JP6403402B2 - COMMUNICATION DEVICE, BASE STATION DEVICE, COMMUNICATION SYSTEM AND COMMUNICATION METHOD - Google Patents

Description

  The present invention relates to a communication device, a base station device, a communication system, and a communication method.

  In the LTE-Advanced system being studied by 3GPP, carrier aggregation (CA) that uses a plurality of frequency bands (component carrier (CC)) at the same time for the purpose of improving frequency utilization efficiency and peak throughput. Technology is employed (see Non-Patent Document 1).

In inter-site carrier aggregation (Inter-Site CA) which is one form of carrier aggregation, a mobile terminal device (UE: User Equipment) is a plurality of base station devices (eNB: E-UTRAN NodeB) installed at different locations. At the same time, they are connected and communicate using a different frequency band (CC) for each base station apparatus.
Furthermore, in communication between a base station apparatus and a mobile terminal apparatus, a network form (dual connectivity) in which C-Plane and U-Plane are separated and transmitted through different base station apparatuses has been proposed. (See Non-Patent Document 2).

Here, C-Plane is a protocol for performing connection management (user management) and mobility control of a mobile terminal device. Information related to connection management of the mobile terminal device is held by MME (Mobility Management Entity). The MME performs user management and mobility control-related processing.
U-Plane is a protocol related to transmission / reception of user traffic and scheduling information. A mobile network composed of a base station device and a mobile terminal device is connected to the external Internet via an S-GW (Serving-Gateway).

In the dual connectivity, a base station apparatus that controls transmission and reception of C-Plane data is referred to as a MeNB (Master eNB). The MeNB is widely deployed in the area mainly for ensuring the coverage of the mobile terminal apparatus. MeNB also performs transmission / reception of U-Plane.
On the other hand, a base station apparatus that transmits and receives only U-Plane is called a SeNB (Secondary eNB). The SeNB is mainly installed in a spot for capacity expansion.

3GPP TS36.300 v11.3.0, “E-UTRA and E-UTRAN overall description”, 2012-09. NTT DOCOMO INC. , “Requirements, Candid Solutions & Technology Roadmap for LTE Rel-12 Onward”, 3GPP Works on Release 12 and onwards, RWS-122010, Jun 20

  However, in the LTE communication system, when traffic is transmitted and received on the communication path for transmitting U-Plane data from the S-GW to the UE via the SeNB, the communication path between the S-GW and the SeNB (back When a malfunction occurs in a hall (backhaul line) or when there is no traffic to be communicated, there is a problem that the efficiency of the system is lowered.

Specifically, when a failure occurs in the communication path between the S-GW and the SeNB, if the connection state between the S-GW and the SeNB continues, the throughput (user throughput) decreases or the connection with the SeNB The efficiency of the system is reduced due to waste of power in the UE caused by continuing the state and waste of resources due to management of unnecessary user information in the S-GW, MME, SeNB, and MeNB.
In addition, when there is no traffic to be communicated on the communication path between the S-GW and the SeNB, if the connection state between the S-GW and the SeNB continues, a UE that is generated to continue the connection state with the SeNB The efficiency of the system is reduced due to the waste of power and the waste of resources by managing unnecessary user information in the S-GW, MME, SeNB, and MeNB.

  The present invention has been made in consideration of such circumstances, and a communication device capable of improving efficiency with respect to a communication path for transmitting U-Plane data from the S-GW to the UE via the SeNB, It is an object to provide a base station device, a communication system, and a communication method.

(1) In order to solve the above-described problem, a communication apparatus according to an aspect of the present invention receives a data signal transmitted from the communication apparatus and transmits the data signal to a terminal apparatus. The base station apparatus and a second base station apparatus that receives a control signal transmitted from the terminal management apparatus and transmits the control signal to the terminal apparatus. A communication monitoring unit that monitors a state of communication with the first base station device, and a communication state between the first base station device and the communication base unit is a predetermined communication state by the communication monitoring unit. A notification control unit that controls to perform a predetermined notification when it is detected. In the predetermined communication state, when a signal is transmitted from the communication device to the first base station device, a response signal of the signal is received from the first base station device within a predetermined time. It is a communication state that was not done.

  (2) According to one aspect of the present invention, in the communication device according to (1) described above, the notification control unit performs notification to release a predetermined resource to the second base station device. A configuration may be used.

  (3) One aspect of the present invention is the communication device according to any one of (1) or (2) described above, wherein the communication monitoring unit communicates with the first base station device. When it is detected that the state is a predetermined communication state, a configuration including a resource release control unit that controls to release a predetermined resource may be used.

  (4) One aspect of the present invention is the communication device according to any one of (1) to (3), wherein the communication monitoring unit uses a timer to perform the first base station. A configuration that monitors the state of communication with the device may be used.

  (5) One aspect of the present invention is the communication apparatus according to any one of (1) to (4), wherein the first base station apparatus and the second base station apparatus A configuration including a data communication control unit that controls to transmit a data signal to one or both of the above may be used.

(6) In order to solve the above-described problem, a base station apparatus according to an aspect of the present invention receives a data signal transmitted from a communication apparatus and transmits the data signal to a terminal apparatus. A first base station apparatus, and a second base station apparatus that receives a control signal transmitted from a terminal management apparatus and transmits the control signal to the terminal apparatus. A communication monitoring unit that monitors a state of communication with the communication device, and a state of communication with the communication device by the communication monitoring unit is a predetermined communication state. A notification control unit that controls to perform a predetermined notification when it is detected. In the predetermined communication state, when a signal is transmitted from the first base station device to the communication device, a response signal of the signal is not received from the communication device within a predetermined time. Communication state.

  (7) According to one aspect of the present invention, in the base station device described in (6) above, the notification control unit performs notification to release a predetermined resource to the second base station device A configuration may be used.

  (8) According to one aspect of the present invention, in the base station device according to any one of (6) and (7) described above, a state of communication with the communication device is determined by the communication monitoring unit. A configuration may be used that includes a resource release control unit that controls to release a predetermined resource when it is detected that the communication state is predetermined.

  (9) According to one aspect of the present invention, in the base station device according to any one of (6) to (8), the communication monitoring unit uses a timer to communicate with the communication device. A configuration may be used that monitors the state of communication between the two.

  (10) According to one aspect of the present invention, in the base station device according to any one of (6) to (9), the data signal transmitted from the communication device is received, and the data The structure provided with the data communication control part which controls to transmit a signal with respect to the said terminal device may be used.

  (11) In order to solve the above problem, a base station apparatus according to an aspect of the present invention receives a data signal transmitted from a communication apparatus and transmits the data signal to a terminal apparatus. A second base station apparatus that receives a control signal transmitted from a terminal management apparatus and transmits the control signal to the terminal apparatus. A base station apparatus that receives a notification in response to detecting that the state of communication between the communication apparatus and the first base station apparatus is a predetermined communication state. A notification control unit that controls to perform the notification, and a control signal communication control unit that receives the control signal transmitted from the terminal management device and controls the terminal device to transmit the control signal. .

  (12) One aspect of the present invention is the base station device according to (11), in which the notification control unit communicates between the communication device and the first base station device from the communication device. When a notification is received in response to detecting that the state of the communication is a predetermined communication state, one or more of the terminal device, the terminal management device, and the first base station device A configuration that controls to perform the predetermined notification may be used.

  (13) One aspect of the present invention is the base station apparatus according to (11) described above, in which the notification control unit includes the communication apparatus, the first base station apparatus, and the first base station apparatus. One or more of the terminal device, the terminal management device, and the communication device when receiving a notification in response to detecting that the state of communication between the devices is a predetermined communication state A configuration that controls to perform the predetermined notification may be used.

  (14) According to one aspect of the present invention, in the base station device according to any one of (11) to (13), the data signal transmitted from the communication device is received, and the data The structure provided with the data communication control part which controls to transmit a signal with respect to the said terminal device may be used.

(15) In order to solve the above-described problem, a communication system according to one embodiment of the present invention receives a data signal transmitted from a communication device, a terminal device, a terminal management device, and the communication device, and receives the data A first base station device that transmits a signal to the terminal device; and a first base station device that receives a control signal transmitted from the terminal management device and transmits the control signal to the terminal device. A base station apparatus, wherein the communication state between the communication apparatus and the first base station apparatus is monitored, and the communication apparatus and the first base station apparatus A predetermined notification is performed when it is detected that the communication state between the two is a predetermined communication state. The predetermined communication state is determined by the other device within a predetermined time when a signal is transmitted from one device of the communication device and the first base station device to the other device. This is a communication state in which no response signal is received.

(16) In order to solve the above-described problem, a communication method according to an aspect of the present invention includes a communication device, a terminal device, a terminal management device, and a data signal transmitted from the communication device, and the data A first base station device that transmits a signal to the terminal device; and a first base station device that receives a control signal transmitted from the terminal management device and transmits the control signal to the terminal device. A communication method in a communication system having two base station devices, wherein a communication state between the communication device and the first base station device is monitored, and the communication device and the first base station When it is detected that the state of communication with the apparatus is a predetermined communication state, a predetermined notification is performed. The predetermined communication state is determined by the other device within a predetermined time when a signal is transmitted from one device of the communication device and the first base station device to the other device. This is a communication state in which no response signal is received.

  According to the present invention, it is possible to improve the efficiency of a communication path for transmitting U-Plane data from the S-GW to the UE via the SeNB.

It is a block diagram which shows the schematic structure of S-GW which concerns on one Embodiment of this invention. It is a block diagram which shows the schematic structure of MeNB which concerns on one Embodiment of this invention. It is a block diagram which shows the outline of the process in the communication system which concerns on one Embodiment (1st Embodiment) of this invention. It is a sequence diagram which shows an example of the procedure of the process performed in the communication system which concerns on one Embodiment (1st Embodiment) of this invention. It is a block diagram which shows schematic structure of SeNB which concerns on one Embodiment of this invention. It is a block diagram which shows the outline of the process in the communication system which concerns on one Embodiment (2nd Embodiment) of this invention. It is a sequence diagram which shows an example of the procedure of the process performed in the communication system which concerns on one Embodiment (2nd Embodiment) of this invention. It is a figure which shows an example of the communication of the data of U-Plane in the case of isolate | separating U-Plane data by S-GW. It is a figure which shows an example of a mode when a malfunction arises in the communication path | route between S-GW and SeNB.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Description of U-Plane data communication during dual connectivity]
First, with reference to FIG. 8, communication of U-Plane data at the time of dual connectivity will be described.
FIG. 8 is a diagram illustrating an example of U-Plane data communication (1A: S-GW flow splitting) when U-Plane data is separated by S-GW2.
In FIG. 8, UE1, SeNB11 and its radio | wireless communication area | region 101, MeNB12 and its radio | wireless communication area | region 102, S-GW2, MME3, and the internet (Internet) 4 are shown.

For C-Plane data, the MME 3 transmits C-Plane data to the MeNB 12, and the MeNB 12 transmits the data to the UE 1.
As for U-Plane data, the S-GW 2 separates data transmitted through the SeNB 11 from U-Plane data from the Internet 4 and transmits the separated data to the SeNB 11, and the SeNB 11 transmits the data to the UE 1. Further, the S-GW 2 transmits the remaining data (data to be passed through the MeNB 12) among the U-Plane data from the Internet 4 to the MeNB 12, and the MeNB 12 transmits the data to the UE 1.

  As described above, in the example of FIG. 8, in the S-GW 2, the traffic that passes through the SeNB 11 is separated from the U-Plane data, and is directly transmitted from the S-GW 2 to the SeNB 11. Thereby, the data of C-Plane is transmitted / received via MeNB12, and the data of U-Plane is transmitted / received via one or both of MeNB12 and SeNB11.

  Note that the communication path for transmitting U-Plane data from S-GW2 to UE1 via SeNB11 is switched from, for example, the communication path for transmitting U-Plane data to UE1 from S-GW2 via MeNB12. It is realized by being established or newly established from the beginning.

Here, although not shown, there is simultaneous communication (3C: MeNB bearer splitting) between the MeNB 12 and the SeNB 11 using C / U separation as a communication method different from the example of FIG.
Specifically, for C-Plane data, the MME 3 transmits C-Plane data to the MeNB 12, and the MeNB 12 transmits the data to the UE 1.
As for U-Plane data, the S-GW 2 transmits U-Plane data from the Internet 4 to the MeNB 12. MeNB12 isolate | separates the data which pass SeNB11 among the received U-Plane data, and transmits to SeNB11, and SeNB11 transmits the said data to UE1. In addition, the MeNB 12 transmits the remaining data (data to be directly transmitted to the UE1) among the received U-Plane data to the UE1.
Thus, in this communication (3C) example, for U-Plane data, one bearer (Bearer) exists between S-GW2 and MeNB12, and two bearers (MeNB12 and UE1) exist in MeNB12. And a single bearer between MeNB12 and SeNB11).

[Explanation when trouble occurs in communication path between S-GW and SeNB]
FIG. 9 is a diagram illustrating an example of a state when a failure occurs in the communication path between the S-GW 2 and the SeNB 11.
As in the example of FIG. 8, when traffic is transmitted / received via the communication path for transmitting U-Plane data from the S-GW 2 to the UE 1 via the SeNB 11, the communication path between the S-GW 2 and the SeNB 11 (back When a problem occurs due to physical disconnection or the like in the (Hall line), for example, the S-GW 2 retransmits the data to be communicated to the SeNB 11 many times, a decrease in throughput, waste of power in the UE 1, The efficiency of the system decreases due to resource waste due to management of unnecessary user information in the S-GW2, the MME3, the SeNB11, and the MeNB12.
In addition, when traffic is transmitted / received via the communication path for transmitting U-Plane data from the S-GW 2 to the UE 1 via the SeNB 11, when there is no traffic to be communicated, the waste of power in the UE 1 or S-GW 2 Moreover, the efficiency of a system falls by the resource waste by management of the unnecessary user information in MME3, SeNB11, and MeNB12.

[First Embodiment]
Hereinafter, the same reference numerals as those shown in FIG. 8 and FIG.
<Outline of communication system>
FIG. 1 is a block diagram showing a schematic configuration of an S-GW 2 according to an embodiment of the present invention.
The S-GW 2 according to the present embodiment includes a communication unit 211, a storage unit 212, and a control unit 213.
The control unit 213 includes a communication monitoring unit 231, a resource release control unit 232, and a resource release notification control unit 233.

The communication unit 211 communicates with an external device wirelessly or by wire. In this embodiment, the communication part 211 transmits / receives a signal between SeNB11 and MeNB12 by a wire communication (or radio | wireless).
The storage unit 212 is configured using a memory and stores various data. As a specific example, the storage unit 212 stores data of a program used by the control unit 213, data of various parameters, data related to data communication, and the like.

The control unit 213 performs various processes and controls by executing a predetermined program.
The communication monitoring unit 231 monitors the communication state of U-Plane data using a communication path between the own device (S-GW2) and the SeNB 11. In the present embodiment, the communication monitoring unit 231 monitors the communication state between the own device (S-GW2) and the SeNB 11 by using an installed timer.
The resource release control unit 232 controls to release the connection state between the own device (S-GW2) and the SeNB 11 when a predetermined communication state is detected by the communication monitoring unit 231. Release device resources.
When the communication monitoring unit 231 detects a predetermined communication state, the resource release notification control unit 233 uses the communication path between the own device (S-GW2) and the SeNB 11 to communicate the U-Plane data. Control is performed so as to notify other devices (for example, MeNB 12) to release the.
The data communication control unit 234 controls U-Plane data communication.

Here, in the present embodiment, the predetermined communication state that triggers the release of the communication state of the U-Plane data that uses the communication path between the S-GW 2 and the SeNB 11, from the S-GW 2 to the SeNB 11. When a signal is transmitted to, a communication state in which a response signal of the signal is not received from the SeNB 11 within a predetermined time is used.
As another configuration example, a communication state in which there is no signal communicated between the S-GW 2 and the SeNB 11 within a predetermined time may be used as the above-described predetermined communication state.
Two or more types of communication states may be used as the predetermined communication state.

FIG. 2 is a block diagram showing a schematic configuration of the MeNB 12 according to the embodiment of the present invention.
The MeNB 12 according to the present embodiment includes a communication unit 311, a storage unit 312, and a control unit 313.
The control unit 313 includes a resource release notification control unit 331, a data communication control unit 332, and a control signal communication control unit 333.

The communication unit 311 communicates with an external device wirelessly or by wire. In the present embodiment, the communication unit 311 transmits and receives (transmits and receives) signals wirelessly with the UE 1 existing in the communication area 102. Moreover, the communication part 311 transmits / receives a signal between S-GW2 and SeNB11 by a wire communication (or radio | wireless).
The storage unit 312 is configured using a memory and stores various data. As a specific example, the storage unit 312 stores data of a program used by the control unit 313, data of various parameters, data related to data communication, and the like.

The control unit 313 performs various processes and controls by executing a predetermined program.
When the notification for releasing the communication state of the data of the U-Plane that uses the communication path between the S-GW 2 and the SeNB 11 is received from the S-GW 2, the resource release notification control unit 331 notifies the notification To other devices (for example, UE1, MME3, and SeNB11).
The data communication control unit 332 controls U-Plane data communication.
The control signal communication control unit 333 controls C-Plane data communication.

FIG. 3 is a block diagram showing an outline of processing in the communication system according to one embodiment (first embodiment) of the present invention.
In FIG. 3, UE1, SeNB11 and its radio | wireless communication area | region 101, MeNB12 and its radio | wireless communication area | region 102, S-GW2, MME3, and the internet 4 are shown.
In the present embodiment, it is assumed that UE1 exists in an overlapping portion of the communication area 101 of SeNB11 and the communication area 102 of MeNB12.
As another configuration example, a configuration in which two or more SeNBs are provided for one MeNB may be used.

With reference to FIG. 3 and FIG. 4, an example of the procedure of the process performed in the communication system which concerns on one Embodiment (1st Embodiment) of this invention is shown.
FIG. 4 is a sequence diagram showing an example of a procedure of processing performed in the communication system according to one embodiment (first embodiment) of the present invention.
Here, for the procedure (1) to the procedure (5) shown in FIG. 3, the procedure T1 shown in FIG. 4 is performed in the procedure (1), and the procedure T2-1 shown in FIG. 4 is executed in the procedure (2). The process T2-2 is performed. In the procedure (3), the process T3 shown in FIG. 4 is performed. In the procedure (4), the process T4-1 to the process T4-3 shown in FIG. ), Process T5-1 to process T5-2 shown in FIG. 4 are performed.

(Assumption)
First, it is assumed that a communication path for transmitting U-Plane data from the S-GW 2 to the UE 1 via the SeNB 11 is established. In this case, S-GW2 and SeNB11 are in a connected state, and SeNB11 and UE1 are in a connected state. Moreover, S-GW2, MME3, and SeNB11 memorize | store and manage the information (user information) regarding the said UE1 about dual connectivity. Various information may be used as the user information, for example, information that identifies the corresponding UE1 (or a user thereof), information on a communication path used by the corresponding UE1, and the like may be included. Good.

Procedure (1)
In S-GW2, when a predetermined signal (message) is transmitted to SeNB 11, communication monitoring unit 231 activates a timer (starts counting) for detecting (detecting) communication disconnection (process T1).
Here, the predetermined signal that triggers the activation of the timer may be, for example, any arbitrary signal, a predetermined specific signal, or a pseudo signal. It may be a signal determined randomly using random numbers or the like.

Procedure (2)
In S-GW2, after a predetermined signal is transmitted to SeNB11 and a timer is activated, a response to the signal from SeNB11 before the count value of the timer reaches a predetermined value (for example, a fixed time) When the signal is received, the communication monitoring unit 231 resets the count value of the timer (for example, resets to zero (0)).
On the other hand, in S-GW2, after a predetermined signal is transmitted to SeNB11 and the timer is activated, when the count value of the timer reaches a predetermined value, the communication monitoring unit 231 It determines with having expired (process T2-1). In this case, in this embodiment, it is considered that a failure has occurred in the communication path (backhaul line) between the S-GW 2 and the SeNB 11.
Here, various values may be used as the predetermined value related to the count value (a count value at which the timer expires).

In S-GW2, according to the expiration of the timer, the resource release control unit 232 uses a communication path for transmitting U-Plane data from the own device (S-GW2) to the UE1 via the corresponding SeNB11. To release the resource related to the UE 1 (process T2-2). In S-GW2, as a resource to be released, for example, there is information stored (managed) by the storage unit 212 with respect to the UE1, and in this case, the resource is released by deleting the information from the storage unit 212.
Note that such release of resources in the S-GW 2 may be performed at any later timing, for example.

Procedure (3)
In S-GW2, in response to the expiration of the timer, the resource release notification control unit 233 sends U-Plane data to UE1 via MeNB12 via the corresponding SeNB11 from its own device (S-GW2). A signal (in this embodiment, a signal for notifying the expiration of the timer) for notifying that the resource relating to the UE 1 that uses the transmission communication path is released is transmitted (process T3).

Procedure (4)
In MeNB12, if the notification signal mentioned above is received from S-GW2, the resource release notification control part 331 will notify the UE1 (signal which notifies the cancellation | release of dual connectivity in this embodiment) to that effect corresponding UE1. (Process T4-1), transmitted to the related MME3 (process T4-2), and transmitted to the related SeNB 11 (process T4-3).
Here, this notification may be performed simultaneously with respect to UE1, MME3, and SeNB11, or may be performed in an arbitrary order. In the example of FIG. 4, for convenience of explanation, the notification is shown in the order of notification to UE1, notification to MME3, and notification to SeNB11.
Further, the notification from the MeNB 12 to the UE 1 is performed, for example, via an RRC (Radio Resource Control) message.

  In the example of FIG. 4, the notification (process T4-2) from the MeNB 12 to the MME 3 is performed in the procedure (4). However, as another configuration example, in the procedure (2) or other timing, Notification may be performed from S-GW2 to MME3.

Procedure (5)
In the MME 3, the resource related to the UE 1 is released based on the content notified from the MeNB 12 by the resource release control function unit (resource release control unit) (process T5-1). In the MME 3, as a resource to be released, for example, there is information stored (managed) by the storage unit regarding the UE 1, and in this case, the resource is released by deleting the information from the storage unit.
Note that such release of resources in the MME 3 may be performed at an arbitrary timing.
In addition, for example, when the MME 3 stores and manages information on the SeNB 11 and MeNB 12 that manages information on the corresponding UE 1 in the storage unit, the MME 3 not only deletes information on the UE 1 as a resource release on the UE 1, A configuration may be used in which information related to SeNB 11 and MeNB 12 that manages information related to the UE 1 (part of information related to the UE 1) is deleted.

In the SeNB 11, the resource related to the UE 1 is released based on the content notified from the MeNB 12 by the resource release control function unit (resource release control unit) (process T5-2). In the SeNB 11, as a resource to be released, for example, there is information stored (managed) by the storage unit regarding the UE 1, and in this case, the information is released by deleting the information from the storage unit.
Such resource release in the SeNB 11 may be performed at an arbitrary timing.

  In UE1, based on the content notified from MeNB12, dual connectivity is cancelled | released, and the own apparatus which uses the communication path which transmits the data of U-Plane to own apparatus (UE1) via SNB11 from S-GW2 It knows that the resource related to (UE1) is released (or released).

  In addition, in MeNB12, when memorize | storing in the memory | storage part 312 and managing the resource (for example, resource regarding UE1) released by cancellation | release of dual connectivity, in the procedure (3) shown in FIG. 4, or other arbitrary timings Alternatively, a configuration may be used in which the resource release control function unit (resource release control unit) releases the corresponding resource based on the content notified from the S-GW 2. The resources to be released in the MeNB 12 include, for example, information stored (managed) by the storage unit 312 regarding the UE 1. In this case, the resources are released by deleting the information from the storage unit 312. However, in this embodiment, since the communication path for transmitting C-Plane data from the MME 3 to the UE 1 via the MeNB 12 is continued, the connection is maintained in this communication path.

Here, in the present embodiment, the communication monitoring unit 231 in the S-GW 2 uses the timer to detect a case where it is considered that a failure has occurred in the communication path between the S-GW 2 and the SeNB 11. As for the communication path between the S-GW 2 and the SeNB 11, a configuration for detecting a case where it is considered that there is no traffic to be communicated may be used. In this other configuration example, the communication monitoring unit 231 in the S-GW 2 activates a timer at the timing when communication of a predetermined signal (message) is performed (when transmission or reception occurs). Then, it is determined whether or not there is a new communication (new transmission or reception) thereafter, and communication (transmission or reception) of a new predetermined signal before the count value of the timer reaches a predetermined value (for example, a fixed time). When the operation is performed, the count value of the timer is reset. In addition, as said predetermined signal used as the opportunity which starts a timer, all the arbitrary signals may be sufficient, for example, and the predetermined specific signal may be sufficient as them. In this other configuration example, regarding the communication path from the S-GW 2 to the UE 1 via the SeNB 11, if traffic does not occur within a predetermined time after transmission or reception is completed, it is assumed that the traffic is not used and Release resources.
As yet another configuration example, the communication monitoring unit 231 in the S-GW 2 executes both of the two types of timer counting methods (a method related to a communication path failure and a method related to presence / absence of traffic) as described above. In this case, for example, when at least one of the timers expires, the related resources are released.

<Summary of First Embodiment>
As described above, in the communication system according to the present embodiment, the UE 1 is connected to the Internet 4 in a wireless communication system capable of simultaneously connecting to and communicating with a plurality of eNBs (MeNB and SeNB in the present embodiment). When the communication path used as the communication path of user traffic data (in this embodiment, U-Plane data) is switched between eNBs, S-GW2 and SNB 11 (two or more SeNBs) In other words, it is possible to release resources such as a base station at an early stage by releasing dual connectivity when a predetermined communication state is reached. In the communication system, when two or more SeNBs exist for one S-GW2, for example, the processing according to the present embodiment is performed for each SeNB.

Therefore, in the communication system according to the present embodiment, as an example, when a failure occurs in the communication path between the S-GW 2 and the SeNB 11, the dual connectivity state of the UE 1 is canceled, and the S-GW 2 and the SeNB 11 By releasing the connection state, it is possible to prevent a decrease in throughput (user throughput), prevent waste of power in UE1 that is caused by continuing the connection state with SeNB11, and unnecessary in S-GW2, MME3, SeNB11, and MeNB12. Resource waste due to management of user information can be prevented, thereby preventing a reduction in system efficiency.
Moreover, in the communication system according to the present embodiment, as another example, when there is no traffic to be communicated in the communication path between the S-GW 2 and the SeNB 11, the dual connectivity state of the UE 1 is canceled, and the S -By releasing the connection state between the GW2 and the SeNB11, the waste of power in the UE1 that occurs in order to continue the connection state with the SeNB11 is prevented, and by managing unnecessary user information in the S-GW2, MME3, SeNB11, and MeNB12 Resource waste can be prevented, thereby preventing a reduction in system efficiency.
As described above, in the communication system according to the present embodiment, the data signal (the present signal is transmitted from the S-GW 2 via the SeNB 11 to the UE 1 while performing the communication of the control signal (in this embodiment, the C-Plane data signal). In the embodiment, the efficiency of the communication path for transmitting the U-Plane data signal) can be improved.

  Here, the communication system according to the present embodiment is applied at the time of setup of U-Plane data communication (1A: S-GW flow splitting) in dual connectivity as shown in FIG. Connection release control can be realized. Note that the communication system according to the present embodiment may be applied to other situations (situations other than the above-described 1A).

[Second Embodiment]
In the following description, the same reference numerals as those shown in FIGS. 1 to 3, 8, and 9 are given as the reference numerals of each device.
Hereinafter, points different from the first embodiment will be described in detail, and descriptions of points similar to the first embodiment will be omitted or simplified.

<Outline of communication system>
The schematic configuration of the S-GW 2 according to the embodiment of the present invention is the same as that shown in FIG. 1 according to the first embodiment. For example, the communication monitoring unit 231 and the resource release notification control unit 233 May or may not be provided.

The schematic configuration of the MeNB 12 according to the embodiment of the present invention is the same as that illustrated in FIG. 2 according to the first embodiment, but the function of the resource release notification control unit 331 of the control unit 313 is the first implementation. Different from form.
In the present embodiment, the resource release notification control unit 331 of the control unit 313 receives a notification from the SeNB 11 for releasing the communication state of the U-Plane data that uses the communication path between the S-GW 2 and the SeNB 11. In such a case, control is performed so that the notification is sent to another device (for example, UE1, MME3, or S-GW2).

FIG. 5 is a block diagram illustrating a schematic configuration of the SeNB 11 according to the embodiment of the present invention.
The SeNB 11 according to the present embodiment includes a communication unit 411, a storage unit 412, and a control unit 413.
The control unit 413 includes a communication monitoring unit 431, a resource release control unit 432, a resource release notification control unit 433, and a data communication control unit 434.

The communication unit 411 communicates with an external device wirelessly or by wire. In the present embodiment, the communication unit 411 transmits and receives (transmits and receives) signals wirelessly with the UE 1 existing in the communication area 101. Moreover, the communication part 411 transmits / receives a signal between S-GW2 and MeNB12 by a wire communication (or radio | wireless). For example, the SeNB 11 and the MeNB 12 are connected by a wired line (backhaul line).
The storage unit 412 is configured using a memory, and stores various data. As a specific example, the storage unit 412 stores data of a program used by the control unit 413, data of various parameters, data related to data communication, and the like.

The control unit 413 performs various processes and controls by executing a predetermined program.
The communication monitoring unit 431 monitors the communication state of U-Plane data using a communication path between the S-GW 2 and the own device (SeNB 11). In the present embodiment, the communication monitoring unit 431 monitors the communication state between the S-GW 2 and the own device (SeNB 11) using an installed timer.
When a predetermined communication state is detected by the communication monitoring unit 431, the resource release control unit 432 performs control so as to release the connection state between the S-GW 2 and the own device (SeNB 11). Release device resources.
The resource release notification control unit 433 communicates the U-Plane data using the communication path between the S-GW 2 and the own device (SeNB 11) when the communication monitoring unit 431 detects a predetermined communication state. Control is performed so as to notify other devices (for example, MeNB 12) to release the.
The data communication control unit 434 controls U-Plane data communication.

Here, in the present embodiment, the predetermined communication state that triggers the release of the communication state of the U-Plane data that uses the communication path between the S-GW2 and the SeNB 11, in the present embodiment, the SeNB 11 to the S-GW 2 When a signal is transmitted to, a communication state is used in which a response signal of the signal is not received from the S-GW 2 within a predetermined time.
As another configuration example, a communication state in which there is no signal communicated between the S-GW 2 and the SeNB 11 within a predetermined time may be used as the above-described predetermined communication state.
Two or more types of communication states may be used as the predetermined communication state.

FIG. 6 is a block diagram showing an outline of processing in the communication system according to one embodiment (second embodiment) of the present invention.
In FIG. 6, UE1, SeNB11 and its radio | wireless communication area | region 101, MeNB12 and its radio | wireless communication area | region 102, S-GW2, MME3, and the internet 4 are shown.
In the present embodiment, it is assumed that UE1 exists in an overlapping portion of the communication area 101 of SeNB11 and the communication area 102 of MeNB12.
As another configuration example, a configuration in which two or more SeNBs are provided for one MeNB may be used.

With reference to FIG. 6 and FIG. 7, an example of the procedure of the process performed in the communication system which concerns on one Embodiment (2nd Embodiment) of this invention is shown.
FIG. 7 is a sequence diagram illustrating an example of a processing procedure performed in the communication system according to the embodiment (second embodiment) of the present invention.
Here, for the procedure (1) to the procedure (5) shown in FIG. 6, the procedure T1 shown in FIG. 7 is performed in the procedure (1), and the procedure T12-1 shown in FIG. The process T12-2 is performed. In the procedure (3), the process T13 illustrated in FIG. 7 is performed. In the procedure (4), the processes T14-1 to T14-3 illustrated in FIG. ), Processing T15-1 to processing T15-2 shown in FIG. 7 are performed.

(Assumption)
First, it is assumed that a communication path for transmitting U-Plane data from the S-GW 2 to the UE 1 via the SeNB 11 is established. In this case, S-GW2 and SeNB11 are in a connected state, and SeNB11 and UE1 are in a connected state. Moreover, S-GW2, MME3, and SeNB11 memorize | store and manage the information (user information) regarding the said UE1 about dual connectivity. As in the case of the first embodiment, various information may be used as the user information.

Procedure (1)
In SeNB11, if a predetermined signal (message) is transmitted with respect to S-GW2, the communication monitoring part 431 will perform the start (count start) of the timer for detecting (detecting) communication disconnection (process T11).
Here, the predetermined signal that triggers the activation of the timer may be, for example, any arbitrary signal, a predetermined specific signal, or a pseudo signal. It may be a signal determined randomly using random numbers or the like.

Procedure (2)
In SeNB11, after transmitting a predetermined signal with respect to S-GW2 and invoking a timer, before the count value of the said timer becomes a predetermined value (for example, fixed time), from said S-GW2 with respect to the said signal When the response signal is received, the communication monitoring unit 431 resets the count value of the timer (for example, resets to zero (0)).
On the other hand, in SeNB11, after transmitting a predetermined signal with respect to S-GW2 and starting a timer, when the count value of the timer becomes a predetermined value, the communication monitoring unit 431 It determines with having expired (process T12-1). In this case, in this embodiment, it is considered that a failure has occurred in the communication path (backhaul line) between the S-GW 2 and the SeNB 11.
Here, various values may be used as the predetermined value related to the count value (a count value at which the timer expires).

In SeNB11, according to the expiration of the timer, the resource release control unit 432 relates to the UE1 that uses a communication path for transmitting U-Plane data from the S-GW2 to the UE1 via its own device (SeNB11). The resource is released (process T12-2). In the SeNB 11, the resources to be released are the same as in the case of the first embodiment.
Note that such release of resources in the SeNB 11 may be performed at any later timing, for example.

Procedure (3)
In SeNB11, in response to the expiration of the timer, the resource release notification control unit 433 transmits the U-Plane data to UE1 from S-GW2 via its own device (SeNB11) to MeNB12. A signal (in this embodiment, a signal for notifying the expiration of the timer) notifying that the resource related to the UE1 that uses is released is transmitted (process T13).

Procedure (4)
In MeNB12, if the notification signal mentioned above is received from SeNB11, the resource release notification control part 331 transmits the signal which notifies that (signal which notifies cancellation | release of dual connectivity in this embodiment) to applicable UE1. (Process T14-1), and transmits to the related MME3 (process T14-2), and transmits to the related S-GW2 (process T14-3).
Here, this notification may be performed simultaneously for UE1, MME3, and S-GW2, or may be performed in any order. In the example of FIG. 7, for convenience of explanation, the notification is shown in the order of notification to the UE 1, notification to the MME 3, and notification to the S-GW 2, but is not limited thereto.
Further, the notification from the MeNB 12 to the UE 1 is performed, for example, via an RRC (Radio Resource Control) message.

  In the example of FIG. 7, the notification (process T14-2) is performed from the MeNB 12 to the MME 3 in the procedure (4). However, as another configuration example, the same content is obtained in the procedure (2) or other timing. Notification may be performed from SeNB11 to MME3.

Procedure (5)
In the MME 3, the resource related to the UE 1 is released based on the content notified from the MeNB 12 by the resource release control function unit (resource release control unit) (process T15-1). In the MME 3, the resources to be released are the same as those in the first embodiment.
Note that such release of resources in the MME 3 may be performed at an arbitrary timing.
In addition, for example, when the MME 3 stores and manages information on the SeNB 11 and MeNB 12 that manages information on the corresponding UE 1 in the storage unit, the MME 3 not only deletes information on the UE 1 as a resource release on the UE 1, A configuration may be used in which information related to SeNB 11 and MeNB 12 that manages information related to the UE 1 (part of information related to the UE 1) is deleted.

In S-GW2, the resource release control unit 232 releases resources related to the corresponding UE1 based on the content notified from the MeNB 12 (process T15-2). In S-GW2, the resources to be released are the same as in the first embodiment.
Note that such release of resources in the S-GW 2 may be performed at an arbitrary timing.

  In UE1, based on the content notified from MeNB12, dual connectivity is cancelled | released, and the own apparatus which uses the communication path which transmits the data of U-Plane to own apparatus (UE1) via SNB11 from S-GW2 It knows that the resource related to (UE1) is released (or released).

  In addition, in MeNB12, when memorize | storing in the memory | storage part 312 and managing the resource (for example, resource regarding UE1) released by cancellation | release of dual connectivity, in the procedure (3) shown in FIG. 6, or other arbitrary timings A configuration may be used in which the resource release control function unit (resource release control unit) releases the corresponding resource based on the content notified from the SeNB 11. The resources to be released in the MeNB 12 include, for example, information stored (managed) by the storage unit 312 regarding the UE 1. In this case, the resources are released by deleting the information from the storage unit 312. However, in this embodiment, since the communication path for transmitting C-Plane data from the MME 3 to the UE 1 via the MeNB 12 is continued, the connection is maintained in this communication path.

Here, in the present embodiment, the communication monitoring unit 431 in the SeNB 11 detects a case where a failure occurs in the communication path between the S-GW 2 and the SeNB 11 using a timer, but as another configuration example, A configuration for detecting a case where it is considered that there is no traffic to be communicated may be used for the communication path between the S-GW 2 and the SeNB 11. The details of the other configuration examples are the same as those in the first embodiment.
As yet another configuration example, the communication monitoring unit 431 in the SeNB 11 may execute both of the two types of timer counting methods described above (a method related to a communication path failure and a method related to the presence or absence of traffic). In this case, for example, when at least one of the timers expires, the related resources are released.

<Summary of Second Embodiment>
As described above, in the communication system according to the present embodiment, the UE 1 is connected to the Internet 4 in a wireless communication system capable of simultaneously connecting to and communicating with a plurality of eNBs (MeNB and SeNB in the present embodiment). When the S-GW 2 switches the communication path to be used as the communication path of user traffic data (U-Plane data in this embodiment) between the eNBs, the SeNB 11 and the S-GW 2 itself (SeNB 11 ) Is monitored, and when a predetermined communication state is reached, resources such as a base station can be released early by releasing dual connectivity. In the communication system, when two or more SeNBs exist for one S-GW2, for example, the processing according to the present embodiment is performed for each SeNB.

Therefore, in the communication system according to the present embodiment, as in the case of the first embodiment, when a failure occurs in the communication path between the S-GW 2 and the SeNB 11, or the communication between the S-GW 2 and the SeNB 11 When there is no traffic to be communicated on the route, the dual connectivity state of the UE 1 is canceled and the connection state between the S-GW 2 and the SeNB 11 is released, thereby preventing a reduction in system efficiency.
As described above, in the communication system according to the present embodiment, the data signal (the present signal is transmitted from the S-GW 2 via the SeNB 11 to the UE 1 while performing the communication of the control signal (in this embodiment, the C-Plane data signal). In the embodiment, the efficiency of the communication path for transmitting the U-Plane data signal) can be improved.

  Here, the communication system according to the present embodiment is applied at the time of setup of U-Plane data communication (1A: S-GW flow splitting) in dual connectivity as shown in FIG. Connection release control can be realized. Note that the communication system according to the present embodiment may be applied to other situations (situations other than the above-described 1A).

[Third Embodiment]
The communication system according to the present embodiment has both the function of the communication system according to the first embodiment and the function of the communication system according to the second embodiment.
In the communication system according to the present embodiment, both the processing as shown in FIGS. 3 and 4 according to the first embodiment and the processing as shown in FIGS. 6 and 7 according to the second embodiment are performed. The processing is executed when the determination (determination) for releasing the dual connectivity connection is first generated by the function according to any of the embodiments.

[Configuration example according to the above embodiment]
As one configuration example, a data signal (U-Plane data signal in the example of FIG. 3) transmitted from the communication device (S-GW2 in the example of FIG. 3) is received and the data signal is transmitted to the terminal device (FIG. 3). In the example of 3, the control signal transmitted from the first base station apparatus (SeNB11 in the example of FIG. 3) and the terminal management apparatus (MME3 in the example of FIG. 3) that performs transmission to the UE1). (In the example of FIG. 3) a second base station device (MeNB12 in the example of FIG. 3) that receives the C-Plane data signal and transmits the control signal to the terminal device; A communication monitoring unit (in the example of FIG. 1, a communication monitoring unit 231) that monitors a state of communication with the first base station device, and the communication monitoring unit To communicate with the first base station apparatus. A communication control device (a resource release notification control unit 233 in the example of FIG. 1) that controls to perform a predetermined notification when it is detected that the state is a predetermined communication state ( In the example of FIG. 3 according to the first embodiment, it is S-GW2).

As a configuration example, in the communication apparatus, the notification control unit notifies the second base station apparatus to release a predetermined resource.
As a configuration example, in the communication apparatus, when the communication monitoring unit detects that the communication state with the first base station apparatus is a predetermined communication state, the predetermined resource is released. The resource release control unit (in the example of FIG. 1, the resource release control unit 232) is controlled.
As a configuration example, in the communication device, the communication monitoring unit monitors a state of communication with the first base station device using a timer.
As a configuration example, in a communication apparatus, a data communication control unit (in FIG. 1) controls to transmit a data signal to one or both of the first base station apparatus and the second base station apparatus. In the example, a data communication control unit 234) is provided.

  As one configuration example, a data signal (U-Plane data signal in the example of FIG. 6) transmitted from the communication device (S-GW2 in the example of FIG. 6) is received and the data signal is transmitted to the terminal device (FIG. 6). In the example of 6, the control signal transmitted from the first base station apparatus (SeNB11 in the example of FIG. 6) and the terminal management apparatus (MME3 in the example of FIG. 6) that performs transmission to the UE1). (In the example of FIG. 6) a second base station device (MeNB12 in the example of FIG. 6) that receives the C-Plane data signal and transmits the control signal to the terminal device; A communication monitoring unit (in the example of FIG. 5, a communication monitoring unit 431) that monitors the state of communication with the communication device, and the communication monitoring unit The state of communication with the communication device A base station apparatus (second storage) that includes a notification control unit (a resource release notification control unit 433 in the example of FIG. 5) that controls to perform a predetermined notification when it is detected that the communication state is a predetermined state. In the example of FIG. 6 according to the embodiment, it is SeNB11).

As a configuration example, in the base station apparatus (first base station apparatus), the notification control unit performs notification to release a predetermined resource to the second base station apparatus.
As one configuration example, in the base station device (first base station device), when the communication monitoring unit detects that the state of communication with the communication device is a predetermined communication state, A resource release control unit (a resource release control unit 432 in the example of FIG. 5) that controls to release resources is provided.
As a configuration example, in the base station apparatus (first base station apparatus), the communication monitoring unit monitors the state of communication with the communication apparatus using a timer.
As one configuration example, in a base station apparatus (first base station apparatus), data communication for receiving the data signal transmitted from the communication apparatus and controlling the data signal to be transmitted to the terminal apparatus A control unit (data communication control unit 434 in the example of FIG. 5) is provided.

  As one configuration example, a data signal transmitted from a communication device (S-GW2 in the examples of FIGS. 3 and 6) is received, and the data signal is sent to the terminal device (UE1 in the examples of FIGS. 3 and 6). Receiving a control signal transmitted from the first base station apparatus (SeNB 11 in the examples of FIGS. 3 and 6) and the terminal management apparatus (MME 3 in the examples of FIGS. 3 and 6). A second base station apparatus in a communication system having a second base station apparatus (MeNB12 in the examples of FIGS. 3 and 6) that transmits the control signal to the terminal apparatus; , Control to perform a predetermined notification when a notification is received in response to detecting that the communication state between the communication device and the first base station device is a predetermined communication state Notification control unit (in the example of FIG. A source release notification control unit 331) and a control signal communication control unit (example in FIG. 2) that receives the control signal transmitted from the terminal management device and performs control to transmit the control signal to the terminal device. Then, a control signal communication control unit 333) is a base station apparatus (MeNB 12 in the example of FIG. 3 according to the first embodiment and FIG. 6 according to the second embodiment).

As one configuration example, in the base station apparatus (second base station apparatus), the notification control unit determines that a state of communication between the communication apparatus and the first base station apparatus is predetermined from the communication apparatus. When the notification corresponding to the detection of the communication state is received, the predetermined notification is sent to one or more of the terminal device, the terminal management device, and the first base station device. (Examples as shown in FIG. 3 and FIG. 4 according to the first embodiment).
As a configuration example, in the base station apparatus (second base station apparatus), the notification control unit performs communication between the communication apparatus and the first base station apparatus from the first base station apparatus. When receiving a notification in response to detecting that the state is a predetermined communication state, the predetermined notification is sent to one or more of the terminal device, the terminal management device, and the communication device. (Examples as shown in FIGS. 6 and 7 according to the second embodiment).
As one configuration example, in a base station apparatus (second base station apparatus), data communication is performed such that the data signal transmitted from the communication apparatus is received and the data signal is transmitted to the terminal apparatus. A control unit (data communication control unit 332 in the example of FIG. 2) is provided.

  As one configuration example, a communication apparatus, a terminal apparatus, a terminal management apparatus, and a first base station that receives a data signal transmitted from the communication apparatus and transmits the data signal to the terminal apparatus And a second base station apparatus that receives a control signal transmitted from the terminal management apparatus and transmits the control signal to the terminal apparatus, wherein the communication apparatus When the communication state between the communication device and the first base station device is detected to be a predetermined communication state, the communication state between the communication device and the first base station device is detected. 6 is a communication system (for example, the communication system shown in FIG. 3 according to the first embodiment and FIG. 6 according to the second embodiment) that performs predetermined notification.

  As one configuration example, a communication apparatus, a terminal apparatus, a terminal management apparatus, and a first base station that receives a data signal transmitted from the communication apparatus and transmits the data signal to the terminal apparatus A communication method in a communication system having a device and a second base station device that receives a control signal transmitted from the terminal management device and transmits the control signal to the terminal device, The state of communication between the communication device and the first base station device is monitored, and it is detected that the state of communication between the communication device and the first base station device is a predetermined communication state A communication method (for example, a communication method performed in the communication system shown in FIG. 3 according to the first embodiment and FIG. 6 according to the second embodiment) that performs a predetermined notification when the notification is made.

[Summary of the above embodiments]
As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

  Further, a program for realizing the function of each device (for example, devices of UE1, S-GW2, MME3, SeNB11, and MeNB12) according to the above-described embodiment is recorded on a computer-readable recording medium, and this Processing may be performed by causing a computer system to read and execute a program recorded on a recording medium.

The “computer system” herein may include hardware such as an operating system (OS) and peripheral devices.
The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM (Read Only Memory), a writable nonvolatile memory such as a flash memory, a portable medium such as a DVD (Digital Versatile Disk), A storage device such as a hard disk built in a computer system.

Further, the “computer-readable recording medium” refers to a volatile memory (for example, DRAM (DRAM) inside a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Dynamic Random Access Memory)) that holds a program for a certain period of time is also included.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
Further, the above program may be for realizing a part of the functions described above. Further, the above program may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

DESCRIPTION OF SYMBOLS 1 ... UE, 2 ... S-GW, 3 ... MME, 4 ... Internet, 11 ... SeNB, 12 ... MeNB, 101-102 ... Communication area, 211, 311, 411 ... Communication part, 212, 312, 412 ... Storage part 213, 313, 413 ... control unit, 231, 431 ... communication monitoring unit, 232, 432 ... resource release control unit, 233, 331, 433 ... resource release notification control unit, 234, 332, 434 ... data communication control unit, 333 ... Control signal communication control unit

Claims (16)

A first base station apparatus that receives a data signal transmitted from a communication apparatus and transmits the data signal to a terminal apparatus; a control signal transmitted from a terminal management apparatus; A second base station device that performs transmission to a terminal device, the communication device in a communication system comprising:
A communication monitoring unit for monitoring a state of communication with the first base station device;
A notification control unit that controls to perform a predetermined notification when the communication monitoring unit detects that the communication state with the first base station apparatus is a predetermined communication state. ,
In the predetermined communication state, when a signal is transmitted from the communication device to the first base station device, a response signal of the signal is received from the first base station device within a predetermined time. Ri communication state der that has not been,
The notification control unit notifies the second base station device to release a predetermined resource.
Communication device. A first base station apparatus that receives a data signal transmitted from a communication apparatus and transmits the data signal to a terminal apparatus; a control signal transmitted from a terminal management apparatus; A second base station device that performs transmission to a terminal device, the communication device in a communication system comprising:
A communication monitoring unit for monitoring a state of communication with the first base station device;
A notification control unit that controls to perform a predetermined notification when it is detected by the communication monitoring unit that a state of communication with the first base station device is a predetermined communication state;
A resource release control unit that controls to release a predetermined resource when the communication monitoring unit detects that the state of communication with the first base station apparatus is the predetermined communication state And comprising
In the predetermined communication state, when a signal is transmitted from the communication device to the first base station device, a response signal of the signal is received from the first base station device within a predetermined time. The communication state that was not done,
Communication device. The notification control unit notifies the second base station device to release a predetermined resource.
The communication apparatus according to claim 2. The communication monitoring unit monitors a state of communication with the first base station device using a timer.
The communication apparatus according to any one of claims 1 to 3. A data communication control unit that controls to transmit a data signal to one or both of the first base station device and the second base station device;
The communication apparatus according to any one of claims 1 to 4. A first base station apparatus that receives a data signal transmitted from a communication apparatus and transmits the data signal to a terminal apparatus; a control signal transmitted from a terminal management apparatus; A first base station apparatus in a communication system having a second base station apparatus that performs transmission to a terminal apparatus,
A communication monitoring unit for monitoring a state of communication with the communication device;
A notification control unit that controls to perform a predetermined notification when the communication monitoring unit detects that the state of communication with the communication device is a predetermined communication state;
In the predetermined communication state, when a signal is transmitted from the first base station device to the communication device, a response signal of the signal is not received from the communication device within a predetermined time. communication state der is,
The notification control unit notifies the second base station device to release a predetermined resource.
Base station device. A first base station apparatus that receives a data signal transmitted from a communication apparatus and transmits the data signal to a terminal apparatus; a control signal transmitted from a terminal management apparatus; A first base station apparatus in a communication system having a second base station apparatus that performs transmission to a terminal apparatus,
A communication monitoring unit for monitoring a state of communication with the communication device;
A notification control unit that controls to perform a predetermined notification when the communication monitoring unit detects that the state of communication with the communication device is a predetermined communication state;
A resource release control unit that controls to release a predetermined resource when the communication monitoring unit detects that the state of communication with the communication device is the predetermined communication state. ,
In the predetermined communication state, when a signal is transmitted from the first base station device to the communication device, a response signal of the signal is not received from the communication device within a predetermined time. Is in communication state,
Base station device. The notification control unit notifies the second base station device to release a predetermined resource.
The base station apparatus according to claim 7. The communication monitoring unit monitors a state of communication with the communication device using a timer.
The base station apparatus according to any one of claims 6 to 8. A data communication control unit configured to receive the data signal transmitted from the communication device and to control the data signal to be transmitted to the terminal device;
The base station apparatus according to any one of claims 6 to 9. A communication apparatus, a terminal apparatus, a terminal management apparatus, a first base station apparatus that receives a data signal transmitted from the communication apparatus and transmits the data signal to the terminal apparatus; A second base station apparatus that receives a control signal transmitted from a management apparatus and transmits the control signal to the terminal apparatus, and a communication system comprising:
Monitoring the state of communication between the communication device and the first base station device;
When it is detected that the communication state between the communication device and the first base station device is a predetermined communication state, a predetermined notification is performed,
The predetermined communication state is determined by the other device within a predetermined time when a signal is transmitted from one device of the communication device and the first base station device to the other device. Ri communication der that the signal response of the signal is not received,
The predetermined notification is a notification for releasing predetermined resources to the second base station device.
Communications system. A communication apparatus, a terminal apparatus, a terminal management apparatus, a first base station apparatus that receives a data signal transmitted from the communication apparatus and transmits the data signal to the terminal apparatus; A second base station apparatus that receives a control signal transmitted from a management apparatus and transmits the control signal to the terminal apparatus, and a communication system comprising:
Monitoring the state of communication between the communication device and the first base station device;
When it is detected that the communication state between the communication device and the first base station device is a predetermined communication state, a predetermined notification is performed,
When it is detected that the state of communication between the communication device and the first base station device is the predetermined communication state, control is performed to release a predetermined resource,
The predetermined communication state is determined by the other device within a predetermined time when a signal is transmitted from one device of the communication device and the first base station device to the other device. It is a communication state that the signal of the response of the signal was not received.
Communications system. The predetermined notification is a notification for releasing predetermined resources to the second base station device.
The communication system according to claim 12. A communication apparatus, a terminal apparatus, a terminal management apparatus, a first base station apparatus that receives a data signal transmitted from the communication apparatus and transmits the data signal to the terminal apparatus; A second base station device that receives a control signal transmitted from a management device and transmits the control signal to the terminal device;
Monitoring the state of communication between the communication device and the first base station device;
When it is detected that the communication state between the communication device and the first base station device is a predetermined communication state, a predetermined notification is performed,
The predetermined communication state is determined by the other device within a predetermined time when a signal is transmitted from one device of the communication device and the first base station device to the other device. Ri communication der that the signal response of the signal is not received,
The predetermined notification is a notification for releasing predetermined resources to the second base station device.
Communication method. A communication apparatus, a terminal apparatus, a terminal management apparatus, a first base station apparatus that receives a data signal transmitted from the communication apparatus and transmits the data signal to the terminal apparatus; A second base station device that receives a control signal transmitted from a management device and transmits the control signal to the terminal device;
Monitoring the state of communication between the communication device and the first base station device;
When it is detected that the communication state between the communication device and the first base station device is a predetermined communication state, a predetermined notification is performed,
When it is detected that the state of communication between the communication device and the first base station device is the predetermined communication state, control is performed to release a predetermined resource,
The predetermined communication state is determined by the other device within a predetermined time when a signal is transmitted from one device of the communication device and the first base station device to the other device. It is a communication state that the signal of the response of the signal was not received.
Communication method. The predetermined notification is a notification for releasing predetermined resources to the second base station device.
The communication method according to claim 15.

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