JP2012147486A - Radio communication device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system, a radio communication device and a radio communication method capable of executing handover at appropriate timing for each application when communication quality deteriorates, regardless of a type of a radio communication system or a type of the application being executed.SOLUTION: A radio terminal 100 includes: a radio state information acquisition part 105 for acquiring radio state information indicative of the state of radio signals transmitted to and received from a radio base station; an EVDO communication part 101 and a WLAN communication part 103 for receiving a communication quality deterioration notice indicative of communication quality deterioration of an application at a communication destination device; a storage part 111 for storing a handover threshold based on the radio state information corresponding to the point of time of receiving the communication quality deterioration notice in association with an application; a handover control part 107 for executing handover to other radio base stations based on the radio state information and the handover threshold.

Description

  The present invention relates to a communication system, a wireless communication apparatus, and a wireless communication method that perform handover according to communication quality of an application.

  In recent years, with the spread of wireless communication technology, an environment in which a plurality of wireless communication systems with different communication methods can be used simultaneously is being prepared. For example, the provision of a wireless communication device that can be connected to both a cdma2000 nx evolution-data only (EV-DO), which is a kind of third-generation mobile phone system, and a wireless LAN system defined by IEEE802.11. It is being considered.

A wireless communication apparatus that can be connected to such a plurality of wireless communication systems monitors the communication quality such as the state (for example, RSSI) or throughput of a wireless signal received from the connected wireless base station, and degrades the communication quality. As a result, the handover to the radio base station of another radio communication system can be executed before the ongoing communication is disconnected.
(For example, patent document 1).

JP 2004-561996 A (pages 11-12, FIG. 5)

  However, the above-described conventional wireless communication apparatus has the following problems. That is, in the wireless communication apparatus, a plurality of applications such as a real-time application such as a voice call using VoIP and a non-real-time application such as browsing a website are used. The real-time application and the non-real-time application have different communication quality thresholds that require handover to another wireless communication system.

  In addition, in a wireless communication apparatus that can be connected to a plurality of wireless communication systems, each wireless communication system has a value (wireless state information) indicating a wireless signal state such as RSSI corresponding to a communication quality threshold value that requires handover. Different. Furthermore, the application executed in the wireless communication device is appropriately changed by the user of the wireless communication device.

  In other words, the above-described conventional wireless communication apparatus has a problem in that handover cannot be executed at an appropriate timing for another wireless communication system for each application executed in the wireless communication apparatus.

  The present invention has been made in view of such a situation, and provides a communication system, a wireless communication apparatus, and a wireless communication method capable of executing a handover at an appropriate timing for each application when communication quality deteriorates. The purpose is to provide.

  In order to solve the problems described above, the present invention has the following features. First, the first feature of the present invention is that a first communication device (communication destination device 200) that executes a predetermined application (for example, VoIP), and the wireless base station (wireless base station 11) that executes the application. A communication system including a second communication device (wireless terminal 100) that performs communication with the first communication device, wherein the first communication device has a communication quality (for example, When it is monitored by the communication quality monitoring unit (communication quality monitoring unit 205) that monitors whether or not the number of packet losses has deteriorated and the communication quality monitoring unit, the communication quality is A notification transmission unit (communication unit 201) that transmits a communication quality deterioration notification (packet P1) indicating that the communication has deteriorated to the second communication device, and the second communication device includes the radio base A wireless state information acquisition unit (wireless state information acquisition unit 105) that acquires wireless state information (for example, RSSI) indicating a state of a wireless signal (wireless signal RS) transmitted and received, and the communication quality deterioration notification as the first When the notification receiving unit (EVDO communication unit 101 and WLAN communication unit 103) receives from the communication device and the notification receiving unit receives the communication quality deterioration notification, the wireless state corresponding to the received communication quality deterioration notification A storage processing unit (handover control unit 107 and storage unit 111) that stores a handover threshold based on information (handover threshold TH) in association with the application; the radio state information acquired by the radio state information acquisition unit; Based on the handover threshold stored in the storage processing unit, another radio base station (radio base station 21 Performing a handover to be summarized in that and a handover execution unit (handover controller 107).

  A second feature of the present invention is a wireless communication device (wireless terminal 100) that executes a predetermined application and performs communication with a communication destination device via a wireless base station, and is transmitted and received with the wireless base station. A wireless state information acquisition unit that acquires wireless state information indicating a state of a wireless signal, and a notification reception unit that receives a communication quality deterioration notification indicating that the communication quality of the application has deteriorated in the communication destination device from the communication destination device A storage processing unit that stores a handover threshold based on the radio state information corresponding to the received communication quality degradation notification in association with the application when the notification reception unit receives the communication quality degradation notification; Based on the radio state information acquired by the state information acquisition unit and the handover threshold stored in the storage processing unit , And summarized in that and a handover execution unit for executing a handover to another radio base station.

According to such a wireless communication apparatus, the handover threshold based on the wireless state information corresponding to the time when the communication quality deterioration notification is received is stored in association with the application.
Here, the communication quality deterioration notification indicates that the communication quality of the application has deteriorated in the communication destination device. Furthermore, handover to another radio base station is executed based on the radio state information acquired by the radio state information acquisition unit and the handover threshold stored in the storage processing unit.

  For this reason, the radio communication apparatus can execute a handover at an appropriate timing to another radio base station according to the application being executed.

  A third feature of the present invention relates to the second feature of the present invention, wherein the handover execution unit is configured to perform communication quality based on the radio state information and the handover threshold acquired by the radio state information acquisition unit. The gist is to execute the handover when it is determined that the network has deteriorated.

  A fourth feature of the present invention relates to the second feature of the present invention, wherein the wireless communication device is connectable to a plurality of wireless communication systems (wireless communication system 10 and wireless communication system 20) having different communication methods. The gist of the handover execution unit is to execute a handover to another radio communication system based on the radio state information acquired by the radio state information acquisition unit and the handover threshold.

  A fifth feature of the present invention relates to the second feature of the present invention, wherein the notification receiving unit sends a communication quality deterioration notification including an identifier (sequence number) identifying data output by the application to the communication destination device. The storage processing unit stores the wireless state information acquired by the wireless state information acquisition unit and the identifier in association with each other over a predetermined period, and the storage processing unit stores the wireless state information The gist is to specify the handover threshold based on the information and the identifier included in the communication quality degradation notification.

  A sixth feature of the present invention relates to the second feature of the present invention, and is summarized in that the storage processing unit determines the handover threshold using a plurality of pieces of radio state information.

  A seventh feature of the present invention relates to the second feature of the present invention, wherein the communication quality for determining whether or not the reception-side communication quality, which is the communication quality of the application executed in the wireless communication device, has deteriorated. And further comprising a determination unit (handover control unit 107 and packet information / communication quality acquisition unit 109A), wherein the storage processing unit determines that the reception-side communication quality has deteriorated by the communication quality determination unit, The gist is to store the radio state information corresponding to the time point when it is determined that the communication quality on the receiving side is deteriorated in association with the application as the handover threshold.

  An eighth feature of the present invention is a wireless communication method for executing a predetermined application and executing communication with a communication destination device via a wireless base station, wherein the state of a wireless signal transmitted and received with the wireless base station is determined. When receiving a communication quality deterioration notification indicating that the communication quality of the application has deteriorated in the communication destination device, and receiving the communication quality deterioration notification. Storing a handover threshold value based on the radio state information corresponding to the received communication quality degradation notification in the storage unit in association with the application, the acquired radio state information, and being stored in the storage unit And executing a handover to another radio base station based on the handover threshold, and That.

  According to the features of the present invention, it is possible to provide a communication system, a wireless communication apparatus, and a wireless communication method capable of executing a handover at an appropriate timing for each application when communication quality deteriorates.

1 is an overall schematic configuration diagram of a communication network including a communication system according to an embodiment of the present invention. It is a functional block block diagram of the radio | wireless communication apparatus which concerns on embodiment of this invention. It is a functional block block diagram of the communication destination apparatus which concerns on embodiment of this invention. It is a figure which shows the operation | movement which performs the hand-over based on the communication quality degradation notification transmitted from the communication destination apparatus by the radio | wireless communication apparatus which concerns on embodiment of this invention. It is a figure which shows the operation | movement which performs the hand-over based on the communication quality degradation notification transmitted from the communication destination apparatus by the radio | wireless communication apparatus which concerns on embodiment of this invention. It is a figure which shows an example of the radio | wireless state information table TB which concerns on embodiment of this invention. It is a figure which shows an example of the packet containing the communication quality degradation notification which concerns on embodiment of this invention. It is a functional block block diagram of the radio | wireless communication apparatus which concerns on the example of a change of this invention.

  Next, an embodiment of the present invention will be described. Specifically, (1) overall schematic configuration of communication network including communication system, (2) functional block configuration of wireless communication device, (3) functional block configuration of communication destination device, (4) operation of communication system, 5) Operation and effect and (6) Other embodiments will be described.

  In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(1) Overall Schematic Configuration of Communication Network Including Communication System FIG. 1 is an overall schematic configuration diagram of a communication network including a communication system according to the present embodiment. The communication system according to the present embodiment includes the wireless terminal 100 and the communication destination device 200.

  The wireless terminal 100 is a small wireless communication device that can be carried by a user. Hereinafter, the wireless terminal 100 is appropriately expressed as MN100 (Mobile Node). The wireless terminal 100 executes a predetermined application, in this embodiment, a voice call application using VoIP. The radio terminal 100 communicates with the communication destination device 200 via the radio base station 11 or the radio base station 21, and specifically executes a voice call application.

  Similar to the wireless terminal 100, the communication destination device 200 executes a voice call application using VoIP. Hereinafter, the communication destination device 200 is appropriately expressed as CN 200 (Corresponding Node).

  In the present embodiment, the MN 100 can be connected to a plurality of wireless communication systems. Specifically, the MN 100 can be connected to the radio communication system 10 and the radio communication system 20.

  The radio communication system 10 includes a radio base station 11 and a backbone network 12. The wireless communication system 10 is compliant with cdma2000 nx evolution-data only (EV-DO), which is a kind of third-generation mobile phone system.

  The radio communication system 20 includes a radio base station 21 and a backbone network 22. The wireless communication system 20 conforms to a wireless LAN system (WLAN) standard defined by IEEE802.11 or the like.

  That is, the MN 100 can be connected to a plurality of wireless communication systems with different communication methods, specifically, the wireless communication system 10 and the wireless communication system 20. When the state (for example, RSSI) of the radio signal RS transmitted from the radio base station (for example, the radio base station 11) constituting the radio communication system 10 deteriorates, the MN 100 configures the radio communication system 20 having a different communication scheme. A handover to the radio base station 21 can be executed.

  In particular, in the present embodiment, the MN 100 receives a communication quality deterioration notification indicating that the communication quality of the voice call application has deteriorated in the CN 200 from the CN 200, and determines whether to execute a handover based on the received communication quality deterioration notification. A threshold value (handover threshold value) used for such determination is set.

(2) Functional Block Configuration of Radio Communication Device FIG. 2 is a functional block configuration diagram of the MN 100 that constitutes the radio communication device in the present embodiment. As shown in FIG. 2, the MN 100 includes an EVDO communication unit 101, a WLAN communication unit 103, a radio state information acquisition unit 105, a handover control unit 107, a packet information acquisition unit 109, a storage unit 111, an application 113, and a path switching unit 115. Prepare.

  The EVDO communication unit 101 performs wireless communication with the wireless base station 11 compliant with EV-DO. The WLAN communication unit 103 performs wireless communication with the wireless base station 21 compliant with the wireless LAN system (WLAN) standard. In particular, in the present embodiment, the EVDO communication unit 101 and the WLAN communication unit 103 receive from the CN 200 a packet P1 (see FIG. 7) including a communication quality deterioration notification indicating that the communication quality of the voice call application has deteriorated. In the present embodiment, the EVDO communication unit 101 and the WLAN communication unit 103 constitute a notification receiving unit.

  The radio status information acquisition unit 105 repeatedly acquires radio status information indicating the status of the radio signal RS transmitted and received with the radio base station 11 (or radio base station 21) at a predetermined cycle. Specifically, the wireless state information acquisition unit 105 acquires wireless state information from the EVDO communication unit 101 or the WLAN communication unit 103 and notifies the handover control unit 107 of the acquired wireless state information.

  As the radio state information, for example, RSSI, CIR, transmission power (TxPower), and the like can be used.

When the EVDO communication unit 101 or the WLAN communication unit 103 receives the packet P1 including the communication quality deterioration notification (see FIG. 7) from the CN 200, the handover control unit 107 displays the radio state information corresponding to the received communication quality deterioration notification. The based handover threshold TH is stored in the storage unit 111 in association with the application.
In the present embodiment, the handover control unit 107 and the storage unit 111 constitute a storage processing unit.

  Specifically, the handover control unit 107 stores the radio state information table TB illustrated in FIG. As shown in FIG. 6, in the radio status information table TB, the application type (G729) and the radio status information (RSSI, CIR, TxPower) are associated with each other. The application type “G729” is a voice call application, and the voice codec used is ITU-T recommendation G.264. 729.

  Further, the handover control unit 107 sets the handover threshold TH based on the radio state information corresponding to the communication quality degradation notification among the plurality of radio state information included in the radio state information table TB. A specific method for setting the handover threshold TH will be described later.

  Further, in the present embodiment, the handover control unit 107 associates the wireless state information with the sequence number (identifier) of the packet including the data output by the application 113 when the wireless state information is acquired, and stores the storage unit 111. Remember me.

  Further, the handover control unit 107 stores a plurality of pieces of radio state information for a predetermined period (for example, 30 seconds). As is clear from the packet sequence number (Packet Info Seq in the figure), the wireless state information table TB includes a plurality of pieces of wireless state information in chronological order.

  In the present embodiment, the handover control unit 107 specifies a handover threshold based on the wireless state information included in the wireless state information table TB and the sequence number included in the communication quality deterioration notification.

  For example, when the sequence number included in the packet P1 received from the CN 200 is “104” (see FIG. 7), the handover control unit 107 Radio state information (for example, RSSI = −81 dBm) associated with “Packet Info Seq” 104 in the state information table TB can be used as a handover threshold. That is, the handover control unit 107 can use the radio state information acquired when the packet having the sequence number “104” is transmitted to the CN 200 as the handover threshold.

  Note that the handover control unit 107 has a plurality of pieces of radio state information associated with a packet transmitted to the CN 200 before or after the packet with the sequence number 104 (for example, radio state information with a Packet Info Seq of 103). ), The handover threshold TH can also be set.

  In addition, the handover control unit 107 determines other radio base stations (for example, radio base stations) based on the radio state information acquired by the radio state information acquisition unit 105 and the handover threshold TH stored in the storage unit 111. Perform a handover to 21). In the present embodiment, the handover control unit 107 constitutes a handover execution unit.

  Specifically, the handover control unit 107 determines whether or not the radio state information repeatedly acquired at a predetermined cycle satisfies a handover condition determined by the set handover threshold TH. If the handover condition is satisfied, the handover control unit 107 notifies the route switching unit 115 of a route switching instruction.

  That is, when it is determined that the communication quality of the voice call application has deteriorated in the CN 200 based on the radio state information and the handover threshold TH, the handover control unit 107 executes a handover.

  The packet information acquisition unit 109 acquires information on packets transmitted / received via the EVDO communication unit 101 or the WLAN communication unit 103. Specifically, the packet information acquisition unit 109 acquires the port number and sequence number of the packet. The packet information acquisition unit 109 notifies the handover control unit 107 of the port number and sequence number of the acquired packet.

  The storage unit 111 stores a radio state information table TB and the like based on control by the handover control unit 107.

  The application 113 is configured by a predetermined application program and an execution environment (CPU or the like). In the present embodiment, the application 113 is a voice call application using VoIP.

  The application 113 outputs RTP packets including voice data encoded by the voice codec to the path switching unit 115 at a predetermined interval (for example, 20 ms). In addition, the application 113 acquires the RTP packet output from the path switching unit 115.

  The route switching unit 115 switches to either the EVDO communication unit 101 or the WLAN communication unit 103, that is, the wireless communication system 10 or the wireless communication system 20 based on the route switching instruction notified from the handover control unit 107.

  The RTP packet output from the application 113 is relayed to the EVDO communication unit 101 or the WLAN communication unit 103 via the path switching unit 115. The RTP packet received via the EVDO communication unit 101 or the WLAN communication unit 103 is relayed to the application 113 via the path switching unit 115.

  In addition, the route switching unit 115 performs EVDO communication based on a threshold corresponding to the contents of the application 113 (for example, the average arrival interval of RTP packets in the past 200 ms is 1.2 times the normal arrival interval). It is also possible to switch to any path of the unit 101 or the WLAN communication unit 103.

(3) Functional Block Configuration of Communication Destination Device FIG. 3 is a functional block configuration diagram of CN 200. As illustrated in FIG. 3, the CN 200 includes a communication unit 201, an application 203, and a communication quality monitoring unit 205.

  The communication unit 201 is configured by a communication interface (for example, Ethernet (registered trademark)) for connecting to a predetermined access communication network (not shown) connected to the backbone network 12 and the backbone network 22.

  In particular, in the present embodiment, when the communication quality monitoring unit 205 monitors that the communication quality of the application 203 has deteriorated, the communication unit 201 includes a packet including a communication quality deterioration notification indicating that the communication quality has deteriorated. P1 is transmitted to MN100. In the present embodiment, the communication unit 201 constitutes a notification transmission unit.

  Specifically, the communication unit 201 transmits a packet P1 including the following contents to the MN 100. That is, the communication unit 201 includes information indicating an application type executed in the application 203 (application = G729 in the figure), a communication quality deterioration notification (quality = deterioration in the figure), and a sequence number (sequence number = in the figure = 104) is included in the packet P1.

  In the present embodiment, a port number is actually used as information indicating the application type. Further, as described above, the sequence number is added to the packet including the data output from the application 113 of the MN 100.

  Similar to the application 113 of the MN 100, the application 203 includes a predetermined application program (voice call application) and an execution environment (CPU or the like).

  The communication quality monitoring unit 205 is connected to the application 203 via middleware or the like, and monitors whether or not the communication quality (for example, the number of packet loss) of the application 203 has deteriorated. When the communication quality monitoring unit 205 detects that the communication quality of the application 203 has deteriorated, the communication quality monitoring unit 205 causes the communication unit 201 to transmit the packet P1.

(4) Operation of Communication System Next, an operation of the above-described communication system (MN 100 and CN 200) will be described. Specifically, an operation in which the MN 100 executes a handover based on a communication quality deterioration notification transmitted from the CN 200 will be described with reference to FIGS. 4 and 5.

  As shown in FIG. 4, in step S10, the MN 100 determines whether or not to calculate a handover threshold TH used for determining whether or not to perform handover.

  Specifically, the MN 100 determines whether to generate a handover threshold TH according to the flow shown in FIG. As shown in FIG. 5, in step S11, the MN 100 determines whether or not there is a handover threshold TH corresponding to the application to be executed, specifically, the voice call application.

  When there is a handover threshold TH corresponding to the voice call application (YES in step S11), in step S12, the MN 100 has N (for example, 10) or more samples of radio state information used for calculating the handover threshold TH. It is determined whether or not.

  When there are N or more samples of the radio condition information used for calculating the handover threshold TH (YES in step S12), in step S13, the MN 100 determines M hours (for example, from the last update time of the currently set handover threshold TH). 72 hours) or more.

  When M hours or more have elapsed since the last update time (YES in step S13), in step S14, the MN 100 determines to newly calculate the handover threshold TH.

  On the other hand, when the determination conditions in steps S11 to S13 are not met, the MN 100 determines not to newly calculate the handover threshold TH.

  4, when it is determined to calculate the handover threshold TH (YES in step S10), in step S20, the MN 100 determines the type of application being executed (for example, voice using G.729 as the voice codec). Call application). The application type can be acquired by referring to the payload type field of the SIP packet or RTP packet used at the start of the communication session.

  In step S30, the MN 100 associates and stores the sequence number of the packet transmitted to the CN 200 and the radio state information when the packet is transmitted.

  In step S <b> 40, the MN 100 determines whether an application communication quality deterioration notification is received from the CN 200. As described above, the communication quality degradation notification is transmitted from the CN 200 to the MN 100 when the communication quality of the application being executed in the CN 200 is degraded.

  When the communication quality deterioration notification is received (YES in step S40), in step S50, the MN 100 acquires radio state information corresponding to the communication quality deterioration notification.

  In step S60, the MN 100 calculates a handover threshold TH. Specifically, when there are N or more samples of radio status information corresponding to the communication quality degradation notification, the MN 100 sets each of the radio status information (RSSI, CIR) included in the radio status information table TB (see FIG. 6). , TxPower), the average value and the variance are calculated. Further, the MN 100 sets the average value of radio state information (for example, RSSI) having the smallest variance as the handover threshold TH.

  Note that the MN 100 may calculate the handover threshold TH using another value (for example, a deviation value) indicating the statistics of the radio state information. Further, the MN 100 can repeatedly calculate the handover threshold TH when there are N or more samples of radio state information corresponding to the communication quality degradation notification.

  When it is determined not to calculate the handover threshold TH (NO in Step S10), in Step S70, the MN 100 determines whether or not the state of the radio signal RS has deteriorated from the current handover threshold TH.

  When the state of the radio signal RS is deteriorated from the current handover threshold TH (YES in step S70), and after calculating the handover threshold TH in step S60, in step S80, the MN 100 determines that another radio communication system (for example, A handover to the radio communication system 20) is performed.

  In step S90, the MN 100 determines whether or not the communication has ended, that is, whether or not the voice call using the voice call application has ended.

When the communication ends (YES in step S90), the MN 100 ends the process.
On the other hand, when the communication has not ended (NO in step S90), the MN 100 repeats the processing from step S10.

  In step S13 described above, when M hours (for example, 72 hours) or more have elapsed since the last update time of the handover threshold TH, sampling of radio state information is performed to calculate a new handover threshold TH. . Here, the MN 100 compares the statistical value of the radio state information newly acquired by the sampling with the statistical value of the radio state information used to calculate the current handover threshold TH, and determines the deviation value of the radio state information. Is 40 to 60, that is, when it can be determined that the handover threshold value TH has reached a certain value, the number of samples of the radio state information may be sequentially increased.

  On the other hand, when the deviation value is out of the range, the MN 100 may determine that the characteristics of the radio propagation path have greatly fluctuated, and may continue sampling the radio state information. The MN 100 may determine whether to change the current handover threshold TH to the newly calculated handover threshold TH after continuing the sampling for a predetermined period.

(5) Action / Effect According to the wireless terminal 100, the handover threshold TH based on the wireless state information corresponding to the communication quality degradation notification (packet P1) is stored in association with the application being executed. Here, the communication quality deterioration notification indicates that the communication quality of the application has deteriorated in the communication destination device 200. Further, based on the radio state information acquired by the radio state information acquisition unit 105 and the handover threshold TH stored in the storage unit 111, a handover to another radio base station (for example, the radio base station 21) is performed. Executed.

  For this reason, the radio terminal 100 can execute a handover at an appropriate timing to another radio base station according to the application being executed. That is, according to the radio terminal 100, when the communication quality of an application deteriorates, a handover can be executed at an appropriate timing for each application.

  Further, according to the wireless terminal 100, by appropriately updating the handover threshold TH, an appropriate handover threshold TH is autonomously set according to the state of the wireless communication system (for example, the state of the wireless propagation path and the traffic volume). Can be set to

  Furthermore, according to the wireless terminal 100, even when a user installs a new application in the wireless terminal 100, by installing middleware or the like that can determine that the communication quality of the application has deteriorated together with the application, It is possible to provide flexibility that can be applied to applications.

  In the present embodiment, the communication quality deteriorates by using the sequence number (identifier) of the packet including the data output by the wireless terminal 100 (application 113) when the wireless state information acquisition unit 105 acquires the wireless state information. The corresponding radio status information is specified. For this reason, even when a plurality of pieces of wireless state information are acquired, it is possible to reliably determine the corresponding wireless state information when the communication quality deteriorates.

(6) Other Embodiments As described above, the contents of the present invention have been disclosed through one embodiment of the present invention. However, it is understood that the description and drawings constituting a part of this disclosure limit the present invention. should not do. From this disclosure, various alternative embodiments will be apparent to those skilled in the art.

  For example, in the above-described embodiment, communication quality degradation in the uplink direction, that is, the direction from the MN 100 to the CN 200 is targeted, but communication quality degradation in the downlink direction, that is, the direction from the CN 200 to the MN 100 is also targeted. be able to.

FIG. 8 is a functional block configuration diagram of a wireless terminal 100A according to a modification of the present invention.
Compared with the wireless terminal 100 (MN 100), the wireless terminal 100A is provided with a packet information / communication quality acquisition unit 109A instead of the packet information acquisition unit 109.

  The packet information / communication quality acquisition unit 109A is connected to the application 113 via middleware or the like, and determines whether or not the communication quality (reception-side communication quality) of the application being executed in the wireless terminal 100A has deteriorated. In the present modification example, the handover control unit 107 and the packet information / communication quality acquisition unit 109A constitute a communication quality determination unit.

  In this modification, the handover control unit 107 determines that the reception-side communication quality is degraded when the packet information / communication quality acquisition unit 109A determines that the reception-side communication quality is degraded. Radio state information corresponding to the time point can be stored as a handover threshold in association with the application.

  As described above, the packet information / communication quality acquisition unit 109A acquires the application being executed in the wireless terminal 100A, specifically, the reception-side communication quality of the voice call application (for example, the arrival interval of the received RTP packet). Accordingly, it is possible to determine the deterioration of communication quality in the direction from the CN 200 to the MN 100.

  Further, in the above-described embodiment, the handover between wireless communication systems having different communication methods has been described as an example. However, the present invention is not necessarily limited to the handover between wireless communication systems having different communication methods. .

In the above-described embodiment, it is possible to cope with deterioration in communication quality using the sequence number of a packet including data output by the wireless terminal 100 (application 113) when the wireless state information acquisition unit 105 acquires wireless state information. Although the wireless state information to be specified is specified, the sequence number does not necessarily have to be used.
For example, when the wireless terminal 100 receives a communication quality deterioration notification, the wireless terminal 100 may associate the latest wireless state information with the communication quality deterioration notification, or the wireless state information acquired before a predetermined number of samples You may make it respond | correspond with a quality degradation notification.

  Further, a function of monitoring and notifying the communication quality of the application to a node (for example, a server or a wireless base station) on the communication network, not a device that executes an application (voice call application) like the communication destination device 200. You may make it provide.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 10 ... Wireless communication system, 11 ... Wireless base station, 12 ... Backbone network, 20 ... Wireless communication system, 21 ... Wireless base station, 22 ... Backbone network, 100, 100A ... Wireless terminal (MN), 101 ... EVDO communication part, DESCRIPTION OF SYMBOLS 103 ... WLAN communication part, 105 ... Radio | wireless state information acquisition part, 107 ... Handover control part, 109 ... Packet information acquisition part, 109A ... Packet information and communication quality acquisition part, 111 ... Memory | storage part, 113 ... Application, 115 ... Path switching , 200 ... Communication destination device (CN), 201 ... Communication unit, 203 ... Application, 205 ... Communication quality monitoring unit, P1 ... Packet, RS ... Radio signal, TB ... Radio state information table, TH ... Handover threshold

A first feature of the present invention is a wireless communication apparatus that performs a handover according to a result of comparing a wireless state with a handover threshold, and an identifier of data transmitted to a communication destination apparatus and a transmission time of the data Upon receiving the quality degradation notification from the communication destination device and the means for storing the radio status in association with each other, the handover threshold is set based on the radio status associated with the identifier included in the quality degradation notification And a means .

A second feature of the present invention is a wireless communication apparatus that performs a handover according to a result of comparing a wireless state with a handover threshold, and is included in the quality deterioration notification when a quality deterioration notification is received from a communication destination apparatus. The gist of the invention is to set the handover threshold based on the identifier of the application to be executed and the radio state .

A third feature of the present invention is a wireless communication apparatus that performs handover according to a result of comparing a wireless state with a handover threshold, and determining that communication quality of data received from a communication destination apparatus has deteriorated The gist is to set the handover threshold based on a radio state at the time when it is determined that the communication quality is deteriorated .

A fourth feature of the present invention is a method for performing handover according to a result of comparing a radio state with a handover threshold in a radio communication device, the identifier of data transmitted to a communication destination device and the data And storing the wireless state at the time of transmission of the wireless communication and the handover based on the wireless state associated with the identifier included in the quality deterioration notification when receiving the quality deterioration notification from the communication destination device And a step of setting a threshold value .

A fifth feature of the present invention is a method for performing handover according to a result of comparing a radio state with a handover threshold in a radio communication device, and when receiving a quality degradation notification from a communication destination device, The gist is to set the handover threshold based on the identifier of the application and the radio state included in the deterioration notification .

A sixth feature of the present invention is a method for performing handover according to a result of comparing a radio state with a handover threshold in a radio communication device, wherein communication quality of data received from a communication destination device is degraded. If it is determined that the communication quality is deteriorated , the gist is to set the handover threshold based on a radio state at the time when it is determined that the communication quality is deteriorated .

Claims (8)

A first communication device;
A communication system comprising a second communication device that executes an application and executes communication with the first communication device via a radio base station,
The first communication device is:
A communication quality monitoring unit that monitors whether the communication quality of the application has deteriorated;
A notification transmission unit that transmits a communication quality deterioration notification indicating that the communication quality has deteriorated to the second communication device when the communication quality monitoring unit monitors that the communication quality has deteriorated;
The second communication device is:
A radio status information acquisition unit that acquires radio status information indicating a status of a radio signal transmitted to and received from the radio base station;
A notification receiving unit for receiving the communication quality degradation notification from the first communication device;
When the notification receiving unit receives the communication quality deterioration notification, a storage processing unit that stores a handover threshold based on the radio state information corresponding to the received communication quality deterioration notification in association with the application;
A handover execution unit that executes a handover to another radio base station based on the radio state information acquired by the radio state information acquisition unit and the handover threshold stored in the storage processing unit Communications system. A wireless communication device that executes a predetermined application and executes communication with a communication destination device via a wireless base station,
A radio status information acquisition unit that acquires radio status information indicating a status of a radio signal transmitted to and received from the radio base station;
A notification receiving unit that receives a communication quality deterioration notification indicating that the communication quality of the application has deteriorated in the communication destination device from the communication destination device;
When the notification receiving unit receives the communication quality deterioration notification, a storage processing unit that stores a handover threshold based on the radio state information corresponding to the received communication quality deterioration notification in association with the application;
A handover execution unit that executes a handover to another radio base station based on the radio state information acquired by the radio state information acquisition unit and the handover threshold stored in the storage processing unit Wireless communication device.   The handover execution unit executes the handover when it is determined that the communication quality has deteriorated based on the radio state information acquired by the radio state information acquisition unit and the handover threshold. Wireless communication device. The wireless communication device can be connected to a plurality of wireless communication systems having different communication methods,
The radio communication apparatus according to claim 2, wherein the handover execution unit executes a handover to another radio communication system based on the radio state information acquired by the radio state information acquisition unit and the handover threshold. The notification receiving unit receives a communication quality deterioration notification including an identifier for identifying data output by the application from the communication destination device,
The storage processing unit stores the wireless state information acquired by the wireless state information acquisition unit and the identifier in association with each other over a predetermined period,
The radio communication apparatus according to claim 2, wherein the storage processing unit specifies the handover threshold based on the radio state information and the identifier included in the communication quality deterioration notification.   The wireless communication apparatus according to claim 2, wherein the storage processing unit determines the handover threshold using a plurality of pieces of the wireless state information. A communication quality determination unit that determines whether or not the reception-side communication quality that is the communication quality of the application being executed in the wireless communication device has deteriorated;
When the communication quality determination unit determines that the reception-side communication quality is deteriorated, the storage processing unit corresponds to the radio state information corresponding to the time point when the reception-side communication quality is determined to be deteriorated. The wireless communication apparatus according to claim 2, wherein the wireless communication apparatus stores the value as the handover threshold in association with the application. A wireless communication method for executing a predetermined application and executing communication with a communication destination device via a wireless base station,
Obtaining radio state information indicating a state of a radio signal transmitted to and received from the radio base station;
Receiving from the communication destination device a communication quality deterioration notification indicating that the communication quality of the application has deteriorated in the communication destination device;
When receiving the communication quality deterioration notification, storing a handover threshold based on the radio state information corresponding to the received communication quality deterioration notification in the storage unit in association with the application;
A wireless communication method comprising: performing handover to another wireless base station based on the acquired wireless state information and the handover threshold stored in the storage unit.

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