JP7033037B2 - Wireless network system - Google Patents

Description

The present invention relates to a wireless network system, and in particular, separates (C / U) a user plane (U-plane) of a protocol layer that handles user data signals and a control plane (C-plane) of a protocol layer that handles control signals. It relates to a wireless network system in which each plane can communicate in a different frequency band.

The user terminal UE and the wireless base station BS transmit and receive each signal of "C-plane" (control signal) for controlling the connection and "U-plane" (user data signal) through which actual data flows. In a C / U separated wireless network, the macrocells that house the small cells maintain connectivity by managing connections and movements using C-Plane, and the small cells use U- using a wide band frequency. Providing high throughput by working with Plane

Patent Document 1 discloses a centralized control method as a network configuration method in a Software-Defined Network (SDN) in which a C-plane and a U-plane are separated.

Patent Document 2 discloses a method in which a macro cell performs C-plane communication and a small cell performs U-plane communication in a wireless network composed of a macro cell and a small cell.

FIG. 4 is a diagram showing the configuration of a conventional C / U separation network, and is composed of a plurality of small cells s accommodating a user terminal UE and a macro cell m accommodating a user terminal UE and a plurality of small cells s. Will be done.

The user terminal UE in the small cell s communicates a user data signal with the small cell base station BS3 by U-plane. A frequency band relatively lower than that of C-plane communication (for example, 2 GHz band) is used for U-plane communication.

The user terminal UE directly communicates the control signal with the macrocell base station BS1 by C-plane. A frequency band relatively higher than that of U-plane communication (for example, 3.5 GHz band) is used for C-plane communication. The user terminal UE moved from the small cell s communicates the user data signal via another small cell base station BS1 or directly with the macro cell base station BS1 by U-plane.

A. Gudipati, D. Perry, L. E. Li, S. Katti, and B. Labs, "SoftRAN: Software Defined Radio Access Network," in ACM HotSDN, 2013. H. Ishii, Y. Kishiyama, and H. Takahashi, "A novel architecture for LTE-B: C-plane / U-plane split and phantom cell concept," in Proc. IEEE Globecom Workshops, 2012.

The configuration method of Patent Document 1 has a problem of lacking scalability because a centralized control method is used. In the configuration method of Patent Document 2, since all the communication of C-plane is entrusted to the macro cell, the communication load is concentrated on the macro cell, and there is a problem that the scalability is lacking as in Patent Document 1.

An object of the present invention is to solve the above technical problems, prevent the processing load due to C-plane communication from concentrating on the macrocell, and provide a wireless network having excellent scalability.

In order to achieve the above object, the present invention has a plurality of small cells accommodating a wireless terminal, a plurality of middle cells accommodating the wireless terminal and the small cell, and a macro cell accommodating the wireless terminal, the small cell and the middle cell. It is a wireless network device in which the C-Plane that handles control signals and the U-Plane that handles user data signals are separated, including the above, and is characterized by having the following configurations.

(1) Each controller of the macro cell and the middle cell is made to process the control signal of each wireless terminal in a distributed manner.

(2) The wireless terminal located in the small cell housed in the middle cell communicates the control signal with each controller of the macro cell or the middle cell by C-Plane.

(3) The wireless terminal in the middle cell communicates the control signal with the macro cell controller via C-Plane.

(4) The wireless terminal located in the middle cell communicates the user data signal with the controller of the middle cell via U-Plane.

(5) The controller of the macro cell controls the communication processing by the macro cell, each middle cell housed in the macro cell, and each small cell housed in each middle cell.

(6) The controller of each middle cell controls the communication processing by the middle cell and each small cell housed in the middle cell.

According to the present invention, the following effects are achieved.

(1) A plurality of middle cells accommodating a wireless terminal and a small cell are provided, the macro cell accommodates each middle cell, and the wireless terminal located in the small cell communicates a control signal with the macro cell or the controller of the middle cell via C-Plane. Therefore, the communication processing by C-Plane can be distributed to each controller of the macro cell and the middle cell, and the scalability can be ensured.

(2) Since the controller of each middle cell is connected under the controller of the macro cell to form a hierarchical structure, the communication processing by C-Plane can be distributed processing by each controller of the macro cell and the middle cell.

(3) Since the wireless terminal located in the middle cell communicates the control signal with the controller of the macro cell via C-Plane, the number of handovers can be reduced even when the wireless terminal moves between the middle cells.

It is a figure which showed the structure of the wireless network which concerns on one Embodiment of this invention. It is a figure which showed the layered connection form between the controller which controls each cell with respect to C-plane. It is a figure which showed the layered connection form between the controller which controls each cell with respect to U-plane. It is a figure which showed the structure of the conventional C / U separation network.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a wireless network according to an embodiment of the present invention, in which a plurality of small cells s accommodating a user terminal UE as a wireless terminal, a user terminal UE, and a plurality of small cells s are shown. It is composed of a plurality of middle cells M that can be accommodated, a user terminal UE, a plurality of small cells s, and a macro cell m that can accommodate a plurality of middle cells M. The macrocell base station BS1 that manages the macrocell m is connected to the backbone (Internet) via the gateway GW.

FIG. 2 is a diagram showing a hierarchical structure between controllers that control the macro cell m and the middle cell M with respect to the C-plane, and the macro cell controller 2 that controls the macro cell m is connected under the GW controller 1 that controls the gateway GW. A middle cell controller 3 that controls each middle cell M is connected under the macro cell controller 2.

The GW controller 1 controls a subordinate macro cell controller 2 and a middle cell controller 3. The macro cell controller 2 controls the macro cell and each of the subordinate middle cell controllers 3. Each middle cell controller 3 controls each middle cell M, respectively.

FIG. 3 is a diagram showing a hierarchical structure of controllers that control each cell m, M, and s with respect to the U-plane. The macro cell controller 2 is connected under the GW controller 1 and the middle is under the macro cell controller 2. A cell controller 3 is connected, a small cell controller 4 that controls each small cell s is connected under each middle cell controller 3, and a large number of user terminal UEs are accommodated in each small cell s.

The GW controller 1 controls a subordinate macro cell controller 2, a middle cell controller 3, and a small cell controller 4. The macro cell controller 2 controls the macro cell m, each of the subordinate middle cell controllers 3 and each small cell controller 4. Each middle cell controller 3 controls each middle cell and each subordinate small cell controller 4. Each small cell controller 4 controls each small cell.

In such a configuration, the user terminal UE in the small cell s housed in the middle cell M communicates a control signal with each controller of the macro cell m or the middle cell M by C-Plane as shown in FIG. .. Therefore, even when a large number of user terminal UEs are accommodated under the control, the processing load related to the control signal can be distributed to the macro cell m and the middle cell M, and the processing load can be prevented from being concentrated on the macro cell m. Become.

Further, since the user terminal UE in the small cell s housed in the middle cell M communicates the user data signal with the controller BS3 of the small cell s in the area by the U-Plane, the speed reduction can be suppressed. ..

On the other hand, since the user terminal UE located in the middle cell M or the macro cell m can communicate the control signal with the controller of the macro cell m by C-Plane, it is possible to make the handover less likely to occur. Further, since the user data signal is communicated with the controller BS2 of the middle cell M in the service area by the U-Plane, the speed reduction can be suppressed.

1 ... GW controller, 2 ... macro cell controller, 3 ... middle cell controller, 4 ... small cell controller

Claims (6)

With multiple small cells that house wireless terminals,
With multiple middle cells that house wireless terminals and small cells,
Including wireless terminals, macrocells accommodating small cells and middle cells,
It is a wireless network system in which C-Plane, which handles control signals of wireless terminals, and U-Plane, which handles user data signals, are separated.
A wireless network system in which each controller of the macro cell and the middle cell processes a control signal of each wireless terminal in a distributed manner. The wireless network system according to claim 1, wherein the wireless terminal located in the small cell housed in the middle cell communicates a control signal with each controller of the macro cell or the middle cell by C-Plane. The wireless network system according to claim 1 or 2, wherein the wireless terminal located in the middle cell communicates a control signal with the controller of the macro cell by C-Plane. The wireless network system according to claim 3, wherein the wireless terminal located in the middle cell communicates a user data signal with the controller of the middle cell by U-Plane. The controller according to any one of claims 1 to 4, wherein the controller of the macro cell controls communication processing by the macro cell, each middle cell housed in the macro cell, and each small cell housed in the middle cell. Wireless network system. The wireless network system according to claim 5, wherein the controller of each middle cell controls communication processing by the middle cell and each small cell housed in the middle cell.

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