JP2018139453A - User device and switching control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid simultaneous switching by a plurality of user devices in a technique allowing the user devices to switch connection among a plurality of wireless communication networks.SOLUTION: A user device having a function to switch connection from/to a first wireless communication network to/from a second wireless communication network includes: a congestion state management unit that stores a first congestion level indicating a congestion level of the first wireless communication network and a second congestion level indicating a congestion level of the second wireless communication network; and a switching control unit that retains a first threshold value related to the first congestion level and a second threshold value related to the second congestion level, compares the first congestion level with the first threshold value and also compares the second congestion level with the second threshold value, and thereby determines whether to switch connection from/to the first wireless communication network to/from the second wireless communication network.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a user apparatus and a base station in a mobile communication system, and particularly relates to a technology for switching from communication using one wireless communication network to communication using another wireless communication network.

With the recent spread of smartphones, it is considered to efficiently offload user data from a cellular network (eg, LTE, 3G) to a wireless LAN network (eg, WiFi (registered trademark)) side.
Currently, there is a coordination at the core network (CN) level as one of the coordination methods between the cellular network and the wireless LAN network. However, in order to perform more dynamic coordination, at the radio access network (RAN) level. Cooperation methods are being considered.
Currently, WiFi interworking is being studied as one of the Study Items in 3GPP Rel-12 (Non-patent Document 1: RP-122038).

3GPP TSG-RAN Meeting # 58, RP-122038, Barcelona, Spain, 4-7 December, 2012

  As one of the coordination controls described above, it has been studied to notify the user apparatus UE of the congestion state on the cellular network side and perform load balancing between the wireless LAN network and the cellular network.

  However, when the congestion state is notified to all the connected user apparatuses UE, a large number of user apparatuses UE move to the wireless LAN network or cellular network side at the same time. There is a problem that can not be done. This problem is called the mass toggle problem.

  For example, in a state where a plurality of user apparatuses UE are initially connected to the cellular network, the base station eNB has notified that the base station eNB has been crowded with the user apparatus UE as illustrated in FIG. In this case, a plurality of user apparatuses UE try to connect to a wireless LAN network (such as a WiFi router). Thereafter, in a state where a plurality of user apparatuses UE are connected to the wireless LAN network, as shown in FIG. 1B, when the base station eNB notifies the user apparatus UE that the base station eNB has become free, This time, multiple user devices attempt to connect to the cellular network.

  The present invention has been made in view of the above points, and it is an object of the present invention to prevent a plurality of user devices from switching at the same time in a technique in which a user device switches connections between a plurality of wireless communication networks. To do.

In order to solve the above problem, according to an embodiment of the present invention, a user apparatus including a function of switching connection between a first wireless communication network and a second wireless communication network,
A congestion state management unit for storing a first congestion level indicating a congestion level of the first wireless communication network and a second congestion level indicating a congestion level of the second wireless communication network;
A first threshold value related to the first congestion level and a second threshold value related to the second congestion level are held, the first threshold value and the first congestion level are compared, and the second threshold value and the second congestion value are compared. A switching control unit that determines whether or not connection switching is performed between the first wireless communication network and the second wireless communication network by comparing the level with a level provided by a user device Is done.

Moreover, according to one Embodiment of this invention, It is a user apparatus containing the function to perform connection switching between a 1st wireless communication network and a 2nd wireless communication network,
A congestion state management unit for storing a first congestion level indicating a congestion level of the first wireless communication network and a second congestion level indicating a congestion level of the second wireless communication network;
The first wireless communication network and the second wireless communication network are compared by comparing the predetermined first threshold value with the first congestion level and comparing the predetermined second threshold value with the second congestion level. And a switching control unit that performs the connection switching when the condition continues for a predetermined period of time when it is determined that the condition for switching the connection is satisfied. The

  According to the embodiment of the present invention, it is possible to avoid switching of a plurality of user apparatuses at the same time in the technology in which the user apparatus switches connection between a plurality of wireless communication networks.

It is a figure for demonstrating a subject. It is a system configuration figure in an embodiment of the invention. It is a figure which shows the outline | summary of 1st Embodiment. It is a figure which shows an example of the notification method in the case of notifying a congestion state for every group. It is a functional block diagram of the base station eNB in 1st Embodiment. It is a flowchart which shows the operation example of the base station eNB in 1st Embodiment. It is a flowchart which shows another operation example of the base station eNB in 1st Embodiment. It is a function block diagram of the base station eNB in 2nd Embodiment. It is a function block diagram of the user apparatus UE in 2nd Embodiment. It is a flowchart which shows the operation example of the user apparatus UE in 2nd Embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below is only an example, and the embodiment to which the present invention is applied is not limited to the following embodiment. For example, although the present embodiment is intended for switching between a cellular network and a wireless LAN network, the present invention is applicable to switching between any wireless communication networks other than switching between a cellular network and a wireless LAN network. . Also, the number of wireless communication networks to be switched may be two or more.

  Moreover, although the cellular network in this Embodiment assumes the cellular network based on LTE, a cellular network is not restricted to LTE, For example, 3G may be sufficient. In the present specification and claims, “LTE” includes not only a communication system corresponding to Release 8 or 9 of 3GPP but also a communication system corresponding to Release 10, 11 or 12 of 3GPP. Used in.

(Overview)
In the present embodiment, the user apparatus UE is gradually shifted to the wireless LAN network / cellular network side. Specifically, there are a first embodiment and a second embodiment. In the first embodiment, instead of performing simultaneous signaling from the cellular network to the user equipment UE, the user equipment UE is controlled by gradually signaling the user equipment UE individually or by grouping the user equipment UE. Gradually, the wireless LAN network / cellular network side is changed.
Further, in the second embodiment, a threshold hysteresis is set in the user apparatus UE individually or for each group, and when the user apparatus UE receives information such as a congestion state from the wireless LAN network / cellular network, Start the transition considering the hysteresis. Since each user apparatus UE performs a transition considering each hysteresis, the user apparatus UE can be gradually transitioned to the wireless LAN network / cellular network side. Hereinafter, the first embodiment and the second embodiment will be described in more detail.

(First embodiment)
First, the first embodiment will be described.

<Overall system configuration, processing details, etc.>
FIG. 2 shows a system configuration diagram in the present embodiment. As shown in FIG. 2, the system of the present embodiment includes a cellular network 10 having a base station eNB and a wireless LAN network 20 having a wireless LAN-AP. The cellular network 10 and the wireless LAN network 20 are connected, and communication is possible between the base station eNB and the wireless LAN-AP.
There are a plurality of user apparatuses UE under the control of the base station eNB and the wireless LAN-AP, and each user apparatus UE is based on congestion state information included in a control signal (signaling) notified from the base station eNB. A function of connecting (transitioning) to the station eNB or the wireless LAN-AP is provided. That is, each user apparatus UE communicates using a first wireless communication unit that performs communication using a first wireless communication network (eg, a cellular network) and a second wireless communication network (eg, a wireless LAN network). And a second wireless communication unit for performing connection switching between the first wireless communication network and the second wireless communication network based on congestion state information received from the base station eNB.
In the present embodiment, for example, as illustrated in FIG. 3, the base station eNB groups the connected user apparatus UE into one or a plurality of groups and notifies the user apparatus UE for each group (individual notification). The user apparatus UE is gradually transitioned by gradually notifying the congestion state.

  The notification method may be individual signaling for each user apparatus such as RRC signaling or MAC signaling, or a special RNTI (Radio Network Temporary ID) may be allocated to the user apparatus UE for each group, and notification may be performed using the RNTI. It is good. RNTI is an ID temporarily given for control. For example, the base station eNB assigns subordinate user apparatuses UE to groups A, B, C,. And RNTI-A, RNTI-B, RNTI-C,... To each user equipment UE of each group. Are assigned by individual signaling. And the base station eNB alert | reports the control signal containing RNTI-A to the user apparatus UE, for example, when changing the user apparatus UE group of the group A. The RNTI may be the same for all user apparatuses UE, and special broadcast information may be prepared for each group. In this case, for example, for each group, each user apparatus is notified in advance of the type of broadcast information to be read (eg, SIB type), and each user apparatus UE receives the broadcast information to be read by itself. Information indicating that the information is congested (or vacant) is extracted from the notification information.

  FIG. 4 shows an example of a notification method for notifying the congestion state for each group. As shown in FIG. 4, when a predetermined condition is satisfied, the base station eNB first notifies the group A, and when the condition is satisfied again, the base station eNB notifies the group B after a predetermined period and further satisfies the condition. If this happens, the group C is notified after a predetermined period.

<When to start signaling, when to stop>
In this Embodiment, there exist the following cases 1 and 2 as a trigger which performs the signaling which the base station eNB notifies a congestion state with respect to the user apparatus UE, and a stop, for example.

(1) Case 1
<When to start>
Case 1 is a case of notifying that the base station eNB of the cellular network is congested. When the base station eNB compares the congestion level in the cellular network (which may be referred to as the congestion level of the base station eNB) with a predetermined threshold and determines that the congestion level exceeds the predetermined threshold, the base station eNB Congestion state information indicating that the base station eNB is congested is notified.
Note that the congestion state information in the present embodiment may be a numerical value corresponding to the congestion level, or may be arbitrary information indicating that the congestion is vacant. In addition, this Embodiment can be used in combination with 2nd Embodiment mentioned later, In that case, the congestion state information notified to user apparatus UE is the threshold value etc. in 2nd Embodiment, etc. Use a comparable congestion level value.
The congestion level is, for example, the number of user equipment UEs in the RRC connected state, the number of bearers that are set, the Non-DRX ratio (the ratio of user equipment UEs that are not in the DRX (discontinuous reception) state), the number of UL individual resource settings (UL individual resources) Is the number of user apparatuses UE to which is assigned. The congestion level is not limited to these, and any value may be used as long as it indicates a congestion state. For example, the congestion level may be determined in consideration of not only information related to the UE in the base station eNB but also information received from devices in the cellular network.
Further, the wireless LAN-AP notifies the base station eNB of the congestion level of the wireless LAN network determined based on the number of connections of the user apparatus UE, the resource usage status, and the like via the cellular network (core network). However, it may be determined whether to report the congestion state information in consideration of the congestion level. For example, even when the base station eNB is congested, if the congestion level received from the wireless LAN-AP is equal to or higher than a certain threshold, it is possible to perform control not to notify the user apparatus UE of congestion state information. .

<When to stop>
After starting the notification of the congestion state information, the base station eNB notifies the congestion state information to each group, for example, every predetermined period while the above condition is satisfied. The base station eNB stops the notification of the congestion state information to the user apparatus UE when determining that the congestion level is lower than the predetermined threshold. The specific value of the congestion level is the same as the start trigger. Moreover, the predetermined threshold value in the case of stopping may be the same as or different from the predetermined threshold value at the start opportunity.

  Similarly to the trigger for starting, it may be determined whether to stop the notification in consideration of the congestion level on the wireless LAN network side received from the wireless LAN-AP via the core network.

  In addition, for example, when the user apparatus UE transitions from the cellular network to the wireless LAN network, the user apparatus UE has a function of notifying the base station eNB of the transition, and the base station eNB changes from the cellular network to the wireless LAN network. When the number of transitioning user apparatuses UE reaches a predetermined threshold, it may be determined that further offloading to the wireless LAN network side is not possible, and notification of congestion state information to the user apparatus UE may be stopped. .

(2) Case 2
Case 2 is a case in which the base station eNB notifies / stops notification of congestion state information indicating that the base station eNB has become free (not congested) to the user apparatus UE.

<When to start>
In Case 2, when the base station eNB compares the congestion level with a predetermined threshold and determines that the congestion level is lower than the predetermined threshold, the base station eNB indicates that the user apparatus UE has become free (not congested). The congestion state information shown is notified. The predetermined threshold value here may be the same as or different from the case 1. For example, a threshold value smaller than that in case 1 may be used.

  As in Case 1, the congestion level is, for example, the number of user equipment UEs in the RRC connected state, the number of bearers set, the Non-DRX ratio (the ratio of user equipment UEs not in the DRX (discontinuous reception) state), UL, For example, the number of individual resource settings (the number of user apparatuses UE to which UL individual resources are allocated).

  In addition, the wireless LAN-AP notifies the base station eNB of the congestion level based on the number of connections of the user apparatus UE, the resource usage status, etc. via the cellular network (core network), and the base station eNB takes the congestion level into account. Then, it may be determined whether or not notification is performed. For example, even when the base station eNB is vacant, when the congestion level received from the wireless LAN-AP is equal to or less than a certain threshold value, it is possible to perform control not to notify the user apparatus UE.

<When to stop>
After starting the notification of the congestion state information, the base station eNB notifies the congestion state information to each group, for example, every predetermined period while the above condition is satisfied. The base station eNB stops the notification of the congestion state information to the user apparatus UE when determining that the congestion level exceeds the predetermined threshold. The specific value of the congestion level is the same as the start trigger. In addition, the predetermined threshold value in the case of making it stop may be the same as the predetermined threshold value in a start opportunity, and may differ.

  Similarly to the trigger for starting, it may be determined whether to stop the notification in consideration of the congestion level on the wireless LAN network side received from the wireless LAN-AP via the core network.

  For example, when the user apparatus UE transitions from the wireless LAN network to the cellular network, the user apparatus UE has a function of notifying the base station eNB of the transition, and the base station eNB changes from the wireless LAN network to the cellular network. When the number of transitioned user apparatuses UE reaches a predetermined threshold value, it may be determined that further transition to the cellular network side is not possible, and notification of congestion state information to the user apparatus UE may be stopped.

<Notification priority control>
As described above, in the present embodiment, the base station eNB divides subordinate user apparatuses UE into groups, and notifies the congestion state for each group. One or a plurality of user apparatuses UE belong to the group. As for grouping, for example, without setting a standard, the number of each group may be determined and arbitrarily (randomly) grouped, or priority may be set according to a predetermined standard and grouped for each priority. And the congestion state information may be notified in order of priority. Examples of priorities include the following.

(1) Priority considering the buffer amount The base station eNB determines the user apparatus UE based on the size of the downlink data buffer amount of the user apparatus UE or the size of the uplink data buffer amount notified from the user apparatus UE. Divide into groups. For example, grouping is performed in the order of the buffer size, such as group 1, group 2, group 3,.

  Then, when the cellular network is congested (corresponding to case 1), the base station eNB notifies the congestion state information preferentially (in order from the group) to the group of user apparatuses UE having a large buffer amount, and the wireless LAN Preferential transition to the network.

(2) Priority by service (QoS) The base station eNB groups the user equipment UE based on the quality of service (QoS, which may be referred to as priority) of the service performed by the user equipment UE. . For example, grouping is performed in the order of priority, such as group 1, group 2, group 3,.

  Then, the congestion state information is preferentially notified to the group of user equipment UE that is providing a high priority service, and the state is preferentially shifted to the wireless LAN network.

(3) Priority based on connection time The base station eNB groups the user equipment UE into groups based on the connection time of the user equipment UE (eg, time in the RRC connected state). For example, grouping is performed in the order of long connection time, such as group 1, group 2, group 3,.

  Then, the base station eNB preferentially notifies the congestion state information to the group of user equipment UE having a long connection time, preferentially transits to the wireless LAN network side, and other user equipment UE having a long connection time More resources on the cellular network side can be used.

(4) Penalty user (eg, AMBR target UE or dynamic low class target UE) or priority for charging The base station eNB has a low priority due to a large amount of data being transmitted or received on the cellular network side. The user apparatus UE is set as one or a plurality of groups and is a group having a low priority different from other user apparatuses UE. Then, the base station eNB preferentially offloads the wireless LAN network by notifying the congestion state information to the user apparatus UE of the low priority group.

  On the other hand, in order to make the user apparatus UE having a high priority not belonging to the low priority group use more resources on the cellular network side, the congestion state information indicating that the cellular network is free is preferentially notified. However, the wireless LAN network may be preferentially shifted to the cellular network.

(5) Priority regarding battery The base station eNB groups the user apparatus UE based on the battery state of the user apparatus UE. For example, groups are grouped in the order of the remaining battery power, such as group 1, group 2, group 3,. The battery remaining amount can be grasped by receiving a notification from the user apparatus UE, for example. Further, the base station eNB should estimate the battery consumption (battery holding), the remaining battery level, etc. based on the capability (usage bandwidth, etc.) of the user apparatus UE, the connection time, etc., and should not consume the battery as much as possible. You may group into the order of the user apparatus UE.

  Then, the base station eNB preferentially notifies the congestion state information to a group of user apparatuses UE that have a large degree that it is better to reduce battery consumption, and preferentially transits to the wireless LAN network. That is, since battery saving is possible for the user apparatus UE when it is connected to the wireless LAN network, the user apparatus UE with a poor battery and the user apparatus UE with a small remaining battery are preferentially shifted to the wireless LAN network.

<Apparatus configuration, processing flow>
FIG. 5 shows a functional configuration example of the base station eNB according to the present embodiment. As shown in FIG. 5, the base station eNB includes a DL signal transmission unit 101, a UL signal reception unit 102, a cellular network congestion state management unit 103, a UE group management unit 104, a wireless LAN network congestion state management unit 105, and notification control. Part 106 is included. FIG. 5 shows only functional units particularly related to the embodiment of the present invention in the base station eNB, and is an illustration for performing an operation in accordance with at least a cellular network communication method (eg, LTE method). It also has a function that does not.

  The DL signal transmission unit 101 includes a function of generating various types of physical layer signals from information on higher layers to be transmitted from the base station eNB and transmitting the signals to the user apparatus UE. The UL signal receiving unit 102 includes a function of receiving various uplink signals from the user apparatus UE and acquiring higher layer information from the received physical layer signals.

  The cellular network congestion state management unit 103 includes a functional unit that calculates a congestion level and a storage unit that stores information on the congestion level. As described above, the congestion level is, for example, the number of user apparatuses UE in the RRC connected state, the number of set bearers, the Non-DRX ratio (the ratio of user apparatuses UE that are not in the DRX (discontinuous reception) state), the number of UL individual resource settings. (The number of user equipment UEs to which UL individual resources are allocated).

  The wireless LAN network congestion state management unit 105 includes a functional unit that receives a congestion level in the wireless LAN network from the wireless LAN network via a core network or the like, and a storage unit that stores information on the congestion level.

  The UE group management unit 104 is configured to identify the user apparatus UE located in the base station eNB arbitrarily or in accordance with the above-described priority-based method and the grouped user apparatus UE. Example: RNTI) is allocated, and the identification information is stored for each group. When grouping according to the priority, the identification information indicating the group and the priority may be associated with each other. For example, when the identification information is represented by a number, the lower the number, the higher the priority. Here, the priority may be a priority that is desired to be changed from the cellular network to the wireless LAN network, or may be a priority that is not desired to be changed from the cellular network to the wireless LAN network. Then, for example, the congestion state information is notified to each group in the order of the numbers.

  The notification control unit 106 compares the congestion level of the cellular network stored in the storage unit of the cellular network congestion state management unit 103 with a predetermined threshold value, and further stores it in the storage unit of the wireless LAN network congestion state management unit 105. By comparing the congestion level of the wireless LAN network being used and a predetermined threshold, the UE group management unit 104 performs control to notify the congestion state information for each group of user apparatuses UE grouped.

Hereinafter, an operation example of the base station eNB configured as illustrated in FIG. 5 will be described with reference to FIG. The operation example shown in FIG. 6 is an example in which the congestion level in the wireless LAN network is considered in addition to the congestion level in the cellular network. Moreover, in this example, as shown in FIG. 4, it is an example in the case of notifying another group (if necessary) after a predetermined period has elapsed after notifying the congestion state to a certain group. FIG. 6 shows an operation example related to one notification. In addition, in this example, the user apparatus UE is grouped into groups of group 1 to group k _max .

  First, the notification control unit 106 of the base station eNB sets k = 1 and targets group 1 (step 101). The notification control unit 106 determines whether k is 1 or whether a predetermined period has elapsed since the notification was given to the group k-1 (previous group) (step 102). If the determination result in step 102 is No, the current process ends, and for example, the determination in step 102 is performed again after a certain time.

  When the determination result in step 102 is Yes, the notification control unit 106 determines whether or not the cellular network is congested (step 103). In the example shown in FIG. 6, the notification control unit 106 acquires the congestion level of the cellular network from the cellular network congestion state management unit 103, compares the congestion level with a predetermined threshold, and the congestion level is equal to or higher than the predetermined threshold. If the congestion level is not equal to or higher than the predetermined threshold, it is determined that the congestion is not occurring.

  In addition, if the threshold value for determining that there is no congestion (vacancy) is made smaller than the threshold value for determining that it is congested, and the congestion level is smaller than the threshold value, congestion is present. It may be determined that there is no (free). In this case, there is a case where neither congestion nor non-congestion (vacancy) occurs. In this case, the current process may be terminated and the process may return to step 102.

  If the determination in step 103 is yes, it is determined that the cellular network is congested, and the process proceeds to step 104. In step 104, the notification control unit 106 determines whether the wireless LAN network is congested. In this example, the notification control unit 106 acquires the congestion level of the wireless LAN network from the wireless LAN network congestion state management unit 105, compares the congestion level with a predetermined threshold, and determines whether the congestion level is equal to or higher than the predetermined threshold. Determine if. If the determination result in step 104 is Yes, the current process is terminated, and if the determination result is No, the process proceeds to step 105.

  In step 105, the notification control unit 106 notifies the user apparatus UE belonging to the group k via the DL signal transmission unit 101 of congestion state information indicating that the cellular network is congested. The user apparatus UE belonging to the group k that has received the information makes a transition to the wireless LAN network when connected to the cellular network.

  If the determination in step 103 is No (when it is determined that the cellular network is not congested), the process proceeds to step 106. In step 106, the notification control unit 106 determines whether the wireless LAN network is congested. In this example, the notification control unit 106 acquires the congestion level of the wireless LAN network from the wireless LAN network congestion state management unit 105, compares the congestion level with a predetermined threshold, and determines whether the congestion level is equal to or higher than the predetermined threshold. Determine if. If the determination result in Step 106 is No, the current process is terminated, and if the determination result is Yes, the process proceeds to Step 107.

  In step 107, the notification control unit 106 notifies the user apparatuses UE belonging to the group k of information indicating that the cellular network is not congested (or information indicating that the cellular network is free). When receiving the information, the user apparatus UE belonging to the group k performs a transition to the cellular network when connected to the wireless LAN network.

In step 108 following steps 105 and 107, if k is incremented and k exceeds k _max (Yes in step 109), the process is terminated, and if k does not exceed k _max (No in step 109). Return to step 102.

  In the operation example shown in FIG. 6, both the congestion level of the cellular network and the congestion level of the wireless LAN network are considered, but notification control may be performed in consideration of only the congestion level of the cellular network. Processing in that case will be described with reference to FIG.

  First, the notification control unit 106 of the base station eNB sets k = 1 and targets group 1 (step 201). The notification control unit 106 determines whether k is 1 or whether a predetermined period has elapsed since the notification was given to the group k-1 (previous group) (step 202). If the determination result in step 202 is No, the current process ends, and for example, the determination in step 202 is performed again after a certain time.

  When the determination result in step 202 is Yes, the notification control unit 106 determines whether the cellular network is congested (step 203). In the example illustrated in FIG. 7, the notification control unit 106 acquires the congestion level of the cellular network from the cellular network congestion state management unit 103, compares the congestion level with a predetermined threshold, and the congestion level is equal to or higher than the predetermined threshold. If the congestion level is not equal to or higher than the predetermined threshold, it is determined that the congestion is not occurring.

  In addition, if the threshold value for determining that there is no congestion (vacancy) is made smaller than the threshold value for determining that it is congested, and the congestion level is smaller than the threshold value, congestion is present. It may be determined that there is no (free). In this case, there is a case where neither congestion nor non-congestion (vacancy) occurs. In this case, the current process may be terminated and the process may return to step 202.

  If the determination in step 203 is yes, it is determined that the cellular network is congested, and the process proceeds to step 204. In step 204, the notification control unit 106 notifies the user apparatus UE belonging to the group k via the DL signal transmission unit 101 of information indicating that the cellular network is congested. The user apparatus UE belonging to the group k that has received the information makes a transition to the wireless LAN network when connected to the cellular network. In step 204, when the user apparatus UE acquires congestion state information in the wireless LAN network and the wireless LAN network is congested, the transition to the wireless LAN network may not be performed.

  If the determination in step 203 is No (when it is determined that the cellular network is not congested), the process proceeds to step 205.

  In step 205, the notification control unit 106 notifies the user apparatuses UE belonging to the group k of information indicating that the cellular network is not congested (or information indicating that the cellular network is free). When receiving the information, the user apparatus UE belonging to the group k performs a transition to the cellular network when connected to the wireless LAN network.

In step 206 following steps 204 and 205, k is incremented. If k exceeds k _max , the process is terminated, and if k does not exceed k _max , the process returns to step 202 (step 207).

  As described above, according to the present embodiment, a base station that communicates with a user apparatus having a function of switching a connection between a first wireless communication network and a second wireless communication network, the base station A group management unit (e.g., UE group management unit 104) that divides a plurality of user devices that are present in a plurality of groups, and congestion state information that indicates a congestion state in the first wireless communication network can be divided by the group management unit. And a notification control unit (for example, notification control unit 106) that performs connection switching between the first wireless communication network and the second wireless communication network for each group. Is provided.

  For example, when the notification control unit determines that the first wireless communication network is congested based on a predetermined condition, the notification control unit groups congestion state information indicating that the first wireless communication network is congested. Notification is made every time, and connection switching from the first wireless communication network to the second wireless communication network is performed for each group. In addition, for example, when the notification control unit determines that the first wireless communication network is not congested based on a predetermined condition, congestion state information indicating that the first wireless communication network is not congested For each group, and switching the connection from the second wireless communication network to the first wireless communication network is performed for each group.

With the above configuration, for example, when the cellular network is congested or vacant, the user equipment UE is gradually shifted from the cellular network to the wireless LAN network, or from the wireless LAN network to the cellular network. And the mass toggle problem can be avoided.

  Further, the notification control unit is configured to notify, for each group, congestion state information indicating a congestion state in the first wireless communication network when a congestion state in the second wireless communication network satisfies a predetermined condition. You can also. Thus, by considering both the congestion state of the transition source and the congestion state of the transition destination, for example, it is possible to perform control such that the transition is not performed when the transition destination is congested.

  Further, for example, the group management unit groups the plurality of user devices based on a predetermined priority, and the notification control unit notifies the congestion state information to each group in an order corresponding to the priority. It can also be configured. In this way, by notifying each group of the congestion state information according to the priority, for example, it is possible to preferentially transition the user apparatus UE that should be transitioned from the cellular network to the wireless LAN network first.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. The system configuration in this embodiment is the same as that in the first embodiment, as shown in FIG. In the present embodiment, for example, the base station eNB notifies the user apparatus UE of the congestion state (hereinafter referred to as congestion level) of the cellular network and the wireless LAN network using broadcast information or the like.

  In addition, threshold values for the congestion levels of the cellular network and the wireless LAN network are notified in advance to each user apparatus UE, and each user apparatus UE holds these threshold values. Hereinafter, the threshold value on the wireless LAN network side is set to X, and the threshold value on the cellular network side is set to Y. Note that these threshold values may be notified from the base station eNB or from a predetermined server. For example, those notified by ANDSF (Access Network Discovery & Selection Function) may be used as these thresholds.

  The user apparatus UE should flow U-plane data to the wireless LAN network or the cellular network based on the congestion level of the wireless LAN network, the congestion level of the cellular network, and the threshold value notified in advance (that is, , Which should be connected).

  For example, when the congestion level of the wireless LAN network is below X and the congestion level on the cellular network side exceeds Y, the user apparatus UE transitions to the wireless LAN network side. Further, for example, even when the congestion level on the wireless LAN network side exceeds X, the user apparatus UE performs control to remain connected to the wireless LAN network side when the congestion level on the cellular network side exceeds Y. be able to.

  In the present embodiment, individual hysteresis is provided for each group of user apparatuses UE in the above control. The number of user apparatuses UE included in the group is one or more. Specifically, there are the following Example 1 and Example 2.

(Example 1) Provide Hysteresis of Congestion State For example, in a group of user apparatuses UE, when Hys1 is a hysteresis on the wireless LAN network side and Hys2 is a hysteresis on the cellular network side, these hysteresis are set as the user apparatus UE of the group. In advance. Further, X and Y are notified in advance to the user apparatus UE.

  As an example, if the congestion state on the wireless LAN network side is lower than X-Hys1 and the congestion state on the cellular network side exceeds Y + Hys2, the user apparatuses UE of the group transition to the wireless LAN network side.

  By making Hys1 and / or Hys2 different values for each group, it is possible to gradually transition for each group.

(Example 2) Providing temporal hysteresis In Example 2, a temporal hysteresis is provided, and control is performed such that a transition is forgotten for a predetermined period even if a transition event due to a congestion state is satisfied.

  For example, in a certain group of user apparatuses UE, T is set as a temporal hysteresis, and the hysteresis is notified in advance to the group of user apparatuses UE. Further, X and Y are notified in advance to the user apparatus UE.

  As an example, when the congestion state on the wireless LAN network side is lower than X and the congestion state on the cellular side exceeds Y, the user apparatus UE does not make a transition immediately, and the state continues for a period T. Transition to the wireless LAN network. By setting T to a different value for each group, the transition can be made gradually for each group.

  Example 1 and Example 2 may be combined. For example, control is performed such that the transition to the wireless LAN network is performed only when the state satisfying the condition for transitioning to the wireless LAN network side in the determination in Example 1 continues for the period T in Example 2.

  The “hysteresis” in the present embodiment is a value for adjusting the threshold value, and may be referred to as a “threshold adjustment value”.

<Device configuration example, processing flow example>
In this Embodiment, the main body which notifies hysteresis to the user apparatus UE is not specifically limited, For example, you may notify from a predetermined | prescribed server and may notify from the base station eNB. That is, the user apparatus UE may receive hysteresis from the cellular network or may receive hysteresis from the wireless LAN network. The same applies to the threshold value described above, and the user apparatus UE may receive the threshold value from the cellular network or the threshold value from the wireless LAN network.

  Moreover, the subject that notifies the user apparatus UE of the congestion levels of the cellular network and the wireless LAN network is not particularly limited, and may be notified from a predetermined server or from the base station eNB, for example. That is, the user apparatus UE may receive the congestion level between the cellular network and the wireless LAN network from the cellular network, or may receive from the wireless LAN network.

  FIG. 8 shows an example of the functional configuration of the base station eNB when notifying the hysteresis and the congestion level between the cellular network and the wireless LAN network from the base station eNB.

  As illustrated in FIG. 8, the base station eNB includes a DL signal transmission unit 201, a UL signal reception unit 202, a cellular network congestion state management unit 203, a UE group management unit 204, a wireless LAN network congestion state management unit 205, and a notification control unit. 206 is included. FIG. 8 shows only functional units that are particularly related to the embodiment of the present invention in the base station eNB, and is an illustration for performing an operation that conforms to at least a cellular network communication system (eg, LTE system). It also has a function that does not.

  The DL signal transmission unit 201 includes a function of generating various types of physical layer signals from information on higher layers to be transmitted from the base station eNB and transmitting the signals to the user apparatus UE. The UL signal receiving unit 202 includes a function of receiving various uplink signals from the user apparatus UE and acquiring higher layer information from the received physical layer signals.

  The cellular network congestion state management unit 203 includes a functional unit that calculates the congestion level of the cellular network and a storage unit that stores information on the congestion level. As described above, the congestion level includes the number of user equipment UEs in the RRC connected state, the number of bearers set, the non-DRX ratio (the ratio of user equipment UEs not in the DRX (discontinuous reception) state), the number of UL individual resource settings (UL). The number of user apparatuses UE to which individual resources are allocated).

  The wireless LAN network congestion state management unit 205 includes a functional unit that receives a congestion level in the wireless LAN network from the wireless LAN network via a core network or the like, and a storage unit that stores information on the congestion level.

  The UE group management unit 204 groups the user apparatuses UE located in the base station eNB arbitrarily or by the method based on the priority described in the first embodiment, and the grouping It includes a storage unit that assigns hysteresis to each user apparatus UE and stores the hysteresis for each group. The notification control unit 206 performs control for notifying hysteresis for each group of user apparatuses UE grouped by the UE group management unit 206, and the cellular network congestion state management unit 203 and wireless LAN network congestion for each user apparatus UE. Control to notify the congestion level managed by the state management unit 205 is performed.

  Note that the UE group management unit 204 can determine the hysteresis in accordance with, for example, the priority level of transition from the cellular network to the wireless LAN network. For example, in Example 1, for a group that has a high priority level for transition from the cellular network to the wireless LAN network (a group that is to be preferentially transitioned from the cellular network to the wireless LAN network), Hys1 and Hys2 are reduced, and the cellular network Hys1 and Hys2 are increased for a group with a low priority to be transferred from to the wireless LAN network.

  Further, in Example 2, for a group having a high priority level for transition from the cellular network to the wireless LAN network (group to be preferentially transitioned from the cellular network to the wireless LAN network), T is decreased and the cellular network is wirelessly transmitted. T is increased for a group with a low priority to be transferred to the LAN network.

  Further, the notification control unit 206 may have a function of notifying the user apparatus UE of threshold values (X and Y described above). In addition, the notification control unit 206 may have a function of notifying the user apparatus UE of threshold values (X-Hys1, Y + Hys2, etc., referred to as “adjusted threshold values”) adjusted for each group. In the latter case, the user apparatus UE performs comparison with the congestion level using the adjusted threshold value received from the base station eNB.

  FIG. 9 shows a functional configuration example of the user apparatus UE according to the present embodiment. The example shown in FIG. 9 is an example when both the congestion level and the hysteresis are received from the base station eNB.

  As illustrated in FIG. 9, the user apparatus UE includes a cellular communication function unit 310 and a wireless LAN communication function unit 320. The cellular communication function unit 310 includes a DL signal reception unit 311, a UL signal transmission unit 312, a cellular network congestion state management unit 313, a wireless LAN network congestion state management unit 314, and a switching control unit 315. Note that FIG. 9 shows only functional units particularly relevant to the present invention in the user apparatus UE, and also has a function (not shown) for performing an operation based on at least a cellular system such as the LTE system.

  The cellular communication function unit 310 is a function unit for performing wireless communication by a cellular method (eg, LTE), and the wireless LAN communication function unit 320 is a function unit for performing communication by a wireless LAN.

  The DL signal receiving unit 311 in the cellular communication function unit 310 includes a function of receiving various downlink signals from the base station eNB and acquiring higher layer information from the received physical layer signal, and transmitting UL signals. Unit 312 includes a function of generating various signals of the physical layer from information on higher layers to be transmitted from user apparatus UE and transmitting the signals to base station eNB.

  The cellular network congestion state management unit 313 includes a functional unit that receives the congestion level of the cellular network from the base station eNB via the DL signal reception unit 311 and a storage unit that stores the received congestion level. The congestion level stored in the storage unit is sequentially updated.

  The wireless LAN network congestion state management unit 314 includes a functional unit that receives the congestion level of the wireless LAN network from the base station eNB via the DL signal reception unit 311 and a storage unit that stores the received congestion level. The congestion level stored in the storage unit is sequentially updated.

  The switching control unit 315 includes a storage unit that holds threshold values notified from the base station eNB and the like (corresponding to X and Y described above) and hysteresis notified from the base station eNB and the like, and also includes the threshold value, hysteresis, and cellularity. Based on the congestion level of the cellular network and the congestion level of the wireless LAN network managed by the network congestion state management unit 313 and the wireless LAN network congestion state management unit 314, switching from the cellular network to the wireless LAN network is performed. A function for controlling switching to the cellular network is provided. Note that, as described above, the switching control unit 315 may receive and store a threshold value (adjusted threshold value) after adjustment with hysteresis from the base station eNB or the like, in which case the switching control unit 315 Comparison with the congestion level is performed using the adjusted threshold value.

  Hereinafter, with reference to FIG. 10, an operation example of the user apparatus UE configured as illustrated in FIG. 9 will be described. In this example, the above-described X and Y are used as thresholds, Hys1 and Hys3 are used as hysteresis relating to the threshold on the wireless LAN network side, and Hys2 and Hys4 are used as hysteresis relating to the threshold value on the cellular network side, as described in Example 2. Use T as temporal hysteresis. Hys1 is larger than Hys3, and the relationship between Hys2 and Hys4 is arbitrary. FIG. 10 shows an operation for one time of the transition determination process performed at regular intervals, for example.

  In step 301, the switching control unit 315 of the user apparatus UE determines whether the congestion level on the wireless LAN network side is less than (less than) X-Hys1. When the congestion level on the wireless LAN network side is lower than X-Hys1 (Yes in step 301), the process proceeds to step 302, and the switching control unit 315 of the user apparatus UE determines whether or not the congestion level on the cellular network side exceeds Y + Hys2. To do. If the determination in step 302 is No, the process is terminated, and if the determination is Yes, the process proceeds to step 303.

  In step 303, the switching control unit 315 of the user apparatus UE determines whether or not the current state (a state in which steps 301 and 302 are Yes) continues for the period T. If the determination in step 303 is No, the process ends. If the determination is Yes, the process proceeds to step 304. In step 304, the switching control unit 315 of the user apparatus UE makes a transition from the cellular network to the wireless LAN network when currently connected to the cellular network.

  In step 301, when the congestion level on the wireless LAN network side is X-Hys1 or higher (No in step 301), the process proceeds to step 305, and the switching control unit 315 of the user apparatus UE sets the congestion level on the wireless LAN network side to X- It is determined whether or not Hys3 is exceeded. If the determination in step 305 is No, the process ends. If yes, the process proceeds to step 306.

  In step 306, the switching control unit 315 of the user apparatus UE determines whether or not the congestion level on the cellular network side is lower than Y + Hys4. If the determination in step 306 is No, the process ends. If yes, the process proceeds to step 307.

  In step 307, the switching control unit 315 of the user apparatus UE determines whether or not the current state (the state in which step 301 is No, 305 and 306 are Yes) continues for the period T. If the determination in step 307 is NO, the process ends. If yes, the process proceeds to step 308. In step 308, the switching control unit 315 of the user apparatus UE makes a transition from the wireless LAN network to the cellular network when currently connected to the wireless LAN network.

  In addition, although the example shown in FIG. 10 is an example in the case of using Hys with respect to the threshold and temporal T, only one of them may be used.

  As described above, according to the present embodiment, the user apparatus includes a function of switching connection between the first wireless communication network and the second wireless communication network, the first wireless communication network or the first wireless communication network. A congestion state management unit (for example, a cellular network) that receives a first congestion level indicating the congestion level of the first wireless communication network and a second congestion level indicating the congestion level of the second wireless communication network from the two wireless communication networks; A congestion state management unit 313 and a wireless LAN network congestion state management unit 314), a first threshold value related to the first congestion level, and a second threshold value related to the second congestion level, and a predetermined first threshold adjustment value By comparing the first threshold value after adjustment and the first congestion level, and comparing the second threshold value after adjustment by a predetermined second threshold adjustment value and the second congestion level, With the first wireless communication network It determines switching control unit whether to perform connection switching between the serial second wireless communication network: a user equipment and a (eg switching control unit 315) is provided.

  In addition, according to the present embodiment, the user apparatus includes a function of switching connection between the first wireless communication network and the second wireless communication network, the first wireless communication network or the second wireless communication. A congestion state management unit (for example, cellular network congestion state management) that receives a first congestion level indicating the congestion level of the first wireless communication network and a second congestion level indicating the congestion level of the second wireless communication network from the network Unit 313 and wireless LAN network congestion state management unit 314), comparing the predetermined first threshold value with the first congestion level, and comparing the predetermined second threshold value with the second congestion level, Switching control for performing connection switching when it is determined that a condition for performing connection switching between the first wireless communication network and the second wireless communication network is satisfied and the condition continues for a predetermined period. Part (example: off) The user device includes a control unit 315) and the place is provided.

  As described above, each user apparatus UE performs comparison with the threshold in consideration of individually set hysteresis (first threshold adjustment value, second adjustment value, predetermined period), so that the user apparatus gradually The UE can be transitioned from the cellular network to the wireless LAN network, or from the wireless LAN network to the cellular network, and the mass toggle problem can be avoided.

The specification discloses at least the following matters.
(Section 1)
A base station that communicates with a user apparatus having a function of switching a connection between a first wireless communication network and a second wireless communication network,
A group management unit that divides a plurality of user devices residing in the base station into a plurality of groups;
Congestion state information indicating a congestion state in the first wireless communication network is notified for each group divided by the group management unit, and for each group, between the first wireless communication network and the second wireless communication network. And a notification control unit for switching connections between the base stations.
(Section 2)
When the notification control unit determines that the first wireless communication network is congested based on a predetermined condition, the notification control unit displays congestion state information indicating that the first wireless communication network is congested for each group. The base station according to claim 1, wherein the base station is notified, and connection switching from the first wireless communication network to the second wireless communication network is performed for each group.
(Section 3)
When the notification control unit determines that the first wireless communication network is not congested based on a predetermined condition, the notification control unit displays congestion state information indicating that the first wireless communication network is not congested for each group. The base station according to claim 1 or 2, wherein notification is made and connection switching from the second wireless communication network to the first wireless communication network is performed for each group.
(Section 4)
The notification control unit notifies, for each group, congestion state information indicating a congestion state in the first wireless communication network when a congestion state in the second wireless communication network satisfies a predetermined condition. 4. The base station according to any one of items 1 to 3.
(Section 5)
The group management unit divides the plurality of user devices into groups based on a predetermined priority, and the notification control unit notifies each group of congestion state information in an order corresponding to the priority. The base station according to any one of Items 1 to 4.
(Section 6)
A user device including a function of switching connection between a first wireless communication network and a second wireless communication network,
A first congestion level indicating the congestion level of the first wireless communication network and a second congestion level indicating the congestion level of the second wireless communication network are received from the first wireless communication network or the second wireless communication network. A congestion state management unit;
A first threshold value related to the first congestion level and a second threshold value related to the second congestion level are held, and the first threshold value after adjustment by a predetermined first threshold adjustment value is compared with the first congestion level. And connecting the first wireless communication network and the second wireless communication network by comparing the second threshold value after adjustment with a predetermined second threshold adjustment value and the second congestion level. A user device comprising: a switching control unit that determines whether or not to perform switching.
(Section 7)
A user device including a function of switching connection between a first wireless communication network and a second wireless communication network,
A first congestion level indicating the congestion level of the first wireless communication network and a second congestion level indicating the congestion level of the second wireless communication network are received from the first wireless communication network or the second wireless communication network. A congestion state management unit;
The first wireless communication network and the second wireless communication network are compared by comparing the predetermined first threshold value with the first congestion level and comparing the predetermined second threshold value with the second congestion level. And a switching control unit that performs connection switching when the condition continues for a predetermined period when it is determined that the condition for performing connection switching is satisfied.
(Section 8)
A congestion state notification control method executed by a base station that communicates with a user apparatus having a function of switching a connection between a first wireless communication network and a second wireless communication network,
A group dividing step of dividing a plurality of user devices residing in the base station into a plurality of groups;
Congestion state information indicating a congestion state in the first wireless communication network is notified for each group divided by the group dividing step, and for each group, between the first wireless communication network and the second wireless communication network. And a step of switching connections between them. A congestion state notification control method comprising:
(Section 9)
A switching control method executed by a user device including a function of switching connection between a first wireless communication network and a second wireless communication network,
A first congestion level indicating the congestion level of the first wireless communication network and a second congestion level indicating the congestion level of the second wireless communication network are received from the first wireless communication network or the second wireless communication network. Steps,
A first threshold value related to the first congestion level and a second threshold value related to the second congestion level are acquired, and the first threshold value after being adjusted by a predetermined first threshold adjustment value is compared with the first congestion level. And connecting the first wireless communication network and the second wireless communication network by comparing the second threshold value after adjustment with a predetermined second threshold adjustment value and the second congestion level. And a step of determining whether or not to perform switching.
(Section 10)
A switching control method executed by a user device including a function of switching connection between a first wireless communication network and a second wireless communication network,
A first congestion level indicating the congestion level of the first wireless communication network and a second congestion level indicating the congestion level of the second wireless communication network are received from the first wireless communication network or the second wireless communication network. Steps,
The first wireless communication network and the second wireless communication network are compared by comparing the predetermined first threshold value with the first congestion level and comparing the predetermined second threshold value with the second congestion level. And switching the connection when the condition continues for a predetermined period when it is determined that the condition for switching the connection is satisfied.

  Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various variations, modifications, alternatives, substitutions, and the like. Will. Although specific numerical examples have been described in order to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified. The classification of items in the above description is not essential to the present invention, and the items described in two or more items may be used in combination as necessary, or the items described in one item may be used in different items. It may be applied to the matters described in (if not inconsistent). The boundaries between functional units or processing units in the functional block diagram do not necessarily correspond to physical component boundaries. The operations of a plurality of functional units may be physically performed by one component, or the operations of one functional unit may be physically performed by a plurality of components. For convenience of explanation, the user apparatus UE and the base station eNB have been described using functional block diagrams. However, each such apparatus may be realized by hardware, software, or a combination thereof. Software operating in accordance with the present invention includes random access memory (RAM), flash memory, read only memory (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server and other suitable It may be stored in any storage medium. The present invention is not limited to the above embodiments, and various modifications, modifications, alternatives, substitutions, and the like are included in the present invention without departing from the spirit of the present invention.

eNB base station UE user apparatus 101, 201 DL signal transmission unit 102, 202 UL signal reception unit 103, 203 cellular network congestion state management unit 104, 204 UE group management unit 105, 205 wireless LAN network congestion state management unit 106, 206 notification Control unit 310 Cellular communication function unit 320 Wireless LAN communication function unit 311 DL signal reception unit 312 UL signal transmission unit 313 Cellular network congestion state management unit 314 Wireless LAN network congestion state management unit 315 Switching control unit

Claims (4)

A user device including a function of switching connection between a first wireless communication network and a second wireless communication network,
A congestion state management unit for storing a first congestion level indicating a congestion level of the first wireless communication network and a second congestion level indicating a congestion level of the second wireless communication network;
A first threshold value related to the first congestion level and a second threshold value related to the second congestion level are held, the first threshold value and the first congestion level are compared, and the second threshold value and the second congestion value are compared. A user apparatus comprising: a switching control unit that determines whether or not to perform connection switching between the first wireless communication network and the second wireless communication network by comparing levels. A user device including a function of switching connection between a first wireless communication network and a second wireless communication network,
A congestion state management unit for storing a first congestion level indicating a congestion level of the first wireless communication network and a second congestion level indicating a congestion level of the second wireless communication network;
The first wireless communication network and the second wireless communication network are compared by comparing the predetermined first threshold value with the first congestion level and comparing the predetermined second threshold value with the second congestion level. And a switching control unit that performs connection switching when the condition continues for a predetermined period when it is determined that the condition for performing connection switching is satisfied. A switching control method executed by a user device including a function of switching connection between a first wireless communication network and a second wireless communication network,
Storing a first congestion level indicating a congestion level of the first wireless communication network and a second congestion level indicating a congestion level of the second wireless communication network in a storage unit;
A first threshold value related to the first congestion level and a second threshold value related to the second congestion level are acquired, the first threshold value and the first congestion level are compared, and the second threshold value and the second congestion level are compared. Determining whether or not connection switching is performed between the first wireless communication network and the second wireless communication network by comparing the level. A switching control method executed by a user device including a function of switching connection between a first wireless communication network and a second wireless communication network,
Storing a first congestion level indicating a congestion level of the first wireless communication network and a second congestion level indicating a congestion level of the second wireless communication network in a storage unit;
The first wireless communication network and the second wireless communication network are compared by comparing the predetermined first threshold value with the first congestion level and comparing the predetermined second threshold value with the second congestion level. And switching the connection when the condition continues for a predetermined period when it is determined that the condition for switching the connection is satisfied.

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