JP2014204397A - Mobile communication method and mobile communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a status mismatch on a GBR bearer between a mobile communication terminal and an EPC, even if degradation of radio channels quality is detected during VoLTE communication using a GBR bearer.SOLUTION: A mobile communication method includes: a process for starting T311 if a mobile communication terminal UE detect an RLF and for starting a network timer equivalent to the T311 if an E-UTRAN detects an RLF when VoLTE communication using a GBR bearer among the mobile communication terminal UE, an EPC, and the E-UTRAN is being performed; a process for releasing a radio resource for the mobile communication terminal UE if the E-UTRAN detects expiration of the network timer, and notify the EPC of the release of radio resource; a process for releasing the GBR bearer according to the notification; and a process for releasing the GBR bearer if the mobile communication terminal UE detects expiration of the T311.

Description

  The present invention relates to a mobile communication method and a mobile communication terminal.

  EPS that transmits and receives data between a mobile communication terminal UE and an EPC (Evolved Packet Core) when performing voice communication or video communication by a VoLTE (Voice over LTE) method defined in the LTE (Long Term Evolution) method As an (Evolved Packet System) bearer, a GBR (Guaranteed Bit Rate) bearer is generally used.

  The GBR bearer is a bearer that guarantees a bit rate by QoS (Quality of Service) control, and is a bearer used for a service with real-time property.

  In the 3GPP specification, a procedure called reconnection processing is defined as a general procedure in wireless communication.

  In the reconnection process, when the mobile communication terminal UE in communication detects out of radio range (a state in which radio quality is deteriorated and communication cannot be continued in a cell in the service area), cell search for return to the area is performed. And a process of trying to re-establish a connection with the radio access network in the detected cell that can be located.

  The mobile communication terminal UE is configured to perform such reconnection processing when it detects out of radio range even during VoLTE communication using the GBR bearer.

  Hereinafter, with reference to FIG. 7, description will be given of an operation when the radio quality is deteriorated when the mobile communication terminal UE performs VoLTE communication using the GBR bearer in the conventional mobile communication system.

  As illustrated in FIG. 7, when the mobile communication terminal UE performs VoLTE communication using a GBR bearer in step S2000, and detects radio quality degradation (RLF: Radio Link Failure) in step S2001, A timer called T311 is started.

  Here, the value of T311 is notified in advance from the E-UTRAN (Evolved-UTRAN) to the mobile communication terminal UE.

  If the mobile communication terminal UE cannot find a cell that can be located by the time T311 expires, the mobile communication terminal UE releases radio resources in step S2002 along with the expiration of T311. State).

  However, the mobile communication terminal UE does not release the GBR bearer used in the VoLTE communication but keeps it internally (see step S2004).

  On the other hand, also in the radio base station eNB in the E-UTRAN, when the degradation of radio quality is detected in step S2101, a network timer corresponding to T311 is started.

  Here, if the connection between the radio base station eNB and the mobile communication terminal UE cannot be reestablished before the network timer expires, the mobile communication terminal UE follows the expiration of the network timer in step S2102. Wireless resources are released, and the EPC is notified in step S2103.

  In response to the notification, the EPC releases the GBR bearer used in the VoLTE communication in step S2104, and performs a GBR release procedure for the mobile communication terminal UE in step S2105.

3GPP TS 23.401 3GPP TS24.301 3GPP TS36.300 3GPP TS36.331

  However, it is assumed that the mobile communication terminal UE is in an out-of-coverage area such as in a tunnel in a situation where a cell that can be located is not found until T311 expires. There is a high possibility that the establishment of the connection between the mobile communication terminal UE and the radio base station eNB will fail and the above-mentioned GBR release procedure will fail.

  Therefore, until the mobile communication terminal UE enters the area and performs the location registration process, the above-described GBR bearer mismatch occurs between the mobile communication terminal UE and the radio base station eNB (step). (See S2201).

  When such a state mismatch occurs, the EPC side recognizes that the mobile communication terminal UE holds the GBR bearer and continues the call even though the GBR bearer is released and the VoLTE communication is disconnected. Therefore, there has been a problem of giving a misunderstanding that the call is continuing to the user of the mobile communication terminal UE.

  Therefore, the present invention has been made in view of the above-described problems, and even when VoLTE communication using a GBR bearer is performed, even when radio quality degradation is detected, the mobile communication terminal and An object of the present invention is to provide a mobile communication method and a mobile communication terminal capable of avoiding a situation in which a state mismatch about a GBR bearer occurs with an EPC.

  A first feature of the present invention is a mobile communication method, in which voice communication or video is performed between a mobile communication terminal, a core network, and a radio access network using a bearer configured to guarantee a bit rate. When performing communication, the mobile communication terminal activates a predetermined timer when it detects a deterioration in radio quality, and activates a network timer corresponding to the predetermined timer when the radio access network detects a deterioration in radio quality. And, when the radio access network detects expiration of the network timer, releases radio resources for the mobile communication terminal and notifies the core network to that effect, and the core network Releasing the bearer in response to the notification, and the mobile communication terminal expires the predetermined timer. And summarized in that has a detection to the step of releasing the bearer.

  A second feature of the present invention is a mobile communication terminal that performs voice communication or video communication between a core network and a radio access network using a bearer configured to guarantee a bit rate. A reconnection processing management unit configured to start a predetermined timer upon detection of degradation of radio quality, and when the expiration of the predetermined timer is detected by the reconnection processing management unit, And a bearer management unit configured to release.

  As described above, according to the present invention, even when VoLTE communication using a GBR bearer is performed, even when radio quality degradation is detected, the GBR is between the mobile communication terminal and the EPC. It is possible to provide a mobile communication method and a mobile communication terminal capable of avoiding a situation in which a state mismatch about a bearer occurs.

1 is an overall configuration diagram of a mobile communication system according to a first embodiment of the present invention. It is a functional block diagram of the mobile communication terminal which concerns on the 1st Embodiment of this invention. FIG. 3 is a sequence diagram showing an operation of the mobile communication system according to the first embodiment of the present invention. It is a flowchart which shows operation | movement of the mobile communication terminal which concerns on the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the mobile communication terminal which concerns on the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the mobile communication terminal which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating a prior art.

(Mobile communication system according to the first embodiment of the present invention)
With reference to FIG. 1 thru | or FIG. 6, the mobile communication system which concerns on the 1st Embodiment of this invention is demonstrated. In this embodiment, the mobile communication system according to this embodiment will be described by exemplifying a WCDMA or LTE mobile communication system. However, the present invention can also be applied to mobile communication systems other than the WCDMA and LTE systems. It is.

  As shown in FIG. 1, the mobile communication system according to the present embodiment includes an E-UTRAN, an EPC, and a mobile communication terminal UE. Here, the E-UTRAN is provided with a radio base station eNB, and the EPC is provided with a gateway device S-GW / P-GW and a mobility management node MME.

  As shown in FIG. 2, the mobile communication terminal UE according to the present embodiment includes a communication control unit 11, a reconnection process management unit 12, a GBR bearer management unit 13, and a call management unit 14.

  The communication control unit 11 is configured to perform the overall communication control functions of the mobile communication terminal UE.

  The reconnection process management unit 12 is configured to perform the above-described reconnection process.

  Specifically, when the mobile communication terminal UE is performing VoLTE communication with the EPC and E-UTRAN using the GBR bearer, the reconnection processing unit 12 activates T311 when detecting the RLF. It is configured as follows.

  Thereafter, when the reconnection processing unit 12 cannot find a cell that can be located before the T311 expires by the cell search, the mobile communication terminal UE enters the standby state (RRC_Idle state) when the T311 expires. It is configured to make a transition and to notify the GBR bearer management unit 13 that T311 has expired.

  The GBR bearer management unit 13 is configured to manage the state of the GBR used by the mobile communication terminal UE.

  For example, the GBR bearer management unit 13 is configured to release the corresponding GBR bearer when receiving a notification that T311 has expired from the reconnection processing management unit 12.

  Here, the GBR bearer management unit 13 may be configured to notify the call management unit 14 that the GBR bearer has been released.

  The call manager 14 is configured to manage whether or not the call at the mobile communication terminal UE is continued.

  For example, the call management unit 14 is configured to notify the user of the mobile communication terminal UE that the corresponding VoLTE communication has been disconnected in response to the notification from the GBR bearer management unit 13 described above. Also good.

  Hereinafter, the operation of the mobile communication system according to the present embodiment will be described with reference to FIGS. 3 to 6.

  1stly, with reference to FIG. 3, the operation | movement when radio | wireless quality deteriorates when the mobile communication terminal UE is performing the VoLTE communication using a GBR bearer in the mobile communication system which concerns on this embodiment is demonstrated.

  As illustrated in FIG. 3, when the mobile communication terminal UE performs VoLTE communication using a GBR bearer in step S1000, when detecting radio quality degradation (RLF) in step S1001, the mobile communication terminal UE activates T311. .

  If the mobile communication terminal UE cannot find a cell that can be located by the time T311 expires, the mobile communication terminal UE releases radio resources in step S1002 upon expiration of T311. In step S1004, the GBR bearer used in the VoLTE communication is released at its own judgment regardless of whether there is an instruction from the EPC.

  On the other hand, also in the radio base station eNB in the E-UTRAN, when the degradation of radio quality is detected in step S1101, a network timer corresponding to T311 is started.

  If the radio base station eNB fails to re-establish a connection with the mobile communication terminal UE before the network timer expires, the radio base station eNB, when the network timer expires, in step S1102, the radio base station eNB The resource is released, and in step S1103, this is notified to the EPC.

  In response to the notification, the EPC releases the GBR bearer used in the VoLTE communication in step S1104.

  Here, in step S1105, the EPC may perform the GBR release procedure for the mobile communication terminal UE, or perform the GBR release procedure in consideration of the possibility that the GBR release procedure is likely to fail. It does not have to be.

  2ndly, with reference to FIG. 4, operation | movement of the reconnection procedure management part 12 of the mobile communication terminal UE which concerns on this embodiment is demonstrated.

  As shown in FIG. 4, when it is determined in step S101 that T311 has expired, the reconnection procedure management unit 12 notifies the GBR bearer management unit 13 of that fact in step S102.

  3rdly, with reference to FIG. 5, operation | movement of the GBR bearer management part 13 of the mobile communication terminal UE which concerns on this embodiment is demonstrated.

  As shown in FIG. 5, when receiving the above notification from the reconnection procedure management unit 12 in step S201, the GBR bearer management unit 13 releases the corresponding GBR bearer in step S202, and calls in step S203. This is notified to the management unit 14.

  4thly, with reference to FIG. 6, operation | movement of the telephone call management part 14 of the mobile communication terminal UE which concerns on this embodiment is demonstrated.

  As illustrated in FIG. 6, when the call management unit 14 receives the above notification from the GBR bearer management unit 13 in step S301, in step S302, the call management unit 14 performs corresponding VoLTE communication to the user of the mobile communication terminal UE. Notify that disconnected.

  The characteristics of the present embodiment described above may be expressed as follows.

  A first feature of the present embodiment is a mobile communication method, in which a GBR bearer (bit rate is guaranteed) between a mobile communication terminal UE and an EPC (core network) and an E-UTRAN (radio access network). When the mobile communication terminal UE detects RLF when performing VoLTE communication (voice communication or video communication) using the bearer configured in (1), T311 (predetermined timer) is started, and E-UTRAN , A step of starting a network timer (predetermined network timer) corresponding to T311 when RLF (deterioration of radio quality) is detected, and a radio for mobile communication terminal UE when E-UTRAN detects the expiration of the network timer described above Releasing the resources and notifying the EPC to that effect, and in response to the notification, the EPC A step of releasing, the mobile communication terminal UE, and summarized in that a step of releasing the GBR bearer detects the expiration of the T311.

  According to such a feature, the mobile communication terminal UE can release the GBR bearer used for VoLTE communication, like the EPC side, when T311 expires before finding a cell that can be located. Therefore, it is possible to solve the problem that the state mismatch about the GBR bearer occurs between the mobile communication terminal UE and the EPC.

  As a result, on the EPC side, although the GBR bearer is released and the VoLTE communication is disconnected, the mobile communication terminal UE recognizes that the GBR bearer is held and the call is continued. The problem of giving a misunderstanding that the call is continuing to the user of the mobile communication terminal UE can also be solved.

  The second feature of the present embodiment is the mobile communication terminal UE, which activates T311 when RLF is detected when VoLTE communication is performed between the EPC and E-UTRAN using a GBR bearer. The reconnection processing management unit 12 configured as described above and the GBR bearer management unit 13 configured to release the GBR bearer when the expiration of T311 is detected by the reconnection processing management unit 12. It is a summary.

  According to this feature, the GBR bearer management unit 13 of the mobile communication terminal UE determines the GBR bearer used for VoLTE communication, similar to the EPC side, when T311 expires before finding a cell that can be located. Since it can be released by itself, it is possible to solve the problem that a state mismatch about the GBR bearer occurs between the mobile communication terminal UE and the EPC.

  As a result, on the EPC side, although the GBR bearer is released and the VoLTE communication is disconnected, the mobile communication terminal UE recognizes that the GBR bearer is held and the call is continued. The problem of giving a misunderstanding that the call is continuing to the user of the mobile communication terminal UE can also be solved.

  Note that the operation of the mobile communication terminal UE described above may be implemented by hardware, may be implemented by a software module executed by a processor, or may be implemented by a combination of both.

  The software module includes a RAM (Random Access Memory), a flash memory, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electronically Erasable and Programmable ROM, a hard disk, a registerable ROM, a hard disk). Alternatively, it may be provided in a storage medium of an arbitrary format such as a CD-ROM.

  Such a storage medium is connected to the processor so that the processor can read and write information from and to the storage medium. Further, such a storage medium may be integrated in the processor. Such a storage medium and processor may be provided in the ASIC. Such an ASIC may be provided in the mobile communication terminal UE. Further, the storage medium and the processor may be provided in the mobile communication terminal UE as a discrete component.

  Although the present invention has been described in detail using the above-described embodiments, it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

UE ... mobile communication terminal 11 ... communication control unit 12 ... reconnection processing management unit 13 ... GBR bearer management unit 14 ... call management unit

Claims (2)

When voice communication or video communication is performed between a mobile communication terminal and a core network and a radio access network using a bearer configured to guarantee a bit rate, the mobile communication terminal Starting a predetermined timer when detecting deterioration of the wireless access network, and starting a network timer corresponding to the predetermined timer when the wireless access network detects deterioration of wireless quality;
When the radio access network detects the expiration of the network timer, releases radio resources for the mobile communication terminal, and notifies the core network to that effect;
The core network releasing the bearer in response to the notification;
And a step of releasing the bearer when the mobile communication terminal detects expiration of the predetermined timer. A mobile communication terminal,
When voice communication or video communication is performed between a core network and a radio access network using a bearer configured to guarantee a bit rate, a predetermined timer is started when a deterioration in radio quality is detected. A reconnection processing management unit configured as follows:
A mobile communication terminal comprising: a bearer management unit configured to release the bearer when expiration of the predetermined timer is detected by the reconnection process management unit.

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