JP6457244B2 - User device and dual connectivity communication method - Google Patents

Description

  The present invention relates to a wireless communication system.

  Currently, the 3rd Generation Partnership Project (3GPP) is proceeding with the formulation of specifications to improve the functionality of LTE-Advanced as the next generation communication standard of LTE (Long Term Evolution). In the LTE-Advanced system, carrier aggregation (CA) technology is introduced in order to achieve a throughput higher than that of the LTE system while ensuring backward compatibility with the LTE system. In carrier aggregation, a component carrier (CC) having a maximum bandwidth of 20 MHz supported by the LTE system is used as a basic component, and by using these multiple component carriers at the same time, wider bandwidth communication is realized. It is planned to do.

  In carrier aggregation up to LTE Release 10 (Rel-10), it is stipulated that user equipment (User Equipment: UE) communicates simultaneously using a plurality of component carriers provided by the same base station (evolved NodeB: eNB). It was done. On the other hand, in Rel-12, the carrier aggregation of Rel-10 is further expanded, and dual connectivity (Dual Connectivity: DC) in which a user apparatus performs simultaneous communication using a plurality of component carriers provided by a plurality of base stations is considered. ing. For example, when all the component carriers cannot be accommodated in a single base station, it is considered that dual connectivity is effectively used in order to achieve the same throughput as Rel-10.

R2-144560

  In order to use the dual connectivity, the user apparatus needs to notify the base station of capability information (Capability) indicating that the dual connectivity is supported. Specifically, as shown in FIG. 1, is this capability information capable of synchronous operation (Sync) for each combination as well as combinations (DC configuration) of dual connectivity component carriers supported by the user equipment? It also indicates whether synchronous and asynchronous operations (Sync + Async) are possible.

  For example, the DC configuration “DC_xA-yA” in FIG. 1 indicates that the user apparatus supports dual connectivity by a combination of one carrier in band x and one carrier in band y, and the combination is synchronized. “Sync = 1” is set when the inter-band dual connectivity is supported, and “Sync + Async = 1” is set when the synchronous and asynchronous inter-band dual connectivity is supported. Similarly, the DC configuration “DC_xA-xA” indicates that the user equipment supports dual connectivity with a combination of two discontinuous carriers in band x, and the DC configuration “DC_xC” indicates the user equipment. Indicates that dual connectivity by a combination of two consecutive carriers in band x is supported. In addition, the DC configuration “DC_xA-yA-zA” supports dual connectivity in which the user apparatus combines one carrier in band x, one carrier in band y, and one carrier in band z. It shows that. When the combination of these three component carriers corresponds to the synchronous inter-band dual connectivity, “Sync = 1” is set, while the combination indicates that the combination corresponds to the synchronous and asynchronous inter-band dual connectivity. The rules are not currently defined (Not defined).

  The provision of notifying capability information regarding a combination of three or more component carriers, except for the availability of synchronous inter-band dual connectivity for the combination of the above three component carriers “DC_xA-yA-zA” Not defined. For this reason, in order to realize dual connectivity with three or more component carriers, it is necessary to provide provisions for notifying capability information regarding combinations of three or more component carriers.

  In dual connectivity using a combination of three or more component carriers, it is necessary to notify which cell group each component carrier belongs to. For example, when performing dual connectivity in bands x, y, and z, as shown in FIG. 2, band x belongs to cell group 1, and bands y and z belong to cell group 2, and bands x, Case 2 where y belongs to cell group 1 and band z belongs to cell group 2 is considered. Depending on the user equipment, only case 1 can be synchronous and asynchronous dual connectivity, and case 2 can only be synchronous dual connectivity. That the entire band x, y, z supports synchronous dual connectivity or synchronous and asynchronous dual connectivity can be represented by the above-mentioned provisions relating to "DC_xA-yA-zA". Perhaps these two cases cannot be distinguished.

  In order to distinguish these cases, it is also conceivable to define additional capability information for notifying which cell group each carrier belongs to. However, there is a concern about an increase in the amount of signaling required to notify such additional capability information.

  In view of the above-described problems, an object of the present invention is to provide a technique for efficiently notifying capability information for dual connectivity by three or more component carriers.

  In order to solve the above problems, an aspect of the present invention is a user apparatus having a dual connectivity function, a wireless communication control unit that controls wireless communication with a base station, and a capability of notifying the base station of capability information An information notification unit, and the capability information notification unit includes higher-level capability information related to a combination of component carriers composed of three or more component carriers supported by the user apparatus in dual connectivity, and a combination of the component carriers. The present invention relates to a user apparatus that notifies lower capability information about a subset.

  Another aspect of the present invention is a dual connectivity communication method by a base station, which is higher capability information regarding a combination of component carriers composed of three or more component carriers supported by the user device in dual connectivity from the user device. Receiving lower capability information about a subset of the combination of component carriers, and synchronous dual connectivity or synchronous between any of the three or more component carriers based on the received lower capability information And determining whether or not asynchronous dual connectivity is possible, and based on the determination, the synchronous dual connectivity or the synchronous and asynchronous dual connectivity Set the combination of fit of component carriers to the user equipment, a dual connectivity communication method and a step of performing scheduling for dual connectivity to the user equipment.

  According to the present invention, capability information for dual connectivity by three or more component carriers can be notified efficiently.

FIG. 1 is a diagram illustrating an example of UE capability notification for dual connectivity. FIG. 2 is a schematic diagram illustrating a synchronous / asynchronous relationship between carriers in a dual connectivity configuration. FIG. 3 is a schematic diagram illustrating a wireless communication system according to an embodiment of the present invention. FIG. 4 is a block diagram illustrating a configuration of a user apparatus according to an embodiment of the present invention. FIG. 5 is a schematic diagram illustrating an example of UE capability notification according to an embodiment of the present invention. FIG. 6 is a schematic diagram illustrating an example of UE capability notification according to an embodiment of the present invention. FIG. 7 is a schematic diagram illustrating an example of UE capability notification according to an embodiment of the present invention. FIG. 8 is a schematic diagram illustrating an example of UE capability notification according to an embodiment of the present invention. FIG. 9 is a schematic diagram illustrating an example of UE capability notification according to an embodiment of the present invention. FIG. 10 is a flowchart showing a dual connectivity communication process by the base station according to one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In the following embodiments, a user apparatus having a dual connectivity function is disclosed. When an embodiment described later is outlined, when a user apparatus supports dual connectivity by a combination of three or more component carriers, higher capability information indicating the combination of the component carriers (DC configuration), and the combination By notifying the lower-level capability information related to a subset of the base station, the capability information related to the combination of the component carriers is notified to the base station. The base station can determine, based on the upper capability information and the lower capability information, between which component carrier of the DC configuration is capable of synchronous dual connectivity or synchronous and asynchronous dual connectivity, Based on this determination, it is possible to execute scheduling for the user apparatus. This makes it possible to realize dual connectivity communication using three or more component carriers without defining and signaling new capability information for a combination of three or more component carriers.

  First, a radio communication system according to an embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic diagram illustrating a wireless communication system according to an embodiment of the present invention.

  As illustrated in FIG. 3, the wireless communication system 10 includes a user device 100 and base stations 200A and 200B. The radio communication system 10 supports dual connectivity in which the user apparatus 100 performs simultaneous communication using component carriers CC # 1 and CC # 2 provided by a plurality of base stations 200A and 200B. As illustrated, the user apparatus 100 communicates between a master base station (MeNB) 200A and a secondary base station (SeNB) 200B using a dual connectivity function. In the illustrated embodiment, only two component carriers CC # 1 and CC # 2 are shown, but as will be described later, three or more component carriers may be used. Although only two base stations 200A and 200B are shown, in general, a large number of base stations 200 are arranged to cover the service area of the radio communication system 10.

  The user apparatus 100 has a dual connectivity function for simultaneous communication with a plurality of base stations 200A and 200B. Typically, the user apparatus 100 may be any appropriate information processing apparatus having a wireless communication function, such as a smartphone, a mobile phone, a tablet, or a mobile router, as illustrated. The user apparatus 100 includes a CPU (Central Processing Unit) such as a processor, a memory apparatus such as a RAM (Random Access Memory) and a flash memory, a wireless communication apparatus for transmitting and receiving radio signals to and from the base stations 200A and 200B, and the like. Composed. For example, each function and process of the user device 100 described later may be realized by the CPU processing or executing data or a program stored in the memory device. However, the user apparatus 100 is not limited to the hardware configuration described above, and may be configured by a circuit that realizes one or more of the processes described below.

  Base stations 200 </ b> A and 200 </ b> B (hereinafter may be collectively referred to as base station 200) are networks such as upper stations and servers that are connected to a core network (not shown) by wireless connection with user apparatus 100. The downlink (DL) packet received from the device is transmitted to the user device 100, and the uplink (UL) packet received from the user device 100 is transmitted to the network device. In the illustrated embodiment, the base station 200A functions as a master base station (MeNB) or a primary base station, and the base station 200B functions as a secondary base station (SeNB). In dual connectivity, the master base station 200A controls simultaneous communication between the user apparatus 100 and the base stations 200A and 200B by dual connectivity and also controls communication with a higher-level core network (not shown). .

  Next, a user apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a block diagram illustrating a configuration of a user apparatus according to an embodiment of the present invention.

  As illustrated in FIG. 4, the user device 100 includes a wireless communication control unit 110 and a capability information notification unit 120.

  The wireless communication control unit 110 controls wireless communication with the base station 200. Specifically, the radio communication control unit 110 transmits and receives various radio channels such as an uplink / downlink control channel and an uplink / downlink data channel between the master base station 200A and the secondary base station 200B, Dual connectivity communication is performed in which a plurality of component carriers provided by the master base station 200A and the secondary base station 200B are simultaneously used to communicate with the master base station 200A and the secondary base station 200B.

  The capability information notification unit 120 notifies the base station 200 of capability information. In typical dual connectivity, the capability information is notified to the master base station 200A. Furthermore, the capability information notification unit 120 includes upper capability information regarding a combination of component carriers composed of three or more component carriers supported by the user apparatus 100 in dual connectivity, and lower capability information regarding a subset of the combination of component carriers, To be notified.

  In one embodiment, the lower capability information may include capability information related to a pair of component carriers constituting a combination of component carriers. Specifically, the capability information notification unit 120 includes a combination of component carriers (DC configuration) “DC_xA-yA-zA” including three component carriers as higher capability information, and a subset “DC_xA− of the component carrier. The base station 200 may be notified of the lower capability information regarding “yA”, “DC_xA-zA”, and “DC_yA-zA”.

  As an example, the user apparatus 100 supports dual connectivity by a combination of one carrier in band 1 (B1), one carrier in band 3 (B3), and one carrier in band 5 (B5). It is assumed that a synchronous operation (Sync) between carriers as shown in FIG. 5 and a synchronous and asynchronous operation (Sync + Async) are supported. At this time, the capability information notification unit 120 includes the higher capability information including the DC configuration “DC_1A-3A-5A” and the lower capability information “DC_1A-3A: Sync”, “DC_1A-5A: Sync + Async” regarding the three subsets, and “DC — 3A-5A: Sync + Async” is notified to the base station 200. When receiving the capability information, the base station 200 determines that the user apparatus 100 is based on the combination of component carriers as shown in FIG. 5 and the synchronization relationship between the component carriers based on the received higher capability information and lower capability information. It can be determined that connectivity communication is possible.

  As another example, the user apparatus 100 supports dual connectivity by a combination of two consecutive carriers in band 1 (B1) and one carrier in band 5 (B5), and the carrier as shown in FIG. Assume that synchronous operation (Sync) and synchronous and asynchronous operation (Sync + Async) are supported. At this time, the capability information notification unit 120 receives the higher capability information including the DC configuration “DC_1C-5A” and the lower capability information “DC_1C: Sync” and “DC_1A-5A: Sync + Async” regarding the two subsets from the base station 200. Notify When the capability information is received, the base station 200 determines that the user apparatus 100 is based on the combination of component carriers as shown in FIG. 6 and the synchronization relationship between the component carriers based on the received higher capability information and lower capability information. It can be determined that connectivity communication is possible.

  As yet another example, the user apparatus 100 supports dual connectivity by a combination of three consecutive carriers in the band 40 (B40), and is synchronized with the synchronization operation (Sync) between carriers as shown in FIG. Assume that asynchronous operation (Sync + Async) is supported. Here, the user apparatus 100 may be considered to be capable of synchronous and asynchronous operation (Sync + Async) with any combination of two consecutive component carriers in the band 40. At this time, the capability information notification unit 120 notifies the base station 200 of higher capability information including the DC configuration “DC_40D” and lower capability information “DC_40C: Sync + Async” regarding one subset. When receiving the capability information, the base station 200 determines that the user apparatus 100 has a dual based on the combination of component carriers and the synchronization relationship between the component carriers as shown in FIG. 7 based on the received higher capability information and lower capability information. It can be determined that connectivity communication is possible.

  As yet another example, the user apparatus 100 supports dual connectivity by combining one carrier of band 5 (B5) and three consecutive carriers of band 40 (B40), as shown in FIG. It is assumed that a synchronous operation (Sync) between carriers and a synchronous and asynchronous operation (Sync + Async) are supported. Here, it is assumed that the user apparatus 100 can perform a synchronization operation (Sync) with any combination of two consecutive component carriers in the band 40. At this time, the capability information notification unit 120 receives the upper capability information including the DC configuration “DC_5A-40D” and the lower capability information “DC_5A-40A: Sync + Async” and “DC_40C: Sync” regarding the two subsets from the base station 200. Notify When the capability information is received, the base station 200 determines that the user apparatus 100 is based on the combination of component carriers as shown in FIG. 8 and the synchronization relationship between the component carriers based on the received higher capability information and lower capability information. It can be determined that connectivity communication is possible.

  In one embodiment, the capability information notification unit 120 may further notify an indicator indicating that the lower capability information should be referred to for the upper capability information. When receiving the indicator, the base station 200 can easily recognize that the lower capability information related to the higher capability information has been notified, and the base station 200 uses the lower capability information for the combination of component carriers for which dual connectivity is set. The corresponding dual connectivity communication can be scheduled.

  In one embodiment, the capability information notification unit 120 further indicates that if all of the subsets of the combination of component carriers are dual-connectable, it is possible to map all of the subsets to cell groups (full fallback). You may notify the indicator which shows. This makes it possible to reduce signaling overhead.

  In one embodiment, the capability information notification unit 120 uses a subset of component carrier combinations for in-band dual connectivity (Intra-band DC) based on a combination of component carriers (class D) including three or more component carriers. When any one corresponds to the synchronization operation, it may be notified that all the combinations of the component carriers in the band are compatible with the synchronization operation. For example, as described above with reference to FIG. 8, when the combination of component carriers indicated by the inner broken line in the band 40 corresponds to the synchronization operation (Sync), the capability information notification unit 120 A combination of component carriers indicated by a broken line may be regarded as corresponding to the synchronization operation (Sync), and “DC — 40D: Sync” may be notified to the base station 200.

  Similarly, the capability information notification unit 120 is one of the subsets of the combination of component carriers for in-band dual connectivity (Intra-band DC) based on a combination of component carriers (class D) composed of three or more component carriers. When one corresponds to synchronous and asynchronous operation (Sync + Async), it may be notified that all combinations of component carriers in the band support synchronous and asynchronous operation (Sync + Async). For example, as described above with reference to FIG. 7, when the combination of the component carriers indicated by the inner broken line in the band 40 corresponds to the synchronous and asynchronous operation (Sync + Async), the capability information notification unit 120 The combination of component carriers indicated by the outer broken line may also be regarded as corresponding to synchronous and asynchronous operation (Sync + Async), and “DC — 40D: Sync + Async” may be notified to the base station 200.

  In one embodiment, the capability information notification unit 120 includes inter-band dual connectivity (intra-band DC) including in-band dual connectivity (Intra-band DC) based on a combination of component carriers (class D) including three or more component carriers. Inter-band DC), if any one component carrier of in-band dual connectivity supports synchronous inter-band dual connectivity, the inter-band synchronous with any component carrier of the in-band dual connectivity You may notify that dual connectivity is possible. For example, as shown in FIG. 9A, three component carriers in band 1 correspond to in-band dual connectivity, and one component carrier in band 5 and one component carrier in band 1 are synchronous (Sync). ) And inter-band dual connectivity. In this case, the capability information notification unit 120 considers that any other component carrier of band 1 corresponds to synchronous interband dual connectivity, and any other component carrier of band 1 is also synchronous. The base station 200 may be notified that it is compatible with (Sync) interband dual connectivity. For example, in the illustrated example, the two component carriers in band 1 and the one component carrier in band 5 correspond to the synchronous (Sync) inter-band dual connectivity. “DC_1C-5A: Sync” is notified to the base station 200 as capability information.

  Similarly, the capability information notification unit 120 includes inter-band dual connectivity (Inter-band DC) including in-band dual connectivity (Intra-band DC) based on a combination of component carriers (class D) including three or more component carriers. ), If any one component carrier of in-band dual connectivity supports synchronous and asynchronous (Sync + Async) interband dual connectivity, synchronous with any component carrier of the in-band dual connectivity and It may be notified that asynchronous (Sync + Async) inter-band dual connectivity is possible. For example, as shown in FIG. 9B, three component carriers in band 1 correspond to in-band dual connectivity, and one component carrier in band 5 and one component carrier in band 1 are synchronous and asynchronous. It is assumed that it corresponds to the inter-band dual connectivity that is ideal (Sync + Async). In this case, the capability information notification unit 120 regards any other component carrier in band 1 as corresponding to synchronous and asynchronous (Sync + Async) interband dual connectivity, and any other component carrier in band 1 May also notify the base station 200 that it supports synchronous and asynchronous (Sync + Async) inter-band dual connectivity. For example, in the illustrated example, the two component carriers in band 1 and the one component carrier in band 5 support synchronous and asynchronous (Sync + Async) inter-band dual connectivity. Notifies the base station 200 of “DC — 1C-5A: Sync + Async” as lower capability information.

  Next, a dual connectivity communication process according to an embodiment of the present invention will be described with reference to FIG. FIG. 10 is a flowchart showing a dual connectivity communication process by the base station according to one embodiment of the present invention.

  As illustrated in FIG. 10, the process is started in response to the user apparatus 100 having the dual connectivity function starting communication with the base station 200.

  In step S101, the base station 200 receives capability information related to dual connectivity from the user apparatus 100. The capability information includes higher capability information (DC configuration) regarding a combination of component carriers composed of three or more component carriers supported by the user apparatus 100 in dual connectivity, and lower capability information (subset of a combination of component carriers). DC configuration of subset).

  In step S102, the base station 200 determines, based on the received lower capability information, which of the three or more component carriers is capable of synchronous dual connectivity or synchronous and asynchronous dual connectivity. .

  In step S103, the base station 200 sets the combination of component carriers for synchronous dual connectivity or synchronous and asynchronous dual connectivity to the user apparatus 100 based on the determination.

  In step S104, the base station 200 performs the scheduling for dual connectivity with respect to the user apparatus 100 according to capability information.

  In step S105, the base station 200 determines whether to continue dual connectivity. The determination may be made based on the quality of each component carrier acquired from the user apparatus 100, for example. Thereafter, the base station 200 ends the communication with the user apparatus 100.

  As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the specific embodiment mentioned above, In the range of the summary of this invention described in the claim, various deformation | transformation・ Change is possible.

10 wireless communication system 100 user equipment 110 wireless communication control unit 120 capability information notification unit 200 base station

Claims (4)

A user device having a dual connectivity function,
A wireless communication control unit for controlling wireless communication with the base station;
A capability information notifying unit for notifying the base station of capability information;
Have
The capability information notification unit includes higher capability information related to a combination of component carriers composed of three or more component carriers supported by the user apparatus in dual connectivity, and lower capability information related to a plurality of subsets of the combination of component carriers, User device that notifies.   The user equipment according to claim 1, wherein the subset of the combination of component carriers is configured by excluding at least one component carrier from a combination of component carriers including the three or more component carriers. A dual connectivity communication method by a base station,
Receiving, from a user apparatus, upper capability information regarding a combination of component carriers composed of three or more component carriers supported by the user apparatus in dual connectivity, and lower capability information regarding a plurality of subsets of the combination of component carriers When,
Performing scheduling for dual connectivity on the user equipment based on the received higher capability information and lower capability information;
A dual connectivity communication method comprising:   The method of claim 3, wherein the subset of component carrier combinations is configured by excluding at least one component carrier from a combination of component carriers composed of the three or more component carriers.

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