JP4810259B2 - MAC multiplexed real-time flow control method, apparatus and program - Google Patents

Description

  The present invention relates to a MAC multiplexed real-time flow control method, apparatus and program in a mobile packet communication node system.

In conventional MAC (Media Access Control) multiplexed flow control,
(A) equal division for equally dividing the maximum transmission rate of the transport channel for each logical channel;
(B) A rate limit for assigning a maximum transmission rate to each logical channel and shaping the maximum transmission rate by the media access control unit;
Is generally adopted.

  Patent Document 1 discloses a method of supporting HSDPA (High Speed Downlink Packet Access) traffic as traffic having different QoS in the third generation mobile phone communication system (Rel99). . Patent Document 2 discloses a method for transmitting HSDPA data to a network element of UTRAN (Universal mobile telecommunication services terrestrial radio access network) via an Iub interface. However, Patent Documents 1 and 2 do not describe real-time control of the transmission rate of the MAC multiplexed logical channel performed in the data link layer.

JP 2003-229901 A JP-A-2005-501494

  The conventional system described above has the following problems.

  In the case of the above (a), a division loss of the transmission rate occurs by dividing the maximum transmission rate equally.

  For example, if the transport channel has two logical channels A and B multiplexed and the maximum transmission rate of the transport channel is 10, 5 is assigned to the logical channels A and B. When the reception buffer storage amounts of the two logical channels A and B are respectively A = 8 and B = 2, the transmission rate of each logical channel is assigned to 5, so that the transmission rate of A = 5 and B = 2 Send with.

  At this time, the transmission rate of the transport channel after MAC multiplexing is 5 + 2, that is, the total = 7, and a loss of 3 occurs for the maximum transmission rate = 10. In the reception buffer of logical channel A, 3 remains, and it cannot be said that optimum flow control is performed.

  On the other hand, in the case of (b) above, when each logical channel transmits data at the maximum transmission rate, if the logical channel is simply multiplexed, the maximum transmission rate of the transport channel will be exceeded. Shaping is required to keep the rate below the maximum transmission rate.

  Furthermore, since packet data overflowed by shaping needs to be buffered in the media access control unit, it is necessary to provide a data buffer for shaping, leading to an increase in the amount of memory.

  Further, in the shaping for the maximum transmission rate of the transport channel, the transmission rate between the logical channels cannot be optimally allocated.

  The present invention was created to solve the above-described problems, and an object of the present invention is to provide an apparatus, a system, and a method that can optimally calculate the transmission rate of each logical channel and realize optimal flow control. To provide a program. Another object of the present invention is to provide an apparatus, a system, a method, and a program that can realize the optimum flow control in real time.

  In order to solve the above-described problems, the invention disclosed in the present application is generally configured as follows.

  The present invention includes a flow control unit in a media access control unit, a maximum transmission rate of a transport channel determined by a radio base station apparatus and notified by an FP layer, and a reception buffer for each logical channel of a radio link control unit By configuring the FP layer to notify the state change during packet communication according to the accumulated amount, real-time flow control is possible, and the maximum transmission rate of the transport channel can be optimally allocated to each logical channel. It is possible.

  An apparatus according to one aspect of the present invention is a radio network controller connected to a radio base station apparatus and a core network through predetermined interfaces, respectively, and a media access control unit that performs data link layer protocol processing And the radio link control unit, the radio link control unit includes a reception buffer for each logical channel, the media access control unit includes a flow control unit that performs logical channel flow control, and the flow control unit includes: From the respective notification information of the maximum transmission rate of the transport channel determined by the radio base station apparatus side and notified in the FP (Frame Protocol) layer, and the accumulation amount of the reception buffer for each logical channel of the radio link control unit , Calculate the transmission rate of the logical channel, and The notification of the transmission rate for the physical channel performed in FP layer.

  In the present invention, when the flow control unit receives a new notification for any one of the maximum transmission rate of the transport channel and the reception buffer storage amount of the logical channel, the flow control unit transmits the logical channel. The rate is calculated, and the transmission rate to the logical channel of the radio link control unit is notified in real time.

  In the present invention, the flow control unit determines a transmission rate of the plurality of logical channels based on a maximum transmission rate of a transport channel that changes in real time during packet communication and a reception buffer accumulation amount of the plurality of logical channels. The maximum transmission rate may be set to a value divided by the ratio of the plurality of reception buffer accumulation amounts.

In the present invention, the maximum transmission rate of the transport channel that changes in real time during packet communication is X, the reception buffer storage amounts of the first and second logical channels are Y (b), Y (c), and the first , The second transmission rate Z (b), Z (c), respectively,
Z (b) = {X / (Y (b) + Y (c))} × Y (b),
Z (c) = {X / (Y (b) + Y (c))} × Y (c),
Ask for.

  In the present invention, the media access control unit performs control to multiplex a plurality of logical channels transmitted from a radio link control unit in the radio control device into one transport channel and transmit the multiplexed logical channel to the radio base station device. The flow control unit performs flow control of the logical channel. When the multiplexing is not performed by the media access control unit, the flow control unit allocates the maximum transmission rate of the transport channel to one logical channel.

  In the present invention, the flow control unit may calculate the transmission rate of the logical channel using other arbitrary information transmitted in the data link layer, for example, priority information of the logical channel.

  A mobile packet communication system according to another aspect of the present invention includes a radio base station apparatus and the radio control apparatus according to the present invention described in the above aspect.

  The mobile packet communication system according to the present invention includes a radio base station apparatus and the radio control apparatus connected to the radio base station apparatus.

  According to the method according to another aspect of the present invention, the radio network controller connected to the radio base station apparatus and the core network via a predetermined interface is configured to transmit data in the data link layer during packet communication in the mobile packet communication system. Provided is a MAC multiplexing real-time flow control method in a mobile packet communication node, characterized in that packet communication flow control is performed in an FP (Frame Protocol) layer in MAC (Media Access Control) multiplexing. The

In the method according to the present invention, a flow control unit disposed in a media access control unit of a radio control device connected to the radio base station device and the core network through a predetermined interface is determined by the radio base station device. From the respective transmission information of the maximum transmission rate of the transport channel notified in the FP (Frame Protocol) layer and the received buffer storage amount for each logical channel of the radio link control unit of the radio network controller, the transmission rate of the logical channel To calculate
The flow control unit performs transmission rate notification to the logical channel of the radio link control unit in the FP layer.
Each of the above steps is included.

  In the method according to the present invention, when the flow control unit receives a new notification from any of the maximum transmission rate of the transport channel and the reception buffer storage amount of the logical channel, the flow control unit optimizes the logical channel. The transmission rate is calculated and the transmission rate is notified to the logical channel in real time.

  In the method according to the present invention, the flow control unit is configured to transmit a transmission rate of the plurality of logical channels based on a maximum transmission rate of a transport channel that changes in real time during packet communication and a reception buffer accumulation amount of the plurality of logical channels. Are respectively set to values obtained by dividing the maximum transmission rate by the ratio of the plurality of reception buffer accumulation amounts.

  In the method according to the present invention, the media access control unit multiplexes a plurality of logical channels transmitted from a radio link control unit in the radio control apparatus into one transport channel and transmits the multiplexed channel to the radio base station apparatus. Control is performed, and the flow control of the logical channel is performed by the flow control unit. When the multiplexing is not performed by the media access control unit, the flow control unit allocates the maximum transmission rate of the transport channel to one logical channel.

A computer program according to another aspect of the present invention performs logical channel flow control in a media access control unit that is connected to a radio base station apparatus and a core network through predetermined interfaces and performs data link layer protocol processing. A maximum transmission rate of a transport channel determined by the radio base station device and notified by an FP (Frame Protocol) layer as a process in the flow control unit to a computer constituting a radio control device including a flow control unit; A process for calculating the transmission rate of the logical channel from the respective notification information of the reception buffer storage amount for each logical channel of the radio link control unit in the radio control device;
A process of performing transmission rate notification to the logical channel of the radio link controller in the FP layer;
It consists of a program that executes

  According to the present invention, since the maximum transmission rate of the transport channel and the reception buffer accumulation amount of each logical channel of the multiplexing source are used, the transmission rate of each logical channel can be calculated optimally.

  According to the present invention, since a change in state during packet communication is notified in real time in the FP layer, the transmission rate of each logical channel can be calculated in real time and notified in the FP layer.

  According to the present invention, the transmission rate of each logical channel is calculated with a simple calculation formula, and the configuration of the flow control unit can be simplified.

  In order to describe the present invention described above in more detail, it will be described with reference to the accompanying drawings. The present invention realizes the flow control of packet communication in the FP (Frame Protocol) layer in the MAC multiplexing performed in the data link layer at the time of packet communication performed in the mobile packet communication node system. The transmission rate of the channel can be controlled in real time, and the transmission capacity of the transport channel can be utilized to the maximum extent.

  According to one embodiment of the present invention, referring to FIG. 2, a “maximum transmission rate” determined by a system / service fixed maximum transmission rate, a dynamic maximum transmission rate in a wireless / wired section, etc., a multiplexing source The “reception buffer accumulation amount” of the logical channel to be notified to the flow control unit 11 in the media access control unit 3 at the FP layer.

  In the radio network controller (also referred to as “RNC”), the flow control unit 11 in the media access control unit 3 calculates the optimum transmission rate of each logical channel c based on the notified information, The calculated transmission rate is notified to each logical channel c in real time in the FP layer. In the following, description will be made in accordance with examples.

  FIG. 1 is a diagram showing a system configuration of an embodiment of the present invention. Referring to FIG. 1, in the mobile packet communication node according to the present embodiment, a radio network controller 1 is connected to a core network 4 that is an exchange network via an Iu interface a, and is wirelessly transmitted from a mobile device 6 in a cell. A radio base station apparatus (Base Transceiver Station; also referred to as “BTS”) 5 that performs transmission / reception is connected via an Iub interface b, and mainly manages radio resources and controls the radio base station apparatus 5.

  The media access control unit 3 and the radio link control unit 2 of the radio network controller 1 perform protocol processing of the data link layer (layer 2).

  FIG. 2 shows an apparatus configuration for packet communication downlink data transfer at the time of MAC multiplexing as an example of the radio control apparatus 1 according to an embodiment of the present invention.

  In FIG. 2, the logical channel c is assembled / generated by the radio link control unit 2, and the media access control unit 3 takes the correspondence between the logical channel c and the transport channel d and transmits the radio base station via the Iub interface b. Packet data communication is performed to the station apparatus 5.

  The radio link control unit 2 temporarily stores the packet data flowing in from the Iu interface a in the reception buffer 7.

  The packet data stored in the reception buffer 7 of the radio link control unit 2 is assembled into a data unit having a fixed bit length, and RLC-PDU (Radio Link Control-Protocol Data Unit) 8 (illustrated as “rPDU”) The data is transmitted from the radio link control unit 2 to the media access control unit 3.

  The transmission of the RLC-PDU 8 performs transmission rate control according to how many RLC-PDUs 8 are transmitted at a constant time interval (TTI) according to the radio transmission capability (Capacity).

  The media access control unit 3 converts the RLC-PDU 8 transmitted from the radio link control unit 2 into a MAC-PDU (Media Access Control-Protocol Data Unit) 9 (illustrated as “mPDU”) and transmits it to the transport channel d. Mapping is performed and transmitted to the radio base station apparatus 5.

  In packet communication downlink data transfer at the time of MAC multiplexing, a plurality of logical channels c transmitted from the radio link control unit 2 are multiplexed on one transport channel d (MAC multiplexing) by the media access control unit 3, and the data Transfer is performed.

  The identification of the logical channel c is performed by the media access control unit 3 based on the parameter value of the C / T field 10 assigned to the MAC-PDU header.

  The transmission rate of each logical channel c is determined by the flow control unit 11 in the media access control unit 3.

  The radio link control unit 2 is not aware of whether or not MAC multiplexing is performed, and the flow control unit 11 of the media access control unit 3 performs flow control of each logical channel c.

  FIG. 3 shows a flow control sequence by the FP layer as a sequence example in one embodiment of the present invention.

  [I] in FIG. 3 schematically shows a control sequence by the FP layer without MAC multiplexing, and the maximum transmission channel (a) is transmitted from the Iub interface b by the maximum transmission rate / notification (a). The transmission rate is notified to the flow control unit 11 in the media access control unit 3.

  In the flow control unit 11, since there is no MAC multiplexing, the maximum transmission rate notified from the Iub interface b is allotted to one corresponding logical channel (a), and the radio link control is performed by the transmission rate / notification (a). Notify part 2. In the example shown in FIG. 3, when the maximum transmission rate of the transport channel (a) is 10, the transmission rate of one logical channel (a) is 10, and when the maximum transmission rate of the transport channel (a) is 5, An example in which the transmission rate of one logical channel (a) is set to 5 is schematically shown.

[II] to [IV] in FIG. 3 show a control sequence by the FP layer with MAC multiplexing. In the flow control unit 11 in the media access control unit 3,
Maximum transmission rate of transport channel (b) + (c) and notification (b) + (c) from Iub interface b, and
From the logical channels (b) and (c), the reception buffer storage amount / notification (b) and (c) reception buffer storage amount,
From these notifications, the optimal transmission rate is calculated and assigned to the logical channels (b) and (c), and the transmission rate / notifications (b) and (c) use the logical channels (b), ( c).

In the flow control unit 11,
Transport channel (b) + (c) maximum transmission rate, logical channel (b) receive buffer storage,
If any one of the reception buffer accumulation amounts of the logical channel (c) is notified, the optimum transmission rate to the logical channels (b) and (c) is calculated, Transmission rate / notification (b) and (c) to channels (b) and (c) are performed.

  For example, in [II] of FIG. 3, the optimal transmission rate is calculated by each notification of the maximum transmission rate from the Iub interface and the received buffer storage amount from the logical channels (b) and (c), and the logical channel (b) , (C) The transmission rate / notification (b), (c) is performed. In [III] of FIG. 3, the optimal transmission rate of the logical channel is reassigned by each notification of the reception buffer accumulation amount from the logical channel (b), and the transmission rate of the logical channel (b), (c) Notifications (b) and (c) are performed. In [IV] in FIG. 3, the optimal transmission rate of the logical channel is reassigned by each notification of the reception buffer accumulation amount from the logical channel (c), and the transmission rate to the logical channels (b) and (c) Notifications (b) and (c) are performed.

  A method for calculating the optimum transmission rate for the logical channels (b) and (c) in the flow control unit 11 will be described later.

  Next, a calculation method of the optimum transmission rate in the flow control unit 11 in the media access control unit 3 at the time of MAC multiplexing of [II] to [IV] of the flow control sequence by the FP layer in FIG. The maximum transmission rate (represented by “X”) of the transport channel (b) + (c), the received buffer storage amount (b) of the logical channel (b) (represented by “Y (b)”), logical The flow control unit 11 of the media access control unit 3 calculates the FP layer of the reception buffer storage amount (c) (represented by “Y (c)”) of the channel (c) and sends the FP to the radio link control unit 2. For the transmission rates (represented by Z (b) and Z (c)) of the logical channels (b) and (c) notified by the layer, the transmission rate calculation in the flow control unit shown in the table format in FIG. 4 is performed. And use are described. In FIG. 4, the maximum transmission rate, the reception buffer accumulation amount, and the transmission rate are shown by numerical weighting. The number with () indicates that the previous state remains unchanged.

  4 illustrates an example in which X = 10, Y (b) = 14, and Y (c) = 6 are notified to the flow control unit 11.

  The transmission rates Z (b) and Z (c) of the logical channels (b) and (c) are calculated by the following equations (1) and (2), respectively.

      Z (b) = {X / (Y (b) + Y (c))} × Y (b) (1)

      Z (c) = {X / (Y (b) + Y (c))} × Y (c) (2)

  By substituting X = 10, Y (b) = 14, and Y (c) = 6 into the equations (1) and (2), Z (b) = 7 and Z (c) = 3 are calculated. Can do.

  In FIG. 4, III shows an example in which the reception buffer accumulation amount Y (b) of the logical channel (b) is changed from 14 to 6 in the packet communication state of II.

  When the state of Y (b) changes, the transmission rate of each logical channel is calculated according to Equation (1) and Equation (2). As a result, Z (b) = 5 and Z (c) = 5 are obtained.

  4 illustrates an example in which the maximum transmission rate X of the transport channel (b) + (c) is changed from 10 to 4 in the packet communication state of III.

  When the state of the maximum transmission rate X of the transport channel (b) + (c) changes, the transmission rate of each logical channel is calculated by the equations (1) and (2). As a result, Z (b) = 2 and Z (c) = 2 are obtained.

  As described above, the allocation of the transmission rate to each logical channel is calculated based on the maximum transmission rate of the transport channel and the ratio of the reception buffer accumulation amount of each logical channel, thereby enabling optimal flow control.

  The operational effects of the above-described embodiment will be described below.

  In this embodiment, since the maximum transmission rate of the transport channel and the reception buffer accumulation amount of each logical channel of the multiplexing source are used, the transmission rate of each logical channel can be calculated optimally.

  In this embodiment, the state change during packet communication is notified in real time in the FP layer, so the transmission rate of each logical channel can be calculated in real time and notified in the FP layer.

  In this embodiment, since the transmission rate of each logical channel can be calculated with a simple formula, the flow control unit can be realized with an easy configuration.

  Another embodiment of the present invention will be described. In another embodiment of the present invention, the basic configuration is the same as that of the above-described embodiment, but the flow control unit is provided in the media access control unit and the flow control is realized in the data link layer. Therefore, the transmission rate can be easily determined using other information (for example, priority for each logical channel peculiar to the service) in the flow control unit.

  As an example of a high-speed packet communication service of the mobile packet communication node system, there is HSDPA (High Speed Downlink Packet Access). In HSDPA, since a high-speed packet communication service is provided to users, the flow control method in the packet communication service in MAC multiplexing is important. However, the flow control of the present invention performs flow control optimally and in real time. It becomes possible.

  Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the configurations of the above-described embodiments, and various modifications that can be made by those skilled in the art within the scope of the present invention. Of course, including modifications.

It is a figure which shows the system configuration | structure of one Example of this invention. It is a figure which shows typically the structure of the radio | wireless control apparatus of one Example of this invention. It is a figure which shows typically the flow control sequence by the FP layer in one Example of this invention. It is the figure which illustrated transmission rate calculation in the flow control part of one example of the present invention in a list form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio control apparatus 2 Radio link control part 3 Media access control part 4 Core network 5 Radio base station apparatus 6 Mobile device 7 Reception buffer 8 RLC-PDU
9 MAC-PDU
10 C / T field 11 Flow controller a Iu interface b Iub interface c Logical channel d Transport channel

Claims (20)

A wireless control device connected to each of the wireless base station device and the core network through a predetermined interface,
A media access control unit for performing data link layer protocol processing and a radio link control unit;
The radio link controller includes a reception buffer for each logical channel,
The media access control unit includes a flow control unit that performs flow control of a logical channel,
The flow control unit determines a maximum transmission rate of a transport channel determined by the radio base station device side and notified by an FP (Frame Protocol) layer, and a reception buffer storage amount for each logical channel of the radio link control unit. A radio control apparatus characterized in that a transmission rate of the logical channel is calculated from each piece of notification information, and a transmission rate for the logical channel of the radio link control unit is notified in an FP layer. The flow control unit receives the new notification when any one of the maximum transmission rate of the transport channel and the reception buffer accumulation amount of the plurality of logical channels of the radio link control unit is received. calculating a channel transmission rate of said notifies the transmission rate to the radio link control unit of the logical channels in real time, the radio control apparatus according to claim 1, wherein a. The flow control unit determines the maximum transmission rate of the plurality of logical channels based on the maximum transmission rate of the transport channel that changes in real time during packet communication and the reception buffer storage amount of the plurality of logical channels. setting each value obtained by dividing a ratio of the plurality of reception buffer accumulation amount, the radio control apparatus according to claim 1, wherein a. The media access control unit performs control to multiplex a plurality of logical channels transmitted from a radio link control unit in the radio control apparatus into one transport channel and transmit the multiplexed logical channel to the radio base station apparatus, and the flow control wherein the part flow control logical channel is performed, the radio control apparatus according to claim 1, wherein a. 5. The radio control apparatus according to claim 4 , wherein when the multiplexing is not performed by the media access control unit, the flow control unit allocates a maximum transmission rate of a transport channel to one logical channel. The flow control unit is transmitted by the data link layer, by using the priority information of the logical channel, to calculate the transmission rate of the logical channel, the radio control apparatus according to claim 1, wherein a. A mobile packet communication system comprising a radio base station apparatus and the radio control apparatus according to any one of claims 1 to 6 . A flow control unit disposed in a media access control unit of a radio network controller connected to the radio base station apparatus and the core network through a predetermined interface is determined by the radio base station apparatus and is an FP (Frame Protocol) layer. From the respective transmission information of the maximum transmission rate of the transport channel to be notified and the reception buffer storage amount for each logical channel of the radio link control unit of the radio controller, the transmission rate of the logical channel is calculated,
The flow control unit performs transmission rate notification to the logical channel of the radio link control unit in the FP layer.
A flow control method for MAC multiplexing in a mobile packet communication node, comprising the above steps. The flow control unit calculates an optimal transmission rate to the logical channel when a new notification is received from any of the maximum transmission rate of the transport channel and the reception buffer storage amount of the logical channel, 9. The flow control method for MAC multiplexing in a mobile packet communication node according to claim 8 , wherein the transmission rate is notified to the logical channel in real time. The flow control unit sets the transmission rate of the plurality of logical channels to the maximum transmission rate based on the maximum transmission rate of the transport channel that changes in real time during packet communication and the reception buffer storage amount of the plurality of logical channels. 9. The MAC multiplexing flow control method in a mobile packet communication node according to claim 8, wherein each of the plurality of reception buffer accumulation amounts is set to a value divided by the ratio of the plurality of reception buffer accumulation amounts. The media access control unit performs control to multiplex a plurality of logical channels transmitted from a radio link control unit in the radio control apparatus into one transport channel and transmit the multiplexed logical channel to the radio base station apparatus, and the flow control 9. The flow control method of MAC multiplexing in a mobile packet communication node according to claim 8 , wherein flow control of the logical channel is performed by a unit. If not performed the multiplexed by the media access control unit, the flow control unit allocates the maximum transmission rate of the transport channel into a single logical channel, according to claim 1 1, wherein the mobile packet communication MAC multiplexing flow control method in a node. 9. The mobile packet communication node according to claim 8 , wherein the flow control unit calculates a transmission rate of the logical channel using logical channel priority information transmitted in a data link layer. MAC multiplexing flow control method. A radio control apparatus is provided that is connected to the radio base station apparatus and the core network through a predetermined interface, and includes a flow control unit that performs logical channel flow control in a media access control unit that performs protocol processing of the data link layer. On the computer,
As processing in the flow control unit,
Notification of the maximum transmission rate of the transport channel determined by the radio base station apparatus and notified by the FP (Frame Protocol) layer, and the reception buffer storage amount for each logical channel of the radio link control unit in the radio control apparatus A process of calculating a transmission rate of the logical channel from the information;
A process of performing transmission rate notification to the logical channel of the radio link controller in the FP layer;
A program that executes In claim 1 4, wherein the program,
A plurality of logical channels transmitted from the radio link control unit are multiplexed on one transport channel and transmitted to the radio base station apparatus, and the processing in the media access control unit that performs flow control of the logical channel includes A program to be executed by a computer. In claim 1 4, wherein the program,
As a process in the flow control unit, when a new notification is received from either the maximum transmission rate of the transport channel or the reception buffer storage amount of the logical channel, an optimum transmission rate to the logical channel is determined. A program for causing the computer to execute a process of calculating and notifying a transmission rate to a logical channel in real time. In claim 1 4, wherein the program,
As the processing in the flow control unit, the transmission rate of the plurality of logical channels is determined based on the maximum transmission rate of the transport channel that changes in real time during packet communication and the reception buffer storage amount of the plurality of logical channels. A program that causes the computer to execute a process of setting the maximum transmission rate to a value obtained by dividing the maximum transmission rate by a ratio of buffer accumulation amount. In claim 1 4, wherein the program,
As a process of the media access control unit, a process of performing a control of multiplexing a plurality of logical channels transmitted from a radio link control unit in the radio control device into one transport channel and transmitting the multiplexed channel to the radio base station device A program to be executed by the computer. The program according to claim 18 , wherein
A program for causing the computer to execute a process in which the flow control unit allocates a maximum transmission rate of a transport channel to one logical channel when the media access control unit does not perform the multiplexing. In claim 1 4, wherein the program,
A program for causing the computer to execute a process of calculating a transmission rate of the logical channel by using the priority information of the logical channel transmitted in the data link layer by the flow control unit.

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