Mobile communication system and communication method thereof

Abstract

A communication method in a mobile communication system that transmits different data to which transmission sequence numbers have been attached, over each of a plurality of paths from a mobile station to a radio network controller via a plurality of base stations; where the radio network controller monitors the communication state of each path, determines to transmit the data over all of a plurality of paths, transmit the data over two or more specified paths, or transmit the data over only one specified path, based on the communication state of each path, and notifies the mobile station of the determined path/paths; and where the mobile station transmits different data to which different transmission sequence numbers have been attached, over said notified path/paths, and the radio network controller rearranges the data received from each path by reference to the transmission sequence numbers and transmits the rearranged data to a core network.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing showing part of the construction of the mobile communication system of the present invention.

FIG. 2 is a drawing that explains a path list PLT.

FIG. 3 is a drawing of a sequence for explaining initial setting of the path list and notification control for identifiers.

FIG. 4A and FIG. 4B are flowcharts of the process for determining the most optimal transmission path/paths.

FIG. 5 is a drawing for explaining the data transmission operation by the mobile station when the radio network controller specifies ID=0 as the identifier that specifies the data transmission path/paths.

FIG. 6 is a drawing for explaining the TSN that are assigned by the MAC-es processing unit of the mobile station for each time slot, and the transmission data image to MAC-e.

FIG. 7 is a drawing for explaining the data transmission operation by the mobile station when the radio network controller specifies ID=1 as the identifier that specifies the data transmission path/paths.

FIG. 8 is a drawing for explaining the TSN that are assigned by the MAC-es processing unit of the mobile station for each time slot, and the transmission data image to MAC-e.

FIG. 9 is a drawing of the construction of a radio network controller that measures the characteristics of the network environment and determines the data transmission path/paths.

FIG. 10 A and FIG. 10B are flowcharts showing the processing performed by the data transmission path determination/notification unit that determines the data transmission path/paths according to the communication delay time.

FIG. 11 A and FIG. 11B are flowcharts showing the processing performed by the data transmission path determination/notification unit that determines the data transmission path/paths according to the number of retransmissions.

FIG. 12 A and FIG. 12B are flowcharts showing the processing performed by the data transmission path determination/notification unit that determines the data transmission path/paths according to the amount of data throughput.

FIG. 13 A and FIG. 13B are flowcharts showing the processing performed by the data transmission path determination/notification unit that determines the data transmission path/paths according to continuity of the FSN.

FIG. 14 is a drawing that shows the construction of a radio communication system in which the lines of the W-CDMA mobile communication system are shared by a plurality of users.

FIG. 15 is a drawing that explains the logical connection in the HSUPA method during handover.

FIG. 16 is another drawing that explains the logical connection in the HSUPA method during handover.

FIG. 17 is a drawing showing the layer structure of each unit in the HSUPA method.

FIG. 18 is a drawing that explains the procedure for creating a data transport block TRB by the mobile station.

FIG. 19 is a drawing that explains the multiplexing relationship of the MAC-d PDU, MAC-es PDU and MAC-e PDU.

FIG. 20 is a drawing that explains an EDCH lub FP frame.

FIG. 21 is a drawing that explains the processing by a radio network controller.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(A) Construction of a Mobile Communication System

FIG. 1 is a drawing showing part of the construction of the mobile communication system of the present invention, comprising: a core network (CN) 11, one radio network controller (RNC) 12, three radio base stations (Nodes B) 13₀ to 13₂, and one mobile station (UE: User Equipment) 14, where the mobile station 14 reaches a cell boundary and is in a soft handover state, and it is connected with the RNC 12 via paths PT0 to PT2. The radio base stations (Nodes B) 13₁ to 13₃ exist in each of the paths PT0 to PT2, and communication is performed between the mobile station 14 and each of the base stations by way of the Uu interface, and communication is performed between each of the base stations 13₁ to 13₃ and the radio network controller 12 by way of the lub interface. The data flow is shown by the solid lines, and the flow of the control signals is shown by the dashed lines.

Radio Network Controller

The radio network controller 12 comprises: a processing unit 12a that performs processing on the frames received from the base stations; and a path control unit 12b that performs control of determining which path/paths the mobile station 14 is to transmit data over. The processing unit 12a comprises: lub interfaces 21₀, 21₁, 21₂, MAC-e processing units 22₀, 22₁, 22₂, a MAC-es processing unit 23, a MAC-d processing unit 24 and RLC processing unit 25.

The lub interfaces 21₀, 21₁, 21₂ control communication with the base stations, as well as measure and store the lub line usage rates. The MAC-e processing units 22₀, 22₁, 22₂ use the lub FP frames (see FIG. 20) that are received from the base stations to perform MAC-e processing, and divide out the MAC-es PDU data and input that data to the MAC-es processing unit 23. The MAC-es processing unit 23 further divides out the MAC-d PDU data from the MAC-es PDU data that was divided out in each MAC-e processing, and by reference to the transmission sequence number TSN, rearranges the data and inputs that data to the MAC-d processing unit 24. The MAC-d processing unit 24 gives the MAC-d PDU data to the RLC processing unit 25 as is as RLC-PDU data, and the RLC processing unit 25 selects specified RLC-PDU data from among the data obtained from each path, removes the header and transmits that data as individual data to the core network 11.

The path control unit 12b comprises: an lub line usage rate monitoring unit 27, path list storage unit 28 and data transmission path determination/notification unit 29. The lub line usage rate monitoring unit 27 makes an inquiry to each of the lub interfaces 21₀, 21₁, 21₂ of the usage rate of the lub lines, and monitors the lub line usage rates between each of the base stations (Nodes B) 13₀ to 13₂ and the radio network controller 12. The path list storage unit 28 stores a path list PLT that correlates path information that indicates over which path/paths the mobile station transmits data, and an identifier (data transmission pattern ID) that specifies that path information.

FIG. 2 is a drawing explaining the path list PLT in a case where three paths are connected between a mobile station and radio network controller due to a handover. The identifier ID=1 specifies transmitting one set of data over path PT0, identifier ID=2 specifies transmitting one set of data over path PT1, identifier ID=3 specifies transmitting one set of data over path PT2, identifier ID=4 specifies transmitting two different sets of data over respective paths PT0, PT1, ID=5 specifies transmitting two different sets of data over respective paths PT1, PT2, ID=6 specifies transmitting two different sets of data over respective paths PT2, PT0, and identifier ID=7 specifies transmitting three different sets of data over respective paths PT0, PT1, PT2. In the figure, org means original data.

For example, when identifier ID=1 is specified, the MAC-es processing unit (described later) of the mobile station 14 creates one set of MAC-es PDU data for each time slot, attaches transmission sequence numbers TSN, inputs the data to one MAC-es processing unit, and that MAC-es processing unit multiplexes a plurality of MAC-es PDU data to create MAC-e data, then transmits that data over one path PT0.

Moreover, when identifier ID=4 is specified, the MAC-es processing unit of the mobile station 14 creates two different sets of MAC-es PDU data for each time slot, attaches different transmission numbers TSN (X1, X2) to the respective data, and inputs the data to two MAC-e processing units, and each respective MAC-e processing unit multiplexes a plurality of MAC-es PDU data to create MAC-e data, then transmits that data over two paths PT0, PT1.

Furthermore, when identifier ID=7 is specified, the MAC-es processing unit of the mobile station 14 creates three different sets of MAC-es PDU data for each time slot, attaches different transmission numbers TSN (X1, X2, X3) to the respective data, and inputs the data to three MAC-e processing units, and each respective MAC-e processing unit multiplexes a plurality of MAC-es PDU data to create MAC-e data, then transmits that data over three paths PT0, PT1, PT2.

Returning to FIG. 1, when the mobile station is connected to the radio network controller by a plurality of paths (three paths in the figure) due to handover control, the data transmission path determination/notification unit 29 transmits a path list PLT to the mobile station, and based on the lub line usage rate for each path, determines whether to transmit data over three paths PT0 to PT2, transmit data over two specified paths, or transmit data over one specified path, and using an identifier notifies the mobile station of which path/paths was determined.

Mobile Station

The mobile station comprises: a processing unit 14a that performs processing of creating transmission data (transport block data) and transmitting that data over a path/paths, and a path control unit 14b that performs control of determining which path/paths to transmit the data over. The processing unit 14a comprises: a RLC processing unit 31, a MAC-d processing unit 32, a MAC-es processing unit 33 and MAC-es processing units 34₀ to 34₂. The RLC processing unit 31 creates RLC PDU data from dedicated channel (DTCH, DCCH) data (see FIG. 18), and the MAC-d processing unit 32 receives that RLC PDU data as MAC-d PDU data and transmits it as is to the MAC-es processing unit 33. The MAC-es processing unit 33 multiplexes MAC-d PDU data, attaches a transmission sequence number TSN and creates MAC-es PDU data. The MAC-es processing unit 33 creates the specified number of different MAC-es PDU data for each time slot according to an instruction from the path control unit 14b, attaches transmission sequence numbers TSN to the data and inputs that data to the corresponding MAC-e processing units 34₀ to 34₂. The MAC-e processing units 34₀ to 34₂ multiplex a plurality of MAC-es PDU data to create MAC-e PDU data, and transmit that data over the corresponding paths PT0-PT2 as transport block data.

The path control unit 14b comprises a path list storage unit 36 and data transmission path ID unit 37. The data transmission path ID unit 37 receives the path list PLT (see FIG. 2) that is sent from the radio network controller 12 according to control by the data transmission path determination/notification unit 29 and stores that path list in the path list storage unit 36, as well as receives an identifier from the data transmission path determination/notification unit 29 that specifies the data transmission path/paths, makes a reference to the path list and obtains the transmission paths that correspond to that identifier, and then inputs the transmission paths to the MAC-e processing unit 33.

(B) Initial Setting of the Path List and Identifier Notification Control

FIG. 3 is a drawing explaining a sequence for explaining initial setting of the path list and identifier notification control. When due to handover control, the mobile station and radio network controller are connected by a plurality of paths, for example three paths, the data transmission path determination/notification unit 29 of the radio network controller 12 receives the path list PLT from the path list storage unit 28 (S01) and notifies the mobile station 14 (S02). The data transmission path ID unit 37 of the mobile station 14 notifies the path list storage unit 36 of the path list PLT that was sent from the radio network controller 12, and the path list storage unit 36 stores that path list (S03).

Next, the data transmission path determination/notification unit 29 makes an inquiry to the tub line usage rate monitoring unit 27 of the lub line usage status (S04), and based on the line usage rate of each lub line lub #0 to lub #2, calculates the optimal data transmission path/paths (S05). Next, the data transmission path determination/notification unit 29 makes a reference to the path list PLT that is stored by the path list storage unit 28 to find the identifier that corresponds to the calculated transmission path/paths (S06), and notifies the mobile station 14 of that identifier (S07).

The data transmission path ID unit 37 of the mobile station 14 makes a reference to the path list PLT that is stored by the path list storage unit 36, finds the data transmission path/paths specified by the identifier (S08) and sets that data transmission path/paths in the MAC-es processing unit 33 (S09).

When HSUPA service is provided, by performing the processing of steps S04 to S09 in realtime according to the line status, the data transmission path/paths of the mobile station are changed, making it possible to transfer data more efficiently.

FIG. 4A and FIG. 4B are flowcharts of the transmission path determination process of steps S05 to S06.

The data transmission path determination/notification unit 29 checks whether the line usage rates η of lub #0, lub #1 and lub #2 are a set value, for example 80% or less. The line usage rate is the ratio of the maximum allowable bandwidth Bmax and the actually allotted bandwidth (used bandwidth) Buse, and can be calculated from the following equation.

η=(Buse/Bmax)×100(%)

When the line usage rates of all of the lines lub #0, lub #1 and lub #2 are 80% or less (steps 101 to 103), the data transmission path determination/notification unit 29 determines that all of the lines lub #0, lub #1 and lub #2 can be used (step 104), and sends the identifier ID=7 (see FIG. 2) to the mobile station (step 105). When the line usage rates of two lines lub #0 and lub #1 are 80% or less and the line usage rate of line lub #2 is greater than 80% (steps 101 to 103), the data transmission path determination/notification unit 29 determines that lines lub #0 and lub #1 can be used and that line lub #2 cannot be used (step 106), and sends the identifier ID=4 to the mobile station (step 107).

When the line usage rates of two lines lub #0 and lub #2 are 80% or less and the line usage rate of line lub #1 is greater than 80% (steps 101 to 102, 108), the data transmission path determination/notification unit 29 determines that lines lub #0 and lub #2 can be used and that line lub #1 cannot be used (step 109), and sends the identifier ID=6 to the mobile station (step 110).

When the line usage rate of one line lub #0 is 80% or less, and the usage rates of two lines lub #1 and lub #2 are greater than 80% (steps 101 to 102, 108), the data transmission path determination/notification unit 29 determines that line lub #0 can be used and that lines lub #1 and lub #2 cannot be used (step 1), and sends the identifier ID=1 to the mobile station (step 112).

When the line usage rates of two lines lub #1 and lub #2 are 80% or less and the line usage rate of line lub #0 is greater than 80% (steps 101, 113 to 114), the data transmission path determination/notification unit 29 determines that lines lub #1 and lub #2 can be used and that line lub #0 cannot be used (step 115), and sends the identifier ID=5 to the mobile station (step 116).

When the line usage rate of one line lub #1 is 80% or less, and the usage rates of two lines lub #0 and lub #2 are greater than 80% (steps 101, 113 to 114), the data transmission path determination/notification unit 29 determines that line lub #1 can be used and that lines lub #0 and lub #2 cannot be used (step 117), and sends the identifier ID=2 to the mobile station (step 118).

When the line usage rate of one line lub #2 is 80% or less, and the usage rates of two lines lub #0 and lub #1 are greater than 80% (steps 101, 113, 119), the data transmission path determination/notification unit 29 determines that line lub #2 can be used and that lines lub #0 and lub #1 cannot be used (step 120), and sends the identifier ID=3 to the mobile station (step 121).

When the line usage rates of all of the lines lub #0, lub #1 and lub #2 are greater than 80% (step 122), the data transmission path determination/notification unit 29 determines that communication is not possible (step 123).

(C) Data Transmission Image

FIG. 5 is a drawing for explaining the data transmission operation by the mobile station 14 when the radio network controller 12 instructs ID=7 as the identifier that specifies the data transmission path/paths. The data transmission path ID unit 37 of mobile station 14 makes a reference to the path list PLT to find the data transmission paths that correspond to identifier ID=7 and sets them in the MAC-es processing unit 33. The MAC-es processing unit 33 creates three different sets of MAC-es PDU data for the first time slot according to an instruction from the data transmission path ID unit 37, attaches respective transmission sequence numbers TSN=1, 2, 3 to each and inputs the data to the MAC-e processing units 34₀ to 34₂. Next, the MAC-es processing unit 33 creates three different sets of MAC-es PDU data for the second time slot, attaches respective transmission sequence numbers TSN=4, 5, 6 to each and inputs the data to the MAC-e processing units 34₀ to 34₂. After that, the MAC-es processing unit 33 similarly creates three different sets of MAC-es PDU data for each time slot, attaches respective transmission sequence numbers TSN=X, Y, Z to each and inputs the data to the MAC-e processing units 34₀ to 34₂.

FIG. 6 is a drawing for explaining the TSN that are assigned by the MAC-es processing unit 33 of the mobile station 14 for each time slot, and the transmission data image to MAC-e. The transmission sequence number TSN increases by three for each time slot. Also, in the case of identifier ID=7, three sets of MAC-es PDU data A1 to A3, A4 to A6, . . . A13 to A15 are transmitted to the MAC-e processing units 34₀ to 34₂ for each time slot.

The MAC-e processing units 34₀ to 34₂ multiplex a plurality of MAC-es PDU data to create MAC-e PDU data and transmits that data as transport block data over the corresponding paths PT0 to PT2. After that, the MAC-es processing unit 33 and MAC-e processing units 34₀ to 34₂ perform the same processing as described above for each time slot and transmit three different sets of data over paths PT0 to PT2.

On the other hand, the MAC-es processing unit 23 of the radio network controller 12 divides out the MAC-d PDU data from the MAC-es PDU data that has been divided out from the MAC-e PDU data by each MAC-e processing unit, as well as rearranges the data by reference to the transmission sequence numbers TSN, then inputs that data to the MAC-d processing unit 24. The MAC-d processing unit 24 gives the MAC-d PDU data as is to the RLC processing unit 25 as RLC-PDU data, and the RLC processing unit 25 removes the header from the RLC-PDU data resulting in dedicated data and transmits this dedicated data to the core network 11.

FIG. 7 is a drawing for explaining the data transmission operation by the mobile station 14 when the radio network controller 12 instructs ID=4 as the identifier that specifies the data transmission path/paths.

The data transmission path ID unit 37 of the mobile station 14 makes a reference to the path list PLT to find the data transmission paths (PT0, PT1) that corresponds to the identifier ID=4 and sets them in the MAC-es processing unit 33. The MAC-es processing unit 33 creates two sets of different MAC-es PDU data for the first time slot according to an instruction from the data transmission path ID unit 37, attaches respective transmission sequence numbers TSN=1, 2 to each and inputs the data to the MAC-e processing units 34₀ to 34₁. Next, the MAC-es processing unit 33 creates two sets of different MAC-es PDU data for the second time slot according to an instruction from the data transmission path ID unit 37, attaches respective transmission sequence numbers TSN=3, 4 to each and inputs the data to the MAC-e processing units 34₀ to 34₁. After that, the MAC-es processing unit 33 similarly creates two different sets of MAC-es PDU data for each time slot, attaches respective transmission sequence numbers TSN=X, Y to each and inputs the data to the MAC-e processing units 34₀ to 34₁.

FIG. 8 is a drawing for explaining the TSN that are assigned by the MAC-es processing unit 33 of the mobile station 14 for each time slot, and the transmission data image to MAC-e. The transmission sequence number TSN increases by two for each time slot. Also, in the case of identifier ID=4, two MAC-es PDU data A1 to A2, A3 to A4, . . . Ax to Ay are transmitted to the MAC-e processing units 34₀ to 34₁ for each time slot.

The MAC-e processing units 34₀ to 34₁ multiplex a plurality of MAC-es PDU data to create MAC-e PDU data and transmit that data as transport block data over the corresponding paths PT0 to PT1. After that, the MAC-es processing unit 33 and the MAC-e processing units 34₀ to 34₁ perform the same processing as described above for each time slot and transmit two different sets of data over the paths PT0 to PT1.

On the other hand, the MAC-es processing unit 23 of the radio network controller 12 divides out the MAC-d PDU data from the MAC-es PDU data that has been divided out from the MAC-e PDU data by each MAC-e processing unit, as well as rearranges the data by reference to the transmission sequence numbers TSN, then inputs that data to the MAC-d processing unit 24. The MAC-d processing unit 24 gives the MAC-d PDU data as is to the RLC processing unit 25 as RLC-PDU data, and the RLC processing unit 25 removes the header from the selected RLC-PDU data resulting in dedicated data and transmits this dedicated data to the core network 11.

(D) Variation of Control for Determining the Data Transmission Path/Paths

In the embodiment described above, the data transmission path/paths were determined by the process shown in FIG. 4A and FIG. 4B based on the line usage rate, however, it is also possible to determine the data transmission path/paths by measuring other characteristics that indicate a network environment instead of using the line usage rate. Change in a network environment can be measured by (1) radio quality, (2) communication delay time between the RNC and Node B, (3) E-DCH throughput status, (4) lub quality, etc. Therefore, it is possible to perform control so that the data transmission path/paths are set by measuring these characteristics. Moreover, it is possible to perform control so that the data transmission path/paths are determined by measuring two or more of these characteristics.

FIG. 9 is a drawing of the construction of a radio network controller 12 that measures the aforementioned characteristics and determines the data transmission path/paths, where the same reference numbers are given to parts that are the same as those of the construction shown in FIG. 1. This construction differs in that there is: a delay measurement unit 51 that measures the communication delay status between the RNC and Nodes B, a radio quality monitoring unit that monitors the radio quality between the mobile station and base stations, and a E-DCH communication quality monitoring unit 53 that monitors E-DCH throughput information or lub quality.

The delay measurement unit 51 acquires the communication delay status between the RNC and Nodes B using a conventional function. In other words, the delay measurement unit 51 periodically transmits a packet for measuring delay to each base station and measures the time until a response is returned, then inputs that time to the data transmission path determination/notification unit 29 as the delay time of the lub line. The data transmission path determination/notification unit 29 determines that the communication quality of an lub line is good when the delay time is short.

The radio quality monitoring unit 52 monitors the radio quality based on the N of HARQ Retransm (number of retransmissions in the radio zone) within the E-DCH lub FP frame shown in FIG. 20, and inputs the number of retransmissions to the data transmission path determination/notification unit 29. The data transmission path determination/notification unit 29 determines that the quality is poor when the number of retransmissions is greater than a set number, and that the quality is good when the number of transmissions is less than that set number.

The E-DCH communication quality monitoring unit 53 monitors the frame amount of E-DCH lub FP (see FIG. 20) that the MAC-e processing units 22₀ to 22₂ received over a set period of time as E-DCH throughput information, and inputs that frame amount to the data transmission path determination/notification unit 29. The data transmission path determination/notification unit 29 determines that the communication quality of a line is good when the frame amount is greater than a set value. Also, the E-DCH communication quality monitoring unit 53 checks the FSN continuity within the E-DCH lub FP (See FIG. 20), and inputs information indicating whether there is continuity or no continuity to the data transmission path determination/notification unit 29. The data transmission path determination/notification 29 unit determines that the quality is good when there is FSN continuity.

FIG. 10 A and FIG. 10B are flowcharts showing the processing performed by the data transmission path determination/notification unit 29 that determines the data transmission path/paths according to the communication delay time, where a combination of data transmission paths is determined so that when the communication delay time of a line is less than a set time, data is transmitted over that line, and when the delay time of a line is greater than a set time, data is not transferred over that line, an identifier ID that specifies that combination is then found and the mobile station is notified of that identifier ID. FIG. 10A and FIG. 10B are flowcharts of processing that follows the same logic as the processing shown in FIG. 4A and FIG. 4B.

FIG. 11A and FIG. 11B are flowcharts showing the processing performed by the data transmission path determination/notification unit 29 that determines the data transmission path/paths according to the number of retransmissions, where a combination of data transmission paths is determined so that when the number of retransmissions of a line is less than a set number of times, data is transmitted over that line, and when greater than the set number of times, data is not transmitted over that line, an identifier ID that specifies that combination is then found and the mobile station is notified of that identifier ID.

FIG. 12A and FIG. 12B are flowcharts showing the processing performed by the data transmission path determination/notification unit 29 that determines the data transmission path/paths according to the amount of data throughput, where a combination of data transmission paths is determined so that when the amount of throughput of a line is greater than a set value, data is transmitted over that line, and when less than the set number of time, data is not transmitted over that line, an identifier ID that specifies that combination is then found and the mobile station is notified of that identifier ID.

FIG. 13 A and FIG. 13B are flowcharts showing the processing performed by the data transmission path determination/notification unit 29 that determines the data transmission path/paths according to FSN continuity, where a combination of data transmission paths is determined so that when there is a line having FSN continuity, data is transmitted over that line, and when there is no FSN continuity, data is not transmitted over that line, an identifier ID that specifies that combination is then found and the mobile station is notified of that identifier ID.

As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.

Claims

1. A communication method in a mobile communication system that transmits different data to which transmission sequence numbers have been attached, over each of a plurality of paths from a mobile station to a radio network controller via a plurality of base stations, comprising: a step of monitoring the communication state of each path by the radio network controller;a step of determining to transmit data over all of a plurality of paths, transmit data over two or more specified paths, or transmit data over only one specified path based on the communication state of each path;a step of notifying the mobile station of the determined path/paths; anda step of transmitting said respective different data to which different transmission sequence numbers have been attached, over said notified path/paths from the mobile station to the radio network controller.

2. The communication method of claim 1, further comprising a step of rearranging said data received from each path by reference to said transmission sequence numbers in the radio network controller and transmitting the data to a core network from the radio network controller.

3. The communication method of claim 1, further comprising in the radio network controller; a step of notifying the mobile station of a correlation list that correlates path information that indicates which path/paths data is to be transmitted over and an identifier that specifies that path information; anda step of notifying the mobile station of said determined path/paths using the identifier.

4. The communication method of claim 1, wherein the radio network controller monitors, in said communication state monitoring step, the line usage rate of each path between the base stations and radio network controller; and determines in said path determination step, to transmit said data over the path/paths whose line usage rate is less than a set value.

5. The communication method of claim 1, wherein the radio network controller monitors, in said communication state monitoring step, the communication delay time in each path between the base stations and radio network controller; and determines, in said path determination step, to transmit said data over the path/paths whose communication delay time is less than a set value.

6. The communication method of claim 1, wherein the radio network controller monitors, in said communication state monitoring step, the amount of data throughput in each path between the base stations and radio network controller; and determines, in said path determination step, to transmit said data over the path/paths whose amount of data throughput is larger than a set value.

7. The communication method of claim 1, wherein the radio network controller monitors, in said communication state monitoring step, the continuity of the transmission sequence numbers FSN in each path between the base stations and radio network controller; anddetermines, in said path determination step, to transmit said data over the path/paths having said continuity.

8. The communication method of claim 1, wherein in said communication state monitoring step, said radio network controller monitors the number of retransmissions in the radio zone of each path as said communication state; andin said path determination step, said radio network controller determines to transmit said data over the path/paths whose number of retransmissions is less than a set value.

9. A radio network controller in a mobile communication system that transmits different data to which transmission sequence numbers have been attached, over each of a plurality of paths from a mobile station to a radio network controller via a plurality of base stations, comprising: a communication state monitoring unit that monitors the communication state of each path;a data transmission path notification unit that determines to transmit data over all of a plurality of paths, transmit data over two or more specified paths, or transmit data over only one specified path based on the communication state of each path, and notifies the mobile station of the determined path/paths; anda processing unit that rearranges the data received from said determined path/paths by reference to said transmission sequence numbers and transmits the data to a core network.

10. The radio network controller of claim 9, further comprising a list storage unit that stores a correlation list that correlates path information that indicates which path/paths data is to be transmitted over, and an identifier that specifies that path information; whereinsaid data transmission path notification unit notifies the mobile station of said correlation list, and uses the identifier to notify the mobile station of said determined path/paths.

11. The radio network controller of claim 9, wherein said communication state monitoring unit comprisesa line usage rate monitoring unit that monitors the line usage rate of each path between the base stations and radio network controller; andsaid data transmission path notification unit determines to transmit said data over the path/paths whose line usage rate is less than a set value.

12. The radio network controller of claim 9, wherein said communication state monitoring unit comprisesa communication delay time measurement unit that measures the communication delay time in each path between the base stations and radio network controller; andsaid data transmission path notification unit determines to transmit said data over the path/paths whose communication delay time is less than a set value.

13. The radio network controller of claim 9, wherein said communication state monitoring unit comprisesa data throughput amount monitoring unit that monitors the amount of data throughput in each path between the base stations and radio network controller; andsaid data transmission path notification unit determines to transmit said data over the path/paths whose amount of data throughput is larger than a set value.

14. The radio network controller of claim 9, wherein said communication state monitoring unit comprisesa frame continuity monitoring unit that monitors the continuity of the transmission sequence numbers FSN in each path between the base stations and radio network controller; andsaid data transmission path notification unit determines to transmit said data over the path/paths having said continuity.

15. The radio network controller of claim 9, wherein said communication state monitoring unit comprisesa retransmission number monitoring unit that monitors the number of retransmissions in the radio zone of each path as said communication state; andsaid data transmission path notification unit determines to transmit said data over the path/paths whose number of the retransmissions is less than a set value.

16. A mobile station in a mobile communication system that transmits different data to which transmission sequence numbers have been attached, over each of a plurality of paths from a mobile station to a radio network controller via a plurality of base stations, comprising: a list storage unit that receives and stores a correlation list from a radio network controller that correlates path information that indicates which path/paths data is to be transmitted over, and an identifier that specifies that path information;a data transmission path receiving unit that receives an identifier from the radio network controller that indicates which path/paths said data is to be transmitted over, and makes a reference to said correlation list to obtain the path/paths that correspond to the identifier; anda processing unit transmits different data, to which transmission sequence number have been attached, over the path/paths that correspond to said identifier.

17. A mobile communication system that transmits different data to which transmission sequence numbers have been attached, over each of a plurality of paths from a mobile station to a radio network controller via a plurality of base stations, wherein said radio network controller comprises:a communication state monitoring unit that monitors the communication state of each path;a data transmission path notification unit that determines to transmit data over all of a plurality of paths, transmit data over two or more specified paths, or transmit data over only one specified path based on the communication state of each path, and notifies the mobile station of the determined path/paths; anda processing unit that rearranges the data received from said determined path/paths by reference to said transmission sequence numbers and transmits the data to a core network; andsaid mobile station comprises:a receiving unit that receives transmission path specification information from the radio network controller that specifies which path/paths data is to be transmitted over; anda processing unit that transmits different data to which transmission sequence numbers have been attached, over the specified path/paths.

18. The mobile communication system of claim 17, wherein said radio network controller further comprises a correlation list storage unit that stores a correlation list that correlates path information that indicates which path/paths data is to be transmitted over, and an identifier that specifies that path information;said mobile station further comprises a list storage unit that receives and stores said correlation list from the radio network controller; andsaid data transmission path notification unit uses the identifier to notify the mobile station of said determined path/paths; and said receiving unit makes a reference to said correlation list to obtain the path/paths that correspond to the identifier received from the radio network controller and inputs the path/paths to the processing unit.