KR20040073884A - A method of selecting status pdu at rlc protocol for mobile communication system - Google Patents

Abstract

PURPOSE: A method for selecting a status PDU of a mobile communication system is provided to select an optimum status PDU to increase stability of an RLC protocol that operates in an acknowledge mode, thereby enhancing a rate of user data. CONSTITUTION: A system calculates a receiving error of a packet data PDU(S100). The system writes a bitmap SUFI(Super Field) status PDU by using the calculated error(S110). The system converts the bitmap SUFI status PDU into an RLIST SUFI status PDU(S120). The system compares a window size of the RLIST SUFI status PDU with a window size of the bitmap SUFI status PDU, and decides whether the RLIST SUFI status PDU is bigger(S130). If so, the system stops converting the bitmap SUFI status PDU into the RLIST SUFI status PDU(S150). The system transmits the bitmap SUFI status PDU, and completes the procedure(S160).

Description

A METHOD OF SELECTING STATUS PDU AT RLC PROTOCOL FOR MOBILE COMMUNICATION SYSTEM}

The present invention improves the stability of packet data transmitted in a mobile communication system, and in particular, the stability of an RLC protocol that selects an optimal status PDU and operates in an acknowledgment mode. The present invention relates to a mobile communication system state PDU selection method for improving the transmission rate and increasing the transmission rate of user data.

UMTS (Universal Mobile Telecommunication System) uses GLOBALSYSTEM FOR MOBILE COMMUNICATION (GSM), which is widely used in other regions, especially in Europe. It is a third generation (3GPP) mobile communication system that can easily access the Internet while moving anywhere in the world.

The RADIO LINK CONTROL (RLC) protocol includes a packet data packet (PDU: PROTOCOL DATA UNIT), which is transmitted and received by a wireless connection between a user terminal (UE) and a base station of a mobile communication system. In order to reduce the transmission error (ERROR), it is to check the error occurrence state of the wirelessly received data and to request retransmission for the errored PDU, called the acknowledgment mode (ACKNOWLEDGE MODE), the packet PD It is the STATUS PDU that confirms the occurrence of the significance error.

According to the 3GPP TS 34.321 standard, the STATUS PDU is classified into three types: a LIST SUFI method, an RLIST SUFI method, and a bitmap SUFI method.

Hereinafter, a state PD selection method of a conventional MS mobile communication system will be described with reference to the accompanying drawings.

1 is a functional block diagram of a general mobile communication system, and FIG. 2 is a flowchart of a state PD selection method of a mobile communication system according to the prior art.

Referring to FIG. 1, a general mobile communication system includes: a mobile terminal (UE) 10 for communicating wirelessly with a counterpart at any time while moving within a certain service area; A base station 20 which forms a service area in which the mobile terminal 10 can communicate while moving, and wirelessly transmits and receives a corresponding signal to and from a wirelessly connected portable terminal 10; A mobile switching center 30 is connected to and controls the base station 20, establishes a communication path by switching, and simultaneously monitors and controls the operation of the entire mobile communication system.

Referring to the mobile communication system of the above configuration in detail, the mobile terminal 10 and the base station 20 in the packet data communication, and transmits and receives the packet data processed by the TCP / IP method, the TCP / IP In order to reduce the loss caused by the error during the wireless transmission process of the processed packet data and to facilitate the recovery, the RLC protocol which operates in the acknowledgment mode (ACK.MODE) is used.

STATUS PDUs for the authentication mode of the ALS protocol include a LIST SUPER (SUFI) method, an RLIST bark method, and a bitmap (BITMAP) bark method.

Hereinafter, a method of selecting a state PDU for the ALLC protocol in the mobile communication system will be described with reference to FIG. 2.

A first step (S10) of determining whether to receive a packet data PD by the mobile communication system; A second step (S20) of arbitrarily selecting one of a state PID method of list bark, alist bark, and bitmap bark when it is determined in step S10 that the packet data PDU is received; In the method selected in step S20, between the mobile terminal 10 and the base station 20 of the mobile communication system, the error occurrence state of the wirelessly received packet data PDU is checked, and the identified information is transmitted as the status PDU. The third step (S30) to notify and end.

A method of selecting a state media in a mobile communication system according to the related art having the above configuration will be described in detail with reference to FIGS. 1 and 2.

When the base station 20 under the control of the mobile terminal 10 or the mobile switching center 30 receives the packet data PD transmitted to each other (S10), the mobile terminal 10 or the mobile switching center 30 The base station 20 under the control of)) randomly selects one of the three state media by the 3GPP TS 34.321 standard (S20).

The STATUS PDU checks whether the packet data PDU wirelessly transmitted is transmitted without an error or if an error occurs, and transmits the checked status information to the PDU. There are three types of data transmission methods: list bark, alist bark, and bitmap bark.

The list bark method is relatively simple, but the data amount is relatively large, and the alist bark method is relatively difficult to write, but the data amount is the smallest, and the bitmap bark method is the easiest to write and the most data amount. many.

By using the state PDU selected in the step S20, the transmission error of the received packet data PDU is confirmed, and the confirmed status information is notified to the sender as the status PDU, so that the transmission error data PDU is retransmitted. It is made (S30).

In the prior art of the above-described configuration, each time the packet data is transmitted, a state PD of a random method is selected each time to check an error occurrence state by wireless transmission and transmit a confirmation result. Has the advantage of reducing

However, since the prior art selects and transmits a random state stateful state every time the packet data medium is transmitted, it is impossible to predict which state stateful state is selected, and also does not select an optimal state state. There are various problems that do not increase the transmission speed of user data.

It is an object of the present invention to provide an optimal state selection method for identifying an error in transmission of packet data wirelessly transmitted by an RLP protocol in a mobile communication system and informing the counterpart of the confirmed information.

The present invention has been made to achieve the above object, in the packet data PDU wireless transmission of the mobile communication system; Calculating a transmission error of the wirelessly received packet data PD; Creating a bitmap bark state PD using the transmission error calculated in the above process; Converting and creating the bitmap bark state PDU created in the above process into an alist bark state PDU; Comparing the sizes of the alist bark state PDUs and the bitmap bark state PDUs converted in the above process to determine whether the alist bark state PDUs are large; If it is determined in the above process that the alist bark state PDU is small, there is a feature of transmitting the converted alist bark state PDU.

1 is a functional configuration diagram of a general mobile communication system,

2 is a flowchart of a method for selecting a state of the mobile communication system according to the prior art;

3 is a flowchart illustrating a state PD selection method according to the present invention.

** Explanation of symbols on the main parts of the drawing **

10: mobile terminal 20: base station

30: mobile switching center

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, a method of selecting a state media in a mobile communication system will be described with reference to the accompanying drawings.

3 is a flowchart illustrating a method for selecting a state media in the mobile communication system according to the present invention.

Referring to FIG. 3, a step (S100) of calculating a reception error of a packet data PD that is wirelessly received and received from a counterpart through the mobile communication system of the present invention; A step (S110) of creating a BITMAP SUFI status PDU using the transmission error calculated in the step S100; Converting and creating a bitmap bark state PDU created in the step S110 into an RLIST SUFI state PDU (S120); A process of determining whether the alist bark state PDU is large by comparing the window size of the RLIST bark state PDU converted in the step S120 and the window size of the bitmap bark state PDU. (S130); If it is determined in step S130 that the window size of the alist sufi status PDU is small, the process of transmitting the completed RLIST SUFI status PDU to the transmitter and proceeding to the end (S140). and; If the window size of the RLIST SUFI status PDU is large in the determining process (S130), the bitmap bark status PDU is changed to the alist bark status PDU. Stopping the conversion creation (S150); The bitmap bark state PDU created in the bitmap bark creation process (S110) is transmitted to the transmitting side, and the process proceeds to completion (S160).

Hereinafter, a method of selecting a state media in a mobile communication system for transmitting a packet data PDU according to the present invention having the above configuration will be described in detail with reference to the accompanying drawings.

The mobile terminal 10 and the base station 20 constituting the mobile communication system are wirelessly connected and transmit packet data at high speed, and in particular, move a UMTS system using the European GSM system. The communication system transmits data at a high speed of 2 Mbps or more, and is a third generation mobile communication system capable of multimedia data communication including voice, data, and video.

The packet data PD transmitted / received in the mobile communication system has a relatively high probability of generating a transmission error due to a change in the surrounding wireless environment, and the packet data transmitted as described above is confirmed by TCP / IP and a simple error occurs. Restores itself and the non-recoverable data PD requests retransmission, but the TCP / IP protocol is for data transmitted over a wired state and for wirelessly transmitted data is RADIO LINK CONTROL (RLC) protocol. to be.

The RLC protocol is to convert the data converted into packet data by the TCP / IP protocol to PDU by RLC protocol and transmit the data, and when a fatal error occurs in the PDU wirelessly received at the receiver, The request for retransmission of the PDU is restored and the notification of an error occurrence state is called a STATUS PDU. The status PDU includes a LIST SUFI method and a 3GPP TS 34.321 standard. There are three types, an RLIST SUFI method and a bitmap SUFI method.

Each state PDU has advantages and disadvantages. For example, the list bar SUFI has a relatively small window size, so the total amount of data is small and easy to prepare. Because of the small window size, the amount of data is small, and the bitmap (BITMAP) bark is the largest window size but the easiest to write.

The present invention is to increase the user data transmission rate by transmitting a lot of user data, since the state of the ALEL protocol to quickly create a state PDU from the received PDU, and to reduce the overall data size to transmit to the sender In particular, the present invention relates to selecting and transmitting the most efficient of three types of state media based on a predetermined criterion.

In general, the bitmap bark method has the advantages of simple implementation, but the RLIST bark method, which has a large window size and a relatively complicated implementation, includes the advantages of the simpler list bark method. Therefore, the alist bark method is most effective in reducing the data size of the PDU.

In addition, the alist bark method may have a larger data size than the bitmap bark method due to a reception error occurrence type of the received data PD.

As an example, the following conditions will be described.

RECEIVE WINDOW = 256

VR (R) = 10

VR (H) = 210

LOST PDU: SN = 10,20,30,40,100,101,102,103,200,204,206

The condition is that the total number of PDU windows (WINDOW) to be received is 256, the 10th PDU window (WINDOW) has caused the first error, and the 210th PDU window (WINDOW). ), And it indicates that the 10th, 20th, 30th, 40th, 100th, 101th, 102th, 103th, 200th, 204th, 206th PDU window (WINDOW) is an errored PDU.

The types of the above-mentioned error occurring PDUs are expressed in three states, respectively, as follows.

First, a status PDU in which a reception error occurs is represented as a LIST PDU.

OCTET 1-2: HEADER, SUFI TYPE FIELD = LIST, LENGTH = 9

OCTET 2-4: SN1 = 10, LENGTH = 0

OCTET 4-6: SN2 = 20, LENGTH = 0

OCTET 6-8: SN3 = 30, LENGTH = 0

OCTET 8-10: SN4 = 40, LENGTH = 0

OCTET 10-12: SN5 = 100, LENGTH = 3

OCTET 12-14: SN6 = 200, LENGTH = 0

OCTET 14-16: SN7 = 202, LENGTH = 0

OCTET 16-18: SN8 = 204, LENGTH = 0

OCTET 18-20: SN9 = 206, LENGTH = 0

OCTET 20-22: SUFI TYPE FIELD = ACK, SN = 210

In the state PDU representation by the LIST SUFI of the above configuration, the octet expresses 8 bits, and in the 1-2 octet which is the first window, the header of the header The contents and the SUFI type are LIST, and 9 windows in which reception error status information is recorded are expressed. In the 2-4 octets, the second window, SN1 (SEQUENCE NO). 1) indicates that a reception error occurred in the 10th data PD, and there is no subsequent reception error data PD.

The overlap of octet 2 in the first window octet 1-2 and the second window octet 2-4 indicates that part of octet 2 is used in window 1 and part of octet 2 is also used in window 2. do.

The 10-12 octets represent the sixth window, indicating that a reception error has occurred in the 100th data PD, and that a reception error has occurred in the next three consecutive data PDs, and the last window 20-22 octets is a state. It indicates that the PDU is operating in the acknowledgment mode (ACK. MODE) and should receive from the SN (SEQUENCE NO) 210 data PDU, and shows that the list bark is composed of a total of 11 windows.

The above list LIST status mode PDU is simply implemented, and thus has a small data size.

Next, a status PDU in which a reception error occurs in the RLIST PDU is expressed as follows.

OCTET 1-3: HEADER, SUFI TYPE FIELD = RLIST, LENGTH = 15, FSN = 10

OCTET 3: CW1 = 0100, CW2 = 0011 (DELTA = 10-> SN = 20)

OCTET 4: CW3 = 0100, CW4 = 0011 (DELTA = 10-> SN = 30)

OCTET 5: CW5 = 0100, CW6 = 0011 (DELTA = 10-> SN = 40)

OCTET 6: CW7 = 1000, CW8 = 1111 (DELTA = 60-> SN = 100)

OCTET 7: CW9 = 0001 (ERROR BURST INDICATOR), CW10 = 0111 (SN = 101,102,103)

OCTET 8-9: CW11 = 0010, CW12 = 1000, CW12 = 0011 (DELTA = 97-> SN = 200)

OCTET 9: CW14 = 0101 (DELTA = 2-> SN = 202)

OCTET 10: CW15 = 0101 (DELTA = 2-> SN = 204)

OCTET 10: SUFI TYPE FIELD = RLIST

OCTET 11-12: LENGTH = 0, FSN = 206

OCTET 13-14: SUFI TYPE FIELD = ACK, SN = 210

The state PD representation by the RLIST SUFI of the above configuration, in octets 1-3, the first window, represents the relative distance value of the received data PD and the header and the bark form. The length of the CW (CODE WORD) is 15 pieces, and the sequence number (FSN: FIRST SEQUENCE NO) of the first data error occurred is the 10th data CD.

Octet 3, the second window, indicates that the relative distance value is 10. Since it is a relative distance value from FSN = 10, it indicates that a reception error occurred in the 20th data PD, and the sixth window (WINDOW) In octet 7 represents three consecutive data errors in receiving error, octet 10 in the tenth window (WINDOW) is alisted in the form of bark, and octets 11-12 in the eleventh window (WINDOW) In this case, octet 13-14, which is the 206th data PD and the twelfth window (WINDOW), operates in the acknowledgment mode and should continue to receive data from the 210th data PD. to be.

Although the RLIST status mode PDU of the above-described configuration is relatively complicated to implement, it includes the advantages of the list transmission method. However, the data size varies depending on an error occurrence type of the received data PDU. There is an advantage to relatively small.

The STATUS PDU in which a reception error occurs as the bitmap PDU, which is the last third of the STATUS PDIDU according to 3GPP TS 34.321, is expressed as follows.

[First State PDU]

OCTET 1-3: HEADER, SUFI TYPE FIELD = BITMAP, LENGTH = 15, FSN = 10

OCTET 4: 0111 1111 (SN = 10-SN17)

OCTET 5: 1101 1111 (SN = 18-SN25)

OCTET 6: 1111 0111 (SN = 26-SN33)

OCTET 7: 1111 1111 (SN = 34-SN41)

OCTET 8: 1111 1111 (SN = 42-SN49)

OCTET 9: 1111 1111 (SN = 50-SN57)

OCTET 10: 1111 1111 (SN = 58-SN65)

OCTET 11: 1111 1111 (SN = 66-SN73)

OCTET 12: 1111 0111 (SN = 74-SN81)

OCTET 13: 1111 1111 (SN = 82-SN89)

OCTET 14: 1111 1111 (SN = 90-SN97)

OCTET 15: 1100 0011 (SN = 98-SN105)

OCTET 16: 1111 0111 (SN = 106-SN113)

OCTET 17: 1111 1111 (SN = 114-SN121)

OCTET 18: 1111 1111 (SN = 122-SN129)

OCTET 19: 1111 1111 (SN = 130-SN137)

[Second state PDU]

OCTET 1-3: HEADER, SUFI TYPE FIELD = BITMAP, LENGTH = 8, FSN = 146

OCTET 4: 1111 1111 (SN = 138-SN145)

OCTET 5: 1111 1111 (SN = 146-SN153)

OCTET 6: 1111 1111 (SN = 154-SN161)

OCTET 7: 1111 1111 (SN = 162-SN169)

OCTET 8: 1111 1111 (SN = 170-SN177)

OCTET 9: 1111 1111 (SN = 178-SN185)

OCTET 10: 1111 1111 (SN = 186-SN193)

OCTET 11: 1111 1101 (SN = 194-SN201)

OCTET 12: 1101 0111 (SN = 202-SN209)

The state PDU representation by the bitmap (FIMAP) bar SUFI of the above configuration is, in octets 1-3, the first window, the contents of the header and the bark type are bitmaps, and LENTH = 15 The number of octets is 16, and FSN = 10 indicates that the sequence number (FSN: FIRST SEQUENCE NO) of the first data error occurred is the 10th data PD.

The second window, octet 4, consists of 8 bits, and if each bit is indicated as 0, it indicates that a reception error has occurred in the corresponding data PD. If it is represented as 1, it indicates that the data PD has been received normally. do.

In the bitmap barbit scheme, one status PD may not be composed of 20 or more octets. Starting from octets 1-3, LENGTH in octets 1-3 of the second state PDU expresses that the next number of consecutive octets is nine.

The LENGTH is represented by a number one less than the actual number of consecutive octets.

Although the bitmap method of the above configuration is relatively complicated to implement, there is an advantage that it can be easily created, and at the same time, the size of the data has the biggest problem.

That is, as in the above example, the bitmap (BITMAP) bark scheme is composed of a total of 31 octets by two state media, and the RLIST bark scheme is composed of a total of 14 octets. Therefore, the alist bark method has a smaller data size than the bitmap bark method.

Hereinafter, the present invention will be described in detail with reference to FIG. 3, and a method of selecting a state PDU of a UMTS mobile communication system is received. The packet data PDU of the RLC protocol is received. The reception error of the received packet PDU is calculated and confirmed (S100).

By using the error occurrence data PDU calculated and confirmed in step S100, the easy to create bitmap barbit method state STATUS is completed (S110), and the created bitmap bark mode state The conversion to the alist bark type state PDU is performed using the PDU (S120).

The octet data size according to the window size of the RLIST bark type state PDU transformed and created as described above is compared with the octet data size according to the window size of the bitmap bar state type PDU of the same contents (S130). ), If the data size of the bitmap bark method state PDU is larger than that determined in the comparison, the conversion creation of the conversion-listed alist bark state PIDU is completed, and the conversion creation is completed. Replies or responds with an acknowledgment signal by the acknowledgment mode (ACK MODE) of the ALS protocol (S140).

If the data size of the RLIST bark is larger than the data size of the bitmap bark determined in the step S130, the process of converting the bitmap bark into the alist bark is made and continued (S120). Stop (S150), and reply or respond to the status of the bitmap (BITMAP) bark method as a confirmation signal by the acknowledgment mode (ACK MODE) of the RLC protocol (S160). ).

Accordingly, in the present invention, when transmitting a packet data PD by the ALS protocol in a UTM-type mobile communication system, an acknowledgment by acknowledgment mode is made faster and with a smaller data size. This reduces the load on the system and increases the transmission speed of user data.

According to the present invention having the above-described configuration, in the state PDU preparation for confirming the packet data PDU transmission by the ALEL protocol of the UTM mobile communication system, the error occurrence information of the received data PDU can be quickly and reduced. There is an industrial use effect.

In addition, since the state PDU is prepared quickly and with little data, there is a convenient effect of reducing the load of the mobile communication system and improving the quality of service.

In addition, since the data size of the status CD is small, there is a convenient effect of using the user data more and faster.

Claims (4)

In the packet data PDU wireless transmission of the mobile communication system, Calculating a transmission error of the wirelessly received packet data PD; Creating a bitmap bark state PD using the transmission error calculated in the above process; Converting and creating the bitmap bark state PDU created in the above process into an alist bark state PDU; Judging whether the alist bark state PDU is large by comparing the sizes of the alist bark state PDU and the bitmap bark state PDU converted in the above process; And determining if the alist bark state PDU is small in the process, and transmitting the converted alist bark state PDU in the mobile communication system. The method of claim 1, wherein the size of the alist bark state PDU in the determination process is large, Stopping the conversion of the bitmap bark state PID into an alist bark state PID; And transmitting the created bitmap bark state PDU. The method of claim 1, wherein the determining process, And comparing the window size of the alist bark state PDU with a window size of the bitmap bark state PDU. According to claim 1, The bitmap bark state PDU records normal and error states from the first data PDU to which the reception error occurred to the last data PDU, And the alist sufi state PDU records a relative distance value of each data PDU in which a reception error has occurred.