JP5229739B2 - Wireless network control apparatus, mobile communication system, reordering control method and program - Google Patents

Description

  The present invention relates to a radio network controller, a mobile communication system, and a reordering control method and program, and more particularly, to a technique for rearranging data packets in accordance with the HSUPA (High Speed Uplink Packet Access) method or the like.

  In recent years, the specification of the HSUPA method by 3GPP (3rd Generation Partnership Project) has been studied. This HSUPA scheme is generally intended to improve the uplink data transmission rate in a mobile communication system employing a W-CDMA (Wideband Code Division Multiple Access) scheme.

  More specifically, an RNC (Radio Network Controller) constituting the mobile communication system terminates an E-DCH FP (Enhanced Dedicated Channel Frame Protocol) frame from the base station, and the E-DCH A reordering process is executed for a plurality of MAC-es PDUs (Medium Access Control Protocol Data Units) included in the FP frame. Here, the MAC-es PDU is a data packet wirelessly transmitted from the mobile station to the base station.

  A general RNC that executes the above-described reordering process is described in Patent Document 1, for example. The reordering processing unit in the RNC rearranges each MAC-es PDU in the order of TSN (Transmission Sequence Number) added thereto. Here, TSN indicates the generation order of MAC-es PDUs by the mobile station.

  In addition, when the reordering processing unit detects a TSN missing number (that is, missing reception of the MAC-es PDU) when rearranging the MAC-es PDUs, it starts a timer for measuring a certain time, thereby It waits for reception of a MAC-es PDU corresponding to the TSN in which the Thereafter, when a waiting MAC-es PDU is received, the reordering processing unit stops the timer, and the MAC-es PDU and a subsequent MAC-es PDU in which the order confirmation has already been completed. Are sequentially transferred to the upper layer. When the timer expires, the reordering processing unit gives up receiving the waiting MAC-es PDU and transfers only the subsequent MAC-es PDU to the upper layer.

JP 2008-301178 A

  However, the above-described Patent Document 1 has a problem in that the throughput of the reordering process (that is, the data transmission rate in the uplink direction) is reduced when reception failure of the MAC-es PDU occurs. This is because even if the waiting MAC-es PDU cannot be received, the reception of the MAC-es PDU is waited for a certain period of time, and the subsequent MAC-es PDU is retained.

  Therefore, an object of the present invention is to provide a radio network control device, a mobile communication system, a reordering control method, and a program capable of improving the throughput of reordering processing.

  In order to achieve the above object, a radio network controller according to an aspect of the present invention includes: a receiving unit that sequentially receives a frame including a plurality of data packets generated by a mobile station from a base station; A reordering unit that rearranges the data packets in the order of the sequence numbers added thereto, and the reordering unit sets a reception waiting time of an expected data packet to be received next in the rearrangement as the mobile station and the base A maximum time that a station can take to retransmit the expected data packet, a sequence number added to one received data packet among data packets to be received later than the expected data packet, and the expected data The transmission between the two data packets by the mobile station calculated based on the sequence number corresponding to the packet. It is set to the first time difference and the time difference.

  The mobile communication system according to one aspect of the present invention receives a mobile station that adds a sequence number to the data packet and transmits the data packet every time a data packet is generated, and receives the data packet within a certain period of time. A base station that generates a frame including a plurality of data packets; and a base station that transmits the frame; and a radio network controller that sequentially receives the frames from the base station and rearranges the data packets in the sequence number order. The wireless network control apparatus receives the expected data packet to be received next in the rearrangement, the maximum time that the mobile station and the base station can retransmit the expected data packet, and the expected data packet It is added to one received data packet among the data packets to be received later. Sequence number, and the calculated on the basis of the sequence number corresponding to the expected data packet, waits difference time between the transmission time difference between the two data packets by the mobile station.

  A reordering control method according to an aspect of the present invention provides a reordering control method in a radio network control device. In this reordering control method, a frame including a plurality of data packets generated by a mobile station is sequentially received from a base station, and when each data packet is rearranged in the sequence number added thereto, the next reception is performed. The reception waiting time of the expected data packet to be received is the maximum time that the mobile station and the base station can take to retransmit the expected data packet and one of the received data packets to be received later than the expected data packet. Is set to a first difference time from a transmission time difference between the data packets by the mobile station, which is calculated based on the sequence number added to the data packet and the sequence number corresponding to the expected data packet.

  Furthermore, the reordering control program according to one aspect of the present invention includes a process of sequentially receiving a frame including a plurality of data packets generated by a mobile station from a base station, and a data network packet received by the radio network controller. When the data is rearranged in the order of the sequence numbers added to the received data, the reception waiting time of the expected data packet to be received next is set to the maximum time that the mobile station and the base station can retransmit the expected data packet, and the expected data. Calculated based on a sequence number added to one received data packet among data packets to be received later than the packet, and a sequence number corresponding to the expected data packet, between the two data packets by the mobile station And a process for setting the first difference time with the transmission time difference.

  In the present invention, a data packet in which reception loss has occurred is waited for a minimum necessary time that can be received in accordance with retransmission control between the mobile station and the base station. For this reason, it is possible to shorten the dwell time of the subsequent data packet when the waiting data packet cannot be received, thereby improving the throughput of the reordering process.

1 is a block diagram showing a configuration example of a radio network control apparatus according to Embodiment 1 of the present invention and a mobile communication system to which the radio network control apparatus is applied. It is the flowchart figure which showed the operation example of the frame selection part used for the radio | wireless network control apparatus which concerns on Embodiment 1 of this invention. It is the flowchart figure which showed the example of whole operation | movement of the order correction | amendment part used for the radio network controller which concerns on Embodiment 1 of this invention. It is the flowchart figure which showed the starting process example of the reordering timer in the order correction | amendment part used for the radio network controller which concerns on Embodiment 1 of this invention. It is the time chart figure which showed the setting operation example of the reordering timer in the order correction | amendment part used for the radio network controller which concerns on Embodiment 1 of this invention. It is the figure which showed the structural example of the reordering table used for the radio | wireless network control apparatus which concerns on Embodiment 1 of this invention. It is the flowchart figure which showed the update process example of the reordering table in the order correction | amendment part used for the radio network control apparatus which concerns on Embodiment 1 of this invention. It is the figure which showed the example of a setting of the reordering table in the order correction | amendment part used for the radio network controller which concerns on Embodiment 1 of this invention. It is the flowchart figure which showed the time-out process example of the reordering timer in the order correction | amendment part used for the radio network controller which concerns on Embodiment 1 of this invention. It is the flowchart figure which showed the transfer process example of the subsequent PDU in the order correction | amendment part used for the radio network controller which concerns on Embodiment 1 of this invention. It is the block diagram which showed the structural example of the radio network control apparatus which concerns on Embodiment 2 of this invention. It is the figure which showed the example of a setting of the receiving window used for the radio network control apparatus which concerns on Embodiment 3 of this invention. It is the flowchart figure which showed the example of whole operation | movement of the order correction | amendment part used for the radio network control apparatus which concerns on Embodiment 3 of this invention. It is the flowchart figure which showed the transfer process example of subsequent PDU in the order correction | amendment part used for the radio network control apparatus which concerns on Embodiment 3 of this invention. It is the flowchart figure which showed the starting process example of the reordering timer in the order correction | amendment part used for the radio network controller which concerns on Embodiment 3 of this invention. It is the block diagram which showed the structural example of the radio network control apparatus which concerns on Embodiment 4 of this invention. It is the figure which showed the example of a setting of effective CFN used for the radio network control apparatus which concerns on Embodiment 4 of this invention. It is the flowchart figure which showed the operation example of the frame selection part used for the radio | wireless network control apparatus which concerns on Embodiment 4 of this invention.

  Embodiments 1 to 4 of a radio network controller according to the present invention and a mobile communication system to which the radio network controller is applied will be described below with reference to FIGS. In the drawings, the same components are denoted by the same reference numerals, and redundant description is omitted as necessary for the sake of clarity.

[Embodiment 1]
A mobile communication system 1 according to the present embodiment shown in FIG. 1 is connected to a mobile station 10, a base station 20 that performs wireless communication with the mobile station 10, and the base station 20 via a wired transmission path. The radio network controller (RNC) 30 provides an upstream data transmission service that conforms to the HSUPA system as an example.

  Among these, the mobile station 10 wirelessly transmits a MAC-es PDU (hereinafter also abbreviated as PDU) 110 to which the TSN 111 is added in the HSUPA service area (cell) 21 formed by the base station 20. In addition, since the general mobile station which operate | moves according to a HSUPA system can be used for the mobile station 10, description is abbreviate | omitted about the detailed structure.

  In addition, the base station 20 generates an E-DCH FP frame (hereinafter sometimes abbreviated as a frame) 120 including a plurality of PDUs 110 received from the mobile station 10 within a certain period, and And send it out. In addition, since the general base station which operate | moves according to a HSUPA system can be used for the base station 20, description is abbreviate | omitted about the detailed structure.

  Furthermore, the radio network controller 30 includes a receiving unit 31 that sequentially receives the frames 120 from the base station 20 and a reordering unit 32 that rearranges the PDUs 110 included in the frame 120 in the order of TSN 111. Although not shown, the wireless network control device 30 also performs general control such as communication connection and switching of a communication path between the mobile station 10 and a public telephone network subscriber terminal or another mobile station.

  The receiving unit 31 receives the frame 120 for each logical channel (E-DCH), and holds the frame 120 received via each logical channel in an individual buffer (not shown).

  The reordering unit 32 includes a frame selection unit 321, an order correction unit 322, and a timer function unit 323 that starts and stops a timer.

  Among these, the frame selection unit 321 selects a normal frame without a transmission error from the frame 120 acquired from the reception unit 31, extracts the PDU 110 from the selected frame, and transfers it to the order correction unit 322.

  In addition, the order correction unit 322 refers to the TSN 111 added to the PDU 110 transferred from the frame selection unit 321 and corrects the order of the PDUs 110. The order correction unit 322 transfers the PDU 110 after the order correction to the data separation unit 33 indicated by a dotted line in FIG. Note that the data separation unit 33 has a function of separating the PDU 110 into MAC-d (dedicated channel) data.

  Further, the order correcting unit 322, when receiving an expected PDU to be received next during the order correction, causes the timer function unit 323 to wait for reception of the expected PDU (hereinafter referred to as “reset”). Instructs start-up of 130 (referred to as an ordering timer). Here, the order correction unit 322 sets the timer value of the reordering timer 130 to the maximum time that the mobile station 10 and the base station 20 can retransmit the expected PDU (hereinafter referred to as the maximum retransmission time), and the expected PDU. And a TSN added to a PDU (that is, a subsequent PDU) received prior to the expected PDU among PDUs to be received later than the expected PDU. Set based on. When receiving the time-out notification 140 indicating the expiration of the reordering timer 130 from the timer function unit 323, the order correction unit 322 gives up receiving the expected PDU, corrects the order of subsequent PDUs, and forwards it to the data separation unit 33.

  Next, the operation of the present embodiment will be described in detail with reference to FIGS. 2 to FIG. 10, only the operation example of the radio network control device 30 is handled, and the description of the operation of the mobile station 10 and the base station 20 is omitted.

  As shown in FIG. 2, first, the frame selection unit 321 in the reordering unit 32 shown in FIG. 1 acquires the E-DCH FP frame 120 from the reception unit 31 (step S1). Then, the frame selection unit 321 refers to CRC (Cyclic Redundancy Check, not shown) set in the header and payload (both not shown) of the frame 120 to determine whether or not the frame 120 is a normal frame. Determine (steps S2 and S3).

  As a result, when it is determined that the frame 120 is a normal frame, the frame selection unit 321 extracts the MAC-es PDU 110 from the payload and transfers it to the order correction unit 322 (step S4). On the other hand, when the frame 120 is not a normal frame, the frame selection unit 321 discards the frame 120 (step S5).

  As shown in FIG. 3, when receiving the PDU 110 from the frame selection unit 321 (step S11), the order correction unit 322 determines whether or not the expected TSN 111e matches the TSN 111 added to the PDU 110 (step S12). ).

  As a result, when the expected TSN 111e does not match the TSN 111, the order correction unit 322 executes the reordering timer start process shown in FIG. 4 (step S13).

  More specifically, when the reordering timer 130 has not been started yet (step S21), the order correction unit 322 calculates the timer value 131 of the reordering timer 130 according to the following equation (1) (step S22). ).

Timer value 130 = maximum retransmission time 132−sending time difference 133 (1)

  Here, the maximum retransmission time 132 in the above equation (1) depends on the retransmission control time per one expected PDU by the mobile station 10 and the base station 20 shown in FIG. 1 and the maximum number of retransmissions of the expected PDU. Time to be determined. Among these, the retransmission control time includes the TTI (Transmission Time Interval, the transmission time interval between PDUs by the mobile station 10) and the number of processes required for HARQ (Hybrid Automatic ReQuest) control (hereinafter referred to as the number of HARQ control processes). It is represented by the product of The number of HARQ control processes becomes “4” when the TTI is set to “10 ms”, and becomes “8” when the TTI is set to “2 ms”. On the other hand, the maximum number of retransmissions is specified by the “Maximum Number of Retransmission for E-DCH” parameter notified from the radio network control apparatus 30 to the base station 20, and can take a value range of “0” to “15”. Therefore, the maximum retransmission time 132 can be expressed by the following equation (2).

Maximum retransmission time 132 = Maximum number of retransmissions × TTI × HARQ control process number
... Formula (2)

  Further, the transmission time difference 133 in the above equation (1) is a transmission time difference between the expected PDU-PDU 110 by the mobile station 10 and can be calculated according to the following equation (3).

Transmission time difference 133 = (TSN111−expected TSN111e) × TTI Expression (3)

  For example, as shown in FIG. 5, TSN = “4” is added in a state where the expected TSN 111e is set to “1” (that is, waiting for reception of the PDU 110_1 with TSN = “1” added). When the received PDU 110_4 is received, the transmission time difference 133 is 3TTI.

  That is, the transmission time difference 133 indicates how much before the transmission time t0 of the expected PDU 110_1 by the mobile station 10 is before the reception time t1 of the PDU 110_4 currently being processed. On the other hand, the maximum retransmission time 132 indicates a time t2 at which the expected PDU 110_1 can be received with the most delay, starting from the time t0. Therefore, the timer value 131 calculated as the difference time between the maximum retransmission time 132 and the transmission time difference 133 indicates a boundary time at which the expected PDU 110_1 can be received with a further delay, starting from the current time t1.

  Then, the order correction unit 322 determines whether or not the timer value 131 calculated in step S22 is “0” or less (that is, whether or not the boundary time has passed) (step S23). .

  As a result, when the timer value 131 ≦ “0” is established, the order correction unit 322 gives up receiving the expected PDU 110_1 and transfers the PDU 110_4 to the data separation unit 33 (step S24). Then, the order correction unit 322 increments the expected TSN 111e by “1” (step S25).

  On the other hand, when the timer value 131> “0” is established, the order correction unit 322 registers TSN111 = “4” and PDU 110_4 as the first record of the reordering table 34 shown in FIG. 6 (step S26). Then, the order correction unit 322 instructs the timer function unit 323 to specify the timer value 131, thereby starting the reordering timer 130 (step S27).

  Thereafter, it is assumed that PDUs 110_2 and 110_3 indicated by dotted lines in FIG. 5 are received in order. In this case, the order correction unit 322 determines that the reordering timer 130 has been started, and repeatedly executes the reordering table update process shown in FIG. 7 (step S28).

  More specifically, the order correction unit 322 first sets a TSN 111c (hereinafter referred to as a comparison target TSN) 111c added to the PDU 110_2 as a comparison target of TSN 111 = “2” as shown in FIG. Then, TSN = “4” included in the last record in the reordering table 34 is set (step S31).

  Now, since TSN111 ("2") <comparison target TSN111c ("4") is established (step S32) and the comparison target TSN111 is a TSN included in the first record in the reordering table 34 (step S33), The order correction unit 322 inserts TSN111 = “2” and PDU 110_2 as the first record of the reordering table 34 as shown in FIG. 8B (step S34).

  Then, the order correction unit 322 performs the above steps S31 to S33 again for the PDU 110_3. As a result, in step S33 described above, the order correction unit 322 determines that the comparison target TSN 111 ("4") is not the TSN included in the first record in the reordering table 34, and the comparison target TSN 111 is displayed as shown in FIG. As shown in b), TSN = “2” included in the immediately preceding record in the reordering table 34 is updated (step S35).

  In this case, since TSN111 ("3")> comparison target TSN111c ("2") is established in step S32, the order correction unit 322 performs comparison in the reordering table 34 as shown in FIG. TSN111 = "3" and PDU 110_3 are inserted at a position immediately behind the target TSN 111c (step S36).

  Further, it is assumed that PDU 110_6 to which TSN 111 = "6" is added is received. In this case, since TSN111 ("6")> comparison target TSN111c ("4") is established in step S32, the order correction unit 322 executes step S36 again, and FIG. As shown in FIG. 5, TSN 111 = “6” and PDU 110 — 6 are registered as the last record of the reordering table 34.

  Thereafter, when the timeout notification 140 is received from the timer function unit 323, the order correction unit 322 executes the timeout process shown in FIG. That is, the order correction unit 322 gives up receiving the expected PDU 110_1 and increments the expected TSN 111e by “1” (step S41). Then, the order correction unit 322 executes the subsequent PDU transfer process shown in FIG. 10 (step S42).

  More specifically, the order correction unit 322 first determines whether or not the expected TSN 111e (“2”) matches the TSN included in the first record in the reordering table 34 (step S51).

  Since TSN = “2” is registered in the first record in the reordering table 34 (see FIG. 8D), the order correction unit 322 transfers the PDU 110_2 to the data separation unit 33. The order correcting unit 322 deletes the first record in the reordering table 34 (step S53) and increments the expected TSN 111e by “1” (step S54).

  Then, the order correction unit 322 determines whether another record is registered in the reordering table 34 (step S55).

  Since there are records relating to TSN = “3”, “4”, and “6” in the reordering table 34, the order correction unit 322 repeatedly executes the above steps S51 to S55, and thus PDU 110_3. And 110_4 are sequentially transferred to the data separator 33, and the expected TSN 111e is updated to "5".

  At this time, since the expected TSN 111e (“5”) does not match the TSN (“6”) included in the first record in the reordering table 34, the order correction unit 322 sets the timer value 131 of the reordering timer 130 to the above value. Is calculated according to the equation (1) (step S56). However, the order correction unit 322 calculates the transmission time difference 133 according to the following equation (4).

・ Transmission time difference 133 =
(First TSN in table 34−expected TSN 111e) × TTI (4)

  Then, the order correction unit 322 determines whether or not the timer value 131 calculated in Step S56 is “0” or less (Step S57).

  As a result, when the timer value 131 ≦ “0” is satisfied, the order correction unit 322 gives up reception of the PDU 110_5 (not shown) to which the expected TSN 111e = “5” is added, and proceeds to the above step S54 to expect TSN 111e is updated to “6”. As a result, the PDU 110_6 is transferred to the data separator 33.

  On the other hand, when the timer value 131> “0” is established, the order correction unit 322 starts the reordering timer 130 (step S58). As a result, reception of the PDU 110_5 is waited.

  In this way, the radio network controller 30 waits for reception of a PDU in which reception loss has occurred for a minimum necessary time that can be received with HARQ control between the mobile station 10 and the base station 20. For this reason, it is possible to reduce the residence time of the subsequent PDU when it is not possible to receive a waiting PDU.

  Returning to FIG. 3, when it is determined in step S12 that the expected TSN 111e matches the TSN 111, the order correction unit 322 immediately transmits the PDU 110 to the data separation unit 33 without registering it in the reordering table 34. Transfer (step S14). In addition, the order correction unit 322 increments the expected TSN 111e by “1” (step S15).

  When the reordering timer 130 has been started (step S16), the order correction unit 322 causes the timer function unit 323 to stop the reordering timer 130 (step S17).

  Further, when there is a record in the reordering table 34 (step S18), the order correction unit 322 executes the subsequent PDU transfer process shown in FIG. 10 (step S19).

  The timer value 131 of the reordering timer 130 is preferably calculated according to the following equation (5).

・ Timer value 130 =
Maximum retransmission time 132−sending time difference 133 + TTI Expression (5)

  In the above equation (5), a margin of 1 TTI is added to the timer value shown in the above equation (1). This is because there is a possibility that the most delayed reception timing of the expected PDU and the execution timing of the timer-out process are the same. By adding a margin for 1 TTI, it is possible to avoid that both timings are the same, thereby preventing the expected PDU from being discarded unnecessarily.

[Embodiment 2]
In radio network control apparatus 30a according to the present embodiment shown in FIG. 11, receiving unit 31 stores a reception time (hereinafter referred to as PDU reception time) 150 of MAC-es PDU 110, and reordering unit 32. Is different from the first embodiment in that the order correction unit 322 sets the reordering timer 130 by further using the PDU reception time 150.

  In operation, the order correction unit 322 calculates the timer value 131 of the reordering timer 130 according to the following equation (6).

Timer value 130 = maximum retransmission time 132-transmission time difference 133
-Buffering time 134 (6)

  Here, the buffering time 134 in the above equation (6) is represented by the following equation (7) in step S22 shown in FIG. 4, and is represented by the following equation (8) in step S56 shown in FIG. be able to. The buffering time 134 in the following equation (7) indicates the holding time of the PDU 110 in the receiving unit 31, and the buffering time 134 in the following equation (8) indicates the holding time of the PDU 110 in the reordering table 34. .

Buffering time 134 = Current time-PDU reception time 150 (7)
・ Buffering time 134 =
Current time-reception time of the first PDU in the table 34 (8)

  By subtracting the buffering time 134, the timer value 131 of the reordering timer 130 can be set more accurately (setting of an extra time value can be prevented). The buffering time 134 may be subtracted from the timer value 131 shown in the above equation (5).

[Embodiment 3]
The radio network control apparatus according to the present embodiment can have the same configuration as radio network control apparatus 30 or 30a shown in the first or second embodiment. However, the order correction unit 322 in the reordering unit 32 determines whether or not the MAC-es PDU 110 is a target of the reordering process using the reception window 160 illustrated in FIG.

  Here, because the value range of TSN 111 is defined as 0-63 (ie, because the value of TSN 111 may circulate during a series of burst transmission cycles of PDU 110 by mobile station 10), receive window 160 is expected TSN 111e. PDU110 to which TSN111 having a value of +0 to +31 in the circulation direction is added as a target of reordering processing, and PDU110 to which TSN111 having a value of −1 to −32 is added to expected TSN111e is reordered. It is preferable to set it so as not to be processed.

  More specifically, the order correction unit 322 determines that the TSN 111 (PDU 110) fits in the reception window 160 when the condition shown in the following equation (9) is satisfied.

Mod {(64 + TSN111−expected TSN111e), 64} <32 (9)

  In operation, the order correction unit 322 executes the processes of steps S61 and S62 shown in FIGS. 13 and 14 in addition to steps S11 to S19 shown in FIG. 3 and steps S51 to S58 shown in FIG. That is, the order correction unit 322 sets the start time 161 of the reception window 160 to the current time at the timing when the expected PDU is transferred to the data separation unit 33, and sets the start time 161 at the timing when the subsequent PDU is transferred. 34 is set to the reception time of the first PDU.

  Further, in the reading timer starting process, the order correction unit 322 executes the processes of steps S63 to S65 shown in FIG. 15 in addition to the steps S21 to S28 shown in FIG. First, the order correction unit 322 determines whether 32 TTI has elapsed from the start time 161 of the reception window 160 (step S63).

  As a result, when 32 TTI has not elapsed since the start time 161, the order correction unit 322 further determines whether or not the TSN 111 is within the reception window 160 (step S64). When the TSN 111 does not fit in the reception window 160, the order correction unit 322 determines that the PDU 110 is an unnecessary PDU (PDU received after the timeout of the reordering timer 130) that gave up reception in the course of the reordering process. Judgment is made and the PDU 110 is discarded (step S65). On the other hand, when the TSN 111 falls within the reception window 160, the order correction unit 322 executes a reordering timer start process similar to that in FIG.

  As a result, it is possible to eliminate the influence of unnecessary PDUs on subsequent processing, thereby reducing the load of reordering processing.

  If it is determined in step S63 that 32 TTI has elapsed from the start time 161, the order correction unit 322 performs the same reordering as in FIG. 4 without executing the determination process shown in step S64. Execute timer start processing.

  As a result, the following effects (A) and (B) can be obtained.

 (A) When the PDU 110 is transmitted in a burst transmission cycle different from the expected PDU, the PDU 110 can be handled as a target of the reordering process. That is, even when the start value of TSN 111 is different for each burst transmission cycle, the reordering process in each burst transmission cycle can be accurately executed.

 (B) A temporary failure occurs in the mobile station 10 or the base station 20, and the PDU 110 or the frame 120 is not transmitted. After that, the failure is recovered and the radio network controller 30 (or 30a) When received, the PDU 110 included in the normally received frame 120 can be prevented from being unnecessarily discarded.

[Embodiment 4]
The radio network control device 30b according to the present embodiment shown in FIG. 16 is different from the first embodiment in that it is connected to a plurality (three in this example) of base stations 20_1 to 20_3.

  In this case, the radio network controller 30b can receive the E-DCH FP frame 120 including the same MAC-es PDU 110 in duplicate from the base stations 20_1 to 20_3. This is because the mobile station 10 multicasts the MAC-es PDU 110 in the overlapping area of the HSUPA service areas 21_1 to 21_3 formed by the base stations 20_1 to 20_3, respectively.

  Therefore, the frame selection unit 321 in the radio network control device 30b monitors duplicate reception of the frame 120 using a CFN (Connection Frame Number) 121.

  Here, considering that the value range of the CFN 121 is defined as 0 to 255, the frame selection unit 321 performs the CFN (hereinafter referred to as a received CFN) added to the received frame as illustrated in FIG. CRN 121 having a value of +0 to +128 in the circulation direction is regarded as a valid CFN 121v and CFN 121 having a value of −1 to −127 is treated as an invalid CFN.

Received CFN121r
More specifically, the frame selection unit 321 determines that the CFN 121 that satisfies the condition expressed by the following equation (10) is an effective CFN 121v.

Mod {(256 + CFN121−received CFN121r), 256} ≦ 128
... Formula (10)

  In operation, the frame selection unit 321 executes the processes of steps S71 to S73 shown in FIG. 18 in addition to steps S1 to S5 shown in FIG. That is, first, the frame selection unit 321 determines whether or not “1280 ms” has elapsed since the previous frame reception time 122 (step S71). This is because the CFN 121 counts up by “1” every “10 ms”.

  As a result, when “1280 ms” has not elapsed since the frame reception time 122, the frame selection unit 321 further determines whether or not the CFN 121 is a valid CFN 121v (step S72). When the CFN 121 is not the valid CFN 121v, the frame selection unit 321 determines that the frame 120 is a duplicate received frame, and proceeds to step S5 to discard the frame 120. On the other hand, when the CFN 121 is the valid CFN 121v, the frame selection unit 321 updates (or sets) the received CFN 121r and the frame reception time 122 (step S73).

  As a result, the same PDU is not transferred to the subsequent order correction unit 322, so that the load of the reordering process can be reduced.

  If it is determined in step S71 that “1280 ms” has elapsed from the frame reception time 122, the frame selection unit 321 does not execute the determination process shown in step S72, but performs step S73. Proceed to

  Thereby, even when the start value of the CFN 121 is different for each burst transmission cycle, it is possible to prevent the frame 120 from being discarded unnecessarily, and therefore, the reordering process in each burst transmission cycle is accurately executed. Can do.

  Note that the present invention is not limited to the above-described embodiments, and it is apparent that various modifications can be made by those skilled in the art based on the description of the scope of the claims.

  For example, each process shown in the above embodiment can be provided as a program for causing a wireless network control apparatus to execute the processes. In this case, it is preferable to store the program in a storage medium such as a memory so that the processor in the wireless network control device can execute the program. Alternatively, the program may be provided as a plug-in to firmware incorporated in an existing control circuit.

DESCRIPTION OF SYMBOLS 1 Mobile communication system 10 Mobile station 20, 20_1-20_3 Base station 21, 21_1-21_3 HSUPA service area 30, 30a, 30b Radio network control device 31 Receiving part 32 Reordering part 33 Data separation part 34 Reordering table 110, 110_1 ~ 110_6 MAC-es PDU
111 TSN
111c Comparison target TSN
111e Expected TSN
120 E-DCH FP frame 121 CFN
121r CFN received
121v Effective CFN
122 frame reception time 130 reordering timer 131 timer value 132 maximum retransmission time 133 transmission time difference 140 timeout notification 150 PDU reception time 160 reception window 161 start time 321 frame selection unit 322 order correction unit 323 timer function unit t0 to t2 time

Claims (18)

A receiving unit for sequentially receiving frames including a plurality of data packets generated by the mobile station from the base station;
A reordering unit that rearranges each data packet in the order of the sequence number added to each data packet;
The reordering unit sets a reception waiting time of an expected data packet to be received next in the rearrangement, a maximum time that the mobile station and the base station can retransmit the expected data packet, and the expected data packet. Calculated based on the sequence number added to one received data packet among the data packets to be received later and the sequence number corresponding to the expected data packet, between the two data packets by the mobile station A wireless network control device that is set to a first differential time with a transmission time difference. In claim 1,
The radio network control apparatus, wherein the reordering unit waits for reception of the expected data packet for a transmission time interval between the data packets by the mobile station after the reception standby time has elapsed. In claim 1 or 2,
The receiver stores the reception time of each data packet;
The reordering unit sets the reception standby time to a time obtained by further subtracting a second differential time between the current time and the reception time of the one data packet acquired from the reception unit from the first differential time. A wireless network control device characterized by setting. In any one of Claims 1-3,
A value within a certain range is circulated and set to the sequence number,
The reordering unit treats a data packet to which a sequence number having a value within a predetermined difference in a circulation direction with respect to a sequence number corresponding to the expected data packet as an object of the rearrangement. Wireless network control device. In claim 4,
When the time corresponding to the predetermined difference elapses from the time when the expected data packet was received last time, the reordering unit treats subsequent data packets as the target of rearrangement regardless of the value of the sequence number. A wireless network control device characterized by that. In any one of Claims 1-3,
A frame number is added to the frame, and a value within a certain range is circulated and set to the frame number,
The reordering unit reorders data packets included in a frame to which a frame number having a value within a predetermined difference in a circulation direction is added to a frame number added to a received frame. A wireless network control device characterized by being treated as a target. In claim 6,
When the reordering unit has passed a time corresponding to the predetermined difference from the reception time of the previous frame, regardless of the value of the frame number, the data packets included in the subsequent frames are subject to the rearrangement. A wireless network control device characterized by being treated as In any one of Claims 1-7,
The frame and the data packet are respectively an E-DCH FP (Enhanced Channel Frame Protocol) and a MAC-es PDU (Medium Access Demand) that are defined in the HSUPA (High Speed Uplink Packet Access) method. A wireless network control device characterized by that. Each time a data packet is generated, a mobile station that transmits the data packet with a sequence number added thereto;
Generating a frame including a plurality of data packets received from the mobile station within a predetermined period, and transmitting the frame;
A radio network controller that sequentially receives the frames from the base station and rearranges each data packet in the sequence number order, and
From the expected data packet, the radio network controller receives the expected data packet to be received next in the rearrangement, the maximum time that the mobile station and the base station can take to retransmit the expected data packet, and Transmission between both data packets by the mobile station calculated based on the sequence number added to one received data packet among the data packets to be received late and the sequence number corresponding to the expected data packet A mobile communication system that waits for a difference time from a time difference. A reordering control method in a radio network controller, comprising:
From the base station, sequentially receive frames including a plurality of data packets generated by the mobile station,
When the data packets are rearranged in the order of the sequence numbers added thereto, the reception waiting time of the expected data packet to be received next is the maximum time that the mobile station and the base station can take to retransmit the expected data packet. Calculated by the mobile station based on a sequence number added to one received data packet among data packets to be received later than the expected data packet, and a sequence number corresponding to the expected data packet. A reordering control method for setting a first difference time with a transmission time difference between both data packets. In claim 10,
A reordering control method, comprising: waiting for reception of the expected data packet after an elapse of the reception waiting time, by a transmission time interval between the data packets by the mobile station. In claim 10 or 11,
Store the reception time of each data packet,
The reordering control method, wherein the reception waiting time is set to a time obtained by further subtracting a second difference time between a current time and a reception time of the one data packet from the first difference time. In any one of Claims 10-12,
When a value within a certain range is cyclically set to the sequence number, a data packet in which a sequence number having a value within a predetermined difference in the circulation direction is added to the sequence number corresponding to the expected data packet A reordering control method characterized in that it is treated as the target of the rearrangement. In claim 13,
When the time corresponding to the predetermined difference elapses from the reception time of the last expected data packet, the subsequent data packet is treated as the target of rearrangement regardless of the value of the sequence number. Ordering control method. In any one of Claims 10-12,
When a frame number is added to the frame and a value within a certain range is circulated and set in the frame number, within a difference predetermined in the circulation direction with respect to the frame number added to the received frame A reordering control method characterized in that a data packet included in a frame to which a frame number having a value is added is treated as the target of rearrangement. In claim 15,
When a time corresponding to the predetermined difference has elapsed since the reception time of the previous frame, regardless of the value of the frame number, data packets included in subsequent frames are treated as the target of the rearrangement. Reordering control method. In any one of Claims 10-16,
A reordering control method using an E-DCH FP frame and a MAC-es PDU defined in the HSUPA scheme as the frame and the data packet, respectively. Wireless network controller
A process of sequentially receiving frames including a plurality of data packets generated by the mobile station from the base station;
When the data packets are rearranged in the order of the sequence numbers added thereto, the reception waiting time of the expected data packet to be received next is the maximum time that the mobile station and the base station can take to retransmit the expected data packet. Calculated by the mobile station based on a sequence number added to one received data packet among data packets to be received later than the expected data packet, and a sequence number corresponding to the expected data packet. A process of setting a first difference time with a transmission time difference between both data packets;
Reordering control program to execute

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