Control decisions in a communication system

[0001] The invention relates to communication systems, in particular the step of deciding how to control communication through a gateway. The decision may be related to control activities such as authorization and control of policies used in gate-routed communications.

[0002] A communication system can be seen as an object enabling communication between at least two entities, such as user equipment, servers, gateways and / or other nodes. The communication system may, for example, include voice, data, multimedia communication, etc. The communication system may enable its user to be provided with various types of services. For example, user equipment may communicate, via a communication system, with an application server (AS). application server), such as the service provider's server.

[0003] The term "service" used above and below will be understood broadly to encompass any service that a user may want, require or provide to him by means of a communication system. The term will also be used to include the provision of free services. Especially, but not exclusively, the term "service" will be used for browsing, downloading, e-mail, streaming services, Internet Protocol Multimedia Services (IMS). Internet Protocol multimedia services), conference services, telephony, gaming, media sharing connections, presence, e-commerce and messaging, such as instant messaging.

[0004] Signaling between different entities associated with a communication system is usually required to control a communication session. Control is usually required to set up a communication session and also later during communication using the set up session. The signaling can be based on an appropriate communication protocol or protocols.

[0005] Communication may be provided through fixed line interfaces and / or wireless communication. An example of a fixed line system is the public switched telephone network (PSTN). Wireless communication can be provided using a mobile communication system. Another example of a wireless communication system is the Wireless Local Area Network (WLAN). Mobile communication systems generally refer to all telecommunications systems that enable wireless communication for users who can move within a supported area of ​​the system. An example of a typical mobile communication system is the Public Land Mobile Network (PLMN).

[0006] A wireless communication system is usually provided through multiple access networks. Access networks are used to provide the user with wireless access

- 2 to the core part of the communication network. An access network usually includes at least the functions of one base station system and a radio network controller. The access network can be configured to provide packet service to user equipment through base stations.

[0007] The mobile communication network can then be used to gain access to other locations, such as other networks, hosts, services offered by specific service providers, etc. Such access is provided through nodes commonly known as access points. Typically, the access point or gateway node of the mobile communication network provides further access to the external network or external host. For example, if the requested service is provided by a service provider located in another network, the service request is routed through the gateway to another network and service provider. Routing can be based on definitions in mobile subscriber data saved in the mobile network.

[0008] The user may be a subscriber to the communication system to be able to use the services provided by the communication system. The data of each subscriber is usually saved in the subscriber database. The database is commonly controlled by the network operator providing the access service. The subscriber's data may contain information on the quality of service (QoS) quality of service), which the subscriber is entitled to receive, priorities, service restrictions, security, authentication, billing etc.

[0009] Many different communication standards and protocols have already been developed. New standards and protocols are also constantly being developed. To distinguish older studies from newer ones, mobile communication standards are divided into different generations. For example, some standards, such as the first digital cellular standard, are associated with the second generation (2G) standards, while newer developments in digital mobile telephony are associated with the third generation (3G) standards.

[0010] Access networks that a user may use to access services may support significantly different functions depending on the standard used and / or the generation / version of the standard. In addition, the user can use access networks based on unlicensed radio or permanent access techniques. Such access techniques can support significantly different functions, depending on the standard, how individual access systems are built, and how these systems are connected to the backbone. It should be noted that, unlike well standardized cellular mobile communication systems, there are no strict and / or universally accepted standards for unlicensed access systems. For example, each of the public wireless local area network (WLAN), residential WLAN and corporate WLANs can formally be considered to be a different type of access network. In addition, public WLAN access networks for different types of open access points (hotspots) can be considered as different types of access networks. For example, other types of WLAN access networks may be provided in hotels in general than in a specific hotel or hotel chain, etc.

[0011] Below, in relation to the Global Radio Positioning System (GPRS), a more detailed example of possible problems is described that may cause differences between types of access networks.

[0012] The GPRS based communication system is an example of a wireless communication system providing packet switched data transmission to mobile user equipment. The GPRS working environment includes at least one service area that is connected through the GPRS backbone. A service area can contain multiple service nodes (SNs) of packet data. In this specification, the service nodes will be called additional GPRS service nodes (SGSN). serving GPRS support nodes). Each SGSN is connected to at least one radio access network. Access networks may relate to 2G or 3G access networks.

The packet data service nodes are in turn connected to an external data network, e.g. gateway support node). In this way, GGSN enables packet data transmission between mobile user equipment and external data networks.

[0014] An example of a data carrier that can be used to carry traffic flows over GPRS is the context of a packet data protocol (PDP). The PDP context typically includes a radio access medium provided between user equipment and a radio network controller and SGSN, and packet switched data channels provided between an additional GPRS service node (SGSN) and a GPRS gateway service node (GGSN). The session between the user's equipment and another entity would then be transferred in the PDP context juxtaposed. A PDP context can carry at least one traffic flow, but in the prior art, all traffic flows in one particular PDP context are treated in the same way as they are transmitted over the network. The similar treatment requirement is based on the PDP context treatment attributes associated with traffic flows. These attributes may include, for example, quality of service and / or billing attributes.

[0015] Some functions associated with the service flow may be controlled by the gateway. When configuring the storage medium, the gateway may apply traffic flow control. You may also need to use traffic flow control for an already set up data carrier. The control is based on the so-called policy. In short, a policy can be treated as a set of rules about how to control traffic flow.

[0016] In certain situations, differences in the type of access networks can cause problems. The problem may be caused by a lack of information at the gate regarding the access network. This can prevent the gate from providing adequate control of the flow of traffic between the various networks it connects. A particular problem concerns the control of a specific service for functions such as quality of service (QoS), security, billing, access control, etc.

[0017] Document WO 02/052 869 describes a resource allocation system for networks. Document EP 130 1048 describes a method of establishing connection in a communication system with various data carriers.

[0018] Embodiments of the invention aim to solve at least one of the above problems.

[0019] According to the invention, a method is provided for deciding the policy controlling communication in a communication system according to claim 1 and [0020] a device according to claim 25.

[0021] Embodiments of the invention may allow a control system to provide service provision for access. The flexibility of communication systems can be improved. The operating costs of the communication system can be reduced. Embodiments may improve performance during call forwarding or other access network change.

[0022] To better understand the invention reference will now be made to the examples and the attached drawings, of which

Fig. 1 schematically shows a communication system in which the invention may be used;

Figures 2 and 3 show block diagrams of signaling according to some simplified embodiments of the invention; and

Fig. 4 is a block diagram illustrating the operation of an embodiment of the invention.

[0023] Certain embodiments of the invention will now be described by way of examples with reference to the GPRS based mobile communication system architecture shown in Figure 1. However, it should be understood that the embodiments of the invention also apply to any other matching network form.

[0024] The mobile communication system can be logically divided into a radio access network (RAN) and a core network (CN). In the simplified representation of Figure 1, each base station 31 to 34 and 48 belongs to a radio access network. The radio access network (RAN) can be controlled by a suitable radio network controller (RNC), base station controller (BSC) or the like. This has not been shown to increase transparency. The radio access network controller is topologically connected to the corresponding backbone unit or units such as, but not limited to, the generic additional packet radio service node 35 and 45 (SGSN). It should be noted that - for the sake of clarity - Fig. 1 shows only a few base stations, usually the core network nodes are connected via appropriate controllers to many base stations.

[0025] User equipment in a radio access network may communicate with a radio network controller via radio network channels, which are usually called radio bearers (RBs). These radio network channels can be configured in a mobile communication network in a known manner. Any user equipment 30 may have in

- at any time, at least one open radio network channel to the radio network controller. The respective radio access network controller communicates via an appropriate interface with an additional node of the GPRS service 35, for example via the Iu interface.

[0026] An additional GPRS node 35, in turn, usually communicates with an additional GPRS gateway support node 40 via the GPRS core network on interface 39. This interface is usually a packet switched data interface. An additional GPRS service node 35 and / or an additional GPRS gateway service node 40 are used to provide GPRS services on the network.

[0027] Also provided is a subscriber database unit 36 ​​for storing information associated with a subscriber of user equipment 30. The subscriber database may in turn contain various records 38 associated with the subscriber, such as subscription details of the subscriber's PDP context of the user equipment.

[0028] The basic principles of operation of mobile user equipment, which can also be called a mobile station, are well known to those skilled in the art. The mobile user equipment is typically configured to communicate wirelessly with other stations, usually with the base stations of the mobile communication system, to enable their mobility. The mobile user equipment may include an antenna element for wirelessly receiving and / or transmitting signals from and / or to the base stations of the mobile communication network. The mobile user equipment may also be provided with a display for displaying images and / or other graphic information to the user of the mobile user equipment. Usually speakers are provided. The operation of the mobile user equipment can be controlled by means of a suitable user interface, such as control buttons, voice commands, etc. In addition, the mobile station is usually supplied with a processor unit and / or memory means. Communication between mobile user equipment and communication network units may be based on any suitable communication protocol. The user may use the user's mobile equipment for tasks such as, but not limited to, making and receiving phone calls, receiving and sending data from and to the network, and for experiencing, for example, multimedia content through a PDP context. For example, the user can access the network using a personal computer (PC), personal digital assistant (PDA), mobile station (MS).

[0029] It should be recognized that although - for clarity - only one user equipment is shown in Fig. 1, many user equipment can simultaneously communicate with the base station.

[0030] All communication between the user equipment 30 in the access network and the additional GPRS gateway service node 40 can be provided through the packet data protocol (PDP) context. Each PDP context typically provides a communication path between specific user equipment and an additional GPRS 40 gateway support node. The PDP context, after setting up, can typically carry multiple flows. Each flow typically represents, for example, a specific service and / or component of a particular service. Hence, the PDP component often represents a logical path

- 6 communication for at least one flow through the network. To implement the PDP context between user equipment and an additional GPRS service node 35, radio access bearers (RABs) are typically set up, which commonly allow data transfer to user equipment. The implementation of these logical and physical channels is known to those of skill in the art and is therefore not further discussed in this document.

[0031] It should be recognized that other access networks, e.g., non-cellular access networks, can also be used to assemble a client access medium between the user equipment and an additional GPRS gateway support node 40. Such client access medium can be seen as equivalent to a PDP context because he also provides a logical communication path through the network. For example, in WLAN access or broadband access networks, client access media can be implemented through virtual private networks (VPN), point-to-point protocol (PPP), communication protocol between two stations ) or mobile IP technology.

[0032] The user equipment 30 can connect, through access to the GPRS network, to servers typically connected to external data networks, such as, but not limited to, the presented Internet Protocol (IP) network 50.

[0033] A policy controller unit 52 connecting to the gate 40 is also known. The policy controller may be provided by a corresponding network unit. For example, the policy controller unit can be delivered through connected policy authorization and control nodes. An IP Session Cobtrol (IPSC) node or policy decision function (PDF) can also be used for this purpose. Policy controller unit 52 may be provided with a database 54 to store information required to perform service-specific authorization and policy decision making.

[0034] In the embodiment of Fig. 1, gate 40 is provided with means for determining the type of access network 41. In a preferred embodiment, the means for determining the type includes a corresponding program code running on the processor provided at gate 40. Possible configurations of means for determining Type 41 and their functions will be described in detail below.

[0035] Fig. 1 also shows the subscription manager unit 56 connected to the policy controller unit 52. The subscription manager may be provided by means of a directory server or other suitable database configured to store information associated with services available to the subscriber. For example, the subscription manager may contain information about services that are available to a specific subscriber or group of subscribers. The subscription manager 56 can store in the database 57 their information, such as indications whether the subscriber can browse the network, send and receive e-mails, receive content from application servers, etc. According to FIG. 1, the subscription manager 56 may be a unit other than database of 38 subscribers associated with the access network.

[0036] In embodiments of the invention, information regarding the appropriate type of access network is used as authorization criteria and policy decisions. The policy on the basis of which the decision is to be made may be, for example, a QoS policy, security policy, billing rule, combined service policy, etc., or a policy covering the appropriate combination of different policies.

[0037] Fig. 2 shows a block diagram according to an embodiment of the invention. At step 100, the node associated with the access network signals to the gateway the data associated with the access bearer or service flow. For example, the node may be SGSN or user equipment. Data can be signaled in a message from SGSN or gateway user equipment. The message may be a request for a recording medium or any other message regarding controlling the recording medium. At step 102, the gateway can determine the node type. For example, it may have to determine if the node associated with the access network supports only one of the 2G and 3G standards or the WLAN standard. Once the node type is known, based on this information, you can determine the type of access network that your equipment can connect to.

[0038] Determination means 41 may be configured to determine the type of access network based on, for example, information received from a packet data node associated with the access network, such as SGSN or a wireless access gateway (WAG). According to this embodiment of the invention, the gateway may determine the type of access network based on information received from the user equipment. The information may include a type indicator included in the message. Instead of using information received from the access network, the decision may also be based on information otherwise available for the gateway.

[0039] For example, if it is possible to have an access system based on 2G or 3G, the SGSN may indicate in the message, for example in the request of the storage medium, whether SGSN 2G or 3G. Based on the capabilities, the gateway can obtain 2G / 3G information from the SGSN address. In a similar manner, based on the indication by the network node sending the message or based on the address of the network node, the gateway may determine that the access network is a WLAN-based access system. The gateway may also obtain the access network type from the message characteristics from the network node or user equipment. For example, determining the type of access network may be based on the format or protocol of the message received from the access network. The type of access network can also be obtained based on information about the physical port through which the gateway receives the message. The gateway can also obtain the access network type from the user's equipment address. These options may in particular be applicable to, but not limited to, WLAN-based access.

[0040] After determining the type in step 104, a decision is made regarding the policy specified for the service to be applied to the data and / or service flow (s). In step 106, the gateway uses flow control (s) on the data carrier in accordance with the decision made in step 104.

[0041] It must be recognized that a decision can be made with respect to the flow of traffic on the storage medium which was compiled some time ago. The traffic flow may be a new flow on the data carrier, or some of the parameters assigned to the traffic flow may have changed. For example, the user may have moved to another access network. [0042] Below is a more detailed description of two illustrative embodiments of the invention with reference to the signaling block diagrams of Figures 3 and 4.

[0043] Fig. 3 is a block diagram of the signaling for a possible procedure for setting up an access bearer. In the example, gate 40 receives an access bearer request message 1, e.g., activation of PDP context for client access bearer.

[0044] Gate 40 can determine at this stage whether policy authorization and control are required. This can be based on a list of access points that require / do not require policy authorization and control. If authorization and policy control is deemed required, the gateway 40 can analyze the address of the appropriate policy controller unit, e.g. based on pre-defined information about the policy controller address. The policy control unit's address can be saved in the gateway for each access point. Instead of storing this information in the gateway, address information can be retrieved from an external database. Address information can be placed on a list or other registry used to store indications whether policy authorization and control is required first.

[0045] Then, gateway 40 sends a request message 2 to policy controller unit 52. The message may include information such as user / subscriber identity, access point (AP), access network type, etc.

[0046] Accordingly, the type of access network may be determined based on various information. For example, SGSN or user equipment may include the access network type indication in message 1.

[0047] Policy controller unit 52 may then use information sent by gateway 40 to analyze information to make policy authorization and control decisions.

[0048] If the subscription profile is not available in the policy controller unit 52, the policy controller unit may determine whether it is possible that the subscriber profile is available in the subscriber manager 56 containing the subscription directory (SD). For home subscribers, the policy controller unit 52 may send a search request message 3 to the subscriber manager to obtain a subscription profile. If the subscription profile is not available (e.g. for subscribers visiting), you can use the default subscription profile instead.

[0049] If information is required from the subscriber manager, the response to the request may be a search response message 4 (subscription profile). Subscription profile

- 9 may contain access specific attributes for each authorized access point and / or service; e.g. QoS 2G / 3G / WLAN policy, 2G / 3G / WLAN security policy and / or 2G / 3G / WLAN charging policy.

[0050] Policy controller unit 52 may want the subscriber manager to send notifications of changes to the subscription profile. If this is to be used, the policy controller entity may send a modification request message to the subscriber manager 5. This message may include information such as the identity of the user equipment, the address of the policy controller entity and the command to add the address. The subscriber manager can then respond to message 5 by sending a modification (status) response message 6 to the policy controller unit.

[0051] Policy controller unit 52 performs authorization and policy-based decision making by using an access network type as a decision criterion. The policy controller unit can send a decision message 7 to gate 40.

[0052] Examples of the parameters included in the decision are parameters such as "subscription identity", "allowed services", "access carrier charging policy", "access carrier QoS policy", "combined service flow services", "combined service flow policies services "," service flow billing policy "," service flow QoS policy, "etc. Of these, the" subscription identity "parameter can be used to identify the subscription. The "allowed services" parameter may indicate the services allowed on the access medium. The parameter "charging policy for access media" may indicate how to charge for access media. The charging policy may indicate, for example, 'online', 'offline with time reporting' and 'offline with volume reporting'. The "access bearer QoS policy" parameter may indicate the maximum quality of service (QoS) class and the access bearer's data transmission speed. The "service connected service flow" parameter may indicate which data processing functions are to be performed for the service flow and in which order. The "linked service flow policy" parameter may indicate the policies for the data processing functions to be implemented for the service flow. The "service flow billing policy" parameter may indicate how the service flow is billed (e.g. online / offline with time reporting / offline with volume reporting). The "service flow QoS policy" parameter may indicate the maximum QoS class values ​​and service flow data rates.

[0053] The decision may also include policies for many service flows. For example, one set of policies may be for one service flow, and another set of policies may be for two service flows.

[0054] If the policy is personalized for the subscription and no further control is required by the policy control unit, for each access medium and / or service flow may be included: access-specific QoS policy, access-specific billing policy, information on connected services access-specific and access-specific policies for connected services. If for

- any of the policies requires further control by the policy controller unit, instead of the policy the controlled flag of the policy controller unit may be included.

[0055] It should be noted that policy controller unit 52 may send to the gateway either policies suitable for the type of access network or policies for all types of access networks. In the latter approach, it may not be necessary to indicate in the 2nd message the type of access network from the gateway to the policy controller unit. In the latter approach, the gateway can use the type of access network to specify the policies to be enforced.

[0056] Access-specific policies that are not personalized for the subscription can be configured for the gateway. If the gateway does not receive the policy from the policy controller unit, then it can use the default policy that is configured for the gateway.

[0057] The policy decision made by policy controller unit 52 is sent to gate 40 in message 7. The gate enforces the policy decision when providing the service.

[0058] The gateway may send a status reporting status message to the policy controller entity. It can simply be an indication of whether the policy was enforced successfully.

[0059] The gateway may then confirm the set of access bearer in message 9 to SGSN and thereby end the access bearer set up procedure on its behalf.

[0060] It should be recognized that although Fig. 3 shows an embodiment of the invention in which the policy decision is made in the external policy controller unit 52, it is possible for the gateway to decide whether the policy is to be applied to a particular carrier and / or service flow. Decision making can be integrated with the determination means 41 of Fig. 1.

[0061] Fig. 4 shows an example of policy control for an existing service flow. This type of operation may be required, for example, if different service flows were allocated with different service flow policies, or if no service flow policy was selected when setting up the access bearer.

[0062] In step 11, the gateway identifies the flow of services. The gateway can then specify that the gateway (at least one) policy for the service flow is not available. Further control of the policy control unit is thus referred to as required for the service flow. The gateway can then analyze the address of the policy controller unit, for example by using previously defined address information. The gateway may map the service flow packet filter to the service flow name and send request policy 12 to the policy controller unit. Message 12 may include parameters such as "service flow name", "access network type". The "access network type" parameter can be used to indicate whether the user equipment has gained access to the service via a 2G, 3G or WLAN access network.

[0063] The policy controller unit could record the type of access network when delivering the first decision to the gateway, as described above with respect to setting up the access bearer. In this case, you no longer need to indicate the type of access network when you request policies for the service flow.

[0064] The policy controller entity may use the service flow name or other service flow identity sent by the gateway to obtain attributes from the subscription profile recorded during the set up of the access bearer. The policy controller unit performs the policy decision procedure and sends the decision to the gate in message 13. The decision on service flow policies can include any access network-specific policies that were not delivered to the gateway during the establishment of the access bearer.

[0065] The policy controller entity may only send policies that relate to a particular type of access network. Alternatively, policies for all types of access networks can be sent to the gateway. If the latter approach is chosen, it is not necessary to include the type of access network in the message 12 to the policy controller unit. In the latter approach, the gateway can use the access network type to specify the policies to be enforced.

[0066] Then the gate enforces policy decision.

[0067] The gateway may send to the policy controller unit a message with a status report 14.

[0068] A third example relates to forwarding a connection from a first type of access network to another type of access network. For example, the user equipment may transfer the connection from the 2G access network to the 3G access network, or between the WLAN access network and the 2G or 3G access network. Connection switching can be controlled by the network, by user equipment or both. Information on connection forwarding can be signaled to the gateway either by the network node or by user equipment. The gateway may download a new type of access network using the method described above for downloading access network types. If the access network type changes, according to Fig. 3 this can trigger authorization and / or policy control for the existing access bearer and / or service flow such that the new access network type is indicated in step 2 of Fig. 3. The same applies to step 12 of Figure 4.

[0069] It should be recognized that signaling step 100 of Figure 2 may not always be necessary. For example, the gateway may be able to determine the type of access network based on other information without any signaling from other nodes. For example, the gateway can be provided with a GPRS access point, which indicates that the access network type is GPRS, a WLAN access point, which indicates that the access network type is WLAN, a circuit switched data access point (CS). circuit switched), which is an indication that the type of network is CS data network etc.

[0070] It should be recognized that while embodiments have been described with respect to user equipment, such as mobile stations, embodiments of the invention apply to all other relevant types of user equipment.

[0071] It should be recognized that the embodiments may be applicable to any gateway, e.g., packet switching gateway, WLAN (wireless local area network), CDMA packet data service node, circuit switched data access server (CSD), remote access server broadband (BRAS), digital subscriber line access multiplexer (DSLAM) or permanent broadband access.

[0072] Detailed examples are given in the context of data carriers, such as PDP contexts. Any suitable data carrier, e.g. PPP sessions, VPN connections or mobile IP connections can be controlled accordingly.

[0073] The above embodiments of the invention are described in the context of a GPRS backbone communication system. The invention also applies to any other communication system in which similar problems may arise.

[0074] In addition, the term policy controller unit is intended to include all controller units configured to control service delivery in systems where services may be provided to users and / or in which different entities associated with the session may have different service delivery criteria.

[0075] It should also be noted that although there is a description illustrating embodiments of the invention above, several variations and modifications are available that can be made to the described solution without departing from the scope of the invention as defined by the appended claims.

Anna Stenzel Patent Attorney