Control unit and paging method

The present invention relates to a control unit and a paging method for calling a communication device that communicates via a base station.

In cellular communication such as LTE (Long Term Evolution), the position information of the communication device is grasped based on the control signals called TAU (Tracking Area Update), Attach Request, and Service Request, and the position of the communication device when receiving an incoming call. Performs call (paging) processing based on information. Here, FIG. 5 shows an outline of the paging process in LTE. The LTE network is called EPS (Evolved Packet System) and is composed of eUTRAN (evolved Universal Terrestrial Radio Network), which is a wireless network, and EPC (Evolved Packet Core), which is a core network.

In FIG. 5 (A), the UE (User Equipment) is a communication device owned by the user, and is, for example, a device equipped with a communication module such as a communication terminal such as a mobile phone or a smartphone or a sensor used in M2M. .. In addition, eNB (evolved Node B) is a radio base station and constitutes eUTRAN. MME (Mobility Management Entity) is a control unit that manages UE location registration, calling, handover between eNBs, etc., together with S-GW (Serving Gateway) and P-GW (Packet data network Gateway) (not shown). Configure EPC.

As shown in Fig. 5 (B), MME manages a set of one or more TAs (Tracking Areas) called Pool Areas. A TA is composed of one or more eNBs. In the case of the example shown in FIG. 5 (B), MME1 manages Pool Area 1, and Pool Area 1 is composed of TA1, TA2, and TA3. Further, TA1 is composed of eNB1 and eNB2, TA2 is composed of eNB3, and TA3 is composed of eNB4.

As shown in FIG. 5C, in the LTE network, the UE transmits a control signal (signaling) called TAU to the MME at a predetermined timing to perform location registration. The TAU transmitted from the UE to the MME includes, for example, identification information (UE_ID) for identifying the UE and identification information (eNB_ID) for identifying the eNB with which the UE communicates. It is used to identify location information. When MME receives TAU, it creates a TA list consisting of one or more TAs, associates it with the UE and holds it, stores it in the location registration response signal (TAUA: Tracking Area Update Accept), and replies to the UE. To do. When the UE receives TAUA, it updates its own TA list.

In the example shown in FIG. 5 (C), the UE sends a TAU to the MME1 via the eNB2, and the MME1 returns a TA list 1 consisting of TA1 and TA2 to the UE in response to this TAU. doing. The timing at which the UE transmits the TAU is, for example, when a certain time has passed since the previous transmission, when the UE moves across the TA list held by the UE, or when the power of the UE is turned on.

After that, when there is an incoming call to the UE, MME1 refers to the TA list held in association with the UE and calls (paging) the UE. The paging range is appropriately set and operated by the administrator. In the example shown in Fig. 5 (D), first, paging is performed only on a narrow range managed by eNB, and each time paging fails, The range of paging is gradually expanded to TA1 and TA list 1.

By the way, the paging success rate and the load of MME associated with paging are in a trade-off relationship, and if the range of paging is expanded, the success rate of paging can be increased, but the load of MME increases. In addition, since it costs money to increase the MME, it is necessary to devise an appropriate setting of the paging range.

In this regard, Patent Document 1 describes that the paging range is different depending on the type of communication device, the type of service, and the like. Specifically, in Patent Document 1, the paging range is narrowed in the case of a non-moving communication device such as an M2M device, while the paging range is widened in the case of a moving communication device such as a smartphone.

<p num="0010"><patcit num="1"><text>Special Table 2013-504234</text></patcit></p>

<p num="0011"> However, in the method described in Patent Document 1, since the paging range is set based only on static information such as the type of communication device, there is room for further improvement. Specifically, even a communication device such as a smartphone does not always move from the place where the location was registered, and may stay at the place where the location was registered when paging. is there. In this regard, in the method described in Patent Document 1, since the change in the position of the communication device is not taken into consideration, the paging is performed in an unnecessarily wide range, although the paging is normally performed in a narrow range, and the load of MME is unnecessary. There was a risk of increasing it.</p><p num="0012"> The present invention has been made in view of such a problem, and an object of the present invention is to provide a control unit and a paging method capable of reducing the load associated with paging.</p>

<p num="0013"> In the first aspect of the present invention, it is a control unit that calls a communication device that communicates via a base station, and registers the position information of the communication device based on a control signal acquired from the communication device. The position registration unit, the range determination unit that determines the range of the communication area to be called according to the elapsed time from the registration of the position information of the communication device to be called when the call instruction is received, and the determined range. Provided is a control unit including a calling unit for calling the communication device in the communication area of the above.</p><p num="0014"> Further, the range determining unit determines the communication area of the first range as the range of the communication area to be called when the elapsed time is shorter than the predetermined time, and when the elapsed time is longer than the predetermined time, the first range is determined. The communication area of the second range wider than the one range may be determined as the range of the communication area to be called.</p><p num="0015"> The predetermined time may be different depending on the type of the control signal acquired from the communication device, or may be different depending on the time when the position information is registered.</p><p num="0016"> Further, after the call to the communication area in the predetermined range, the first profile that calls the communication area in the specific range including the predetermined range and the communication area in the specific range without making the call to the communication area in the predetermined range. Further including a second profile for making a call, the range determining unit determines the first profile or the second profile according to the elapsed time, and the calling unit determines the determined profile based on the determined profile. , The communication device may be called.</p><p num="0017"> The second aspect of the present invention is a paging method for calling a communication device that communicates via a base station, and registers the position information of the communication device based on a control signal acquired from the communication device. When the step and the call instruction are received, the step of determining the range of the communication area to be called according to the elapsed time from registering the position information of the communication device to be called, and the communication area of the determined range. In the above, a paging method including a step of calling the communication device and a step of calling the communication device is provided.</p>

<p num="0018"> According to the present invention, the load associated with paging can be reduced.</p>

<figref num="1">It is a figure which shows the functional structure of a control unit.</figref><figref num="2">It is a figure which shows an example of the profile list and UE list stored in the storage part.</figref><figref num="3">It is a figure which shows the method of determining the range to be called by the range determination part.</figref><figref num="4">It is a flowchart which shows the processing flow of a control unit.</figref><figref num="5">It is a figure which shows the outline of the paging process in the conventional LTE.</figref>

[Functional configuration of control unit 1] FIG. 1 is a block diagram showing a functional configuration of the control unit 1 of the present invention. The control unit 1 corresponds to an MME in an EPC, and includes a communication unit 2, a storage unit 3, and a control unit 4 as shown in FIG.

The communication unit 2 is connected to an external device via a predetermined communication line, and performs a predetermined communication with the external device. As an example, the communication unit 2 is connected so as to be able to communicate with the base station (eNB) 50, receives a control signal (signaling) from the communication device (UE) 60 via the base station 50, and communicates. The TA list is transmitted to the device 60. In the present embodiment, the communication device 60 is a mobile communication device such as a mobile phone or a smartphone.

The storage unit 3 is composed of, for example, a ROM, a RAM, or the like. The storage unit 3 stores various programs and various data for operating the control unit 1. Further, the storage unit 3 stores the profile list 31 and the TA list 32. Here, an example of the profile list 31 and the TA list 32 is shown in FIG.

As shown in FIG. 2A, the profile list 31 stores a plurality of profiles that define the paging range. In the example shown in FIG. 2 (A), the profile with profile ID "1" first makes a call to the communication area managed by the base station 50 to which the UE has registered the location, and if this call fails, Subsequently, a call is made to the communication area managed by the TA including the base station 50, and if this call fails, a call is subsequently made to the communication area managed by the TA list including the TA. Prescribe. On the other hand, the profile with profile ID "3" stipulates that the call is made to the communication area managed by the TA list from the beginning without making the call to the communication area managed by the base station 50 or TA. Profile list 31 is used to determine the extent to which control unit 1 paging.

As shown in FIG. 2B, the UE list 32 shows the base station 50 corresponding to the position of the communication device 60 for each communication device 60 whose position is registered based on the control signal (TAU) for location registration. , TA, TA list, etc., as well as information about the time when the location was registered, etc. are stored. By referring to the UE list 32, it is possible to grasp the base station 50, TA, TA list, etc. corresponding to the position where the communication device 60 exists at the timing of performing the position registration. The UE list 32 is used to determine the range in which the control unit 1 performs paging of the UE, and is used to identify the base station 50 instructed when paging to the determined range.

Returning to FIG. 1, the control unit 4 is composed of, for example, a CPU. The control unit 4 comprehensively controls the functions related to the control unit 1 by executing various programs stored in the storage unit 3, and functions as the position registration unit 41, the range determination unit 42, and the calling unit 43. ..

The location registration unit 41 identifies the location information of the communication device 60 based on the location registration control signal (TAU) acquired from the communication device 60, and registers it in the UE list 32. The registration of location information by the location registration unit 41 is already known, and corresponds to the above-mentioned creation of the TA list. The location information (that is, the TA list) registered by the location registration unit 41 is stored in the location registration response signal (TAUA) and returned to the communication device 60.

When the range determination unit 42 receives the call instruction, the range determination unit 42 determines the range of the communication area to be called according to the elapsed time since the position information of the communication device 60 to be called is registered. Here, with reference to FIG. 3, a method of determining the range to be called by the range determination unit 42 will be described.

&lt;How to determine the paging range&gt; Even if the communication device 60 is movable, it cannot move far immediately after the location registration, and it is expected that it exists in the vicinity of the registered location, but the location registration is performed. If more than a certain amount of time has passed since then, it may exist at a position away from the registered position. Therefore, as shown in FIG. 3A, the range determination unit 42 calls the communication area in a narrow range when the elapsed time from the registration of the position information is shorter than the threshold value T. When the elapsed time is longer than the threshold value T, a wide range of communication areas is determined as the range of the communication area to be called. As an example, the range determination unit 42 selects a profile with profile ID "1" or "2" whose calling range gradually becomes wider when the elapsed time is shorter than the threshold value T, and the elapsed time is shorter than the threshold value T. If it is long, select the profile with profile ID "2" or "3" that makes a wide range of calls from the beginning.

In this way, in order to determine the range for paging by taking into account the dynamic information such as the progress information after registering the location information, the range is set using only static information such as the type of communication device. A more suitable range can be determined as compared with the case of determining. As a result, it is possible to suppress paging to an unnecessarily wide range just because it is a movable communication device, and it is possible to reduce the load associated with paging.

Here, the threshold value T is appropriately set by the administrator, may be a fixed value, or may be appropriately changed. Hereinafter, an example in which the threshold value T is changed based on a predetermined condition will be described.

&lt;Method of determining threshold T&gt; As described above, the communication device 60 is the control unit 1 when a certain time has passed since the last transmission, when the communication device 60 moves across the TA list held by the communication device 60, when the power of the UE is turned on, or the like. A control signal (TAU) for location registration is transmitted to (MME). In other words, the communication device 60 transmits the TAU due to the passage of time, movement, power ON, or the like. When the communication device 60 transmits TAU due to movement, the communication device 60 is likely to be moving, while when the communication device 60 transmits TAU with the passage of time, the communication device 60 is stopped. Probability is high.

Therefore, the threshold value T may be changed according to the type of the control signal (TAU) acquired from the communication device 60. Specifically, as shown in FIG. 3 (B), when the position information of the communication device 60 is registered based on the TAU transmitted with the movement, the threshold value T is shortened and transmitted with the passage of time. If registered based on the TAU to be performed, the threshold value T is lengthened. As a result, paging can be performed for a more appropriate range, and the load associated with paging can be reduced. The type of control signal (TAU) can be specified based on the additional information (cause of occurrence) included in the TAU. As an example, the TAU transmitted over time will be added as the cause of occurrence "Extended Periodic Timer".

Further, the threshold value T may be changed by taking into account not only the type of the most recent control signal (TAU) but also the type of the control signal (TAU) a plurality of times in the past. For example, even if the TAU is transmitted over time, the communication device 60 (user) may be transmitted multiple times in succession over time, depending on whether the TAU is transmitted over time for the first time. ) Is presumed to be different. That is, in the latter case, the communication device 60 (user) is likely to stay in the same place, while in the former case, such a tendency is not observed.

Therefore, the threshold value T may be different depending on the ratio of the types of the control signal (TAU) a plurality of times in the past and the number of times the control signals (TAU) of the same type are consecutive. For example, if the TAU with the passage of time is only once, the threshold value T is lengthened by the first hour, and if the TAU with the passage of time continues multiple times, the threshold value T is longer than the first hour. Increase by 2 hours. The same applies to the TAU associated with movement. If the TAU associated with movement is only once, the threshold value T is shortened by the third time, and if the TAU associated with movement is repeated multiple times, the threshold value T is set to the third. Shorten the 4th hour, which is longer than 3 hours. This makes it possible to set the paging range more appropriately.

Further, since the moving speed is different between the case where the user is moving on foot and the case where the user is moving by car, train, or the like, the moving distance is different even if the elapsed time is the same. Therefore, in order to appropriately set the paging range, it is preferable to take the moving speed into consideration. This movement speed can be grasped from, for example, the acquisition interval of TAU accompanying the movement. As an example, when the acquisition interval is short, it can be grasped that the moving speed is high, and when the acquisition interval is long, it can be grasped that the moving speed is slow.

Therefore, the threshold value T may be changed according to the acquisition interval for acquiring the control signal (TAU) from the communication device 60. Specifically, even when the TAU accompanying the movement is acquired, if the acquisition interval is long, the threshold value T is shortened by the fifth hour, and if the acquisition interval is short, the threshold value T is set to the fifth hour. 6th hour longer than. This makes it possible to set the paging range more appropriately.

Further, the communication device 60 (user) is likely to move, for example, during commuting / returning time and the like, and has a wide range of movement, but is unlikely to move during the night, and the range of movement is also narrow. Therefore, the threshold value T may be changed according to the time when the control signal (TAU) is acquired from the communication device 60. Specifically, the threshold value T is shortened for commuting / returning time and the like, and the threshold value T is lengthened from the commuting time to the commuting time.

It should be noted that the activity time and activity mode of the user are different for each user. Therefore, in addition to the time when the TAU is acquired, the threshold value T may be changed by using the attribute information of the user. As an example, for users with commuting time in the 8 o'clock range, the threshold T is shortened from 7:00 to 10:00, while for users with commuting time in the 10 o'clock range, from 9:00 to 11:00. During that time, the threshold value T is shortened. Further, for example, the threshold value T during working hours is shortened for users in the sales position, while the threshold value T during working hours is lengthened for users who perform desk work. As a result, the paging range can be set according to the user's attributes (activity time and activity mode), so that the load associated with paging can be reduced.

The user attribute information can be acquired by any method, for example, from the contract information of the communication device 60. Further, the attribute information of the user can also be acquired from the log information of the location registration of the communication device 60 which is sequentially performed. That is, since the tendency of the time zone in which the location is registered and the tendency of the type (cause of occurrence) of TAU can be acquired from the log information, the activity time and activity mode of the user can be acquired by analyzing this information. ..

Although various elements for determining the threshold value T have been described above, each of these elements may be used alone, or may be used in combination as appropriate.

Returning to FIG. 1, the calling unit 43 calls (paging) the communication device 60 to be called in the communication area within the range determined by the range determining unit 42. Specifically, the calling unit 43 controls one or a plurality of base stations 50 that manage the communication area in the determined range, and calls the target communication device 60. When the communication device 60 receives the paging, the communication device 60 sends a service request to the control unit 1 (MME) and accepts the incoming call.

[Processing of control unit 1] The functional configuration of the control unit 1 of the present invention has been described above. Subsequently, the processing flow of the control unit 1 will be described with reference to FIG. FIG. 4 is a flowchart showing the processing flow of the control unit 1.

First, in step S1, the position registration unit 41 of the control unit 1 determines whether or not TAU has been received from the communication device 60. When the TAU is received, subsequently, in step S2, the location registration unit 41 creates and registers the TA list, stores the TA list in the TAUA, and returns the TA list to the communication device 60. At this time, the location registration unit 41 registers the type of TAU, the time of reception, and the like.

Subsequently, in step S3, the control unit 1 determines whether or not there is an incoming call to the communication device 60. If there is no incoming call, the process ends, and if there is an incoming call, then in step S4, the range determination unit 42 of the control unit 1 paging according to the elapsed time since receiving the TAU. Determine the range. Specifically, the range determination unit 42 widens the paging range when the elapsed time is longer than the threshold value T, and narrows the paging range when the elapsed time is shorter than the threshold value T. More specifically, when the profile list 31 shown in FIG. 2 (A) is used, if the elapsed time is longer than the threshold value T, the profile with the profile ID "2" or "3" is selected and elapsed. If the time is shorter than the threshold value T, the profile with profile ID "1" or "2" is selected.

Subsequently, in step S5, the calling unit 43 calls the communication device 60 that has received an incoming call within the paging range determined in step S4. Subsequently, in step S6, the control unit 1 determines whether or not there is a response from the communication device 60. At this time, if there is no response from the communication device 60, in step S7, the calling unit 43 determines whether or not the number of retransmissions remains. As shown in FIG. 2A, the profile list 31 defines the number of retransmissions, and if there is no response from the communication device 60, paging to a wider range is executed again according to the number of retransmissions. To do. Therefore, if it is determined in step S7 that the number of retransmissions remains, the paging range is updated according to the selected profile in step S8, and the process is moved to step S5.

On the other hand, if it is determined in step S7 that the number of retransmissions does not remain, then in step S9, the control unit 1 executes a predetermined error process and ends the process. If there is a response from the communication device 60 in step S6, then in step S10, the control unit 1 executes a predetermined connection process and ends the process.

[Effect of control unit 1] As described above, when the control unit 1 performs paging of the communication device 60, the range of paging is changed according to the elapsed time from the registration of the position information of the communication device 60. As a result, the paging range can be different based on the dynamic information of elapsed time, so that paging does not occur over a wide range even when the communication device 60 (user) is not moving. , The load associated with paging can be reduced. On the other hand, when there is a high possibility that the communication device 60 (user) is moving, that is, when the elapsed time is long, paging is performed over a wide range from the beginning, so that the paging success rate can be increased.

By appropriately changing the threshold value T of the elapsed time for different paging ranges according to the type and time of TAU, paging can be performed for a more appropriate range. As a result, the load associated with paging can be reduced and the paging success rate can be increased.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various changes or improvements can be made to the above embodiments. In particular, the specific embodiments of the distribution / integration of the devices are not limited to those shown above, and all or a part thereof may be in arbitrary units according to various additions or the like, or according to the functional load. It can be functionally or physically distributed and integrated.

In the above embodiment, the type of profile to be acquired is different according to the elapsed time since the acquisition of TAU, but the configuration for changing the paging range according to the elapsed time is not limited to this. Absent. For example, the paging range may be changed by rewriting the specified contents of the profile according to the elapsed time.

Further, in the above embodiment, one threshold value T is used as a determination criterion for different types of profiles, but the threshold value T is not limited to one, and a plurality of threshold values T may be used. For example, if the threshold value T1 is set to the first predetermined time and the threshold value T2 is set to the second predetermined time longer than the first predetermined time, and the elapsed time after acquiring the TAU is within the first predetermined time, Select the profile with profile ID "1", select the profile with profile ID "2" if it is between the first predetermined time and the second predetermined time, and if it exceeds the second predetermined time, the profile ID You may choose the profile of "3".

Further, the plurality of threshold values T may be appropriately changed based on the type of TAU and the like. At this time, a plurality of threshold values T may be changed collectively, or each threshold value T may be changed individually. In addition, to change individually means, for example, to change the threshold value T1 but not to change the threshold value T2, or to make the amount of change of the threshold value T2 different from the threshold value T1.

1 ... Control unit (MME) 2 Communication department 3 Memory 31 Profile list 32 UE list 4 Control unit 41 Location registration department 42 Range determination section 43 Caller 50 Base station (eNB) 60 Communication device (UE)