Abstract:
Disclosed is a method for optimizing signaling in a mobile communication network, wherein a terminal devices equipped with a subscription is attempting to register to the mobile communication network. The method includes detecting an indication on an unsuccessful registering attempt; updating a counter value maintained for the subscription, the counter value indicating a number of the unsuccessful registering attempts; comparing the updated counter value with a predetermined maximum counter value; and if the updated counter value meets the predetermined maximum counter value instructing to disable a radio communication of the terminal device. Also disclosed are a terminal device computer program code and a subscription.

Description:
TECHNICAL FIELD 
     The invention concerns in general the technical field of telecommunications. Especially the invention concerns optimization of network resource utilization. 
     BACKGROUND 
     The development in telecommunications area has caused that there are more and more subscriber connections i.e. subscriptions existing in mobile communications networks. One reason for the increase of subscriptions within the networks is that more and more devices, or machines, are arranged to communicate with each other. This concept is known with a term Machine-to-Machine, or M2M, communication. More specifically, M2M concept may be described so that machines use network resources to communicate with remote application infrastructure for the purposes of monitoring and control, either of the “machine” itself, or the surrounding environment. Naturally it is so that each device being involved in the M2M communication shall be equipped with necessary hardware enabling the communication and comprise a necessary subscription in order to have access to utilizing the telecommunication network resources in question. The subscription refers to a Universal Integrated Circuit Card, UICC, which is an integrated circuit element that securely stores the international mobile subscriber identity (IMSI) and the related key used to identify and authenticate subscribers of mobile communication devices within a mobile communication network. In general, the subscription is known with a term Subscriber Identity Module, SIM, especially in 2G mobile communication systems and Universal Subscriber Identity Module, USIM, in 3G mobile communication systems. So called embedded UICC is the latest development within the era wherein the functionalities of UICC is brought to a device in an embedded solution and not as a separate functional entity. 
     The increase of subscriptions within telecommunication networks has caused side effects, which are not desirable. Namely, each subscription, when coupled to a communication terminal with enabled radio part, produces signaling traffic in the network. This is even true when the subscription itself is inactivated i.e. the subscription does not have access right in using the network resources. In such a situation the subscription initiates an access attempt(s) towards the network, but the network does not provide the access when noticing that the subscription is not set active within the network. By taking into account the increase of subscriptions in a network, e.g. at least partly due to M2M development, the described access attempt procedure accumulates a lot unwanted utilization of network resources in the network in question. 
     Thus, there is need to develop solution, which mitigates the challenge as described above and which optimizes the utilization of network resources. 
     SUMMARY 
     An objective of the invention is to present a method, a terminal device, a computer program code and a subscription for optimizing an amount of traffic between the terminal device and a mobile communication network. Another objective of the invention is that the method, the terminal device, the computer program code and the subscription implements a logic which optimize radio communication in a context of network registration. 
     The objects of the invention are reached by a method, a terminal device and a computer program code as defined by the respective independent claims. 
     According to a first aspect, a method for optimizing signaling in a mobile communication network is provided, wherein one or more terminal devices equipped with a subscription is attempting to register to the mobile communication network, the method comprises detecting an indication on an unsuccessful registering attempt; updating a counter value maintained for the subscription, the counter value indicating a number of the unsuccessful registering attempts; comparing the updated counter value with a predetermined maximum counter value; and if the updated counter value meets the predetermined maximum counter value instructing to disable a radio communication of the terminal device. 
     The method may further comprise setting a period of time to maintain the radio communication of the terminal device in a disabled state. The period of time may be set on a basis of one of the following: at least one predetermined value stored in the terminal device, receipt of information from a network. Moreover, the period of time set for maintaining the radio communication of the terminal device in a disabled state may be dependent on an order of such a state. 
     The radio communication may be disabled in at least one of the following manner: turning off the radio part of the terminal device, turning off the terminal device, setting a predetermined mode within the terminal device. 
     According to a second aspect, a terminal device equipped with a subscription is provided wherein the terminal device comprising a processing unit with at least one processor and a memory unit with at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the terminal device at least to detect an indication on an unsuccessful registering attempt; update a counter value maintained for the subscription, the counter value indicating a number of the unsuccessful registering attempts; compare the updated counter value with a predetermined maximum counter value; and if the updated counter value meets the predetermined maximum counter value instruct to disable a radio communication of the terminal device. 
     The terminal device may further be configured to set a period of time to maintain the radio communication of the terminal device in a disabled state. The period of time may be set on a basis of one of the following: at least one predetermined value stored in a memory of the terminal device, receipt of information from a network. Moreover, the period of time set for maintaining the radio communication of the terminal device in a disabled state may be dependent on an order of such a state. 
     The terminal device may be configured to disable the radio communication in at least one of the following manner: turning off the radio part of the terminal device, turning off the terminal device, setting a predetermined mode within the terminal device. 
     According to a third aspect, a computer program code is provided which comprises one or more sequences of one or more instructions which, when executed by one or more processors, cause a terminal device to at least perform the method according to the first aspect of the invention. 
     According to fourth aspect, a subscription comprising a memory is provided, wherein a computer program code according to the third aspect is stored in in the memory of the subscription. 
     The exemplary embodiments of the invention presented in this patent application are not to be interpreted to pose limitations to the applicability of the appended claims. The verb “to comprise” is used in this patent application as an open limitation that does not exclude the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. 
     The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. 
         FIG. 1  illustrates an example of an environment wherein the solution according to the present invention may be implemented. 
         FIG. 2  illustrates an example of the method according to the invention. 
         FIG. 3  illustrates an example of a terminal device implementing at least part of the present invention. 
         FIG. 4  illustrates an example of a signaling according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an example of an environment in which a solution according to the present invention may be implemented. For clarity reason only one terminal device is disclosed in  FIG. 1 . The terminal device  110  is arranged to communicate wirelessly towards the mobile communication network. The terminal device  110 , such as M2M device, comprises necessary hardware and software elements to implement the communication interface in question. A subscription  111  i.e. UICC element is arranged, or implemented, in the terminal device  110 . The mobile communication network is typically described to consist of two entities—from a radio access network, RAN,  120  and from a core network, CN,  130 . The radio access network  120  implements the wireless communication towards the terminal device  110  and provides the terminal device  110  a connection to core network  130 . The core network  130  is a central part of telecommunication network in providing the services to subscribers, who are connected to the radio access network. The services provided by the core network may be, but are not limited to, authentication, call control and switching, charging and so on. 
       FIG. 1  discloses at least some main elements within the radio access network  120  and core network  130 . The main elements in the radio access network  120  may be, but are not limited to, base stations  121  and radio network controller  123  controlling the traffic between the base stations and core network  130 . The main elements in the core network  130  may be, but are not limited to, mobile switching center  131  and/or gateway mobile switching center  133 , which are configured to manage and control circuit switched domain. As regards the packet switched domain the main elements may be, but are not limited to, a serving GPRS support node, SGSN,  135 , Gateway GPRS support node, GGSN,  137  and Mobility Management Entity, MME (not disclosed in  FIG. 1 ). The GMSC and GGSN may provide gateways to corresponding networks, such as circuit switched network  141 , like PSTN, and packet based network  143 , like IP network such as Internet. In addition to the mentioned elements the core network comprises one or more registers  139 , such as HLR/VLR or HSS, which are configured to store and manage user-related and subscription-related information. The mentioned elements in the radio access network  120  and in the core network  130  are examples mainly from 3G mobile communication network, but the invention is also applicable in other networks implementing different communication technology. 
       FIG. 2  discloses an example of the method according to the invention. Within the method it is arranged a detection  201  of registration attempts of a subscription  111  to the network with a monitoring such a procedure. More specifically, it may be arranged that unsuccessful registration attempts are detected. If an unsuccessful registration attempt is detected, a counter value representing unsuccessful registration attempts of the subscription  111  is updated  203 , e.g. added with one. In the next phase it is compared  205  if the updated counter value meets a predetermined value set for the subscription  111 . For example, the predetermined value may be three. If the predetermined value is not met, the detection  201  may be continued (arrow on the right in  FIG. 2 ). If the comparison  205  indicates that the predetermined value is met, an instruction is generated and delivered  207  so that registration attempts are restricted. The restriction instruction may e.g. be that a utilization of radio interface of the terminal device is disabled for the registration attempt. In its simplest form the instruction is configured to disable the radio part of the terminal device  110 . Disabling the radio part may also be achieved by setting the terminal device  110  into a predetermined mode, such as a flight mode, in order to prevent any radio traffic from and to the terminal device  110 . According to another implementation of the invention the instruction may be configured to switch off the terminal device. The principal idea in any of the mentioned methods to disable the registration attempt is that any radio communication is prevented, or disabled, from the terminal device  110  for at least some period of time. 
     According to an example of the invention the method as described above may be implemented in the terminal device  110 . The implementation may be arranged with a configurable logic in the terminal device  110 , which is arranged to monitor any registration attempts originating from the subscription  111  of the terminal device  110  into which a cancellation is received from the network side. The detection of unsuccessful registration attempt may e.g. be based on the signaling from the network indicating that the subscriber&#39;s access to the network is rejected. Moreover, the logic may comprise an implementation, such as a counter, in which it is maintained information on the number of unsuccessful registration attempts to the network, which counter information is updated accordingly when the unsuccessful registration attempt is detected. Moreover, the logic comprises a comparison function wherein the value in the counter is compared with a predetermined value stored in the terminal device  110  retrievable by the logic. The logic is configured to continue monitoring if the counter value does not meet the predetermined value. In case the predetermined value is met, the logic is configured to establish an instruction and by delivering the instruction message to a radio part in the terminal device  110  the logic disables any registration attempts by the subscription towards the network. According to another implementation of the invention the instruction message may comprise an instruction to switch off the terminal device  110 . In such a case the logic may comprise an internal timer running within the terminal device  110  even if the terminal device  110  is turned off. When the period of time set in the timer has passed, the logic is configured to turn on the terminal device  110  in order to re-initiate the registration attempt as described. 
     In the previous description the idea is that the radio communication of the terminal device  110  is disabled for a certain period of time if a predetermined limit set for registration attempts is reached. According to a further implementation of the invention it may be arranged that the first period of time set for the disabling the radio communication differs from a second period of time set for the second disabling the radio communication, and so on. With such an arrangement it is possible to optimize the utilization of network resources even more. Naturally, this kind of arrangement requires that a further logic is arranged within the terminal device  110  which is configured to monitor and maintain information on how many times the radio communication has been disabled. Furthermore, the logic comprises information on periods of time defined for each occasions, i.e. order, of disabled radio communication. For example, the first period of time of disabling may be one week, second period of time of disabling may be two weeks, and so on. 
       FIG. 3  illustrates, as an example, a terminal device  110  into which the logic, as described above, may be arranged. Only the relevant parts in view of the invention are disclosed. The terminal device  110  comprises a processing unit  310  comprising one or more processors, memory unit  320  comprising one or more memory elements and a radio part  330 . The memory unit  320  is configured to store portions of computer program code  321 A- 321 N, which store instructions to implement the described logic when at least some of the portions of computer program code  321 A- 321 N are executed by the processing unit  310 . Additionally, the memory unit  320  may be configured to store the predetermined maximum counter value to be used in the comparison as described. Thus, as an end result if the predetermined condition is fulfilled the radio part  330  is disabled. Alternatively or in addition, the memory unit  320  may comprise a value for a timer defining a period of time for keeping the terminal device in a turned off mode. Namely, if the message instructs the terminal to turn off, the processing unit  310  may be configured to initiate a timer starting with a value predetermined in the memory unit  320  and in response to running out of the predetermined period of time, the processing unit may be configured to turn on the device for further registration attempts. Moreover, the subscription  111 , such as UICC, is arranged within the terminal device  110 , which is configured to, together with other parts of the terminal device  110 , to initiate the registration towards the network. In other words, the processing unit  310  and the UICC  111  may be arranged to cooperate with the radio part  330  in order to possibly detect the mentioned kinds of triggering events in order to enable the utilization of the present invention. 
     According to another example of the invention the method as described may be implemented in the mobile communication network into which the subscription belongs to. A network element, such as a MSC  131  or SGSN  135  may be arranged to monitor unsuccessful registration attempts of subscriptions belonging under management of the network element. The network element may be configured to maintain a counter describing a number of unsuccessful registration attempts, which is updated when such a registration attempt is detected by the network element. Moreover, the network element is configured to store, or to have an access to, information disclosing a maximum number of unsuccessful registration attempts allowed for a subscription. The information may be stored in a memory of the network element, or even more preferably in a register  139  storing information on subscriptions into which the network element may initiate queries e.g. according to specifications. The updated value of the counter is arranged to be compared with the maximum number of unsuccessful registration attempts and if the maximum number of unsuccessful registration attempts is met, the network element is configured to compose and deliver an instruction message, e.g. through signaling, that the delivery of registration attempts from the terminal device  110  is restricted. The restriction may e.g. be achieved with a signaling disabling the radio in the terminal device  110 . 
     According to some further example of the invention it may be arranged that the disabling of the radio part in the terminal device  110  is a predetermined period of time. This is because it may be advantageous to allow additional registration attempts after the predetermined period of time. The telecom operator managing the subscription may e.g. reactivate the subscription during the period of time and thus the terminal device may initiate together with the subscription the registration attempt towards the network resulting a successful access to the network. The predetermined period of time for disabling of the radio part in the terminal device  110  may be stored in the memory unit of the terminal device  110 . The period of time may be individually set for each subscription or given as a default value to all subscriptions. Moreover, the period of time may be reconfigured through configuration settings, for example. Additionally, the logic within the terminal device  110  is configured to receive a clock signal as an input and the logic is configured to run a timer. The timer value is thus compared to the predetermined period of time set for the disabling the radio part and when the predetermined period of time is met, the logic is configured to establish an instruction and signal it to the radio part to enabling again the radio part in the terminal device. In  FIG. 3  the terminal device  110  comprises an internal clock circuit  340  for providing the clock signal in the logic. Alternatively to storing a default value for the mentioned predetermined period of time the network may deliver a value for the period of time either independently to the registration attempt or in response to the registration attempt. Such an implementation provides an opportunity to adjust the period of time optimally from the network point of view. 
     Next it is described in a more detailed manner the communication between the terminal device and the network on a basis of which the registration attempt may be judged to be unsuccessful by referring to  FIG. 4 . Herein it is assumed that the terminal device is equipped with a subscription  111 , such as UICC, either by a physical integrated circuit card or by an embedded solution. The subscription is granted by, and thus belongs to, a certain mobile communication network.  FIG. 4  discloses only the relevant elements in order to describe some aspects of the invention. In the initial phase the terminal device  110  generates a registration request  401  towards to a network wherein at least an identity of the subscription is delivered to a network element, such as MSC, MME or SGSN. The request is herein considered as a registration attempt to the network. In response to a receipt of the registration request the network element initiates a query  403  towards a register, such as HLR or VLR, which register stores information on the subscription. The query comprises the identity of the subscription requesting the registration to the network. The register is configured to respond to the query with an indication disclosing the status of the subscription, e.g. if the subscription is valid or not. In both cases the network element responds  407  to the terminal device  110 . If the subscription is valid and thus active, the response  407  informs on a successful registration. If the subscription is not valid, the response  407  indicates on unsuccessful registration. In the case of a delivery of the unsuccessful registration response  407  the counter value is updated as described in the terminal device  110  or in the network or in both. The registration message  401  may be, but is not limited to, a subscription attachment request, such as IMSI attach. In some implementation of the invention, the unsuccessful registration response  407  may comprise information relating to the period of time defining the period how long the radio communication is disabled by the terminal device. Such piece of information may be delivered by the network even if the logic is arranged in the terminal device.  110 . 
     The terminal device  110  may be a terminal dedicated to M2M communication equipped with a subscription, such as integrated circuit element like UICC card. In order to initiate M2M communication the subscription shall be registered to the network. The present invention provides a solution for reducing signaling in the network due to deactivated subscriptions causing unnecessary signaling in the network. The invention is not limited to M2M communication only, but may be applied in any similar environment within the limits set by the claims attached hereto. 
     In the description above it is described that the mentioned logic and necessary parameters thereto, such as counter value, is stored in the terminal device  110 , and more specifically in the memory unit  320  of the terminal device  110 . However, the mentioned logic, implemented e.g. with a computer program code comprising one or more sequences of one or more instructions to be executed with the processing unit  310 , may also be stored in one or more memory elements residing in the subscription  111 , such as in the UICC. In such a case the processing unit  310  is configured to access the computer program code residing in memory elements of the subscription  111  and execute at least one portion of the computer program code in order to achieve the execution of the logic as described. 
     Some advantageous embodiments according to the invention were described above. The invention is not limited to the embodiments described. The inventive idea can be applied in numerous ways within the scope defined by the claims attached hereto.