KR100763581B1 - Disposal method of service data unit in downlink buffer of mobile communication system - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method for discarding a service data unit of a mobile communication system downlink buffer.

2. The technical problem to be solved by the invention

According to an embodiment of the present invention, a service data unit (SDU) is input into a mobile communication system downlink buffer to determine a lifetime, and thus index information of the service data unit or the service data unit may be used. A mobile communication system for providing high-speed data service by quickly and efficiently discarding unnecessary service data units by storing them in the corresponding block nodes of a life-time buffered life buffer, and then discarding the service data units that have exceeded their lifetimes. Its purpose is to provide a method of discarding a service data unit of a downlink buffer.

3. Summary of Solution to Invention

The present invention provides a method of discarding a service data unit of a downlink buffer of a mobile communication system, the method comprising: blocking a life buffer for each service life of a service data unit; Measuring a waiting time as a service data unit is input to the downlink buffer; Identifying a lifetime of the input service data unit and storing the service data unit in a corresponding block of the life buffer; And discarding the service data unit in the corresponding block in the lifetime buffer as the measured latency exceeds the lifetime.

4. Important uses of the invention

The present invention is used in a mobile communication system.

Description

Method for discarding service data unit of down link buffer in mobile communication system}

1 is a diagram illustrating an embodiment of a general packet scheduling method;

2 is a structural diagram of an embodiment of a life buffer blocked for each service life of a service data unit according to the present invention;

3 is a flowchart illustrating a method for discarding a service data unit of a downlink buffer of a mobile communication system according to the present invention;

4 is a flowchart illustrating another embodiment of a method for discarding a service data unit of a downlink buffer of a mobile communication system according to the present invention.

* Explanation of symbols for the main parts of the drawings

21: first block 22: second block

23: third block

The present invention relates to a method for discarding a service data unit of a downlink buffer of a mobile communication system. More particularly, the service data unit (SDU) is input into a downlink buffer of a mobile communication system. Move to discard the service data unit that has expired after storing the service data unit or index information of the service data unit in a corresponding block node of a lifetime buffer blocked for each service data unit; A service data unit discard method of a communication system downlink buffer.

In general, the SDU input to the link buffer is output through wireless transmission through a procedure of scheduling and retransmitting a packet. However, some of the SDUs or segments of the SDUs that are not selected during the contention process of the scheduling should be discarded in the buffer without being transmitted when their lifetime is exceeded.

As a prior art, the improved service data unit discard method (public number 2006-0051574) for specific data segmentation in a wireless communication system provides an SDU discard procedure that eliminates the risk of unnecessary reset procedure due to an incorrect SDU discard procedure. .

That is, the enhanced service data unit discard method for specific data partitioning in a wireless communication system includes protocol data including a length indicator of the last discarded SDU, using the sequence of SDUs including at least one last discarded SDU. If the unit (PDU) does not contain any new SDUs, generating a mobile receiving window superfield (MRW SUFI), setting the 'NLENGTH' field of the mobile receiving window superfield to 0, moving the final sequence number Setting a receiving window field SN_MRWLENGTH to the sum of the sequence number SN of the PDU containing the length indicator of the last discarded SDU plus 1 and transmitting the mobile receiving window superfield. Discard the sequence of data units.

As another conventional technology, 'variable split transmission method of a service data unit and a transmission device using the same' (Publication No. 2006-0067025), when receiving a NACK message for a PDU previously transmitted from a reception device, transmits the corresponding SDU to a radio channel. The present invention is to transmit all SDUs normally without being affected by the radio channel environment by retransmitting a PDU generated by inserting a predetermined header into each SDU after dividing them variably according to the environment. The method includes: transmitting a service data unit (SDU) by converting it into a protocol data unit (PDU); A partitioning step of variably dividing the corresponding SDU according to a radio channel environment upon receiving a NACK (uNACKnowledge) message for the transmitted PDU (Protocol Data Unit); Generating a plurality of PDUs by inserting a predetermined header into each of the divided transmission entities (TE); And a retransmission step of retransmitting the generated plurality of PDUs.

As another conventional technology, 'a packet scheduling method for real-time traffic transmission in a mobile communication system and a recording medium storing a program for implementing the same' (published number 2005-0064722), respectively, the normalized SDU discard rate for each set session is set. After calculating, the order of scheduling target is determined based on the calculated normalized SDU discard rate. Transmission data of each session is allocated to the transmission area in the determined order. In this case, the normalized SDU discard rate is based on information including the number of SDUs discarded up to the current slot of the session, the number of SDUs transmitted up to the current slot, the number of SDUs discarded if no transmission is made to the next slot, and the maximum allowable SDU discard rate. Calculated on the basis of

This conventional technique proposes a methodology such as appropriately dividing the SDU or performing sequence processing in connection with the operation of the retransmission method and the scheduler.

That is, in the conventional technology, due to the characteristics of a mobile communication system, packets received from a plurality of links are stored in a downlink buffer. At this time, a downlink buffer storing such a large amount of packets is individually inspected within a short scheduling time to have a long lifetime. There is a problem that can not discard the finished SDU.

The present invention has been proposed to solve the above-mentioned problem. As a service data unit (SDU) is input to a downlink buffer of a mobile communication system, the service data unit or the service data unit is checked by checking a lifetime. The index information of the service data unit is stored in the corresponding block node of the lifetime buffer, which is blocked for each service data unit, and then discards the service data unit that has exceeded its lifespan. An object of the present invention is to provide a method for discarding a service data unit of a mobile communication system downlink buffer to provide a service.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a method of discarding a service data unit of a downlink buffer of a mobile communication system, the method comprising: blocking a life buffer for each service life of a service data unit; Measuring a waiting time as a service data unit is input to the downlink buffer; Identifying a lifetime of the input service data unit and storing the service data unit in a corresponding block of the life buffer; And discarding the service data unit in the corresponding block in the lifetime buffer as the measured waiting time exceeds the lifetime.

Another method of the present invention provides a method of discarding a service data unit of a downlink buffer of a mobile communication system, the method comprising: blocking a life buffer for each service life of a service data unit; Measuring a waiting time as a service data unit is input to the downlink buffer; Identifying a lifetime of the input service data unit and storing an index in a downlink buffer of the service data unit in a corresponding block of the life buffer; And a service data unit discarding step of discarding the corresponding service data unit in the downlink buffer using the index of the service data unit stored in the corresponding block in the lifetime buffer as the measured waiting time exceeds the lifetime. It is characterized by.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating an embodiment of a general packet scheduling method.

As shown in FIG. 1, the packet scheduler receives a plurality of input links and performs a process of selecting a certain amount of output links from the links. In this case, if the SDU in the link buffer that is not selected in the selection process exceeds its own lifetime, it is meaningless even if it is transmitted later in the radio section, but rather takes up the process processing time delay and occupies the capacity of the radio channel. Adversely affects.

Therefore, these unnecessary SDUs must be discarded quickly.

2 is a structural diagram of an embodiment of a life buffer blocked for each service life of a service data unit according to the present invention.

The downlink of the mobile communication system has its own Quality of Service (QoS). The lifetime of these QoS parameters is one of the main parameters. Therefore, the arrival time is given for each input SDU to measure the lifetime.

The arrival time can be set to the value of a specific counter at the time the SDU is input. For this purpose, the downlink buffer manager (controller) uses a scan counter. The scan counter is a counter whose value is updated for each interrupt of a period sufficiently shorter than its lifetime.

At this time, the lifetime (T) applied to the input SDU is expressed as Equation 1 below.

T = Nsi * SI

In this case, the SI (Scanning Interval) means an interrupt period of the scan counter, and Nsi means the number of nodes of the corresponding block in the life buffer.

As shown in Fig. 2, each block of the lifespan buffer consists of Nsi node combinations. Each node stores an SDU or SDU index corresponding to its lifetime. A discard node is a node that stores an SDU or SDU index that has exceeded its lifetime. Here, the index means the address of the corresponding SDU stored in the link buffer.

In one example, the first block of the lifespan buffer consists of nodes for storing SDUs or SDU indexes whose lifespan T has 6 * SI. At this time, the first block has six nodes and each node is referred to as 0, 1, ... 5. The buffer manager extracts an SDU whose lifetime is 6 * SI from the input SDU, and stores the SDU in the node of the first block having the current scan counter value of 6.

That is, when the current scan counter value is 3672, an SDU whose lifetime is 6 * SI is stored in node 0, and the stored SDU must be transmitted before the scan counter value becomes 3678. The reason is that when the counter value is 3678, node 0 must store an SDU whose newly input lifetime is 6 * SI.

When the current scan counter value is 3678, if the input SDU still exists at node 0 when the scan counter value is 3672, the SDU should be discarded. This is called SDU discard.

The SDU to be discarded is moved to the Discard node and notified to the transmission controller of L2 (layer 2). Since the transmission control function for performing the SDU discard procedure is a unique function of the ordinary L2, it will not be described in detail.

SDUs discarded according to the SDU discard procedure are deleted from the discard node entry. In case of timely transmission before the SDU discard procedure arrives, the SDU received the notification of completion of transmission from the transmission control function is deleted from the original node. That is, if a node is emptied by timely transmission, SDU discard due to time delay does not occur.

3 is a flowchart illustrating a method for discarding a service data unit of a downlink buffer of a mobile communication system according to the present invention.

First, a life buffer is blocked for each service life of the service data unit (301).

Thereafter, as the service data unit is input to the downlink buffer, the downlink buffer manager (controller) operates the scan counter to measure the waiting time (302).

In operation 303, the service data unit is checked and the service data unit is stored in the corresponding block of the life buffer. At this time, the life is recorded in the service data unit.

The service data unit is then discarded in the corresponding block in the lifetime buffer as the measured latency exceeds the lifetime (404).

Of course, even when the service data unit is normally transmitted before the measured waiting time, the service data unit is deleted. This is a common technique.

The service buffers having the same lifetime are stored in the same block through the life buffers divided by blocks, and when the service life is over, the service data units in the block are discarded collectively, thereby efficiently managing the buffers.

4 is a flowchart illustrating another embodiment of a method for discarding a service data unit of a downlink buffer of a mobile communication system according to the present invention.

First, a life buffer is blocked for each service life of the service data unit (401).

Thereafter, as the service data unit is input to the downlink buffer, the downlink buffer manager (controller) operates the scan counter to measure the waiting time (402).

In operation 403, the lifetime of the input service data unit is checked and an index in the downlink buffer of the service data unit is stored in the corresponding block of the life buffer.

Then, as the measured waiting time exceeds the lifetime, the corresponding service data unit in the downlink buffer is discarded using the index of the service data unit stored in the corresponding block in the lifetime buffer (404). At this time, the index of the service data unit is also deleted.

Of course, when the service data unit is normally transmitted before the measured waiting time, the service data unit is deleted from the downlink buffer. This is a common technique.

By using the life buffer divided by block, the index of the service data unit having the same lifetime is stored in the same block, and when the service life is over, the corresponding service data unit in the downlink buffer is discarded collectively by using the index in the block. The buffer can be managed efficiently.

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention as described above, the service data unit (SDU: Service Data Unit (SDU) as the service data unit (SDU) is input into the mobile communication system downlink buffer to check the lifetime (lifetime) to the service data unit or the index information of the service data unit service data By storing the service data unit that has exceeded its lifespan after storing it in the corresponding block node of the lifetime buffer that is blocked by the lifetime of the unit, it is possible to quickly and efficiently discard unnecessary service data units to provide high-speed data service. It works.

Claims (5)

A method of discarding a service data unit of a mobile communication system downlink buffer, Blocking a life buffer for each service life of the service data unit; Measuring a waiting time as a service data unit is input to the downlink buffer; Identifying a lifetime of the input service data unit and storing the service data unit in a corresponding block of the life buffer; And Discarding the service data unit in the corresponding block in the lifetime buffer as the measured waiting time exceeds the lifetime. The service data unit discard method of the mobile communication system downlink buffer comprising a. A method of discarding a service data unit of a mobile communication system downlink buffer, Blocking a life buffer for each service life of the service data unit; Measuring a waiting time as a service data unit is input to the downlink buffer; Checking a lifetime of the input service data unit and storing an index in a downlink buffer of the service data unit in a corresponding block of the life buffer; And A service data unit discarding step of discarding a corresponding service data unit in the downlink buffer by using an index of a service data unit stored in the corresponding block in the lifetime buffer as the measured waiting time exceeds a lifetime. The service data unit discard method of the mobile communication system downlink buffer comprising a. The method according to claim 1 or 2, The waiting time is, A method of discarding a service data unit of a downlink buffer of a mobile communication system, characterized by using a scan counter whose value is updated for each interrupt of a period shorter than a lifetime. The method of claim 3, wherein The life (T) is, A method of discarding a service data unit of a downlink buffer of a mobile communication system, characterized by the following Equation A. Equation A T = Nsi * SI In this case, the SI (Scanning Interval) means an interrupt period of the scan counter, and Nsi means the number of nodes of the corresponding block in the life buffer. The method of claim 2, The service data unit discarding step, Deleting an index of the corresponding service data unit in the life buffer The service data unit discard method of the mobile communication system downlink buffer comprising a.

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