GB2441288A

GB2441288A - Communication control system and communication control method

Info

Publication number: GB2441288A
Application number: GB0725388A
Authority: GB
Inventors: Takeshi Matsusawa; Noboru Umeda; Takahisa Aoki; Takayoshi Motegi
Original assignee: SoftBank BB Corp
Current assignee: SoftBank Corp
Priority date: 2005-05-30
Filing date: 2007-12-31
Publication date: 2008-02-27
Anticipated expiration: 2027-12-31
Also published as: WO2006129603A1; GB2441288B; JPWO2006129603A1; GB0725388D0

Abstract

A user plane control part (U) integrates user planes (U-Plane) that are separated and extracted from a network logic connection and a packet logic connection and tat are used to control the transmission of user data related to a mobile terminal. A control plane control part (C) integrates control planes (C-Plane) that are separated and extracted from the network logic connection and the packet logic connection and that are used to control the transmission of a control signal related to the user data. Then, packet communication is used to establish communication for the user and control planes separated from the network logic connection. In this way, in a core network having the network logic connection and packet logic connection between a mobile terminal and a radio base station, the mutual dependency between the user plane and the control plane can be eliminated to improve the node usage efficiency and reduce the communication delay.

Description

SPECIFICATION

COMMUNICATION CONTROL SYSTEM AND COMMUNICATION CONTROL METHOD

TECHNICAL FIELD

(0001) The present invention relates to a mobile communication system and a node for use in controlling the operation thereof, and more particularly to an interface configuration between a radio network control device and core network equipment in a packet communication network.

BACKGROUND ART

[0002) In the case of W-CDMA (Wideband-CDMA), conventionally, the configuration of connection between a radio network control device and core network equipment for a packet communication network is defined in 3GPP TS 23.060 and TS 25.410.

[0003] More specifically speaking, as illustrated in Fig. 9, the network configuration in accordance with W-CDMA includes a core network 3 which is a switching network connectable to an external network 4, a RAN (Radio Access Network) 2 including an RNC (Radio Network Control Device) 23, and a mobile terminal 1. Between the core network and the radio network control device, there are logic connections including connections referred to as lu-CS and lu-PS (illustrated in the figure as connections 71 and 72). The connection lu-CS is a logic connection between an MSC (Mobile Switching Center)74 of the core network 3 and the radio network control device 23 and serves as a connection of a circuit switching domain 75 for voice communication. On the other hand, the connection lu-PS is a logic connection between a packet switch (SGSN: Serving GPRS Support Node) 76 of the core network 3 and the radio network control device 23 and serves as a connection of a packet switching domain 79 for data communication.

(0004] Furthermore, each of the logic connections (lu-CS and lu-PS) as described above is composed of a user plane (U-Plane) provided for user data and a control plane (C-Plane) provided for signaling (for example, refer to Patent Document 1) 1/13 [0005] However, the packet switching in the above network configuration is performed by a packet processing node in both the C-Plane and U-Plane. These C-Plane and U- Plane are implemented and processed by hardware as an integrated connection, and thereby there is a problem in that, when one of the processing capacity and circuit capacity reaches a limit, it is needed to expand facilities even if the other does not reach a limit.

[0006] Also, in the above network configuration, despite the fact that the protocol stack of the CS domain in the C-Plane has the same configuration as that of the PS domain in the C-Plane, these protocol stacks have been implemented as separate protocol stacks to have a significant influence on the processing capacity.

[0007] Furthermore, luFlex functionality is sometimes introduced into the above network configuration. This luFlex functionality is the functionality of selecting a core node capable of setting a logical connection (lu-CS and lu-PS) from a pool area. More specifically speaking, in the case where standard nodes are used without luFlex as illustrated in Fig. 10(a), connections are fixedly established between the RNC 23 and the MSC 74 and between the RNC 23 and the SGSN 76 in one-to-one correspondences respectively. Contrary to this, if the luFlex functionality is introduced, the RNC 23 can appropriately select core nodes (the MSC 74 and the SGSN 76) in pool areas. However, since the C-Plane and the U-Plane have to be integrally selected in the case of the conventional system, while the C-Plane and U-Plane have different processing capacities and different loads may be placed on the circuit capacities thereof in a node, the selected node may not optimally operate when the above differences are significant, and thereby the node selection is eventually restricted.

[0008] Also, in the case of the conventional system, a node for processing the U-Plane is needed for each of the circuit switching and the packet switching, so that the usage efficiency of the transmission equipment between nodes is degraded, requiring consideration about the processing delay due to the degraded usage efficiency. 2/13

Patent Document 1: Japanese Patent Published Application No. 2004-194015

DISCLOSURE OF THE INVENTION

[0009] Taking into consideration the above circumstances, it is an object of the present invention to provide a communication control system and a communication control method which are capable of improving the usage efficiency of nodes and reducing communication delay, in a core network having a circuit switching logic connection and a packet switching logic connection, by eliminating the mutual dependency between the user plane and the control plane, separating the settings of the processing capacity and the circuit capacity, and making it possible to individually conduct the management and operation of the respective planes.

(00101 In order to accomplish the object as described above, the present invention provides a communication control system and a communication control method for connecting a mobile terminal with a core network having a circuit switching logic connection which defines a circuit switching domain and a packet switching logic connection which defines a packet switching domain, wherein a user plane control unit integrates user planes (U-Planes) which are separated and extracted from the circuit switching logic connection and packet switching logic connection respectively and operable to control the transmission of user data for use in relation to the mobile terminal, wherein a control plane control unit integrates control planes (C-Planes) which are separated and extracted from the circuit switching logic connection and packet switching logic connection respectively and operable to control the transmission of control signals for use in relation to the user data, and wherein the user plane and control plane which are separated from the circuit switching logic connection establish a communication by packet communication.

[0011] In accordance with the present invention as described above, the user and control planes, which are separated and extracted from the circuit switching logic connection and the packet switching logic connection, are integrated in 3/13 accordance with these plane classes respectively, so that the respective plane classes are made independent from each other in terms of the processing capacity and circuit capacity, and thereby the transmission bandwidth can be reduced by making effective use of resources.

[0012] It is preferred in the above invention that the user plane control unit and control plane control unit serve to generate management information for each user by transmitting and receiving data each other. In this case, it is possible to manage, for each user, the planes which are separated and extracted from the circuit switching domain and the packet switching domain respectively, and appropriately perform the account process and the address management process.

[0013] It is preferred in the above invention that, in the control plane control unit, the circuit switching logic connection and the packet switching logic connection share a common protocol stack for use in relation to the control planes thereof. In this case, by the use of the shared protocol stack, it is possible to omit the resources and processes which are used redundantly for the purpose of controlling the control planes of the circuit switching logic connection and packet switching logic connection, and as a result the reduction of the processing load and time can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] [Fig. 1] A block diagram for schematically showing the configuration of a communication control system in accordance with an embodiment.

[Fig. 2] A schematic representation showing a communication control method in accordance with the embodiment.

[Fig. 3] A block diagram for showing the configuration of connections in accordance with the embodiment.

(Fig. 4] An explanatory view for showing the protocol stack of a control plane in accordance with the embodiment.

[Fig. 5] An explanatory view for showing the control unit as modularized in accordance with the embodiment.

[Fig. 6) An explanatory dual view for showing the integration 4/13 of planes in accordance with the embodiment.

(Fig. 7] An explanatory dual view for showing the selection of modules in accordance with the embodiment when the luFlex functionality is introduced.

[Fig. 8] An explanatory view for showing the setting of transmission paths in accordance with the embodiment.

[Fig. 9] A block diagram for showing a conventional communication control system.

[Fig. 10] An explanatory view for showing luFlex functionality introduced in the conventional communication control system.

BEST MODE FOR CARRYING OUT THE INVENTION

(0015] (Configuration Of Communication Control Unit) An embodiment of the present invention will be explained in conjunction with the accompanying drawings. Fig. 1 is a block diagram for schematically showing the configuration of a communication control system of the present embodiment.

Incidentally, a communication control method of the present invention is implemented by operating the communication control system of the present embodiment.

[0016] As shown in the same figure, in the case of the present embodiment, it is assumed that a communication network is available for connecting a mobile terminal 1 used by a user with an external network 4 through a RAN 2 and a core network 3 in order to establish communication. The core network 3 includes a circuit switching logic connection as a circuit switching domain and a packet switching logic connection as a packet switching domain.

[0017] The RAN 2 is a network for establishing radio communication with the mobile terminal 1, and specifically composed of a node B (radio base station) 21, a RNC (radio network control device) 23, and an lub (connection) 22 for connecting the node B and the RNC 23. This RAN 2 includes the circuit switching logic connection of the circuit switching domain for voice communication, and the packet switching logic connection of the packet switching domain for data communication. Each logic connection is composed of a control plane (C-Plane) for signaling and a user plane (U-Plane) for 5/13 user data (voice signals and data communication signals).

[0018) Fig. 2 is a schematic representation showing the communication control method performed by the RNC 23. As shown in the same figure, the RNC 23 extracts the C-Planes and the 0-Planes from the circuit switching logic connections and the packet switching logic connections which are separately implemented in an MSC (Mobile Switching Center: Mobile Telephone Exchange), an SGSN (Serving GPRS Support Node: Packet Switch) and a GGSN (Gateway GPRS Support Node: Gateway Packet Switch) respectively. The extracted C-Planes are integrated in a connection 5 (lu-C) provided for the control plane and a node 31. The extracted U-Planes are integrated in a connection 6 (lu-U) provided for the user plane and a node 32.

[0019) Both the logic connection of the circuit switching domain and the logic connection of the packet switching domain are made IP-based between the core network 3 and the RAN 2, as illustrated in Fig. 3, and all data is transmitted and received as I? packets between the RNC 23 and an MSC 33 of the core network 3.

[0020] Also, as illustrated in Fig. 4, the circuit switching logic connection and the packet switching logic connection are designed to share a common protocol stack for use in the control planes thereof by the RNC 23. More specifically speaking, this protocol stack includes RANAP (Radio Access Network Application Part), SCCP (Signaling Connection Control Part), M3UA (MTP3 User Adaptation), SCTP (Strea!n Control Transmission Protocol), IP (Internet Protocol), and Data Link.

[0021] RANAP defines an application protocol which is used by a radio access network, SCCP is an existing circuit switching network protocol, M3UA provides an adaptation for making an existing circuit switching network protocol, which is used in the upper layer, adapted for use in the IP network of the lower layer, SCTP is a transport protocol on the IP network and IP defines the rules for communicating with the communication partner. Then, the transmission and reception of call control arid the like between the RNC 23 and the MSC 33 and between the RNC 23 and SGSN (in the user plane node) is performed by the application functions defined by RANAP, and 6/13 the control based on RANAP is transmited through the lower layer. When this transmission is performed, an adapter such as M3UA is interposed as an intermediate layer for making use of the above protocol, i.e., IP.

[0022] Furthermore, in the function block of each of the control plane node 31 and the user plane node 32, the hardware of the control unit which is conventionally implemented as a single block is divided into two modules as control units for the control plane and the user plane respectively. Namely, the hardware of the control unit is divided into a control unit C for the C-Plane and a control unit U for the U-Plane as illustrated in Fig. 5, and the control unit C and the control unit U are connected by Ethernet (registered trademark) in order to transmit and receive data each other. Also, the management information for each user is generated in order to share the account information and the address management process between the control unit C and the control unit U. (0023] (Action/Effect Of The Present Embodiment) In accordance with the present embodiment, the user and control planes, which are separated and extracted from the circuit switching logic connection and the packet switching logic connection, are integrated in accordance with these plane classes respectively, so that the respective plane classes are made independent from each other in terms of the processing capacity and circuit capacity, and thereby the transmission bandwidth can be reduced by making effective use of resources.

[0024] More specifically described, in the case of the nodes (MSC, SGSN, GGSN) of the core network 3 of the conventional system in which each node fixedly has a processing capacity and a circuit capacity, when the circuit capacity reaches a maximum limit, addition of the node itself is needed as illustrated in Fig. 6(a) even if the processing capacity still has room. Contrary to this, in the case of the present embodiment, the user planes and control planes are integrated according to these plane classes respectively as illustrated in the same figure (b), and thereby when the circuit capacity reaches a maximum limit, this situation can be dealt with only by adding a module relevant to the circuit capacity. 7/13

[00251 Furthermore, in accordance with the present embodiment, when luFlex functionality is introduced as illustrated in Fig. 7, it is possible to select an appropriate C-Plane module and an appropriate ti-Plane module from a plane pool and solve node imbalance by load sharing and so forth. More specifically described, when luFlex functionality is introduced, the RNC 23 can select a core node (MSC, SGSN) from the pool areas.

However, if this luFlex functionality is introduced in the conventional system, the selected node may not perform an optimal operation because the node has a circuit capacity and a processing capacity. Contrary to this, in the case of the present embodiment, since the user planes and control planes are integrated according to these plane classes respectively, it is possible to optimize the luFlex functionality by is improving the flexibility of the selection of C-Plane and U-Plane modules, solving node imbalance by load sharing, and so forth.

[0026] Also, in accordance with the present embodiment, since the ti-Planes of the circuit switch and packet switch are integrated as illustrated in Fig. 8(b), transmission paths can be set up only for necessary user planes, and the delay can be reduced by simplifying the configuration of transmission paths.

More specifically described, in the case of the conventional system, when user data is exchanged between a circuit switch and a packet switch (for example, when telephone call is made between the circuit switch and the packet switch) as illustrated in the same figure (a), it is required to set up transmission paths for both the circuit switch and the packet switch between the nodes for processing the user data, and thereby a delay occurs depending upon the distance between the nodes. Contrary to this, in the case of the present embodiment, since the user planes and control planes are integrated according to these plane classes respectively, it is possible to set up transmission paths only for necessary user planes, and reduce the delay by simplifying the configuration of transmission paths.

[0027] In addition to this, since the control unit C for the C-Plane and the control unit U for the U-Plane are connected by Ethernet (registered trademark) in the case of the RNC 23 8/13 of the above embodiment in order to transmit and receive data each other and provided with the functionality of generating the management information for each user, it is possible to manage, for each user, the planes which are separated and extracted from the circuit switching domain and the packet switching domain respectively, and appropriately perform the account process and the address management process.

[0028] Furthermore, in the case of the above embodiment, since the circuit switching logic connection and the packet io switching logic connection are designed to share a common protocol stack for use in the control planes thereof by the RNC 23, it is possible to omit the resources and processes which are used redundantly for the purpose of controlling the respective planes, reduce the processing load and shorten the processing time.

INDUSTRIAL APPLICABILITy

[0029] As has been discussed above, in accordance with the communication control system and the communication control method of the present invention, it is possible to improve the node usage efficiency and reduce the communication delay by making it possible to eliminate the mutual dependency between the user plane and the control plane and individually conduct the management and operation of the respective planes.

[0030] Namely, since the connections of the core network are provided separately for the C-Plane and the U-Plane, it is possible to improve the flexibility in designing the system and in expanding or reducing the facility in accordance with the requirements of processing capacity and circuit capacity.

Also, the procedure of controlling the connections and the management of users can be simplified by integrating the control of the circuit switching logic connection and the packet switching logic connection.

[0031) In addition to this, since the core network nodes are provided separately for the C-Plane and the U-Plane, it is possible to select the most suitable module for each plane when the luFlex functionality is used. Furthermore, appropriate bearer conversions can be performed by nodes independent of the type of U-Plane such as the type for 9/13 circuit switch or the type for packet switch, and in addition to this it is possible to set up effective transmission paths between nodes and obtain delay reduction. 10/13

Claims

WHAT IS CLAIMED IS: [1] A communication control system for connecting a

mobile terminal with a core network having a circuit switching logic connection which defines a circuit switching domain and a packet switching logic connection which defines a packet switching domain, said communication control unit comprising: a user plane control unit which integrates user planes which are separated and extracted from said circuit switching logic connection and packet switching logic connection respectively and operable to control the transmission of user data for use in relation to said mobile terminal; and a control plane control unit which integrates control planes which are separated and extracted from said circuit switching logic connection and packet switching logic connection respectively and operable to control the transmission of control signals for use in relation to said user data, wherein said user plane and control plane which are separated from said circuit switching logic connection establish a communication by packet communication.

[2] The communication control system as claimed in claim 1 wherein said user plane control unit and control plane control unit serve to generate management information for each user by transmitting and receiving data each other.

(3] The communication control system as claimed in claim 1 wherein, in said control plane control unit, said circuit switching logic connection and said packet switching logic connection share a common protocol stack for use in relation to the control planes thereof.

(4] A communication control method for connecting a mobile terminal with a core network having a circuit switching logic connection which defines a circuit switching domain and a packet switching logic connection which defines a packet switching domain, said communication control unit comprising: integrating user planes which are separated and 11/13 extracted from said circuit switching logic connection and packet switching logic connection respectively and operable to control the transmission of user data for use in relation to said mobile terminal; and integrating control planes which are separated and extracted from said circuit switching logic connection and packet switching logic connection respectively and operable to control the transmission of control signals for use in relation to said user data, wherein said user plane and control plane which are separated from said circuit switching logic connection establish a communication by packet communication.

[5] The communication control method as claimed in claim 4 wherein said user plane control unit and control plane control unit, which are separated and extracted, serve to generate management information for each user by transmitting and receiving data each other.

[6) The communication control method as claimed in claim 4 wherein said circuit switching logic connection and said packet switching logic connection share a common protocol stack for use in relation to the control planes thereof which are separated and extracted. 12/13