KR100446527B1 - Method for transmitting and receiving packet data unit in wireless packet data telecommunication system - Google Patents

Abstract

The present invention relates to a method of transmitting and receiving a packet data unit by assigning a sequence number to a packet data unit. According to the present invention, when a service data unit is provided, it is determined whether the service data unit is a signaling message. If the service data unit is a signaling message, the present invention adds a header indicating a signaling message to the service data unit, and assigns a sequence number. After configuring the packet data unit to transmit the packet data unit, the receiving side checks and rearranges the received packet data units in sequence number.

Description

METHODS FOR TRANSMITTING AND RECEIVING PACKET DATA UNIT IN WIRELESS PACKET DATA TELECOMMUNICATION SYSTEM}

The present invention relates to a wireless packet data communication system, and more particularly, to a method of transmitting and receiving a packet data unit by assigning a sequence number to the packet data unit.

In the conventional CDMA2000 mobile communication system, packet data is transmitted through a supplementary channel (SCH), but voice or signaling information requiring high reliability is transmitted through a fundamental channel (FCH) or a dedicated control channel (Dedicated Control Channel). It is specified to transmit only through DCCH). This is because the quality of the additional channel (SCH) is not as good as that of the basic channel (FCH) or the dedicated control channel (DCCH).

The CDMA2000 1xEVDV (Evolution in Data and Voice) system, which is a more advanced system than the CDMA2000 mobile communication system, is proposed for simultaneous support of voice service and high-speed packet data service. PDCH). Since the quality of the packet data channel (PDCH) is as good as the basic channel (FCH) or the dedicated control channel (DCCH), it is possible to transmit information requiring high transmission probability and reliability. For example, in the CDMA2000 1xEVDV system, a signaling message may be transmitted together with other data (voice and packet data) through a packet data channel (PDCH). The signaling message and data traffic are divided into a predetermined size and transmitted through a packet data channel (PDCH) in the form of a packet data unit (PDU). In this case, HARQ (Hybrid Automatic Repeat reQuest) is used to increase the reliability of data transmission in the packet data channel (PDCH). When receiving data at the receiving side, the HARQ requests retransmission of the unreceived data when damaged data is received or an error occurs during receiving and thus incomplete data cannot be received.

However, the data traffic is assigned a sequence number when divided into packet data units (PDUs), but the signaling message is not assigned a sequence number when divided into packet data units (PDUs). Therefore, when the HARQ transmission of the packet data unit (PDU), the receiving side may receive the data transmitted later than the data previously transmitted by the transmitting side, the receiving order may be changed when receiving. That is, even if all packet data units obtained by dividing the signaling message are completely received, the receiving side cannot reconstruct it, and thus there is a problem in that the message is not normally received.

Accordingly, an object of the present invention is to provide a method for transmitting a divided packet data unit of a signaling message when transmitting a signaling message through a packet data channel in a wireless packet data communication system.

Another object of the present invention is to provide a method of receiving a divided packet data unit of a signaling message through a packet data channel in a wireless packet data communication system.

Another object of the present invention is to provide a method for assigning a sequence number to a divided packet data unit of a signaling message when transmitting a signaling message through a packet data channel in a wireless packet data communication system.

Another object of the present invention is to provide a method for reconstructing a signaling message using a sequence number of a packet data unit received through a packet data channel in a wireless packet data communication system.

In order to achieve the above objects, the present invention provides a method for transmitting a packet data unit in a wireless packet data communication system, the method comprising: determining whether a service data unit is a signaling message when a service data unit is provided; And if the service data unit is a signaling message, adding a header indicating a signaling message to the service data unit, assigning a sequence number to configure a packet data unit, and transmitting the packet data unit to a receiving side. The above method is characterized by consisting of three processes.

In order to achieve the above objects, the present invention provides a method for receiving a packet data unit in a wireless packet data communication system, comprising analyzing a header of a packet data unit received from a transmitting side to determine whether the received packet data unit is a signaling message. Determining whether a lost packet data unit exists by checking a sequence number included in a header of the received packet data unit when the received packet data unit is a signaling message. And re-ordering the at least one received packet data unit according to the sequence number if there is no lost packet data unit as a result of the determination.

1 is a hierarchical configuration diagram of a CDMA2000 1xEVDV system according to the present invention;

2 is a diagram illustrating data processing between a link access control layer and a medium access control layer for a signaling message applied to the present invention.

3 illustrates a format of a multiplexed type 5 packet data unit according to an embodiment of the present invention.

4 is a diagram illustrating a process of receiving a packet data unit according to a typical HARQ transmission.

5 is a diagram illustrating a format of a packet data unit including a sequencing field according to an embodiment of the present invention.

6 illustrates a format of a packet data unit including a sequencing field according to another embodiment of the present invention.

7 is a flowchart illustrating a process of transmitting a packet data unit including a sequence number according to an embodiment of the present invention.

8 is a flowchart illustrating a process of receiving a packet data unit including a sequence number according to an embodiment of the present invention.

9 is a diagram illustrating a packet data unit process in HARQ transmission through a packet data channel according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

1 illustrates a hierarchical configuration diagram according to an Open Systems Interconnection (OSI) reference model of a CDMA2000 1xEVDV system according to the present invention.

Referring to FIG. 1, the CDMA2000 1xEVDV (hereinafter referred to as "1xEVDV") system includes a higher signaling layer 100, a data service layer 110, a voice service layer 120, and a link access control (LAC). 130, a Radio Link Protocol (RLP) 140, a Media Access Control (MAC) layer 150, and a Physical (PHY) layer 160. The upper signaling layer 100, the data service layer 110 and the voice service layer 120 are layers 3 to 7 of OSI, and the link access control layer 130 and the radio link protocol layer 140 The media access control layer 150 is two layers of OSI, and the physical layer 160 is one layer of OSI. In a typical CDMA200 system, a base station directly connecting a mobile communication terminal and a wireless channel performs a function of Layer 1 of OSI, and a base station controller connecting the base station and a network performs functions of Layers 2 to 7 of OSI.

The upper signaling layer 100 processes signaling information for the physical layer 160 interface. The data service layer 110 and the voice service layer 120 process traffic for data service and voice service, respectively.

Meanwhile, the radio link protocol layer 140 segments the data stream generated by the data service layer 110 and adds a sequence number to each divided unit to generate predetermined packet data. Thereafter, the generated predetermined packet data is transferred to the medium access control layer 150 to add a header. However, the present invention relates to the transmission of signaling messages, and the detailed description thereof will be omitted since the transmission of the data stream is contrary to the gist of the present invention.

2 is a diagram illustrating data processing between a link access control layer and a medium access control layer for a signaling message applied to the present invention.

Referring to FIG. 1 and FIG. 2, the signaling information transmission procedure will be described. The signaling information generated in the higher signaling layer 100 is transferred to the link access control layer 130. The first sublayer 112 of the link access control layer 130 adds headers related to authentication, sequencing, and addressing to the transferred signaling information. The second sublayer 114 generates a signaling message by adding a report field and a length field related to the quality of the radio link to the signaling information to which the header is added. Subsequently, in the third sublayer 116, the signaling message is segmented into a size that can be transmitted by the media access control layer 150, and then a SOM (Start Of Message) indicating the start or continuation of the message for each divided unit. The bits are added to generate a service data unit (SDU) of a predetermined size.

The generated service data unit (SDU) of the predetermined size in the link access control layer 130 is transferred to the medium access control layer 150. The media access control layer 150 adds a header to the service data unit (SDU) for transmission from the physical layer 160 to the receiver through a packet data channel to generate a packet data unit (PDU). . The packet data unit (PDU) is delivered to the physical layer 160.

Referring to the procedure at the time of reception of the packet data unit, the physical layer 160 delivers at least one packet data unit received from the transmitting side physical layer 160 to the media access control layer 150. The media access control layer 150 extracts a service data unit (SDU) by removing a header from the received at least one packet data unit and transfers it to the corresponding layer.

According to the 3rd Generation Partnership Project (3GPP2) standard, the format of the packet data unit is classified into five types according to the type of the physical channel 160. Among these, the type of packet data unit transmitted through the packet data channel (PDCH) is a multiplexed type 5 packet data unit. 3 illustrates a format of a multiplex type 5 packet data unit according to an embodiment of the present invention.

Referring to FIG. 3, the multiplexing type 5 packet data unit includes a multiplexing type 5 header of 6 to 22 bits, an extension header and an information field of 10 bits.

The multiplex type 5 header is composed of a 3-bit Service Indicator (SID) field, an 1-bit extended indication field, a 2-bit length indication field, and a length field of 0 to 16 bits. When the service identifier (SID) field is "000", this indicates signaling, "001" to "110" indicate a corresponding service index, and "111" indicates non-service. If the value of the extension indication field is "0", the extension header is omitted. If the extension indication field is "1", the extension header is added after the length field. When the length indication field is "00", the length is omitted, "01" indicates that the length field is 8 bits, "10" indicates that the length field is 16 bits, and "11" indicates that the payload is fixed. Indicates length.

The extension header is present only when the value of the extension indication field of the multiplex type 5 header is "1", as mentioned above, and is used to extend the use of the packet data unit according to the multiplex type 5. The first two bits of the extension header are extension type fields, indicating the extended use of the multiplexed type 5 packet data unit. Currently, only "01" is used, and if the value of the extension type field is "01", the extension header is a 2-bit encapsulation type field, a 2-bit capsule unit size field, and 4-bit spare for byte alignment. It consists of fields.

The encapsulation type field is a field indicating which multiplex type of service data unit the following payload contains, "01" indicates multiplexing type 1, "10" indicates multiplexing type 2, and "11" indicates multiplexing. Represents type 4. The unit size field of the capsule indicates the size of the service data unit carried in the payload, "00" indicates a full rate, "01" indicates a rate of 1/2, and "10" indicates A transmission rate of 1/4 is indicated, and "11" represents a transmission rate of 1/8.

4 is a diagram illustrating a process of receiving a packet data unit according to a typical HARQ transmission.

Referring to FIG. 4, when one signaling message is divided into three packet data units (PDUs) and transmitted through different HARQ channels, the receiving side transmits later than the packet data unit (PDU) previously transmitted by the transmitting side. A situation of receiving a packet data unit (PDU) occurs. Specifically, the first packet data unit '0' transmitted is received, the second packet data unit '1' is not received, and the third packet data unit '2' is transmitted. This situation occurs. In this case, the physical layer 160 requests retransmission for the second packet data unit '1'. The first transmitted packet data unit '0' and the third transmitted packet data unit '2' are transmitted to the media access control layer 150, and the second transmitted packet data unit ( '1') is normally received, it passes to the media access control layer 150.

As such, when the packet data unit (PDU) transmitted later is received before the packet data unit (PDU) transmitted earlier, the order is changed because the packet data unit (PDU) of the signaling message does not have a sequence number. The received packet data units (PDUs) could not be distinguished in the media access control layer 150. Accordingly, when the media access control layer 150 delivers the packet data units (PDUs) to the link access control layer 130 without using a separate implementation technique, the order of the packet data units (PDUs) is different. Will be reversed. Therefore, even though all the packet data units (PDUs) are successfully received by the media access control layer 150, the received packet data units are reversed in order to fail to reconstruct the signaling message. Accordingly, the present invention solves the above problems by assigning a sequence number to a packet data unit (PDU) in which a signaling message is divided.

5 is a diagram illustrating a format of a packet data unit including a sequencing field according to an embodiment of the present invention.

5 is compared with FIG. 3, the last 4 bits of the extension header are used as a field for assigning a sequence number (sequencing field). Since the sequencing field is 4 bits, 16 sequence numbers up to " 0000 to 1111 " can be assigned. This means that up to 16 packet data units (PDUs) can be distinguished. By assigning a sequence number as described above, it is possible to solve a problem caused by changing the reception order of the packet data units (PDUs).

6 illustrates a format of a packet data unit including a sequencing field according to another embodiment of the present invention.

The packet data unit (PDU) of FIG. 6 includes a header for indicating that the packet data unit (PDU) is a signaling message and an information field including a service data unit (SDU). In order to assign a sequence number to the packet data unit (PDU), a sequencing field is added in the header. In FIG. 6, a sequencing field is added after the length field of the multiplex type 5 header.

For example, the sequencing field includes 4 bits, and 16 sequence numbers up to " 0000 to 1111 " can be assigned. This means that up to 16 packet data units (PDUs) can be distinguished. It is possible to solve the problem caused by the reception order of the packet data units changed at the receiving side.

7 is a flowchart illustrating a process of transmitting a packet data unit including a sequence number according to an embodiment of the present invention.

Referring to FIG. 7, it should be noted that FIG. 7 is executed in the media access control layer 150.

Referring to FIG. 7, in operation 700, the medium access control layer 150 receives a service data unit (SDU) from the link access control layer 140. In operation 710, it is determined whether the service data unit (SDU) received by the media access control layer 150 is a signaling message. According to the determination result, if the service data unit (SDU) is a signaling message, the process proceeds to step 730; otherwise, the process proceeds to step 720. In step 720, it is determined that the service data unit (SDU) received by the medium access control layer 150 is data. In step 750, a header indicating that data is added to the received service data unit (SDU) is added. do.

In step 730, the media access control layer 150 adds a header for a signaling message to the received service data unit (SDU) to configure a multiplex type 5 packet data unit. In other words, the multiplexing type 5 header having a service identifier (SID) field value of FIG. 3 is “000”. In step 740, a sequence number is assigned to a header of the packet data unit.

As a method of assigning a sequence number to the packet data unit, as described with reference to FIG. 5, a sequence number of "0000" to "1111" is assigned using a sequencing field in an extension header. Alternatively, as mentioned in FIG. 6, a sequence number of "0000" to "1111" is assigned to the sequencing field in the multiplex type 5 header.

In step 750, the media access control layer 150 transmits the packet data unit (PDU) to the physical layer 160. Then, the physical layer 160 transmits the packet data unit (PDU) to a receiver through a packet data channel (PDCH).

8 is a flowchart illustrating a process of receiving a packet data unit including a sequence number according to an embodiment of the present invention.

Referring to FIG. 8, in step 805, the media access control layer 150 receives a packet data unit (PDU) transmitted from the transmitting side from the physical layer 160. In step 810, the medium access control layer 150 separates and analyzes a header of the received packet data unit (PDU). In operation 815, it is determined whether the received packet data unit (PDU) is a signaling message using the analyzed result. The criterion of the determination is a service identifier (SID) field of a multiplex type 5 header among headers separated from the packet data unit. That is, when the service identifier (SID) field is "000", the packet data unit (PDU) is determined to be a signaling message. If the received packet data unit (PDU) is not a signaling message according to the determination result, the packet data unit (PDU) is determined as data, and the process proceeds to step 820 to transmit to the radio link protocol.

If the packet data unit is a signaling message, the flow proceeds to step 825 to store the packet data unit (PDU) in a buffer existing between the link access control layer 130 and the medium access control layer 150. In step 830, the sequence number of the stored packet data unit (PDU) is checked. In operation 835, the system determines whether there is a retransmission request for the lost packet data unit (PDU) upon reception. For example, a packet data unit (PDU) having a sequence number of 1 is received, a packet data unit (PDU) having a sequence number of 2 is not received, and a packet data unit (PDU) having a sequence number of 3 is received. In this case, the physical layer 160 transmits a packet data unit (PDU) having a sequence number of 3 to the medium access control layer 150 and requests retransmission of the packet data having the sequence number of 2 through HARQ.

If there is a retransmission request, the process returns to step 805 and if there is no retransmission request, the process proceeds to step 840. The absence of a retransmission request means that the packet data units (PDUs) have been completely received without error. If there is no retransmission request, the received packet data units (PDUs) are rearranged according to sequence numbers. In operation 845, the rearranged message is transmitted to the link access control layer 130.

9 is a diagram illustrating a packet data unit processing procedure in HARQ transmission through a packet data channel according to an embodiment of the present invention.

Referring to FIG. 9, when receiving packet data units (PDUs) that are divided into three, a signaling message assigned a sequence number, a packet data unit (PDU) having a sequence number of 0 is received, and a sequence number of 1 and 1 is received. If a packet data unit (PDU) of 2 is not received, retransmission is requested for the packet data units (PDUs) of the sequence numbers 1 and 2 above. The packet data unit (PDU) having the sequence number 0 is stored in a buffer existing between the link access control layer 130 and the medium access control layer 150.

If a packet data unit (PDU) having a sequence number of 2 is received according to the retransmission request and a packet data unit (PDU) having a sequence number of 1 is not received, the packet data unit (PDU) having a received sequence number of 2 is received. Store in a buffer and request retransmission for a packet data unit (PDU) of sequence number 1 that has not been received. When a packet data unit having a sequence number of 1 is received, it is stored in the buffer. Thereafter, the data is rearranged according to the sequence number of the packet data (PDUs) stored in the buffer and transferred to the link access control layer 130.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

According to the present invention as described above, by assigning a sequence number to the divided packet data unit of a signaling message and transmitting the packet number, the packet data unit can be rearranged on the receiving side according to the sequence number. There is an advantage that can prevent the order of change.

Claims (5)

A method of transmitting a packet data unit in a wireless packet data communication system, the method comprising: If a service data unit is provided, determining whether the service data unit is a signaling message; A second step of configuring a packet data unit by adding a header indicating a signaling message to the service data unit and assigning a sequence number when the service data unit is a signaling message; And a third process of transmitting the packet data unit to a receiving side. The method of claim 1, The packet data unit includes an extension header including a header and a sequence number for indicating that the packet message is a signaling message, and an information field including the service data unit. The method of claim 1, And said packet data unit comprises a header for indicating that it is a signaling message and an information field including said service unit, and includes a sequence number in said header. A method for receiving a packet data unit in a wireless packet data communication system, the method comprising: A first step of analyzing a header of a packet data unit received from a transmitting side to determine whether the received packet data unit is a signaling message; A second step of determining whether a lost packet data unit exists by checking a sequence number included in a header of the received packet data unit when the received packet data unit is a signaling message as a result of the determination; And if there is no lost packet data unit as a result of the determination, rearranging at least one received packet data unit according to the sequence number. The method of claim 4, wherein the first process is And if the service identifier field included in the header of the received packet data unit is "000", determine as a signaling message.