RU2455787C2 - Call termination control - Google Patents

Abstract

FIELD: information technology.

SUBSTANCE: telecommunication network contains service control entity (SCE205) and service switching entity (SSE204). Service control entity is made capable to perform steps of receive from service switching entity (SSE204) the indication that the first call attempt failed, receive from service switching entity (SSE204) the indication of additional call attempt, receiving call information related to the first call attempt, determination of call establishment procedure for additional call attempt based on call information related to the first call attempt, and sending instruction to service switching entity (SSE204) to continue setting up additional call attempt according to call establishment procedure.

EFFECT: higher quality of call control.

25 cl, 10 dwg

Description

FIELD OF THE INVENTION

The present invention relates to telecommunication networks, in particular to methods and devices for controlling call setup in an intelligent network.

State of the art

In a telecommunication network, a call initiated by the calling entity to the called entity may not result in a successful connection between the two entities. For example, the called object may be involved in another call, that is, busy or unable to answer the call while the call is made. In addition, in mobile networks, the call may fail because the called object may not be available for some reason. For example, the called object may be located in an area that is shielded from receiving a radio signal, or the user equipment of the called object may be turned off.

When the first call attempt failed, the caller may initiate the second call attempt at a later time. Since the caller usually does not know when the circumstances that prevented the completion of the first call attempt were corrected or changed, it is not unusual for the caller to make several additional call attempts before the call is finally completed.

To provide greater convenience to subscribers, telecommunication service providers offer call termination services for use in situations in which the call is not completed due to a called object that is unavailable, such as busy or unreachable. An example is the Busy Subscriber Extension Service (CCBS). CCBS was defined, for example, in 3GPP (Third Generation Partnership Project) TS (Technical Specification) 22.093.

When the called object is busy or unreachable, call termination services are usually designed to offer the calling object the option of automatic callback when the called object becomes available for callback. Typically, a switching node, such as a mobile switching center (MSC) that serves the caller, offers the caller the option to automatically call back when the callee appears inaccessible, such as busy or unreachable. If the calling entity accepts the offer, the procedure begins with the switching node serving the called entity in order to monitor the availability of the called entity. Once it is discovered that the called object is again available or unoccupied, that is, no longer busy or in reverse radio communication with the network, then the switching entity serving the calling entity is notified. This switching object initiates a call to the calling object and, if the calling object answers, the call to the called object is configured. Alternatively, the switching entity sends a specific notification to the calling entity, informing the calling entity that the called entity is now available through which the calling entity can initiate a call to the called entity.

In addition to the so-called network-based services, such as call termination services, that is, the services that are executed and managed by the switching nodes, there are also intelligent network services that are run and managed by the Intelligent Network (IN). According to the IN concept, service intelligence or service logic is separate from switching functions. This division mainly enables network operators to develop and deploy services and features independently of suppliers, allowing more flexible development of services, simplified deployment, lower cost and greater autonomy. Examples of IN protocols are Intelligent Network Application Protocol (INAP), Advanced IN (AIN), and Advanced Mobile Network Logic (CAMEL) Applications. INAP was developed for fixed line networks and is the primary protocol used for fixed line INs outside of North America. AIN is an option designed for North America.

CAMEL is a network characteristic of Phase 2+ of the Global System for Mobile Communications (GSM) and Broadband Code Division Multiple Access (WCDMA), which are defined in 3GPP TS 22.078. CAMEL is based on the INAP kernel with modifications in order to take into account, inter alia, the mobility of the subscriber. In particular, CAMEL allows the subscriber to use the services defined for the operator, even when roaming outside the home land mobile public network (PLMN) of the subscriber. The CAMEL-based smart network contains as the main objects: a service switching object for task switching, also called SSF (service switching function) or gsmSSF (GSM service switching function) and a service control object containing the service intelligence or logic also called SCP (point service control) or gsmSCF (GSM service control function).

Figure 1 depicts a schematic overview of a telecommunications network containing an intelligent network in accordance with the prior art.

The smart network includes a service control point 101 and a service switching function 102. In addition, the switching nodes MSC 103, MSC 104 and MSC 105 are shown, each of which may be a Mobile Switching Center (MSC). The MSC 103 serves the caller, and the MSC 105 serves the called object. 1 further depicts a calling entity CE100 and a calling entity CE106.

Intelligent network services are executed by and under service control point 101. The service control point 101 is capable of communicating with the service switching function 102 using an intelligent network protocol such as CAMEL or INAP. The service switching function 102 of this example is aligned with the switching node 103, i.e., the switching node serving the caller. Alternatively, the service switching function 102 may be implemented as a separate node.

Call termination services, as indicated above, are network-based services that are run and controlled by switching nodes, while IN services are run under the control of the service control entity and are only used for specific calls. Due to two levels of control, which are also separate from each other, inconsistencies can occur when the IN services are involved in calls, which may be in addition to the call termination service. This may cause the call termination to fail.

SUMMARY OF THE INVENTION

The aim of the invention is the provision of methods, devices and computer programs that improve call termination in a telecommunication network.

This goal is achieved by methods, devices, computer programs and computer readable media, as described in the independent claims. Advantageous embodiments are described in the following claims.

In an embodiment, a call setup from a caller to a callee in a telecommunications network is described. The call contains the first call attempt and an additional call attempt, and the telecommunication network contains the service control object and the service switching object, the switching node and the subscriber database.

The service control entity receives from the service switching entity an indication that the first call attempt failed at the first time. At the second moment of time (for example, seconds, minutes, hours, days later than the first moment of time), the service control object receives an indication of an additional call attempt from the service switching object, receives call information related to the first call attempt, determines the call setup procedure for an additional call attempt based on the call information related to the first call attempt, and sends an instruction to the service switching entity to continue setting up the additional call attempt in accordance with call establishment procedure.

The service switching entity receives from the switching node an indication that the first call attempt failed at the first time, and sends an indication that the first call attempt failed to the service control entity. At the second moment of time, the service switching entity receives an indication of an additional call attempt from the switching node, sends an indication of the additional call attempt to the service control object, receives an instruction from the service management object to continue setting up an additional call attempt, and establishes an additional call attempt in accordance with the instruction.

In accordance with embodiments, the service control entity is provided with an indication of an additional call attempt. The service control entity is now aware that the additional call attempt refers to the first call attempt that failed, and therefore that the network-based call termination service is involved. The service control entity obtains the call information related to the first call attempt and determines a call setup procedure for the additional call attempt based on the call information related to the first call attempt. The service control object is now fully authorized to take control of the additional call attempt. The service control entity may determine how to continue the additional call attempt. He may decide to apply the same call setup procedure as for the first call attempt, or not change the additional call attempt. Therefore, inconsistencies in handling an additional call attempt are avoided.

In an embodiment, the service control entity sends an instruction to initiate storing the call information related to the first call attempt on one of: the service switching entity and the subscriber database connected to the service control entity, and receives the stored call information related to the first call attempt , together with the reception of an indication of an additional call attempt. The advantage is that the service control object does not need to occupy insufficient internal memory resources for storing call information, this option remains for a pre-assigned node configured to store information for a longer period.

In an embodiment, an indication of an additional call attempt is received by the service control entity in an initial message containing an information element for indicating an additional call attempt. The use of the initial message advantageously provides that the service control entity is informed of an additional call attempt at the initial stage of the call. This allows the service control entity to take control of the processing of the additional call attempt at an early stage. The information element is preferably specialized, that is, predefined values can be used to indicate an additional attempt to call at predefined positions in the initial message with predefined values known to both the service control object and the service switching object. A common designation with predefined values and predefined positions of the information item in the initial message facilitates the insertion and retrieval of the value for both switching the service and the service control object. The initial message and the specialized information element are preferably standardized, although if standardization is not possible, custom extensions can be used.

In an embodiment, an indication of the stored call information associated with the first call attempt is received by the service control entity in the initial message containing an information element for indicating the stored call information. The use of the initial message advantageously ensures that the service control object provides a gain in knowledge of the stored call information associated with the first call attempt and the initial stage of the additional call attempt. This allows the entity to take control of the processing of the call attempt at an early stage, even before the additional call attempt has been completed.

In an embodiment, the call information indicates one of: a call charge size, a number translation scheme applicable to the target number of the called object, and an additional service interaction indicator for the call. The use of the call charge amount indicated in the call information related to the first call attempt has the advantage that the charge will be charged to the caller according to the same charge as the first call attempt, even if the charge has changed due to due to the time of day or due to a change in the location of the caller.

In a further aspect, the switching node sends an indication that the first call attempt has failed to the service switching object, receives an instruction from the service switching object to initiate storage of the call information related to the first call attempt, sends an instruction to the subscriber database to initiate storage of the call information relating to the first call attempt, receives from the subscriber database an indication that the called object is available, receives stored call information from the subscriber database, about wearing the first call attempt, an attempt to initiate an additional call from a caller to the caller that sends an indication of further attempts to call on the service switching object and sends the stored paging information related to the first call attempt, at the service switching entity.

In an additional aspect, the subscriber database receives instructions for initiating storage of the call information related to the first call attempt, stores call information related to the first call attempt, receives an indication that the called object is available, sends an indication that the called object is available to the node switching, and sends stored call information related to the first call attempt.

In addition, the invention relates to a service control entity, a service switching entity, a switching node, and a subscriber database. It also relates to computer programs loaded into the processing unit of the service control object, the service switching object, the switching node and the subscriber database, respectively, for performing any of the steps of the previously mentioned methods, when executed on the corresponding device. The computer program may be stored on a computer readable medium. The computer-readable medium may be a permanent or rewritable memory in a service control entity, a service switching entity, a switching node or a subscriber database, or located externally. A computer program may also be transmitted to a service control entity, a service switching entity, a switching node, or a subscriber database, for example, via a cable or radio link as a sequence of signals.

Further, detailed embodiments of the present invention will be described in order to provide those skilled in the art with a complete and complete understanding. However, these embodiments are illustrative and are not intended to be limiting.

Brief Description of the Drawings

Figure 1 depicts a schematic illustration of a telecommunications network containing an intelligent network in accordance with the prior art.

2 is a sequence diagram illustrating messages exchanged in a telecommunications network in an exemplary embodiment of the invention.

Figure 3 depicts a flow diagram of the steps of a method performed by a service control entity.

Figure 4 depicts a flow diagram of the steps of a method carried out by a service switching entity.

Figure 5 depicts a sequence diagram of the steps of the method carried out by the switching node.

6 depicts a flow diagram of the steps of a method carried out by a subscriber database.

7 depicts a block diagram of an embodiment of a service control entity.

Fig. 8 is a block diagram of an embodiment of a service switching entity.

Fig.9 depicts a block diagram of an embodiment of a switching node.

10 is a block diagram of an embodiment of a subscriber database.

Detailed description

2 is a sequence diagram showing messages exchanged in a telecommunication network in an exemplary embodiment of the invention. Pictured is a calling entity CE201, a subscriber database SD202, a switching node SN203, a service switching entity SSE204, and a service management entity SCE205. The caller CE201 communicates with the switching node SN203. The subscriber database SD202 contains the subscriber information about the calling entity CE201, and is able to exchange information with the switching node SN203 and additional subscriber databases, for example, with the subscriber database associated with the called entity not shown in FIG. 2. The service switching entity SSE204 communicates with the switching node SN203. Preferably, the service switching entity SSE204 is aligned with the switching node SN203. The service control entity SCE205 contains service logic for executing intelligent network services and is capable of communicating with the service switching entity SSE204.

The service control entity SCE205 and the service switching entity SSE204 are part of an intelligent network, as described with reference to FIG. 1. The service control object SCE205 has functions similar to those of the service control point 101 of FIG. 1, but is improved with new features, as will be described in detail below with reference to FIG. 7. The service switching entity SSE204 has functions similar to those of the service switching function 102 of FIG. 1, but is improved with new features, as will be described in detail below with reference to FIG. The switching node SN203 is also part of the network described with reference to FIG. The switching node SN203 has functions similar to those of the MSC 103 of FIG. 1, but is improved with new features, as will be described in detail below with reference to FIG. 9.

The embodiment depicted in FIG. 2 provides an exemplary sequence of messages exchanged between the devices presented above after detecting that the first call attempt has failed. Messages exchanged before failure detection are regular messages used to set up a call between the caller and the callee and to detect that the callee is not available and therefore the first call attempt failed. In the following description, messages, also called steps, are executed as follows.

In a first step 210, the switching node SN203 sends a notification that the first call attempt failed on the service switching entity SSE204. A first call attempt may fail, for example, because the called object is busy or unreachable, due to network congestion, or because the called object is not responding to the call. The switching node SN203 may receive an indication from an additional switching node serving the called entity, not shown, wherein the indication passes through the switching node serving the calling entity. According to an embodiment, the switching node SN203 may also send an indication of the cause of the failure to the service switching entity SSE204. An indication of the cause of the failure can be sent in the same message as an indication that the first call attempt failed, or in a separate message. The message may be a release message (REL) as specified in the user integrated call control protocol (ISUP) of a Service Integrated Digital Network (ISDN).

In the next step 211, the service switching entity SSE204 sends an indication that the first call attempt failed to the service management entity SCE205, for example, in an event report. If the indication of the cause of the failure is received by the service switching entity SSE204 in step 210, it may also send the indication of the cause to the service control entity SCE205. The reason for the failure, in a further embodiment, may include a cause diagnosis giving an indication of whether the call termination service, such as CCBS, can be applied to the call.

The service control entity SCE205 obtains the call information related to the first call attempt in step 212. The call information may include an indication of each of the following: caller ID, caller ID, dialed number (e.g., short number associated with the called object), time and The date of the first call attempt, and the location of the caller during the first call attempt. According to a preferred embodiment, the call information may additionally indicate one of the following: call charge size, number translation scheme applicable to the target number of the called object and an indicator of the interaction of additional services for the call.

The service control entity SCE205 initiates storage of call information related to a first call attempt for subsequent reference during an additional call attempt. Call information may be stored in the internal memory of the service control entity SCE205. Alternatively, the service control entity SCE205 sends an instruction to another device for storing call information. The following embodiments are shown in the following steps of FIG. 2.

According to step 213, the service control entity SCE205 sends an instruction to the service switching entity SSE204 to initiate storage of the call information related to the first call attempt for further reference. The instruction can be sent in the message ContinueWithArgument (CWA) (Continue with argument) CAMEL. In subsequent embodiments, not shown, the service control entity SCE205 sends an instruction to initiate storage of the call information directly to SD202.

At step 214, the service switching entity SSE204 sends the instruction adopted at step 213 to the switching node SN203.

According to step 215, the switching node SN203 provides the calling entity CE201 with the option of initiating an additional call attempt when the called entity becomes available. The caller CE201 sends a response to the switching node SN203 in step 216.

At step 217, the switching node SN203 sends the instruction received at step 214 to the subscriber database SD202, for example, in a Mobile Application Protocol (MAP) message. According to an embodiment, the instruction is sent to the subscriber database SD202, provided that the response from the calling entity CE201, received at step 216, indicates that the calling entity CE201 has chosen to initiate an additional call attempt when the called party becomes available.

The subscriber database SD202 stores, in step 218, the call information related to the first call attempt in response to an instruction received from the switching node SN203. Alternatively, the instruction is received directly from the service control entity SCE205.

In accordance with step 219, the subscriber database SD202 receives an indication that the called object is available. The indication may be received from the subscriber database associated with the called entity.

At step 220, the subscriber database SD202 sends an indication to the switching node SN203 that the called object is available.

At step 221, the subscriber database SD202 sends stored call information related to the first call attempt. If the instruction adopted in step 217 is received from the switching node SN203, then the stored call information is sent back to the switching node SN203. According to an embodiment, steps 220 and 221 may be combined into one step, whereby an indication that the called entity is available and stored call information is sent to the switching node SN203 in a MAP message that the remote user is free.

Alternatively, if the instruction adopted at step 217 is received directly from the service control entity SCE205, then the stored call information is sent back to the service management entity SCE205.

The exemplary method continues further at step 222, in which the switching node SN203 performs the step of initiating an additional call attempt from the calling entity CE201 to the called entity. According to an embodiment, the switching node SN203 sends a message to the calling entity CE201 to signal that the called entity is available. If the calling entity CE201 sends a message to the switching node SN203 indicating that it is accepting an additional call attempt, the switching node SN203 initiates the setup of the calling attempt to the called object.

In accordance with step 223, the switching node SN203 performs the step of sending an indication of an additional call attempt to the service switching entity SSE204.

The switching node SN203 sends the stored call information related to the first call attempt to the service switching entity SSE204 in step 224. According to an embodiment, steps 223 and 224 may be combined in one step.

In accordance with step 225, the service switching entity SSE204 sends an indication of an additional call attempt to the service control entity SCE205. The service switching entity SSE204 may send an indication to the service management entity SCE205 in an initial message, preferably in a CAMEL discovery starting point (IDP) message.

The service switching entity SSE204 sends the call information related to the first call attempt, if received from the switching node SN203, to the service control entity SCE205 in step 226. The call information may be sent in the same message as the indication of the additional call attempt in step 225.

According to an alternative embodiment, the stored information is received directly by the service control entity SCE205 from the subscriber database SD202. The service control entity SCE205 may send a request to the subscriber database SD202 to retrieve stored call information.

At step 227, the service control entity SCE205 determines a call setup procedure for an additional call attempt based on the call information related to the first call attempt. The service logic of the service control entity SCE205 can analyze the call information obtained in the previous step and determine a suitable call setup procedure that will be applied to the additional call attempt using the call information from the first call attempt. The SCE205 may, for example, combine call handling for an additional call attempt with a call operation that was applied to the first call attempt. This may include, for example, using the same amount of payment and using the same number translation scheme.

In accordance with step 228, the instruction is sent from the service control entity SCE205 to the service switching entity SSE204 to continue setting up an additional call attempt in accordance with the call setup procedure.

In step 229, the service switching entity SSE204 sends a message to the switching node SN203 to establish a call in accordance with the instruction from the service management entity SCE205.

In the following paragraphs, a detailed description is given with reference to figures 3 through 6 of exemplary methods implemented by the corresponding devices depicted in figure 2.

Figure 3 depicts exemplary steps performed by a service control entity in accordance with an embodiment of the invention.

At the initial stage, the service switching object sends a message to the service management object, for example, in the BCSM event report (base call status model) CAMEL, which indicates that the first call attempt from the calling object to the called object has failed. The service switching entity may receive an indication from the switching node serving the called entity.

The service control entity performs the step of receiving an indication that the first call attempt failed at step 301. According to an embodiment, the service control entity may also receive an indication of the cause of the failure, for example, busyness or unreachability of the called object, network congestion, or no response to the call of the called object. The cause of the failure may, in a further embodiment, comprise a diagnosis of the cause. The service control entity may use the cause of failure to resolve further actions for the call, allowing the service control entity to take into account more information when deciding how to handle the call, thereby increasing flexibility. An indication of the cause of the failure, including diagnostics, can be received in a message that also contains an indication that the first call attempt failed, or in a separate message.

The method may continue at step 302, in which the service control entity performs the step of receiving, from the service switching entity, an indication of an additional call attempt from the calling entity to the called entity. The service control object is now informed that an additional call attempt has been initiated in relation to the first call attempt that failed. In accordance with an embodiment, an indication of an additional call attempt may be received in the initial message, for example, in a CAMEL starting point of detection (IDP) message containing an information element for indicating an additional call attempt.

At step 303, the call information related to the first call attempt is received by the service control entity. The call information may include one of the following: the identifier of the calling object, the identifier of the called object, the dialed number (for example, the short number associated with the called object), the time and date of the first call attempt, and the location of the calling object during the first call attempt. According to a preferred embodiment, the call information may additionally indicate one of the following: call charge size, number translation scheme applicable to the intended number of the called object and the interaction indicator of additional services for the call.

In an embodiment, the call information related to the first call attempt is received from the external memory of the service control object after it was stored during the first call attempt. Alternatively, the service control entity may send an instruction to the service switching entity in advance to initiate storage of call information related to the first call attempt, for example, in a subscriber database. The instruction may be sent in a ContinueWithArgument (CWA) CAMEL message. A subscriber database that can store call information may be a home location register (HLR) associated with the caller. In a further alternative embodiment, the service control entity sends an instruction to initiate storing the call information related to the first call attempt directly to the subscriber database.

The stored call information related to the first call attempt may subsequently be restored during the setup of the additional call attempt. It can be adopted by the service control object, by means of the service switching object and additional switching nodes between the subscriber database and the service switching object, together with the step of receiving an indication of an additional call attempt. In a preferred embodiment, the stored information related to the first call attempt can be received in the same initial message as the indication of the additional call attempt. The initial message may comprise an information element for indicating stored call information. According to an alternative embodiment, the stored call information is received directly by the service control entity from the subscriber database. The service control entity may request the subscriber database to send stored call information.

In accordance with step 304, the service control entity performs the step of determining a call setup procedure for an additional call attempt based on the call information related to the first call attempt. The service logic of the service control object can analyze the call information obtained in the previous step and determine a suitable call setup procedure that will be applied to the additional call attempt using the call information from the first call attempt. For example, a service control entity may decide to leave the target number as received, associated with the called number, unchanged, that is, not to apply the number translation scheme to an additional call attempt. This is partly an advantage in the following situation. It can occur when the switching node that performs the call termination service, after call control returns from the service control object, releases the call when it realizes that the target number has been changed by the service in the service control object, for example, a virtual private network service (VPN ) The reason for this behavior is that an additional call attempt is no longer regarded by the switching node as related to the first call attempt, and is considered prohibited. In accordance with the steps taken by the service control entity, the service management entity is aware that the additional call attempt refers to the failed first call attempt, and it may decide not to change the target number. Therefore, an additional call attempt can be established by the switching node. In another example or addition, a service control entity may define a call setup procedure that applies the same charge as was applied to the first call attempt. The advantage of this is that a charge is charged to the caller according to the charge for the first call attempt, even if the charge could change due to the time of day, or the location of the caller.

In a further example, the service control entity may define a call setup procedure that applies the same extension service interaction indicator that was applied to the first call attempt in accordance with the stored call information related to the first call attempt.

According to step 305, the instruction is sent from the service management entity to the service switching entity to continue setting up an additional call attempt in accordance with the call setup procedure. The instruction can be sent in a CAMEL Connect, Continue, or ContinueWithArgument message (continue with argument), depending on the type of instruction. The service management entity may, prior to sending the instruction and depending on the type of instruction, provide the service switching entity with payment instructions, such as CAMEL Apply charging, Furnish charging information or Send charging information. At this point, the method may end or may continue with any of the steps described herein.

4 depicts exemplary steps performed by a service switching entity in accordance with an embodiment of the invention.

At the initial stage, the switching node transmits a message containing an indication that the first call attempt from the caller to the callee failed, the service switching entity.

According to step 401, the service switching entity may carry out the step of receiving, from the switching node, an indication that the first attempt to call the called entity has failed. A message containing an indication that the first call attempt failed may also indicate the cause of the failure, for example, the called object is busy or unreachable, network congestion has occurred, or the called object has not been answered. The message may be an ISUP Release Message (REL).

Subsequently, the service switching entity performs the step of sending an indication that the first call attempt to the called object failed on the service management entity in step 402. The service switching entity may send an indication to the service management entity in an event report, preferably in a BCSM CAMEL event report message. In an embodiment, the service switching entity may also send an indication of the cause of the failure, if received from the switching node, to the service management entity in the same or separate message.

According to an embodiment, the service switching entity may receive an instruction from the service management entity to initiate storage of the call information related to the first call attempt, for example, in a subscriber database. The instruction can be accepted in the CAMEL ContinueWithArgument message (continue with argument) (CWA). A subscriber database that can store call information may be a home location register (HLR) associated with the caller. The service switching entity may send instructions to the switching node for further direction to the subscriber database.

At 403, the service switching entity may perform the step of receiving, from the switching node, an indication that an additional call attempt to the called entity has been initiated. The indication may be received in the ISUP IAM (Initial Address Message). The ISUP protocol that is used between the switching node and the service switching entity may be an external ISUP or ISUP within the node.

According to an embodiment, previously stored call information related to the first call attempt can be received by the service switching entity, via one or more switching nodes, from the subscriber database in conjunction with the step of receiving an indication of the additional call attempt. In a preferred embodiment, the stored information related to the first call attempt can be received in the same message as the indication of the additional call attempt, for example, the ISUP IAM message. The message may comprise an information element for indicating stored call information.

In accordance with step 404, the service switching entity performs the step of sending an indication of an additional call attempt to the service management entity. The service switching entity may send an indication to the service management entity in the initial message, preferably in the CAMEL discovery starting point (IDP) message. The message may contain an information element to indicate that the additional call attempt relates to the first call attempt that failed. In a further embodiment, the service switching entity may send the call information related to the first call attempt, if received from the switching node, to the service management entity in the same or separate message. The initial message may comprise an information element for indicating stored call information.

In accordance with step 405, the service switching entity performs the step of receiving an instruction from the service management entity to continue setting up an additional call attempt. The instruction may be received in a CAMEL Connect, Continue, or ContinueWithArgument message, depending on the type of instruction. The service switching entity may, prior to receiving instructions, receive payment instructions such as CAMEL Apply charging, Furnish charging information or Send charging information.

The method may continue at step 406, where the service switching entity performs the step of executing the instruction, that is, establishing an additional call attempt in accordance with the received instruction.

At this point, the method may end or may continue with any of the steps described herein.

5 depicts exemplary steps performed by a switching node in accordance with an embodiment of the invention. The switching node may be a mobile switching center (MSC).

In a first step 501, the switching node performs the step of sending an indication that the first call attempt from the calling object to the called object has failed to the service switching object. The switching node may receive an indication from an additional switching node serving the called object. The switching node may send an indication that the first call attempt failed to the service switching object in a message that also contains an indication of the cause of the failure, for example, the called object is busy or unreachable, network congestion has occurred, or the called object has not been answered. The cause of failure may optionally include a diagnosis of the cause. The message may be an ISUP Release Message (REL).

The method may continue at block 502, wherein the switching node performs the step of receiving instructions from the service switching entity to initiate storage of the call information related to the first call attempt.

At step 503, the switching node sends the instruction received at step 502 to the subscriber database, preferably to the home location register (HLR) associated with the caller. The switching node may send an instruction in a Mobile Application Protocol (MAP) message. According to an embodiment, the switching node may provide the caller with the option of initiating an additional call attempt when the callee becomes available. The caller sends a response to the switching node. According to a further embodiment, step 503, that is, sending instructions for initiating storage of the call information related to the first call attempt to the subscriber’s database, is carried out on the condition that the response from the caller indicates that the caller chooses to accept the offer for an additional call attempt when the called object becomes available.

In accordance with step 504, the switching node may receive an indication that the called object is available. According to an embodiment, the indication is received from the subscriber database associated with the called object by the subscriber database associated with the calling object.

The switching node receives stored call information related to the first call attempt from the subscriber database, preferably from the subscriber database associated with the caller, at step 505. According to an embodiment, steps 504 and 505 can be combined into one step, wherein an indication that the called object is available and the stored information is received by the switching node in the MAP message that the remote user is free.

An exemplary method continues at block 506, where the switching node performs the step of initiating an additional call attempt from the caller to the callee. According to an embodiment, the switching node sends a message to the caller to signal that the callee is available. If the caller sends a message indicating that he allows an additional call attempt to the switching node, the switching node initiates the setup of the call attempt to the called object.

In accordance with step 507, the switching node performs the step of sending an indication of an additional call attempt to the service switching entity. The switching node sends an indication, for example, in the initial ISUP address message (IAM), to the service switching object.

At step 508, the switching node sends the stored information related to the first call attempt to the service switching entity. According to an embodiment, steps 507 and 508 can be combined into one step in which an indication of an additional call attempt and stored call information are sent to the service switching entity in a single ISUP Initial Address Message (IAM). The IAM message contains an information element for indicating stored call information.

The switching node may, at this stage, receive an instruction from the service switching entity to establish an additional call attempt, which may be based on the call information related to the first call attempt.

At this point, the method may end or may continue with any of the steps described herein.

6 depicts exemplary steps performed by a subscriber database in accordance with an embodiment of the invention. The subscriber database may be a home location register (HLR). Preferably, the HLR associated with the caller.

In a first step 601, a subscriber database receives an instruction for storing call information related to a first call attempt from a caller to a callee. The instruction is received, for example, in a busy call termination request message (CCBS) MAP. The CCBS MAP request message contains an information element for indicating call information related to the first call attempt. According to an embodiment, the instruction is received from the switching unit. Alternatively, the instruction is received from the service control entity. In the next step 602, the subscriber database stores call information related to the first call attempt. The subscriber database may receive multiple requests for storing call information related to the corresponding multiple first call attempts associated with the same calling party. The call information associated with each of the plurality of first call attempts can be stored individually by the subscriber database.

In accordance with step 603, the subscriber database receives an indication that the called object is available. The indication may be received from the subscriber database associated with the called entity.

The subscriber database, at step 604, sends an indication that the called object is available on the switching node.

At 605, the subscriber database sends stored call information related to the first call attempt. If the instruction received at block 601 is received from the switching node, the stored call information is sent back to the switching node. According to an embodiment, steps 604 and 605 can be combined into one step, in which an indication that the called object is available and stored call information is sent to the switching node in a MAP message that the remote user is free. Alternatively, if the instruction adopted at block 601 is received directly from the service control entity, the stored information is sent back to the service control entity.

Preferably, the call information in the subscriber database is deleted after it is sent either to the switching node or to the service control object. It will also be deleted if the indication that the called object is available is not received within a predetermined time limit, or when the CCBS user data is deleted from the subscriber database for another reason.

At this point, the method may end or may continue with any of the steps described herein.

The invention, in addition, is implemented in devices that are described in more detail below with reference to Figs. 7, 8, 9 and 10. The reference numbers are used for illustration only and are not intended to be limiting.

7 shows an embodiment of a service control object SCE7 comprising a message receiving unit RU7, a message transmitting unit TU7, a message and information processing unit PU7, and a call information handling unit CU7, and preferably, a storage unit SU7 for storage and / or obtaining stored information.

The service management entity may be a standalone device. However, it is possible that the service control entity operates on a switching node, for example, as hardware and / or a software subunit of the switching node. The service control object can be installed and put into operation on the switching unit, without using together any of the RU7, TU7, PU7, CU7 units with the switching unit, or using at least one of the RU7, TU7, PU7, CU7 units with blocks of the switching node. An alternative embodiment is a service control entity in accordance with a computer program loaded into a processing unit of a switching node.

The processing unit PU7 may be configured to process an indication that the first call attempt has failed, received by the receiving unit RU7 from the service switching entity. In addition, the processing unit PU7 may be configured to process an indication of an additional call attempt received by the receiving unit RU7 from the service switching entity. The call information handling unit CU7 may be configured to receive call information related to the first call attempt. The processing unit PU7 may further be configured to determine a call setup procedure for an additional call attempt, based on the call information related to the first call attempt, and to initiate the transfer of instructions to the service switching entity, by the transmission unit TU7, to continue setting up the additional call attempt, in accordance with the call setup procedure.

According to an embodiment, the call information handling unit CU7 may be configured to initiate the transfer of instructions for initiating storage of the call information related to the first call attempt by the transfer unit TU7, to one of: a service switching entity and a subscriber database connected to the entity service management. Additionally, the call information handling unit CU7 may be configured to process the stored call information related to the first call attempt received by the reception unit RU7, together with receiving an indication of the additional call attempt.

Preferably, an indication of the additional call attempt is received at the receiving unit RU7 in the initial message containing an information element for indicating the additional call attempt. The processing unit PU7 may be configured to process this information. In particular, the processing unit PU7 may be configured to extract information from the message and obtain an indication of an additional call attempt from the extracted information. Additionally, stored call information related to the first call attempt is preferably received in the initial message. The call information handling unit CU7 may be further configured to retrieve stored call information from the message and obtain stored call information, based on which the determination of the call setup procedure for an additional call attempt can be performed by the processing unit PU7.

In an embodiment, the call information indicates one of: call charge size, number translation scheme applicable to the target number of the called object, and an indicator of the interaction of additional services for the call.

Fig. 8 depicts an embodiment of a service switching entity SSE8 comprising an input unit IU8, an output unit OU8, a processing unit PU8 for processing messages and information, comprising a call information handling unit CU8, and preferably, a storage unit SU8 for storing and / or receiving stored information .

The service switching entity may be a standalone device, and the input unit IU8 and the output unit OU8 may be external interfaces, such as a reception unit for receiving messages and a transmission unit for transmitting messages, respectively. Preferably, the service switching entity operates on the switching node, for example, as hardware and / or software subunit of the switching node. The service switching object can be installed and put into operation on the switching node, without using any of the IU8, OU8, PU8, SU8 blocks together with the switching node, or using at least one of the IU8, OU8, PU8, SU8 blocks together with switching unit blocks comprising a unit for receiving messages, a transmission unit for sending messages, a processing unit for processing messages and information, and preferably, a storage unit. A preferred embodiment is a service switching entity in accordance with a computer program loaded into the processing unit of the switching node.

The processing unit PU8 may be configured to process an indication that the first call attempt failed, received by the input unit IU8, from the switching unit, and to initiate the sending of the indication, via the output unit OU8, to the service control entity. In addition, the processing unit PU8 may be configured to process the indication of the additional call attempt received by the input unit IU8 from the switching unit and initiate the transmission of the indication of the additional call attempt via the output unit OU8 to the service control object. The processing unit PU8 may be further configured to process an instruction received by the input unit IU8 from the service control entity to continue setting up an additional call attempt and to establish an additional call attempt in accordance with the received instruction.

According to an embodiment, the input unit IU8 may be configured to receive an instruction for initiating storage of call information related to a first call attempt from a service control entity. The call information handling unit CU8 may be configured to initiate the transfer, via the output unit OU8, to the switching unit of instructions for initiating storage of the call information related to the first call attempt. Additionally, the input unit IU8 may be configured to receive stored call information related to the first call attempt from the switching unit, together with receiving an indication of an additional call attempt. The call information handling unit CU8 may further be configured to initiate sending, via the output unit OU8, to the service control object of the stored call information related to the first call attempt, together with sending an indication of the additional call attempt.

Preferably, the call information handling unit CU8 may further be configured to initiate sending stored call information related to the first call attempt, via the output unit OU8, to the service control entity in an initial message containing an information element for indicating the stored call information. Additionally, the processing unit PU8 may be configured to initiate the transmission of an indication of an additional call attempt, via the output unit OU8, to the service control object, in an initial message containing an information element for indicating stored call information.

In an embodiment, the call information indicates one of: call charge size, number translation scheme applicable to the target number of the called object, and an indicator of the interaction of additional services for the call.

FIG. 9 shows an embodiment of a switching unit SN9 comprising an input unit IU9, an output unit OU9, a processing unit PU9 for processing messages and information, comprising a call information handling unit CU9, and preferably, a storage unit SU9 for storing and / or receiving stored information.

The processing unit PU9 may be configured to send an indication that the first call attempt failed, via the output unit OU9, to the service switching entity. The input unit IU9 may be configured to receive an instruction to initiate storage of the call information related to the first call attempt from the service switching entity. The call information handling unit CU9 may be configured to initiate the transfer, via the output unit OU9, to the subscriber database of instructions for initiating storage of the call information related to the first call attempt. Additionally, the input unit IU9 may be configured to receive, from a subscriber database, an indication that the called object is available, and receive call information related to the first call attempt. The processing unit PU9 may be configured to initiate an additional call attempt from the calling object to the called object, and to initiate the transmission of the indication of the additional call attempt, via the output unit OU9, to the service switching entity. The call information handling unit CU9 may further be configured to initiate sending, by the output unit OU9, to the service switching entity, stored call information related to the first call attempt.

According to an embodiment, the processing unit PU9 may be configured to provide, via the output unit OU9, the option for the caller to initiate an additional call attempt when the called object is available, and to process, optionally, a response from the caller received by the IU9 input.

10 shows an embodiment of a subscriber database SD10 comprising an input unit IU10, an output unit OU10, a processing unit PU10 for processing messages and information, comprising a call information handling unit CU10, and preferably, a storage unit SU10 for storing and / or receiving stored information .

The input unit IU10 may be configured to receive instructions for initiating storage of call information related to the first call attempt. The call information handling unit CU10 may be configured to store the call information related to the first call attempt in the storage unit SU10. Additionally, the input unit IU10 may be configured to receive an indication that the called object is available. The processing unit PU10 may be configured to initiate the transmission of an indication that the called object is available on the switching unit through the output unit OU10. The call information handling unit CU10 may be further configured to retrieve the call information related to the first call attempt from the storage unit SU10, and to initiate sending stored call information related to the first call attempt by the output unit OU10.

According to an embodiment, an instruction for initiating storage of call information related to the first call attempt is received by the input unit IU10 from the switching unit. Additionally, the stored call information related to the first call attempt is sent via the output unit OU10 to the switching node.

According to another embodiment, an instruction for initiating storage of the call information related to the first call attempt is received by the input unit IU10 from the service control entity. Additionally, the call information related to the first call attempt is sent, by the output unit OU10, to the service control entity.

IN protocols such as the CAMEL application subsystem (CAP, for example CAPv4, see 3GPP TS 29.078 and 3GPP TS 23.078) are preferably modified by at least one of the following detailed extensions in order to provide the service switching entity and the service management entity with in accordance with the invention:

a) a new piece of information (IE) can be added to the message "start point of discovery" (InitialDP or abbreviated IDP) to indicate to the service control entity that activation refers to an additional call attempt related to the first call attempt that failed:

Information Item Name Description Configuring a call termination service This IE indicates that service invocation refers to an additional call attempt related to the first call attempt that failed

An IDP containing a new item of information can be used by the service switching entity to send an indication of an additional call attempt to the service management entity.

b) a new item of information (IE) can be added to the message "start point of detection" (InitialDP or abbreviated IDP) to indicate to the control object of the service stored information related to the first call attempt.

Information Item Name Description Free format call information data This IE contains an indication of the call information related to the first call attempt

An IDP containing a new item of information can be used by the service switching entity to send an indication of the call information related to the first call attempt to the service management entity.

c) The ContinueWithArgument (CWA) message can be used to transfer information regarding the instruction for initiating storage of the call information related to the first call attempt to the service switching entity for an additional call attempt. A new information element (IE) "free format call information data" may be added for this purpose to "ContinueWithArgument".

Information Item Name Description Free format call information data This IE contains an indication of the call information related to the first call attempt

The ContinueWithArgument message contains new free format call information data that can be used by the service control object to send instructions to the service switching object to initiate storage of the call information.

In addition, the MAP protocol is preferably modified by the following extension in order to provide the switching node and the subscriber database with capabilities in accordance with the invention.

a) A new information item (IE) can be added to the MAP REGISTER CC ENTRY message, the MAP CCBS REQUEST message, and the MAP REMOTE USER FREE message to indicate stored information related to the first call attempt.

Information Item Name Description Free format call information data This IE contains an indication of the call information related to the first call attempt

Obviously, the invention can be implemented in any telecommunications network, such as GSM, code division multiple access (CDMA), time division multiple access (TDMA), universal mobile telecommunications system (UMTS) or 4G network. A service control entity is typically implemented in a single device or may be distributed across multiple devices. The corresponding applies to the service switching entity. The service control object and the service switching object can be implemented as separate functions on the same device or platform.

Claims (25)

1. A method for controlling call setup from a calling module (CE201) to a called module in a telecommunications network, the call comprising a first call attempt and an additional call attempt, and the telecommunication network comprising a service control node (SCE205) and a service switching module (SSE204), wherein (SCE205) service management performs the steps in which:
receive from the service switching module (SSE204) an indication that the first call attempt has failed, receive an indication of an additional call attempt from the service switching module (SSE204),
receive call information related to the first call attempt,
determining a call setup procedure for an additional call attempt based on the call information related to the first call attempt, and sending an instruction to the service switching module (SSE204) to continue setting up the additional call attempt in accordance with the call setup procedure. 2. The method according to claim 1, further comprising the steps of: sending an instruction to initiate storing the call information related to the first call attempt to one of: a service switching module (SSE204) and a subscriber database (SD202) connected to the node (SCE205) service control, receive the stored call information related to the first call attempt, together with receiving an indication of an additional call attempt. 3. The method according to claim 2, in which an indication of an additional call attempt is received in the initial message containing an information element for indicating an additional call attempt. 4. The method according to claim 2, in which the stored call information related to the first call attempt is received in an initial message containing an information element for indicating stored call information. 5. The method according to claim 1, in which the call information indicates one of: call charging, number translation schemes applicable to the target number of the called module and an indicator of the interaction of additional services for the call. 6. A method for controlling call setup from a calling module (CE201) to a called module in a telecommunication network, the call comprising a first call attempt and an additional call attempt, and the telecommunication network comprising a service control node (SCE205), a service switching module (SSE204), and a node (SN203) switching, and the module (SSE204) switching services performs the steps in which:
receive from the switching node (SN203) an indication that the first call attempt has failed,
sending an indication that the first call attempt failed to the service control node (SCE205),
receive an indication of an additional call attempt from the switching unit (SN203),
send an indication of an additional call attempt to the service control node (SCE205),
receiving an instruction from the service control node (SCE205) to continue setting up an additional call attempt, and
establish an additional call attempt in accordance with the instructions. 7. The method according to claim 6, further comprising stages in which:
receiving an instruction from the service control node (SCE205) to initiate storing the call information related to the first call attempt,
send an instruction to the switching node (SN203) to initiate storing the call information related to the first call attempt,
receive the stored call information related to the first call attempt from the switching node (SN203) together with receiving an indication of the additional call attempt, and send the stored call information related to the first call attempt to the service control node (SCE205) together with sending the indication of the additional attempt call. 8. The method according to claim 7, in which the stored call information related to the first call attempt is sent to the service control node (SCE205) in the initial message containing the information element to indicate the stored call information. 9. The method of claim 7, wherein the indication of the additional call attempt is sent to the service control node (SCE205) in the initial message containing an information element for indicating the additional call attempt. 10. The method according to claim 7, in which the call information indicates one of: the size of the call charge, the number translation scheme applicable to the target number of the called module and an indicator of the interaction of additional services for the call. 11. A method for controlling call setup from a calling module (CE201) to a called module in a telecommunication network, the call comprising a first call attempt and an additional call attempt, and the telecommunication network comprising a service control node (SCE205), a service switching module (SSE204), a database (SD202) of the subscriber and the node (SN203) switching, and the node (SN203) switching performs the steps in which:
send an indication that the first call attempt has failed, to the service switching module (SSE204),
receiving an instruction from the service switching module (SSE204) for initiating storage of call information related to the first call attempt,
send instructions to the subscriber’s database (SD202) to initiate the storage of the call information related to the first call attempt,
receive from the subscriber database (SD202) an indication that the called module is available,
receive from the subscriber database (SD202) stored call information related to the first call attempt,
initiate an additional call attempt from the calling module (CE201) to the called module,
sending an indication of an additional call attempt to the service switching module (SSE204), and
send the stored call information related to the first call attempt to the service switching module (SSE204). 12. The method according to claim 11, further comprising the steps of: providing the calling module (CE201) with an option to initiate an additional call attempt when the called module becomes available, receiving a response to this option from the calling module (CE201). 13. A method for controlling call setup from a calling module (CE201) to a called module in a telecommunication network, the call comprising a first call attempt and an additional call attempt, and the telecommunication network comprising a service control node (SCE205), a service switching module (SSE204), a database (SD202) of the subscriber and the node (SN203) switching, and the database (SD202) of the subscriber performs the steps in which:
receiving an instruction to initiate storing call information related to the first call attempt,
store call information related to the first call attempt,
receiving an indication that the called module is available, sending an indication that the called module is available, to the switching node (SN203), and
send stored call information related to the first call attempt. 14. The method according to item 13, in which the instruction for initiating the storage of call information related to the first call attempt is received from the switching node (SN203). 15. The method according to 14, in which the stored call information related to the first call attempt is sent to the switching node (SN203). 16. The method according to item 13, in which the instruction for initiating the storage of call information related to the first call attempt is received from the service control node (SCE205). 17. The method of claim 16, wherein the stored call information related to the first call attempt is sent to the service control node (SCE205). 18. Node (SCE205) service control, configured to implement the steps of the method in accordance with any one of claims 1 to 5. 19. The module (SSE204) switching services, configured to carry out the steps of the method in accordance with any of paragraphs.6-10. 20. The node (SN203) switching, configured to carry out the steps of the method in accordance with any of paragraphs.11 and 12. 21. The database (SD202) of the subscriber, configured to carry out the steps of the method in accordance with any of paragraphs.13-17. 22. A computer-readable medium storing a computer program loaded into a processing unit of a service control unit (SCE205), the computer program comprising portions of program code configured to perform method steps in accordance with any one of claims 1-5. 23. A computer-readable medium storing a computer program loaded into a processing unit of a service switching module (SSE204), the computer program comprising portions of program code configured to perform method steps in accordance with any of claims 6-10. 24. A computer-readable medium storing a computer program loaded into the processing unit of the switching unit (SN203), the computer program comprising portions of program code configured to carry out the steps of the method in accordance with any of claims 11 and 12. 25. A computer-readable medium storing a computer program loaded into a subscriber database processing unit (SD202), the computer program comprising portions of program code configured to perform method steps in accordance with any one of claims 13-17.

Images