figure 3 shows an embodiment in which the policy decision is taken at a policy control entity 52, it is possible for the gateway itself to decide the policy to be applied to a specific access bearer and / or a service flow The gateway can be provided with a suitable software and physical support to provide the decision-making functions. The decision making can be integrated with the means 41 for determining Figure 1.

Figure 4 shows an example of policy control for a service flow that already exists. This type of operation may be required, for example, if different service flows have been assigned with different service flow policies, or if the service flow policy is not decided when the access bearer is established.

In step 11 the gateway identifies a service flow. Next, the gateway can determine that (one or more) the policies for the service flow are not available on the gateway. An additional control is thus determined by a policy control entity being necessary for the service flow. The gateway can then resolve the address of the policy control entity, for example, using the predefined address information. The gateway can assign the service flow packet filter within a service flow name and send a request message 12 to the policy control entity. Message 12 may include parameters such as "service flow name", "type of access network." The parameter "type of access network" can be used to indicate whether the user equipment has accessed the service through, for example, a 2G, 3G or a WLAN access network.

The policy control entity may have the type of access network stored when the first decision is provided to the gateway, as described above with reference to the establishment of the access bearer. In this case, it is no longer necessary to indicate the type of access network, when the policies for a service flow are requested.

The policy control entity may use the name of the service flow or other identity of the service flow sent by the gateway to obtain the attributes of the subscriber profile stored in the access bearer establishment. The policy control entity performs a policy decision procedure and sends the decision in message 13 to the gateway. The decision regarding service flow policies may include any of the specific policies of the access networks that were not provided to the gateway in the establishment of the access bearer.

The policy control entity may send only the policies that are relevant to the type of specific access network. Alternatively, policies for all types of access network can be sent to the gateway. If the last approach is selected, it is not necessary to indicate the type of access network to the policy control entity in message 12. In this last approach, the gateway can use the type of access network to determine the policies that should run

Next, the gateway executes the policy decision.

The gateway can send a "status report" (status) message 14 to the policy control entity.

A third example of use refers to the transfer from an access network of a first type to an access network of another type. For example, a user equipment can be transferred from a 2G access network to a 3G access network, or between a WLAN access network and a 2G or 3G access network. The handover can be controlled by the network, by the user equipment, or by both. Information about the handover can be signaled to the gateway or through a network node or through a user equipment. The gateway can obtain the new type of access network by means of the procedures described above to obtain the types of access networks. If the type of access network changes this can trigger authorization and / or policy control for an existing access bearer and / or for the service flow, as shown in Figure 3 such that the new type Access network is indicated in step 2 of Figure 3. The same can be applied for step 12 of Figure 4.

It will be appreciated that the signaling step 100 of Figure 2 may not always be necessary. For example, a gateway may be able to determine the type of an access network based on other information without any signaling from other nodes. For example, the gateway can be provided with a GPRS access point, this being an indication that the type of access network is GPRS, a WLAN access point, this being an indication that the type of access network is WLAN, a circuit switched data access point (CS), this being an indication that the type of access network is data by CS, and so on.

It should be appreciated that although the embodiments of the present invention have been described in relation to a user equipment such as mobile stations, the embodiments of the present invention can be applied to any other suitable type of user equipment.

It will be appreciated that the embodiments can be applied to any gateway, for example a WLAN access data packet gateway (wireless local area network), a CDMA access data packet service node, a network access server circuit switched data access (CSD), or a broadband remote access server (BRAS) or a fixed broadband access digital subscriber line access multiplexer (DSLAM).

Detailed examples are given in the context of data carriers, such as PDP contexts. Any of the suitable data carriers, for example, PPP sessions, client VPN connections or mobile IP connections can be controlled accordingly.

The embodiments of the present invention are described above in the context of a communication system that is based on a GPRS backbone network. This invention can also be applied to any of the other communication systems in which similar problems may exist.

In addition, the term policy controller entity is intended to cover all controller entities configured to control the provision of services in systems where services can be provided for users and / or in which different entities associated with A session may have different criteria for provisioning services.

It is also noted herein that although the foregoing describes exemplary embodiments of the invention, there are various variations and modifications that can be made to the disclosed solution without departing from the scope of the present invention as defined in the attached claims.