JP2012222609A - Radio communication method and system, and base station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the probability that it is possible to continue QoS service when handover is performed between radio systems having different communication standards.SOLUTION: When a moving part A10 performs handover between radio systems A and B which use radio techniques having different communication standards, an enquiry is made before performing the handover as to whether or not it is possible to continue QoS service by the radio system B as a handover destination. The handover is performed if possible. Additionally the QoS service is dispersed between different radio systems by preferentially performing the handover with respect to a base station of the radio systems which has enough resources.

Description

  The present invention relates to a radio communication method and system, and a base station, and more particularly, a radio communication method and system in which a mobile device can perform handover while continuing service between systems using different (standard) standards and protocols of radio communication. , Relating to base stations.

  There are a plurality of systems with different standards in a wireless communication system. For example, a 3GPP2 (3rd Generation Partnership Project 2) HRPD (High Rate Packet Data) system and a 3GPP E-UTRAN (Evolved Universal Radio Access Network) are assumed. When a mobile device moves across an area where communication can be performed in wireless communication systems with different standards, the interface for switching the wireless communication system while continuing the service that the mobile device is currently performing. Work on work technology has also begun. For example, the standard regarding the interworking of the HRPD system and the E-UTRAN system is defined in Non-Patent Document 1 or Non-Patent Document 2.

FIG. 1 is a diagram showing an area where a plurality of wireless systems exist. This figure is an example of an area where a plurality of radio communication systems are mixed, and represents an area with good radio quality when the mobile device communicates with the base stations (1 to 5) of the radio systems A to D. In FIG. 1, the base station (1, 2) of the wireless system A is a base station compatible with E-UTRAN, the base station 3 of the wireless system B is a base station compatible with the 3G wireless system, and the base station 4 of the wireless system C is The base station corresponding to WiMAX and the base station 5 of the wireless system D are assumed to be Wi-Fi compatible base stations. The mobile device A has a function capable of communicating with all these wireless communication systems, and can perform handover between the wireless communication systems while continuing the service.

The 3rd Generation Partnership Project (3GPP) Specifications, [online], The 3rd Generation Partnership Project, [January 27, 2011 search], Internet <URL: http: // www. 3 gpp. org / -specifications-> The 3rd Generation Partnership Project 2 (3GPP2) Specifications, [online], The 3rd Generation Partnership Project 2, [January 27, 2011 search], Internet <URL: http: // www: 3gpp2. org / Public_html / specs / index. cfm>

FIG. 2 is an example of a handover sequence between wireless communication systems related to the present invention and the embodiment.
In this example, it is assumed that the mobile device A10 is located in both areas of the base station 1 of the wireless system A and the base station 3 of the wireless system B. The mobile device A10 has established a wireless connection of the best effort flow with the base station 1 of the wireless system A (step 100), and a service guaranteeing QoS (Quality of Service) in the base station 1 of the wireless system A (Hereinafter, sometimes referred to as QoS service). Further, the mobile device A10 receives a pilot signal from the base station 1 of the wireless system A and a pilot signal from the base station 3 of the wireless system B (steps 101 and 102). The mobile device A measures the radio field intensity of the pilot signals from the wireless systems A and B, and reports it to the base station 1 of the connected wireless system A (step 103). The base station 1 of the radio system A compares the radio field intensity of the radio system A reported by the mobile unit with the radio field intensity of the radio system B and determines whether or not to perform handover (step 104). When it is determined that the base station 1 is to be handed over to the base station 3 of the wireless system B, the base station 1 instructs the mobile device A10 to perform the handover (step 105). Receiving the handover instruction, the mobile device A10 performs a handover to the base station 3 of the wireless system B (106), and establishes a wireless connection of the best effort flow (107). As a result, the service assigned to the best effort flow can be continued even after the handover. Here, when the mobile device A10 wants to continue the QoS service provided by the base station 1 of the wireless system A, the mobile device A10 makes a QoS flow establishment request to the base station 3 of the wireless system B (step 108). . The base station 3 of the wireless system B performs QoS flow establishment determination (step 109). As a result, if it is determined that establishment is impossible because wireless resources capable of guaranteeing QoS quality cannot be secured, the establishment of the QoS flow is established. The failure is notified to the mobile device A10 (step 110).
In the handover sequence shown in FIG. 2, in the handover execution determination (step 104), it is not considered whether the QoS service can be continued in the base station 3 of the wireless system B. When there is no available resource to be allocated to, there is a problem that the establishment of the QoS flow after the handover (step 109) fails and the QoS service cannot be continued. In such a handover method, the establishment of the QoS flow is performed between the mobile device and the handover destination radio system, and is not detected by the base station of the handover source radio system.

As described above, conventionally, when a handover between different wireless systems such as (standard) standards and protocols of wireless communication is performed, if the addition of the QoS flow in the handover destination system fails, the QoS service cannot be continued. There was a case.

In the present invention, in view of the above points, when a handover is performed between wireless systems having different (standard) standards, protocols, etc. (hereinafter sometimes referred to as communication standards) of wireless communication, the QoS service is continued. The aim is to increase the probability of possible.

  In particular, when performing a handover between wireless communication systems using wireless technologies having different communication standards, the present invention inquires whether the QoS service can be continued in the handover destination system before the handover is performed. Perform a handover. In addition, according to the present invention, QoS service can be distributed among different wireless communication systems by performing handover preferentially for base stations of wireless systems with sufficient resources.

According to the first solution of the present invention,
A wireless communication method and a wireless communication system in a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The first base station that is the handover source performs handover based on profile information that is an index indicating whether or not it is suitable for performing a predetermined service for each service quality information that represents the communication quality of each wireless system. Performing handover candidate selection to select one or more other base stations of the candidate radio system;
The first base station includes service quality information indicating communication quality of each radio system for guaranteeing a service that the mobile station continues to the one or a plurality of other base stations. Send a resource confirmation request, which is a request to secure the resources necessary to continue
The second base station that has received the resource confirmation request determines whether resources for the service corresponding to the service quality information can be secured, and sends a resource confirmation response including the result of the determination to the first base station. To the base station of
When the first base station receives a resource confirmation response indicating that resources can be secured from the second base station, the first base station hands over the mobile station to the second base station. A wireless communication method and a wireless communication system are provided.

According to the second solution of the present invention,
A wireless communication method and a wireless communication system in a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The first base station that is the handover source provides a service that indicates the communication quality of each radio system for guaranteeing the service that the mobile station continues to one or more other base stations of the handover candidate radio system. Send a resource confirmation request, which includes quality information and is a request to secure resources necessary for the continuation of the service,
One or more other base stations receiving the resource confirmation request perform a service quality resource confirmation process for calculating the number of flows that can guarantee the requested service quality, and confirm the number of flows that can be guaranteed for the service quality information. Send it to the first base station in a response message,
When the first base station receives a resource confirmation response from the one or more other base stations, the first base station is an index indicating whether or not the first base station is suitable for performing a service, which is predetermined for each service quality information. By weighting the number of received flows to certain profile information, a handover destination metric that is an index as to whether or not it is suitable as a handover destination for each service quality is calculated, and based on the handover destination metric, a handover candidate metric is calculated. There are provided a wireless communication method and a wireless communication system characterized in that a handover destination determination for selecting a second base station in a wireless system is performed and the mobile device is handed over to the second base station.

According to the third solution of the present invention,
A base station in a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The base station of the handover source is based on profile information, which is an index indicating whether or not it is suitable for performing a service predetermined for each service quality information indicating the communication quality of each wireless system. Perform handover candidate selection to select one or more other base stations of the wireless system,
The base station includes service quality information indicating communication quality of each wireless system for guaranteeing the service that the mobile station continues to the one or more other base stations, and Send a resource confirmation request, which is a request to secure the necessary resources,
Any of the other base stations that have received the resource confirmation request determines whether resources for the service corresponding to the service quality information can be secured, and sends a resource confirmation response including a result of the determination, If sent to the base station,
When the base station receives a resource confirmation response indicating that resources can be secured from any of the other base stations, the base station hands over the mobile station to the other base station. Is provided.

According to the fourth solution of the present invention,
A base station in a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The handover source base station provides service quality information indicating the communication quality of each radio system to guarantee the service that the mobile station continues to one or more other base stations of the handover candidate radio system. A resource confirmation request that is a request for securing resources necessary for the continuation of the service,
One or more other base stations receiving the resource confirmation request perform service quality resource confirmation processing to calculate the number of flows that can guarantee the requested service quality, and confirm the number of flows that can be guaranteed for the service quality information. When included in the response message and transmitted to the base station,
When the base station receives a resource confirmation response from the one or more other base stations, profile information that is an index indicating whether or not the base station is suitable for performing a service is predetermined for each service quality information In addition, by weighting the number of received flows, a handover execution destination metric that is an index as to whether or not the handover execution destination is suitable for each service quality is calculated, and based on the handover execution destination metric, a handover candidate radio system is calculated. There is provided a base station characterized in that a handover destination determination for selecting one of the other base stations is performed, and the mobile device is handed over to one of the other base stations.

According to the present invention, it is possible to increase the probability that the QoS service can be continued by performing handover when the QoS service can be continued in the handover destination system. Further, according to the present invention, it is possible to distribute quality of service between systems and prevent quality deterioration due to load concentration on a specific system.

It is a figure showing the area where a some radio | wireless system exists. It is the figure which showed the example of the handover sequence between systems relevant to this invention. It is the figure which showed the inter-system handover sequence of 1st embodiment by this invention. It is a figure showing the example of transmission power allocation of a forward link. It is a figure showing which frequency band of a forward link is allocated to the user of which area. It is explanatory drawing of a system profile memory. It is explanatory drawing of a QoS management memory. It is a system configuration figure in an embodiment by the present invention. It is a functional block diagram of the base station of 1st embodiment by this invention. It is a flowchart figure about hand-over candidate selection (step 204, 209). It is the figure which showed the inter-system handover sequence of 2nd embodiment by this invention. It is explanatory drawing of a confirmation result storage memory. It is explanatory drawing of the implementation destination determination metric storage memory. It is a flowchart figure about handover execution destination determination (step 416). It is an example of the determination flag memory which memorize | stored the QoS resource confirmation necessity determination flag. It is a flowchart figure of the QoS resource confirmation process of 1st embodiment by this invention. It is a flowchart figure of the QoS resource confirmation process of 2nd embodiment by this invention. It is a functional block diagram of the base station of 2nd embodiment by this invention.

Hereinafter, although one embodiment of the present invention is described based on a drawing, the present invention is not limited to this embodiment.

1. First embodiment

1-1. System / Device FIG. 8 shows a system configuration for explaining the operation of this embodiment. This system includes a mobile device A10, a base station 1 of the wireless system A, a mobility management device 6 of the wireless system A, a base station 3 of the wireless system B, a mobility management device 7, a monitoring device 8 and a backbone network 9 of the wireless system B. Prepare. The base stations 1 and 3 perform wireless data communication with the mobile device A10. The mobile device management apparatuses 6 and 7 perform call information management and mobile management of the mobile device A10. The mobile device management apparatuses 6 and 7 also have a function of transferring data to and from the mobile device A10 via the IP network. The monitoring device 8 collects statistical information of call processing operations from each device in order to grasp the service operation status. The monitoring device 8 may be connected to each system independently, or both may be connected. Between the base station 1 of the wireless system A and the base station 3 of the wireless system B, call processing information necessary for the handover of the mobile device A10 is transferred.

In the first embodiment, the selection of the inter-system handover candidate is determined using the profile information of the handover destination wireless communication system held in the handover source base station.
FIG. 9 shows a functional block diagram of the base station in the first embodiment. The base station includes a wireless communication interface 20, a wired network interface 21, a data processing unit 22, a call processing control unit 23, a handover control unit 24, a QoS resource confirmation unit 25, a QoS resource management unit 26, and a QoS information management unit 27.
The wireless communication interface 20 performs modulation / demodulation processing and wireless protocol processing on a wireless signal. The wired network interface 21 performs wired network communication with the mobile device management device, the monitoring device, and other base stations. The call processing control unit 23 establishes the wireless connection with the mobile device. Traffic data transmitted / received to / from the mobile device is processed by the data processing unit 22, and traffic control is performed so as to ensure a delay and a bandwidth to be guaranteed for the QoS flow. The handover control unit 24 periodically receives the radio wave conditions of the neighboring base stations measured by the mobile device from the mobile device, and selects a base station having a good radio state as a handover candidate. Further, the handover control unit 24 uses the profile information of the handover destination wireless communication system to select a handover candidate in order to determine whether the system is suitable for continuing the QoS service. As shown in FIG. 6 (described later), the profile information is stored in the system profile memory 28 and includes handover metric information. When it is necessary to continue the QoS service at the time of the handover, the handover control unit 24 inquires whether the QoS service can be continued at the handover candidate base station, and when it can be continued, determines the handover destination base station and performs the handover. The QoS information management unit 27 manages the QoS information performed by the mobile device, and determines whether or not the QoS service needs to be continued when the handover is performed. As shown in FIG. 7 (described later), the QoS information is stored in the QoS management memory 29 and includes quality information that needs to be guaranteed for each QoS class. When the QoS service needs to be continued, the QoS resource confirmation unit 25 transmits a resource confirmation request message to the handover candidate destination base station via the wired network interface 21, and sets the QoS resource at the handover candidate base station. Ask if it can be secured. The QoS resource management unit 26 manages the maximum allowable number of flows that can be established by the base station and the number of resources that can be allocated to the QoS service, and can allocate a QoS flow when a resource confirmation request message is received. The resource confirmation response message is transmitted via the wired network interface 21.

FIG. 6 is an explanatory diagram of the system profile memory.
This system profile memory shows an example of a handover metric used for determining a handover candidate (details will be described later). The system profile memory 28 includes a metric that is an index indicating whether or not the system is suitable for performing a service corresponding to each QoS class (eg, QCI (QoS Class Identifier)) for each wireless system. The profile information is stored.

FIG. 7 is an explanatory diagram of the QoS management memory.
This QoS management memory shows an example of quality that needs to be guaranteed for each QoS class (eg, QCI). The QoS management memory 29 stores priority, communication quality that requires QoS guarantee (eg, delay budget (allowable delay), packet loss rate, guaranteed bit rate, etc.) corresponding to the QoS class.

1-2. Overview of Operation FIG. 3 is a handover sequence according to the first embodiment of the present invention. The handover sequence operation will be described below with reference to FIG.
In this example, it is assumed that the mobile device A10 is located in both areas of the base station 1 of the wireless system A and the base station 3 of the wireless system B. The mobile device A10 has established a best-effort flow wireless connection with the base station 1 of the wireless system A (step 200), and provides the QoS service with the base station 1 of the wireless system A. Further, the mobile device A10 receives the pilot signal from the base station 1 of the wireless system A and the pilot signal from the base station 3 of the wireless system B (steps 201 and 202). The mobile device A10 measures the radio field intensity of the pilot signals from the wireless systems A and B and reports to the base station 1 of the connected wireless system A (step 203). The base station 1 of the wireless system A makes a handover execution determination (step 220) based on the radio field intensity. For example, when the radio field intensity of the base station 1 is lower than a predetermined threshold value, or when the radio field intensity of another base station is lower than a predetermined threshold value, the radio wave between the base station 1 and the other base station is determined. For example, when the difference in intensity becomes higher than a predetermined threshold value in another base station, it can be appropriately implemented. If the base station 1 of the wireless system A determines that the handover needs to be performed, the base station 1 performs handover candidate selection (step 204). In FIG. 3, two systems of wireless systems A and B are assumed, but when there are other wireless systems that can be handed over, they can be included in the selection of handover candidates. In this case, the one with the best radio field intensity is selected from the base stations of a plurality of radio systems. As a result of the handover candidate selection, when the base station 3 of the wireless system B is selected as a handover candidate and it is necessary to continue the QoS service performed by the mobile device A10, it is desired to continue to the base station 3 of the wireless system B A resource confirmation request message including the QoS information of the QoS flow is transmitted (step 205). The QoS information includes information on allowable delay (eg, allowable packet delay) for guaranteeing QoS and guaranteed bit rate. These QoS information may be transmitted as a QoS class such as QCI defined in Non-Patent Document 1, for example. The base station 3 of the wireless system B confirms whether the requested QoS can be guaranteed by the QoS resource confirmation process (step 221).

FIG. 16 shows a flowchart of the QoS resource confirmation process. This process is executed by the QoS resource management unit 26, for example.

The QoS resource management unit 26 first determines whether the total number of flows after adding the QoS flow notified by the resource confirmation request message is equal to or less than the maximum allowable number of flows that can be established in the base station (step 601). For example, in the base station, when the maximum allowable flow number is set in advance and the number of currently established flows is managed and grasped, 1 is added to the number of flows or the number determined by QoS class information is added. It is sufficient to determine whether the number is within the maximum allowable flow number. If the number is less than the maximum allowable number of flows, the QoS resource management unit 26 refers to, for example, the QoS management memory shown in FIG. 7, and determines whether radio resources that can be transmitted at the guaranteed bit rate specified by the QoS information can be secured. Determination is made (step 602). If the radio resource can be secured, the QoS resource management unit 26 determines whether the packet can be transferred within the allowable delay specified by the QoS information (step 603). If the packet can be transferred within the allowable delay, the QoS resource management unit 26 determines that the QoS flow can be added (step 604) and ends the process. In other cases, the QoS resource management unit 26 determines that the QoS flow cannot be added and ends the process.

  Returning to FIG. 3, when the resource cannot be secured as a result of the QoS resource confirmation process, a resource confirmation response message is returned indicating that the QoS resource cannot be secured (step 206). Receiving the resource confirmation response, the base station 1 of the wireless system A determines that the handover is not performed for the base station when QoS addition is not possible (step 207). When a plurality of radio system base stations are included in the handover candidate selection targets, except for the radio system base station that is determined not to perform handover in step 207, the procedure is performed again from handover candidate selection in step 204, A handover destination may be determined. If it is determined that the handover is not to be performed, the handover operation is stopped until it is determined in the handover execution determination that the handover needs to be performed again.

  The base station 1 of the wireless system A continuously receives the radio field strength report from the mobile device A10 (step 208), and when it is determined that the handover needs to be performed again in the handover execution determination (step 222), the handover candidate A selection is made (step 209). When the base station 3 of the wireless system B is selected again as a handover candidate and the QoS service performed by the mobile device A10 needs to be continued, the QoS information of the QoS flow to be continued to the base station 3 of the wireless system B A resource confirmation request message including is transmitted (step 210). As described with reference to FIG. 16, the base station 3 of the wireless system B confirms whether or not a resource capable of guaranteeing the requested QoS can be secured by the QoS resource confirmation process (step 223). Returns a resource confirmation response message indicating that the QoS resource can be secured (step 211). The base station 1 of the wireless system A that has received the resource confirmation response determines that a handover is performed to the base station if QoS can be added (step 212), and the base station of the wireless system B to the mobile device A10. A handover instruction to the station 3 is given (step 213). The mobile device A10 performs handover to the base station 3 of the wireless system B (step 214), and establishes a wireless connection of the best effort flow (step 215). Next, the mobile device A10 makes a QoS flow establishment request (step 216), and if the QoS flow establishment determination result can be established (step 217), the base station 3 of the wireless system B notifies the QoS flow establishment success notification. (Step 218). Thereafter, the wireless connection of the QoS flow is established, and the QoS service is continued (step 219).

In the handover sequence shown in FIG. 3, before the handover execution determination is made, a resource confirmation request (steps 205 and 210) is made to the base station of the handover candidate destination wireless system, and the response can be added with QoS (step 211). ), The probability that the QoS flow can be established is increased in the QoS flow establishment determination (step 217). The resource confirmation request is transmitted including the QoS information to be continued, and when the resource confirmation response is returned as the QoS addition is possible, the requested resource is reserved in the base station 3 of the wireless system B. Is also possible. The reserved resource is reserved until the QoS flow establishment request (step 216) is received, but is released when the QoS establishment request is not sent for a certain period of time, so that other users can use it. You can also.
In step 206, when the base station 3 of the wireless system B returns a resource confirmation response message indicating that the QoS resource cannot be secured, the base station 3 of the wireless system B uses the resources of other base stations in the same wireless system. When an optimal base station can be selected as a handover destination according to the usage situation, it can be notified as a handover destination redirection information included in a resource confirmation response message. When the base station 1 of the wireless system A that has received the handover destination redirection information can perform a handover to the redirection destination base station, the base station 1 again performs a resource confirmation request to the redirection destination base station, and performs a handover sequence. Can continue. However, if a handover candidate base station continues to be in a state where QoS cannot be added, and the state where handover cannot be performed continues, the handover to the optimal base station is performed when a handover condition corresponding to the radio strength is established as before. You may make it implement.

1-3. Handover candidate selection (steps 204 and 209)

Handover candidate selection (steps 204 and 209) includes a plurality of base stations in radio system A and base stations of radio systems B, C, and D, which are radio communication systems other than radio system A shown in FIG. Can be done as a candidate. However, in the following description, as an example, description will be given mainly focusing on candidate selection between different wireless communication systems. Handover candidate selection between systems is performed only when a condition that requires handover between systems is satisfied.
In the sequence of FIG. 3, when it is determined in step 207 that the handover is not performed, the handover execution determination (step 222) and the handover candidate selection (step 209) are repeated thereafter. If this sequence is started from a state where quality has deteriorated, the wireless quality will deteriorate while the handover destination selection process is being performed, and handover must be performed without sufficient candidate selection being performed. There may be a case where the situation becomes impossible. Further, at the cell boundary, there may be a possibility that sufficient QoS guarantee cannot be obtained due to quality degradation due to interference from other cells. Therefore, handover candidate selection may be started from a state in which the radio quality of the connected base station is better than that in the conventional handover in the system. In the following, an example of timing for performing handover candidate selection will be described.

  FIG. 4 shows an example of transmission power allocation of the forward link transmitted by the base station of the wireless system A. The base station 1 of the wireless system A uses an allocation band A30 with a reduced transmission power for mobile stations located near the cell, and an allocation band C32 with an increased transmission power for users at cell boundaries. Wireless resources are allocated, and an allocated bandwidth B31 is allocated to an intermediate mobile station. On the other hand, the base station 2 of the wireless system A has an allocation band C32 in which the transmission power is reduced for the mobile station located near the cell, and an allocation band A30 in which the transmission power is increased for the user at the cell boundary. It is assumed that radio resources are allocated using, and allocated band B31 is allocated to intermediate mobile devices.

  FIG. 5 is a diagram showing which frequency band of the forward link is allocated to a user in which area. This figure shows in which area of the base station 1 of the radio system A and the base station 2 of the radio system A the allocated bands A, B, and C are used when the transmission output allocation is determined as shown in FIG. Represents. The radio wave environment for mobile devices at the cell boundary is improved by separating the frequency band allocated to the cell boundary between base stations. For example, when the mobile device A10 moves to the cell boundary, the mobile device A10 is scheduled to the allocated band C32 with increased transmission power, thereby operating to ensure the QoS quality of the user at the cell boundary. Since the radio field strength received from a mobile device in the vicinity of the cell is large and the radio field strength received from the mobile device at the cell boundary is small, it is received from the mobile device to which radio resource the mobile device is allocated. Judgment shall be based on the radio field intensity. However, if the number of mobile devices on the cell boundary increases, there is a possibility that the radio resources of the allocated band C32 may be insufficient, and radio resources should be allocated to the users on the cell boundary using the allocated band B31 and the allocated band A32. It may be necessary. In this case, the radio wave environment will be deteriorated from the user at the cell boundary, which may affect the maintenance of QoS. For this reason, handover candidate selection is performed when the transmission power required for allocation to the mobile station has changed from the allocated band A30 to the allocated band B31, and the QoS flow of the mobile station allocated to the cell boundary band. Handover control can be performed so that the number does not increase. Also, classify the transmission power required for allocation to mobile devices as described above, specify the probability of performing handover candidate selection between radio systems when moving between classes, and implement probability as approaching cell boundary By increasing the inter-system handover in a stepwise manner, it is possible to reduce the number of resources allocated to the QoS at the cell boundary and to prevent an unnecessarily inter-system handover from occurring.

Handover candidate selection can also be performed based on the priority of each system.
FIG. 6 is an example of a handover metric used for handover candidate selection. The information in FIG. 6 can be set in advance. The handover metric is used to determine which radio system is suitable for the mobile device to continue the ongoing QoS service, and is held as profile information of the handover destination radio communication system in the handover source base station. . According to Non-Patent Document 1, the quality required for QoS service is defined for each QoS class, and identification information called QCI is assigned to each QoS class. Consider a case in which QCIs of 1, 4, and 9 are assigned to voice, streaming video, and file transfer services as shown in FIG. The definition of the QoS quality that should be guaranteed for the services whose QCI is 1, 4, and 9 is as shown in FIG. The priority in FIG. 7 is higher when the value is smaller, and the priority is higher in the order of the QCI values of 1, 4, and 9. The delay budget defines an allowable delay required for QoS guarantee, and it is necessary to perform packet transfer so as not to exceed this delay. The packet loss rate defines the loss rate required for continuation of service, and it is necessary to perform packet transfer mainly so that the packet loss in wireless transmission does not exceed this value. The bit rate guarantee is necessary when the QCI is 1 or 4, and it is necessary to set a bit rate to be guaranteed separately from the QCI.
The handover metric in FIG. 6 is a summary of QoS services suitable for each wireless system for each QCI. The metric value has a minimum value of 0 and a maximum value of 7, indicating that the radio system is suitable for QoS service in descending order. When the value is 0, the target wireless system is unconditionally removed from the handover candidates. Although the handover metric is defined for each radio system in FIG. 6, it may be defined for each base station.
The wireless system A in FIG. 6 corresponds to, for example, an E-UTRAN system, and is suitable for all services. However, since the quality may not be stable just after starting service deployment, the metric is an intermediate value. 4 is set. The wireless system B corresponds to, for example, a 3G wireless system, and has a wide cell radius and a wide service area. Therefore, the wireless system B is the most suitable wireless system for a QCI = 1 service corresponding to a voice service. Is set to 6 which is the largest in all radio systems. However, since the wireless system B may have inferior wireless throughput performance compared to other systems, the metrics for other QCIs are small and 2 is set. The wireless system C corresponds to, for example, a WiMAX system, and has a wide service area. However, since the system is mainly for data communication, the voice service is not performed, and the metric for QCI = 1 is set to 0. Yes. Since the wireless system C has high wireless throughput performance, the wireless system C is suitable for the service of QCI = 4 and 9, and the metric is set to a higher value of 5. The wireless system D corresponds to, for example, a Wi-Fi system and has a narrow service area but high wireless throughput. Therefore, the wireless system D is suitable for transferring a large amount of traffic all at once. For a service with QCI = 9, The metric is set to 7. The wireless system D does not perform voice service, and 0 is set for the metric of QCI = 1.

FIG. 10 is a flowchart for handover candidate selection (steps 204 and 209). This figure shows an example of handover candidate selection when the handover metric of FIG. 6 is used. Here, it is assumed that the processing is performed for a wireless system that satisfies a certain reception quality. The operation of each step in the flowchart will be described below. This process is executed by the handover control unit 24, for example.
The handover control unit 24 sorts one or a plurality of services being executed by the mobile station that performs handover candidate selection, in descending order of priority of the QCI with reference to the QoS management memory shown in FIG. 7 (step 301). Next, the handover control unit 24 refers to the system profile memory shown in FIG. 6, compares the handover metrics in the order of QCI having the highest priority, and selects the system with the largest metric (step 302). If the QCI metric with the highest priority has the same value in a plurality of systems, the handover control unit 24 selects the system with the largest metric by comparing the QCI metric with the next highest priority. When all the QCI metrics have the same value, the handover control unit 24 selects at random. Next, the handover control unit 24 determines whether or not the QoS service can be implemented in the selected system by determining whether or not there is a handover metric for any QCI that is in service in the selected system. (Step 303). If the determination result in step 303 is that QoS can be implemented, the handover control unit 24 determines the selected system as a handover candidate and ends the handover candidate selection process. If it is determined in step 303 that there is a service incapable of performing QoS, the handover control unit 24 excludes the selected system from the handover candidates (step 305). When the selected system is excluded from the handover candidates, the handover control unit 24 determines whether all the handover candidates are excluded (Step 306). When all handover candidates are excluded, the handover control unit 24 terminates the processing as no inter-system handover candidate (step 307). If all the handover candidates are not excluded, the handover control unit 24 reselects the system having the largest handover metric at step 302 and continues the process until the end condition is satisfied.
For example, when the mobile device A10 that is performing a service of QCI = 4 (streaming video) and QCI = 9 (file transfer) performs handover candidate selection, the handover metric of FIG. When applied, it becomes as follows. Since the priority of QCI is 5 when QCI = 4 and 9 when QCI = 9, the priorities increase in the order of QCI = 4 and QCI = 9 (corresponding to step 301). When the system with the largest handover metric is selected for QCI = 4, the wireless system C is 5 with the largest value, and the wireless system C is selected as the system with the largest handover metric (corresponding to step 302). When the mobile station A 10 confirms whether the handover metric of the wireless system C is 0 with respect to the QCIs 4 and 9 that are in service, both 5 are set and it is determined that the service can be performed (corresponding to step 303). Thereby, the wireless system C is determined as a handover candidate (corresponding to step 304).

2. Second embodiment

2-1. System / Device

The system is the same as that described in the first embodiment.

FIG. 18 shows a functional block diagram of the base station in the second embodiment. The QoS resource confirmation unit 25 obtains the number of flows that can guarantee the QoS service from another wireless system, and stores the number of flows information as shown in FIG. 12 described later in the confirmation result storage memory 18. The handover control unit 24 calculates an execution destination determination metric as shown in FIG. 13 to be described later calculated using the information in the confirmation result storage memory 18 and the handover metric information stored in the system profile memory 28. The data is stored in the storage memory 19 and a handover destination is selected. Detailed operation will be described with reference to the sequence of FIG.
In the second embodiment, the blocks and configurations having the same reference numbers as in the first embodiment are the same as those described above.

FIG. 12 is an explanatory diagram of the confirmation result storage memory.
The confirmation result storage memory 18 stores the number of flows that can guarantee QoS at the time of handover according to each QoS class (eg, QCI) for each wireless system.
FIG. 13 is an explanatory diagram of an execution destination determination metric storage memory.
The execution destination determination metric storage memory 19 stores the calculated handover execution destination metric for each wireless system in accordance with each QoS class (eg, QCI).

2-2. Overview of operation

FIG. 11 is a handover sequence according to the second embodiment of the present invention. In the second embodiment, the inter-system handover candidate is selected using the availability information of the handover destination resource.
Hereinafter, the handover sequence operation in the embodiment of FIG. 11 will be described.
In this example, it is assumed that the mobile device A10 is located in both areas of the base station 1 of the wireless system A and the base station 3 of the wireless system B. The mobile device A10 has established a wireless connection with the best effort flow with the base station 1 of the wireless system A (step 400), and provides the QoS service with the base station 1 of the wireless system A. Further, the mobile device A10 receives pilot signals from the base station 1 of the wireless system A, the base station 3 of the wireless system B, and the base station 4 of the wireless system C (steps 401 to 403). The mobile device A10 measures the radio field intensity of the pilot signals from the wireless systems A, B, and C and reports to the base station 1 of the connected wireless system A (step 404). The base station 1 of the wireless system A makes a handover execution determination (step 417) based on the radio field intensity. For example, when the radio field intensity of the base station 1 is lower than a predetermined threshold value, or when the radio field intensity of another base station is lower than a predetermined threshold value, the radio wave between the base station 1 and the other base station is determined. For example, when the difference in intensity becomes higher than a predetermined threshold value in another base station, it can be appropriately implemented. The base station 1 of the wireless system A needs to continue the QoS service performed by the mobile station A10 at the handover destination base station, and the radio field strengths of the base station 3 of the wireless system B and the base station 4 of the wireless system C are high. If it is determined that it is above a certain level, a resource confirmation request is transmitted to the base station 3 of the wireless system B and the base station 4 of the wireless system C (steps 405 and 406). The resource confirmation request is transmitted including the QoS information of the QoS flow to be continued. The QoS information includes information on allowable packet delay (eg, allowable packet delay) and guaranteed bit rate for guaranteeing QoS. These QoS information may be transmitted as QoS class information such as QCI defined in Non-Patent Document 1, for example. Receiving the resource confirmation request, the base station 3 of the wireless system B and the base station 4 of the wireless system C perform QoS resource confirmation processing, and calculate the number of flows that can guarantee the requested QoS (steps 418 and 419).

FIG. 17 shows a flowchart of the QoS resource confirmation process. This process is executed by the QoS resource management unit 26, for example. In addition, this flowchart is performed for each QoS flow.
The QoS resource management unit 26 initializes the number of QoS flows that can be guaranteed first to 0 (step 701). Next, the QoS resource management unit 26 determines whether the total flow number after adding the QoS flow notified by the resource confirmation request message is equal to or less than the maximum allowable flow number that can be established in the base station (step 702). . For example, in the base station, when the maximum allowable flow number is set in advance and the number of currently established flows is managed and grasped, 1 is added to the number of flows or the number determined by QoS class information is added. It is sufficient to determine whether the number is within the maximum allowable flow number. If the number is less than the maximum allowable number of flows, the QoS resource management unit 26 refers to, for example, the QoS management memory shown in FIG. 7, and determines whether radio resources that can be transmitted at the guaranteed bit rate specified by the QoS information can be secured. Determination is made (step 703). If radio resources can be secured, the QoS resource management unit 26 refers to, for example, the QoS management memory illustrated in FIG. 7 and determines whether the packet can be transferred within the allowable delay specified by the QoS information ( Step 704). If the packet can be transferred within the allowable delay, the QoS resource management unit 26 adds 1 to the number of QoS flows that can be guaranteed and counts up (step 705). The QoS resource management unit 26 updates the resource state in the base station to the temporary resource state when the QoS flow is added (step 706), and performs again from step 702, so that the flow can be as long as QoS guarantees. Continue counting up the number. When the conditions in steps 702 to 704 are not satisfied, the QoS resource management unit 26 ends the process.

Returning to FIG. 11, after completing the QoS resource confirmation processing, the QoS resource management unit 26 includes the calculated guaranteed number of flows in the resource confirmation response message and transmits it (steps 407 and 408).
FIG. 12 shows an example of the number of flows that can guarantee QoS at the time of handover in each radio system base station. The result of obtaining the number of flows that can guarantee QoS from other radio systems is stored in the confirmation result storage memory 18. To do.

Receiving the resource confirmation response, the base station 1 of the wireless system A performs handover execution destination determination (step 416). When the base station 3 of the wireless system B is selected in the handover execution destination determination, a handover instruction to the mobile station A10 to the base station 3 of the wireless system B is given (step 409). The mobile device A10 performs handover to the base station 3 of the wireless system B (step 410), and establishes a wireless connection of the best effort flow (step 411). Next, the mobile device A10 makes a QoS flow establishment request (step 412), and if the QoS flow establishment determination result can be established (step 413), the base station 3 of the wireless system B issues a QoS flow establishment success notification. (Step 414). Thereafter, the wireless connection of the QoS flow is established, and the QoS service is continued (step 415).

  In the handover sequence of FIG. 11, in the handover destination determination (step 416), the determination is made using the number of flows that can guarantee the QoS service in each wireless system, thereby increasing the probability that the QoS flow can be established, It is possible to distribute the QoS flow implemented in each system. The resource confirmation request is transmitted including the QoS information to be continued. When a resource confirmation response is returned, the resource requested by the base station of each radio system can be reserved. The reserved resource is secured until the QoS flow establishment request (step 412) is received, but is released when the QoS establishment request is not sent for a certain period of time, so that other users can use it. You can also.

2-3. Handover execution destination determination (step 416)

FIG. 14 is a flowchart of handover destination determination (step 416). An example of handover destination determination (step 416) will be described with reference to the flowchart of FIG. In the determination example of FIG. 14, the metric used for the determination is recalculated as the handover destination determination metric using the number of flows that can guarantee the QoS service in each wireless system and the value of the handover metric in FIG. The implementation destination is being determined. The execution destination determination metric is calculated by the following equation.

Implementation destination determination metric = number of flows that can guarantee QoS service x handover metric

Hereinafter, the operation of each step in the flowchart of FIG. 14 will be described. This process is executed by the handover control unit 24, for example.
The handover control unit 24 sorts one or a plurality of services being performed by the mobile station that performs handover candidate selection with reference to the QoS management memory shown in FIG. 7 in descending order of QCI priority (step 501). Next, the handover control unit 24 refers to the system profile memory shown in FIG. 6 and the confirmation result storage memory shown in FIG. 12, and performs handover destinations for each QoS class (for example, QCI) for each wireless system. An execution destination determination metric is calculated for each base station (step 502). Here, FIG. 13 shows an example of the calculation result of the execution destination determination metric. The implementation metric determined when using the handover metric in FIG. 6 and the number of flows that can guarantee QoS at the time of handover in each radio system base station shown in FIG. 12 is as shown in FIG. Stores the calculated execution destination determination metric in the execution destination determination metric storage memory 19. Next, the handover control unit 24 compares the execution destination determination metrics in the order of the QCI having the highest priority, and selects the base station with the largest metric (step 503). When the QCI metric with the highest priority is the same value in a plurality of base stations, the handover control unit 24 selects the base station with the highest metric by comparing the QCI metrics with the next highest priority. . The handover control unit 24 selects at random when all the QCI metrics have the same value. Next, the handover control unit 24 determines whether or not the QoS service can be continued in the selected base station by determining whether or not there is a handover metric for any QCI being serviced in the selected base station. Is determined (step 504). If the determination result in step 504 is that QoS can be continued, the handover control unit 24 determines the selected base station as a handover destination, and ends the handover destination determination process. If it is determined in step 505 that there is a service that cannot continue QoS, the handover control unit 24 excludes the selected base station from the handover destination (step 506). When the selected base station is excluded from the handover execution destination, the handover control unit 24 determines whether all the handover execution destination candidate base stations have been excluded (step 507). When all handover destination candidates are excluded, the handover control unit 24 ends the process assuming that there is no inter-system handover destination (step 508). If all the handover execution destination candidates are not excluded, the handover control unit 24 reselects the base station having the maximum execution destination determination metric in step 503 and continues the processing until the end condition is satisfied.

  For example, when the mobile device A10 that is performing a service of QCI = 4 (streaming video) and QCI = 9 (file transfer) makes a handover execution destination determination, the execution destination determination metric of FIG. Applying this flowchart results in the following. Since the priority of QCI is 5 when QCI = 4 and 9 when QCI = 9, the priorities increase in the order of QCI = 4 and QCI = 9 (corresponding to step 501). When the base station having the maximum implementation destination determination metric in FIG. 13 is selected for QCI = 4, the base station 3 of the wireless system B and the base station 5 of the wireless system D are 64 having the largest value. Is selected. When the base station with the largest implementation destination determination metric of QCI = 9 is selected for these two base stations, the base station 3 of the wireless system B is 128, the wireless system D base station 5 is 112, and the wireless system B Base station 3 is selected (corresponding to step 503). When the mobile station A10 confirms whether the handover metric of the base station 3 of the wireless system B is 0 with respect to the QCIs 4 and 9 that are performing the service, it is determined that both 5 are set and the service can be performed (step 504 equivalent). As a result, the base station 3 of the wireless system B is determined as a handover destination (corresponding to step 505).

  In the handover execution destination determination, if the situation where it is determined that there is no inter-system handover execution destination (step 508) continues because the number of QoS resources that can be secured at the handover execution destination continues to 0, A handover can be performed when a handover condition corresponding to the radio strength is established. In this case, the base station that performed the handover execution destination determination collects as statistical information that the QoS resource reservation has failed and reports it to the monitoring device 8. Based on the accumulated statistical information, the monitoring device 8 can identify the area where the QoS service is not continued when the handover is performed, and can optimize the area by newly installing a base station in the area.

2-4. Processing by Cell Radius or Transmission Power In determining the handover destination, it is possible to select a system having a wide cell radius in the case of high-speed movement in consideration of the moving speed of the mobile device. In this case, the cell radius is set in advance in the base station of the handoff in the memory of each base station. In this case, the execution destination determination metric of step 502 in the handover execution destination determination flowchart of FIG. The cell radius is an index representing the area size, and may be replaced with the transmission power of each base station.

Implementation destination determination metric = number of flows that can guarantee QoS service × handover metric × cell radius of the base station

When it is determined that the mobile device is moving at a high speed by using GPS information, a gyro sensor, or the like, and it is determined that the mobile device is moving at a certain speed or more, an execution destination determination metric that takes the cell radius into consideration It can be used to perform hand-over destination determination. This increases the probability that a mobile device that is moving at high speed will perform handover to a base station with a wide cell radius.

2-5. Mobile devices that do not require QoS guarantees

In addition, a mobile device that does not require QoS guarantee, such as a mobile device that performs only the best effort service, may perform a handover without performing the resource confirmation request (steps 405 and 406) of FIG. Is possible.

FIG. 15 is an example of a determination flag memory that stores a QoS resource check necessity determination flag. Whether the resource confirmation request can be skipped is determined based on the QoS resource confirmation necessity determination flag shown in FIG. This flag information is stored in advance in the system profile memory 28.
This process can be executed by, for example, the handover control unit 24.
The handover control unit 24 refers to the determination flag memory in the system profile memory, and skips if the flag is 1, and skips if the flag is 0. In the example of FIG. 15, 1 is set for the QCI = 9 service of the wireless system D, and the mobile device that performs only the QCI = 9 service does not perform the resource confirmation request. D can be handed over. In this case, when the handover control unit 24 determines that the resource confirmation request can be skipped in the handover execution determination (step 417) of FIG. 11, the handover execution destination determination (step 416) is performed without executing the resource confirmation request. To select a base station of the wireless system D unconditionally and give a handover instruction to the mobile device. For example, the wireless system D is assumed to be Wi-Fi, and the cell radius is narrow but the wireless throughput is high. Therefore, the best effort traffic in the area is unconditionally flowed to the wireless system D and data offload is performed. Is possible. In addition, after handing over a radio system that is not suitable for QoS, a mobile device that has started the QoS service selects a system that is suitable for QoS guarantee and performs handover again when the QoS service is activated.

The present invention can be appropriately applied to handover between systems having different wireless communication systems, wireless communication standards, standards, protocols, and the like.

1-2 base station 3 in radio communication system 3 base station 4 in radio communication system B base station 5 in radio communication system C base station 6 in radio communication system D mobility management device 7 in radio system A mobility management device in radio system B 8 Monitoring device 9 Backbone IP network 10 Mobile device A
18 Confirmation result storage memory 19 Implementation destination determination metric storage memory

20 wireless communication interface 21 wired network interface 22 data processing unit 23 call processing control unit 24 handover control unit 25 QoS resource confirmation unit 26 QoS resource management unit 27 QoS information management unit 28 system profile memory 29 QoS management memory 30 base of wireless system A Station allocated bandwidth A
31 Allocated bandwidth B of base station of wireless system A
32 Allocated bandwidth C of base station of wireless system A
100 to 110 Steps 200 to 223 of the conventional handover sequence Steps 300 to 308 of the handover sequence of the first embodiment Steps 400 to 419 of the handover candidate selection flowchart Steps 500 to 509 of the handover sequence of the second embodiment Steps 600 to 606 of the determination flowchart Steps 700 to 707 of the QoS resource confirmation processing flowchart of the first embodiment Steps of the QoS resource confirmation processing flowchart of the second embodiment

Claims (15)

A wireless communication method in a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The first base station that is the handover source performs handover based on profile information that is an index indicating whether or not it is suitable for performing a predetermined service for each service quality information that represents the communication quality of each wireless system. Performing handover candidate selection to select one or more other base stations of the candidate radio system;
The first base station includes service quality information indicating communication quality of each radio system for guaranteeing a service that the mobile station continues to the one or a plurality of other base stations. Send a resource confirmation request, which is a request to secure the resources necessary to continue
The second base station that has received the resource confirmation request determines whether resources for the service corresponding to the service quality information can be secured, and sends a resource confirmation response including the result of the determination to the first base station. To the base station of
When the first base station receives a resource confirmation response indicating that resources can be secured from the second base station, the first base station hands over the mobile station to the second base station. Wireless communication method. A wireless communication method in a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The first base station that is the handover source provides a service that indicates the communication quality of each radio system for guaranteeing the service that the mobile station continues to one or more other base stations of the handover candidate radio system. Send a resource confirmation request, which includes quality information and is a request to secure resources necessary for the continuation of the service,
One or more other base stations receiving the resource confirmation request perform a service quality resource confirmation process for calculating the number of flows that can guarantee the requested service quality, and confirm the number of flows that can be guaranteed for the service quality information. Send it to the first base station in a response message,
When the first base station receives a resource confirmation response from the one or more other base stations, the first base station is an index indicating whether or not the first base station is suitable for performing a service, which is predetermined for each service quality information. By weighting the number of received flows to certain profile information, a handover destination metric that is an index as to whether or not it is suitable as a handover destination for each service quality is calculated, and based on the handover destination metric, a handover candidate metric is calculated. A radio communication method comprising: performing a handover destination determination for selecting a second base station in a radio system; and handing over the mobile device to the second base station.
In a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The first base station that is the handover source performs handover based on profile information that is an index indicating whether or not it is suitable for performing a predetermined service for each service quality information that represents the communication quality of each wireless system. Performing handover candidate selection to select one or more other base stations of the candidate radio system;
The first base station includes service quality information indicating communication quality of each radio system for guaranteeing a service that the mobile station continues to the one or a plurality of other base stations. Send a resource confirmation request, which is a request to secure the resources necessary to continue
The second base station that has received the resource confirmation request determines whether resources for the service corresponding to the service quality information can be secured, and sends a resource confirmation response including the result of the determination to the first base station. To the base station of
When the first base station receives a resource confirmation response indicating that resources can be secured from the second base station, the first base station hands over the mobile station to the second base station. Wireless communication system. In a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The first base station that is the handover source provides a service that indicates the communication quality of each radio system for guaranteeing the service that the mobile station continues to one or more other base stations of the handover candidate radio system. Send a resource confirmation request, which includes quality information and is a request to secure resources necessary for the continuation of the service,
One or more other base stations receiving the resource confirmation request perform a service quality resource confirmation process for calculating the number of flows that can guarantee the requested service quality, and confirm the number of flows that can be guaranteed for the service quality information. Send it to the first base station in a response message,
When the first base station receives a resource confirmation response from the one or more other base stations, the first base station is an index indicating whether or not the first base station is suitable for performing a service, which is predetermined for each service quality information. By weighting the number of received flows to certain profile information, a handover destination metric that is an index as to whether or not it is suitable as a handover destination for each service quality is calculated, and based on the handover destination metric, a handover candidate metric is calculated. A wireless communication system, wherein a handover destination determination for selecting a second base station in a wireless system is performed, and the mobile device is handed over to the second base station.
The service quality information is a service quality class,
The first base station is
A system profile memory that stores, as the profile information, a metric indicating an index as to whether or not each radio system is suitable for performing a service according to each service quality class,
When the first base station performs the handover candidate selection process, the first base station refers to the system profile memory, and a service having a higher priority among service quality classes of one or a plurality of services being performed by the mobile station 4. The wireless communication system according to claim 3, wherein a wireless system having a larger metric value in order of quality class is selected as a handover candidate wireless system. The service quality information is a service quality class,
The second base station is
Corresponding to the service quality class, it has a service quality management memory that stores the communication quality that requires service quality assurance.
The first base station transmits the resource confirmation request including communication quality that requires service quality assurance,
When the second base station receives the resource confirmation request, the second base station refers to the service quality management memory to determine whether the communication quality included in the resource confirmation request can be secured, and the determination result is used as the resource confirmation response. 4. The wireless communication system according to claim 3, wherein the wireless communication system is returned after being included.   The wireless communication system according to claim 3, wherein, when the requested resource can be secured, the second base station reserves and secures the resource until the user actually performs handover. . 8. The base station that reserves resources necessary for continuation of service of quality of service according to the resource confirmation request, cancels the reservation when the user does not actually perform handover for a certain period of time. Wireless communication system.
The service quality information is a service quality class,
The first base station is
A system profile memory that stores, as the profile information, a metric indicating an index as to whether or not each radio system is suitable for performing a service according to each service quality class,
The first base station transmits the resource confirmation request including communication quality that requires service quality assurance,
When the second base station receives the resource confirmation request, the second base station returns a resource confirmation response including the number of resources that can be currently reserved for each quality of service class,
When the first base station performs the handover candidate selection process, the first base station refers to the system profile memory, and the number of flows for which resources can be secured for each service quality class with respect to the base station of each radio system The weighted handover destination metric is calculated in the order of the service quality class with the highest priority among the service quality classes of one or more services being implemented by the mobile station. 5. The radio communication system according to claim 4, wherein the radio system is selected as a handover candidate radio system.   10. The wireless communication system according to claim 9, wherein an index corresponding to a moving speed of a mobile device, a cell radius of a base station, or transmission power is further weighted with respect to a metric used for determining the handover destination. The first base station is
According to the service quality class of the mobile station, equipped with a determination flag memory indicating that only the best effort service is performed,
When the first base station refers to the determination flag memory in the handover execution determination and determines that the mobile station is performing only the best effort service, the corresponding radio system does not perform the resource confirmation request. 5. The wireless communication system according to claim 4, wherein handover is performed to a base station.
  The wireless communication system according to claim 3 or 4, wherein if the service quality resource cannot be secured by the resource confirmation request, the service quality resource is notified of failure in securing the service quality resource. The handover destination base station is selected when triggered by a change in transmission power to the mobile device, or is performed probabilistically as the mobile device approaches the cell boundary of the wireless system base station with which communication is in progress. Item 5. The wireless communication system according to Item 3 or 4.
A base station in a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The base station of the handover source is based on profile information, which is an index indicating whether or not it is suitable for performing a service predetermined for each service quality information indicating the communication quality of each wireless system. Perform handover candidate selection to select one or more other base stations of the wireless system,
The base station includes service quality information indicating communication quality of each wireless system for guaranteeing the service that the mobile station continues to the one or more other base stations, and Send a resource confirmation request, which is a request to secure the necessary resources,
Any of the other base stations that have received the resource confirmation request determines whether resources for the service corresponding to the service quality information can be secured, and sends a resource confirmation response including a result of the determination, If sent to the base station,
When the base station receives a resource confirmation response indicating that resources can be secured from any of the other base stations, the base station hands over the mobile station to the other base station. . A base station in a wireless communication system capable of performing handover without interrupting services between wireless systems using different wireless communication methods or wireless communication standards,
The handover source base station provides service quality information indicating the communication quality of each radio system to guarantee the service that the mobile station continues to one or more other base stations of the handover candidate radio system. A resource confirmation request that is a request for securing resources necessary for the continuation of the service,
One or more other base stations receiving the resource confirmation request perform service quality resource confirmation processing to calculate the number of flows that can guarantee the requested service quality, and confirm the number of flows that can be guaranteed for the service quality information. When included in the response message and transmitted to the base station,
When the base station receives a resource confirmation response from the one or more other base stations, profile information that is an index indicating whether or not the base station is suitable for performing a service is predetermined for each service quality information In addition, by weighting the number of received flows, a handover execution destination metric that is an index as to whether or not the handover execution destination is suitable for each service quality is calculated, and based on the handover execution destination metric, a handover candidate radio system is calculated. A base station that performs a handover execution destination determination for selecting any of the other base stations and hands over the mobile device to any of the other base stations.

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