JP5287083B2 - Base station and call reception method - Google Patents

Description

  The present invention relates to a mobile communication network, and more particularly to a base station and a call reception method.

  In a mobile communication network, a base station accepts a call setup request issued by a user terminal, pays out a logical resource number in response thereto, and notifies the user terminal of the paid out logical resource number.

  FIG. 1 is a flowchart showing a conventional call acceptance method 10. In FIG. 1, a call acceptance (call setting) request signal issued by a user terminal (UE) is accepted as a call acceptance signal by a lower platform (PF) layer of a base station (eNodeB), and is directly used as an upper application ( Sent to the AP) layer. The application (AP) layer manages logical resources to be paid out for each call acceptance request. When the call acceptance signal is received from the platform (PF) layer, the application (AP) layer determines a logical resource number to be paid out to the application (AP) layer, and uses the user terminal (via the platform (PF) layer as a call acceptance response signal). UE).

  Here, the platform layer is a layer that analyzes a received signal and distributes it to each functional unit, controls the entire base station, and performs monitoring control of the user terminal. On the other hand, the application layer is a layer that performs call processing and manages logical resources related thereto.

  As shown in FIG. 1, when a large number of call acceptance signals (11) are received from a user terminal (UE) in a short period of time, the PF layer sends the large number of call acceptance signals (11) to the AP layer. Performs a logical resource number payout process for the many call acceptance signals (11) (12), and returns a call acceptance response (13) to the user terminal (UE) via the PF layer.

  If it is determined that the AP layer is in a congestion state (14), the AP layer then discards the call acceptance signal received from the user terminal (UE) via the PF layer (15, 16), thereby controlling congestion. I do. Regardless of whether the PF layer is in a congested state, all call setup requests from the user terminal (UE) are accepted and sent to the AP layer.

  FIG. 2 is a block diagram showing a conventional base station 20. The base station 20 includes an application (AP) function unit 21 corresponding to the application (AP) layer of FIG. 1 and a platform (PF) function unit 22 corresponding to the platform (PF) layer.

  The AP function unit 21 manages a call processing control unit 211 that processes a call received from the PF function unit 22, a logical resource processing unit 212 that notifies the call processing control unit 211 of a logical resource number, and manages the logical resource number. And a logical resource management unit 213 that performs state update.

  The PF function unit 22 includes a signal analysis unit 221 that analyzes a signal received from a user terminal (UE), and a call setting reception unit 222 that receives a call processing signal output from the signal analysis unit 221. The PF function unit 22 further includes a device control unit 223 that controls the entire components of the base station 20 and a monitoring control unit 224 that performs monitoring control based on the maintenance monitoring signal output from the signal analysis unit 221.

For determining congestion in a mobile communication network, a technique for determining whether or not a call processing processor of an exchange is congested is known.
JP-A-1-318343

  As described above, in the conventional base station, the PF layer sends all the call setup request signals received from the user terminal to the AP layer, and the AP layer manages the logical resources and performs the logic for each call acceptance (call setup) request. Resources are being paid out. Even when congestion occurs in the AP layer, the PF layer sends it to the AP layer when it receives a call setup request signal from the user terminal. As a result, the signal processing capability of the base station is consumed, and the service quality of the base station as a whole is degraded. In particular, when a large number of calls are accepted in a short period of time, a large processing capacity is spent in transmitting and receiving signals between the PF layer and the AP layer in the base station, which may affect other functions. It was.

  The call reception method according to an embodiment includes: a second layer that pays out logical resources in response to a call reception received from a user terminal via the first layer; And the first layer determines whether there are remaining payable logical resources paid out from the second layer in response to the call reception from the user terminal. Paying out the logical resource.

  The method further includes the step of the first layer determining whether or not the payable logical resource that has been paid out from the second layer remains, and if not, notifying the user terminal of a congestion state. But you can.

  In addition, a base station according to another embodiment includes a first function unit that receives a call setup request from a user terminal, and a second function that pays out logical resources in response to a call reception from the first function unit. The second functional unit has a payable logical resource processing unit that pays out payable logical resources to the first functional unit, and the first functional unit is payable A payable logical resource management unit that manages a logical resource issued from the logical resource processing unit, and whether or not the payable logical resource remains is determined according to the call reception from the user terminal. A logical resource processing unit for paying out the logical resource.

  It is possible to reduce the processing load for call reception and reduce the processing time.

  Embodiments of the present invention will be described in detail with reference to the drawings. Throughout the drawings, the same or corresponding components are denoted by the same reference symbols.

  In the present embodiment, even when a large number of call acceptance requests occur in a short time in a call setup sequence in a LTE (Long Term Evolution) radio base station apparatus (hereinafter, eNodeB), the base station (eNodeB) is congested. This is a call acceptance method that pays out logical resources so as not to fall into an overload state. The present embodiment is a call acceptance method by an eNodeB radio base station apparatus, but may be a third generation, fourth generation, or other radio base station apparatus in other embodiments.

  FIG. 3 is a flow diagram illustrating a call acceptance method 300 according to one embodiment. This flowchart shows the operation of the user terminal (UE), the platform (PF) layer of the base station (eNodeB), and the application (AP) layer of the same base station (eNodeB). In the present embodiment, various steps are described as occurring in a certain order. However, in other embodiments, these steps may occur in a different order from the present embodiment. Also, some of these steps may be omitted, and other steps may be added.

  In the call accepting method 300 of the present embodiment, the AP layer notifies the PF layer of the number of logical resources (m) that can be paid out and the logical resource number when the operation of the apparatus is started (step S301).

  For example, the AP layer manages the logical resource number and the state of the logical resource in association with each other using the logical resource payout management table 40 shown in FIG. 4A as a database. The management table 40 shown in FIG. 4A indicates that logical resource numbers 1 to m are “paid out” to the PF layer, and logical resource numbers m + 1 to n are “unpaid out”. Here, m ≦ n. In this way, the AP layer can grant part or all of the managed logical resources to the PF layer.

  Returning to FIG. 3, the PF layer updates the logical resource payout management table of the PF layer with these resource information notified from the AP layer (step S <b> 303).

  For example, the PF layer uses the logical resource payout management table 45 shown in FIG. 4B as a database, and manages the logical resource number and the state of the logical resource in association with each other. The management table 45 illustrated in FIG. 4B indicates that the logical resources 1 to k are “paid out” to the user terminal (UE), and the logical resources k + 1 to m are “unpaid (empty)”. Here, k ≦ m.

  Returning to FIG. 3 again, when the PF layer receives the call acceptance request from the user terminal (UE) (step S305), the PF layer checks the logical resource payout management table 45 of the PF layer, and payout is possible (that is, payout is permitted). The presence / absence of a logical resource is determined (step S307).

  In step S307, if no payable logical resources remain (No), the fact that the logical resources cannot be paid out due to congestion is returned to the user terminal (UE) as a call acceptance response (step S309). That is, when the base station (eNodeB) is temporarily overloaded and there are no more logical resources that can be paid out managed by the PF layer, a new logical resource number and logical Until the resource number is paid out, the PF layer does not respond to a new call acceptance request from the user terminal (UE). Thereafter, the congestion state in the AP layer is resolved, and the number of logical resources and the logical resource number that can be newly paid out from the AP layer are notified to the PF layer (step S327), so that the PF layer is the user terminal (UE). A new call acceptance request from can be accepted.

  If it is determined in step S307 that there are remaining logical resources that can be paid out (Yes), the logical resource number (C-RNTI) to be paid out is determined (step S311), and the logical resource number to be paid out (C-RNTI = x) ) Is returned to the user terminal (UE) as a call acceptance response (step S313). The PF layer updates the number of payable logical resources and the resource number managed by the logical resource payout management table 45 (see FIG. 4B) (step S315).

  When the user terminal (UE) transmits a call setup request (step S317), the logical resource number (C-RNTI = x) issued by the PF layer is notified to the AP layer via the PF layer (step S317). S319).

  The AP layer recognizes that the PF layer has issued a logical resource by this call setting request, and determines whether there is a logical resource that can be newly issued (step S321).

  If there is no logical resource that can be paid out in step S321 and it is determined that the state is congested (No), the AP layer has nothing to do with the logical resource payout until it receives the next call setup start request from the user terminal (UE). do not do.

  If it is determined in step S321 that there are logical resources that can be paid out (Yes), the AP layer calculates the number of logical resources that can be paid out (step S325), and sets the number of logical resources and logical resource numbers that can be newly paid out in the PF layer. (Step S327). Thereby, the payable logical resource of the PF layer can be dynamically updated.

  Upon receiving notification of the number of logical resources that can be newly paid out and the logical resource number, the PF layer updates the logical resource payout management table 45 (see FIG. 4B) (step S329).

  As described above, the AP layer notifies the PF layer in advance of the number of logical resources and the logical resource number corresponding to the number of calls that can be processed simultaneously within a predetermined time without causing a congestion state, and when the PF layer accepts the call, Congestion control is performed by performing call acceptance processing for the number of calls corresponding to the number of resources and not sending a call acceptance request to the AP layer. The PF layer manages a part of the management of the logical resources to be paid out for each call setting, thereby causing the processing delay and the influence on the service due to the congestion in the AP layer and the increase of the signal processing amount of the entire base station apparatus (eNodeB). Stable operation is possible without causing

  In the above embodiment, it is determined whether there is a logical resource that the AP layer can pay out to the PF layer in response to a call setup start request (steps S317 and 319) from the user terminal (UE) (step S321). In another embodiment, when the PF layer determines that there are no payable logical resources (No in step S307), the PF layer notifies the AP layer, and the AP layer can pay out to the PF layer at that time. You may determine if there are resources.

  Also, in response to the occurrence of the call release sequence, the AP layer updates the state of the released logical resource logical resource delivery management table (see FIG. 4A) from “payout permitted” to “unpaid”, and the AP layer again It can be managed as a logical resource to be managed. On the other hand, the PF layer manages the released logical resource as “paid-out” as it is, and updates it to “free” when notified from the AP layer as a payable logical resource again. Thereby, the PF layer can pay out the released logical resource to the user terminal (UE) again.

  FIG. 5 is a flowchart showing a modification of the call acceptance method shown in FIG. The call acceptance method 500 shown in FIG. 5 is the same as the call acceptance method 300 shown in FIG. 3 from S301 to S329, but the timing for determining whether there is a payable logical resource (step S321) is different. Specifically, in the call reception method 300, it is determined whether there is a payable logical resource in response to reception of a call setting start request from the user terminal (UE) (step S321). In the call reception method 500, when the AP layer notifies the PF layer of the number of payable logical resources and the logical resource number (step S301), it starts a periodic timer (step S501) and receives a timeout notification of the periodic timer ( It is determined whether there is a payable logical resource in accordance with step S503) (step S321).

  Thereby, the AP layer can determine whether there is a logical resource that can be paid out at a constant period, regardless of reception of the call setup start request from the user terminal (UE).

  FIG. 6 is a flowchart showing a modification of the call acceptance method shown in FIG. The call reception method 600 shown in FIG. 6 is the same as the call reception method 300 shown in FIG. 3 from S301 to S329. However, in the call acceptance method 600, when the AP layer receives a call setup start request from the user terminal (UE) (steps S317 and S319), the AP layer uses the resource number (C-RNTI = x) associated with the call setup start request. Obtaining and changing the state of the logical resource number in the AP layer logical resource delivery management table 40 (see FIG. 4A) to “in use” (step S601). That is, in the call reception methods 300 and 500 shown in FIGS. 3 and 5, respectively, the AP layer manages only whether or not the logical resource has been issued, but in the call reception method 600 shown in FIG. The layer also manages whether the logical resource is in use. When a call release sequence occurs and logical resources are released (step S603), the AP layer determines whether there are any logical resources that can be paid out (step S321).

  In this way, the AP layer manages whether or not the logical resource is in use separately from the PF layer, so that the used logical resource can be paid out when a call release sequence occurs. It is possible to determine whether there is a payable logical resource. This makes the call acceptance method even more dynamic and efficient.

  FIG. 7 is a block diagram illustrating a base station 70 according to one embodiment. The base station (eNodeB) 70 illustrated in FIG. 7 is a base station that can implement the call reception method described with reference to FIGS. 3, 5, and 6, and is illustrated in FIGS. 3, 5, and 6. An application (AP) function unit 71 corresponding to the application (AP) layer and a platform (PF) function unit 72 corresponding to the platform (PF) layer are included.

  The AP function unit 71 processes a call acceptance request and a call setting start request received from the PF function unit 72, and transmits a call acceptance response to the PF function unit 72, and a call processing control unit A logical resource processing unit 212 that notifies a logical resource number between the logical resource management unit 211 and a logical resource management unit 213 that manages the logical resource and updates the state.

  The AP function unit 71 further includes a payable logical resource processing unit 711. The payable logical resource processing unit 711 refers to the AP layer logical resource payout management table 40 (see FIG. 4A, not shown in FIG. 7) managed by the logical resource management unit 213, and sends it to the PF function unit 72. The number of payable logical resources and the resource number can be notified.

  The PF function unit 72 includes a signal analysis unit 221, a call setting reception unit 222, a device control unit 223, and a monitoring control unit 224. The signal analysis unit 221 analyzes a signal received from a user terminal (UE) and sends the signal to a related component. Specifically, when the signal received from the user terminal is a call processing signal, the signal is sent to the call setting reception unit 222 that processes the call processing signal. When the signal is a device control signal, the device control signal is processed and sent to the device control unit 223 that controls the entire base station (eNodeB) 70. When the signal is a maintenance monitoring signal, the signal is sent to the monitoring control unit 224 that performs monitoring control based on the maintenance monitoring signal.

  The PF function unit 72 further indicates the number of payable logical resources and the resource number notified from the payable logical resource processing unit 711 of the AP function unit 71, and the PF layer logical resource payout management table 45 (see FIG. 4B, FIG. 7). The payable logical resource management unit 721 is managed using (not shown).

  The PF function unit 72 further refers to the payable logical resource number managed by the payable logical resource management unit 721 at the time of call setting reception, and determines whether there is a payable logical resource. A logical resource processing unit 722 that determines a number and notifies the call setting reception unit 222 of the number is provided.

  As described above, conventionally, every time a call acceptance request is received, the congestion state is determined in the AP layer, which is an upper layer, and if it is congested, the call acceptance request is discarded. In the layer, the call setup sequence processing was continued despite the congestion state. For this reason, the processing capacity of the base station is wasted, and the service of the entire base station apparatus is degraded.

  In this embodiment, since the number of received calls can be limited to the number of calls that can be processed simultaneously in the AP layer by controlling the delivery of logical resources in the PF layer, which is a lower layer, without causing a congestion state, Therefore, stable operation is possible without wasting processing capacity of the base station and causing processing delays and the like, and without degrading the service of the entire base station apparatus.

  At the same time, since the logical resource number is paid out for each call reception in the AP layer, it takes time to notify the logical resource number to the user terminal (UE) in the call setting sequence. However, in this embodiment, the PF layer pays out logical resources to the user terminal (UE), so that the time required for the call setup sequence can be shortened and the effect that radio resources can be used effectively can be expected. .

  As described above, the congestion control method in the present invention is not limited to a radio base station apparatus compliant with LTE (Long Term Evolution), but a radio base station compliant with W-CDMA or CDMA2000, or a fourth generation radio base station. The present invention can also be applied to congestion control due to temporary overload in a station or the like.

  Further, it will be apparent to those skilled in the art that the call acceptance methods shown in FIGS. 3, 5, and 6 can be executed by a microprocessor, a controller, a computer, and the like provided in the radio base station apparatus.

  Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the specific embodiment, and various modifications and changes are within the scope of the gist of the present invention described in the claims. It can be changed.

In addition, the following additional remarks are described about said embodiment.
(Appendix 1)
In response to the call reception received from the user terminal through the first layer that analyzes and distributes the received signal, the second layer that performs call processing notifies the first layer of the logical resources that can be paid out. Stages,
A call accepting method including: the first layer paying out payable logical resources notified from the second layer in response to accepting a call from a user terminal.
(Appendix 2)
The first layer further includes the step of determining whether or not the payable logical resource notified from the second layer remains, and if not, notifying the user terminal of the congestion state further includes the step of: the method of.
(Appendix 3)
When the first layer pays out payable logical resources notified from the second layer in response to call reception from the user terminal, the payable logic notified from the second layer. The method of claim 1, further comprising updating a first database that manages resources.
(Appendix 4)
The second layer determining whether there is a logical resource that can be paid out in addition to the logical resource that has already been paid out;
The method according to claim 1, further comprising the step of notifying the first layer of any payable logical resources.
(Appendix 5)
After the second layer notifies the first layer of logical resources that can be paid out, the logical resources that can be paid out in addition to the logical resources that have already been paid out in response to reception of a call setup start request from the user terminal The method according to appendix 4, in which it is determined whether there is any.
(Appendix 6)
The second layer determines whether there is a logical resource that can be paid out in addition to the already notified logical resource after a predetermined time has elapsed since the second layer paid out the logical resource that can be paid out to the first layer. The method described.
(Appendix 7)
The supplementary note 1 further includes the step of the second layer updating a second database for managing payable logical resources notified to the first layer in response to a call setup start request from the user terminal. The method described in 1.
(Appendix 8)
The method according to claim 4, wherein the second layer notifies the first layer of logical resources that can be paid out, and then a call release sequence occurs to determine whether there are logical resources that can be paid out.
(Appendix 9)
A first function processing unit that analyzes and distributes a received signal from a user terminal, and a second function processing unit that performs call processing that pays out logical resources in response to call reception from the first function processing unit And
The second function processing unit includes a payable logical resource processing unit that notifies the first functional processing unit of a payable logical resource,
The first function processing unit includes a payable logical resource management unit that manages the logical resource notified from the payable logical resource processing unit, and the payable logical resource according to call reception from the user terminal. A base station that includes a logical resource processing unit that determines whether or not a resource remains and pays out the logical resource if the resource remains.
(Appendix 10)
The logical resource processing unit determines whether or not the payable logical resource notified from the payable logical resource processing unit managed by the payable logical resource management unit remains. If not, the logical resource processing unit is congested with the user terminal. The base station according to appendix 9, which notifies the state.

It is a flowchart which shows the conventional call reception method. It is a block diagram which shows the conventional base station. It is a flowchart which shows the call reception method by one Embodiment. It is a figure which shows the logical resource delivery management table of AP layer. It is a figure which shows the logical resource delivery management table of PF layer. It is a flowchart which shows the modification of the call reception method shown in FIG. It is a flowchart which shows the other modification of the call reception method shown in FIG. 2 is a block diagram illustrating a base station according to one embodiment. FIG.

Explanation of symbols

70 base station 71 AP function unit 72 PF function unit 211 call processing control unit 212 logical resource processing unit 213 logical resource management unit 221 signal analysis unit 222 call setting reception unit 223 device control unit 224 monitoring control unit 711 payable logical resource processing unit 721 Distributable logical resource management unit 722 Logical resource processing unit

Claims (8)

In response to the call reception received from the user terminal through the first layer that analyzes and distributes the received signal, the second layer that performs call processing notifies the first layer of the logical resources that can be paid out. Stages,
A call accepting method including: the first layer paying out payable logical resources notified from the second layer in response to accepting a call from a user terminal. The method according to claim 1, further comprising: determining whether or not the payable logical resource notified from the second layer remains, and notifying the user terminal of the congestion state if the first layer does not remain. The call acceptance method described. The second layer determining whether there is a logical resource that can be paid out in addition to the logical resource that has already been paid out;
The call acceptance method according to claim 1, further comprising a step of notifying the first layer of any logical resources that can be paid out. A first function processing unit that analyzes and distributes a received signal from a user terminal, and a second function processing unit that performs call processing that pays out logical resources in response to call reception from the first function processing unit And
The second function processing unit includes a payable logical resource processing unit that notifies the first functional processing unit of a payable logical resource,
The first function processing unit includes a payable logical resource management unit that manages the logical resource notified from the payable logical resource processing unit, and the payable logical resource according to call reception from the user terminal. A base station having a logical resource processing unit that pays out resources.   The logical resource processing unit determines whether or not the payable logical resource notified from the payable logical resource processing unit managed by the payable logical resource management unit remains. If not, the logical resource processing unit is congested with the user terminal. The base station according to claim 4, which notifies a state. In response to the call reception received from the user terminal through the first layer that analyzes and distributes the received signal, the second layer that performs call processing notifies the first layer of the logical resources that can be paid out. Stages,
  The first layer pays out payable logical resources notified from the second layer in response to call reception from a user terminal;
  The first layer determines whether or not the payable logical resource notified from the second layer remains, and if not, notifies the user terminal of a congestion state;
  When the first layer pays out payable logical resources notified from the second layer in response to call reception from the user terminal, the payable logic notified from the second layer. Updating a first database managing resources;
  The second layer determining whether there is a logical resource that can be paid out in addition to the logical resource that has already been paid out;
  Notifying the first layer of any payable logical resources, and
  After the second layer notifies the first layer of logical resources that can be paid out, the logical resources that can be paid out in addition to the logical resources that have already been paid out in response to reception of a call setup start request from the user terminal Call acceptance method to determine if there is. In response to the call reception received from the user terminal through the first layer that analyzes and distributes the received signal, the second layer that performs call processing notifies the first layer of the logical resources that can be paid out. Stages,
  The first layer pays out payable logical resources notified from the second layer in response to call reception from a user terminal;
  The first layer determines whether or not the payable logical resource notified from the second layer remains, and if not, notifies the user terminal of a congestion state;
  When the first layer pays out payable logical resources notified from the second layer in response to call reception from the user terminal, the payable logic notified from the second layer. Updating a first database managing resources;
  The second layer determining whether there is a logical resource that can be paid out in addition to the logical resource that has already been paid out;
  Notifying the first layer of any payable logical resources, and
  The call accepting method for determining whether there is a logical resource that can be paid out in addition to the already notified logical resource after a predetermined time has elapsed after the second layer has paid out the logical resource that can be paid out to the first layer. . In response to the call reception received from the user terminal through the first layer that analyzes and distributes the received signal, the second layer that performs call processing notifies the first layer of the logical resources that can be paid out. Stages,
  The first layer pays out payable logical resources notified from the second layer in response to call reception from a user terminal;
  The first layer determines whether or not the payable logical resource notified from the second layer remains, and if not, notifies the user terminal of a congestion state;
  When the first layer pays out payable logical resources notified from the second layer in response to call reception from the user terminal, the payable logic notified from the second layer. Updating a first database managing resources;
  The second layer determining whether there is a logical resource that can be paid out in addition to the logical resource that has already been paid out;
  Notifying the first layer of any payable logical resources;
  The second layer updates a second database that manages payable logical resources notified to the first layer in response to a call setup start request from the user terminal;
  The second layer determining whether there is a logical resource that can be paid out in addition to the logical resource that has already been paid out;
  Notifying the first layer of any payable logical resources, and
  A call accepting method in which the second layer notifies the first layer of payable logical resources to the first layer, and then a call release sequence occurs to determine whether there is a payable logical resource.

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