KR100867578B1 - Method of retransmitting a radio link control block fast in a mobile communication terminal - Google Patents

Abstract

A method for fast retransmission of an RLC block in a mobile terminal includes transmitting a radio link control (RLC) block; And when a specific field of the RLC block is enabled and it is determined that the data of the RLC block is signaling data including control information, or a response message indicating that the RLC block has not been received normally, Retransmitting the RLC block to the other system or another terminal when it is determined that the reception is received from the other system or another terminal. The Received Bitmap Block (RRB) in the response message includes information on an RLC block normally received by the other system or another terminal among the RLC blocks and an RLC block that is not normally received by the other system or the other terminal.

GPRS, RLC, LLC, Mobile Terminal, Packet Uplink Message, RBB

Description

Method of retransmitting a radio link control block fast in a mobile communication terminal

1 is a view schematically showing a GPRS protocol structure of a mobile terminal to which the present invention is applied;

2 is a flowchart provided to explain a method of retransmitting an RLC block in a mobile terminal according to an embodiment of the present invention;

3 is a view schematically showing the structure of an LLC block according to an embodiment of the present invention;

4 is a diagram illustrating a structure of an RLC block according to an embodiment of the present invention;

5 is a diagram illustrating whether to retransmit an RLC block when the Fast Retrans field of the RLC block transmitted to the network is set to '1' or '0';

FIG. 6 is a flowchart illustrating a process of a mobile terminal when a packet uplink message is received in step S260 of FIG. 2.

Brief description of the main parts of the drawing

7: LLC layer module 9: RLC layer module

13: GSM RF Layer Module

The present invention relates to a retransmission method of a radio link control (RLC) block in a mobile terminal.

UMTS (Universal Mobile Telecommunication System), a third generation mobile communication system that is being standardized in 3GPP, defines a general packet radio service (GPRS) system to provide packet data services such as the Internet.

The GPRS system has its own IP-based backbone network for communication between a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN) performing packet switching. In addition, the GPRS system provides a roaming service for subscribers of an ISP network for interworking with an ISP (Internet Service Provider) network, and a mobile IP system for providing a mobile IP service is also defined.

GPRS was originally designed for Global System for Mobile Communication (GSM), but was also adopted in IS-136. GPRS is a new bearer service for GSM, which can simplify and improve the performance of wireless access to packet data networks. As a result, GPRS improves radio resource usage efficiency, provides advantages of high data rate, short access time setting, and simplifies access to packet data networks.

The main elements of the GPRS architecture are the Base Subsystem, which includes a Base Controller (BSC), which includes a mobile terminal, a Base Transceiver Station (BTS), and a Packet Control Unit (PCU). System: BSS) and Serving GPRS Support Node (SGSN).

The Gateway GPRS Support Node (GGSN) enables data transfer between GPRS networks and external data networks such as the Internet. One or more GGSNs are connected to the SGSN via the Internet Protocol based on the GPRS backbone network. When the mobile terminal communicates with an external data network, the GGSN acts as an IP router between the mobile terminal and the external network. Packet Data Channels (PDCHs) are used as physical channels for packet data delivery in GPRS.

A Packet Data Protocol context is created to convey user data, for example other data not created by the GPRS protocol. All messages, including PDP context messages, are delivered using a temporary block flow between the mobile terminal and the GPRS network.

In the mobile terminal, the GRPS protocol structure on the transport plane includes an application layer, an IP / X.25 layer, a subnetwork dependent convergence protocol (SNDCP) layer, a logical link control (LLC) layer, a radio link control (RLC) layer, and a media access control (MAC). ) Layer, and the GSM RF layer.

Among these, the RLC layer divides the data to be transmitted within the maximum transmission unit (MTU) of the network to generate an RLC block. The RLC block is delivered to the lower layer for each radio block (1 Radio Block = 18.46 msec), and the RLC block (456 bits) is delivered in a frame unit (114 bits) through the GSM RF layer. At this time, the RLC layer performs buffer and window management on the transmitted RLC block.

The mobile terminal sends an RLC block to the network and enters a standby state until receiving a packet uplink message from the network. When the packet uplink message is received, the terminal performs buffer / window management by dividing the RLC block received by the Ack and the RLC block received by the Nack by using Received Block Bitmap (RBB) in the packet uplink message.

More specifically, the mobile station checks the RBB, deletes the RLC block received with the Ack from the buffer, and retransmits the RLC block received with the Nack. Thereafter, the mobile terminal enters the standby state again until it receives the packet uplink message again.

The actual network environment is characterized by strong signal interference, high traffic, and weak signal region. Due to this characteristic, there is a problem in that the reception of the packet uplink message is delayed from the network to increase the waiting time of the terminal, or the network does not receive the RLC block, and thus all transmitted RLC data blocks are received by the Nack.

Accordingly, an aspect of the present invention is to provide a method for retransmitting an RLC block in a mobile terminal so that the RLC block can be efficiently retransmitted from a mobile terminal to a network.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above may be clearly understood by those skilled in the art from the following description. There will be.

In order to achieve the above technical problem, a method for fast retransmission of an RLC block in a mobile terminal according to an embodiment of the present invention includes the steps of transmitting a radio link control (RLC) block; And when a specific field of the RLC block is enabled and it is determined that the data of the RLC block is signaling data including control information, or a response message indicating that the RLC block has not been received normally, Retransmitting the RLC block to the other system or another terminal when it is determined that the reception is received from the other system or another terminal.
The Received Bitmap Block (RRB) in the response message includes information on an RLC block normally received by the other system or another terminal among the RLC blocks and an RLC block that is not normally received by the other system or the other terminal.
The specific field is a Fast Retrans field, and when the Fast Retrans field is set to '1', the specific field is determined to be enabled.

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Retransmitting the RLC block is performed until a response message from the network is received from the transmitted RLC block.

When the specific field is disabled, the response message for the transmitted RLC block does not perform retransmission of the RLC block until received from the network, and enters a standby state.

The response message is a packet uplink message.

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Hereinafter, the present invention will be described with reference to the accompanying drawings.

1 is a diagram schematically illustrating a GPRS protocol structure of a mobile terminal to which the present invention is applied.

Referring to FIG. 1, in the mobile terminal to which the present invention is applied, the GPRS protocol structure includes an application layer module 1, an IP / X.25 layer module 3, a SubNet work Dependent Convergence Protocol (SNDCP) layer module 5, A Logical Link Control (LLC) layer module 7, a Radio Link Control (RLC) layer module 9, a Media Access Control (MAC) layer module 11, and a GSM RF layer module 13 are included.

The application layer module 1 provides various applications to the user and enables the application requested by the user to be executed. Applications that can be provided by the mobile terminal include various services such as multimedia message service (MMS), short message service (SMS), wireless application protocol (WAP), Java, and over the air (OTA).

The IP / X.25 layer module 3 allows user data to be transferred via a GPRS network to an external data network such as the Internet. The SNDCP layer module 5 controls the transfer of packet data units of the user data network layer between the mobile terminal and the SGSN.

The LLC layer module 7 is used for transferring data between a mobile terminal and a Serving GPRS Support Node (SGSN) in a GPRS network. Controls delivery of user data network layer packet data units (N-PDUs).

The RLC layer module 9 divides the data to be transmitted within the maximum transmission unit (MTU) of the network to generate an RLC block. The RLC block 456 bits is delivered to the lower layer for each radio block frame period (= 18.46 msec), and the RLC block is delivered to the network in frame units (114 bits) through the GSM RF layer module 13.

In addition, there is a Session Management (SM) layer module 15 that performs session management of GPRS and a Gprs Mobility Management (GMM) layer module 17 that performs mobility management of GPRS.

The GMM layer module 17 performs mobility management of GPRS and uses the services of the LLC layer module 7 to convey messages between the mobile terminal and the SGSN.

In the embodiment of the present invention, signaling data including control information from the SM layer module 15 and the GMM layer module is provided to the LLC layer module 17.

2 is a flowchart provided to explain a method of retransmitting an RLC block according to an embodiment of the present invention.

Referring to FIG. 2, when the LLC layer module 7 receives data from a higher layer, the signaling received from the higher layer includes control information transferred from the SM layer module 15 and the GMM layer module 17. Check whether the data is user data transmitted through the application layer module 1, the IP / X.25 layer module 3, and the SNDCP layer module 5 (S210). The LLC layer module 7 displays the confirmed result in the signal data field included in the header of the LLC block.

3 is a diagram schematically illustrating a structure of an LLC block according to an embodiment of the present invention. Referring to FIG. 3, the LLC block 300 is composed of an LLC header 310 and an LLC data block 320 which is an actual data portion. In an embodiment of the present invention, the LLC data block 310 includes a signal data field ( 315) is newly added.

More specifically, when the received data is signaling data including control information (S215: Y), the LLC layer module 7 may be configured in the signal data field 315 included in the header 310 of the LLC block 300. The field value '1' is set (S220).

In contrast, when the received data is user data (S215: N), the LLC layer module 7 sets '0' as a field value in the signal data field 315 (S225). The signal data field 315 is newly added in the present invention, and the size of the signal data field 315 is 1 bit.

The LLC layer module 7 transfers the LLC block to the lower layer RLC layer module 9 every frame period (4.615 msec).

The RLC layer module 9 checks the signal data field 315 included in the LLC header 310 of the LLC block 300, so that the actual data included in the LLC data block 320 includes the control information. Whether it is data or user data is checked (S230).

4 is a diagram schematically illustrating a structure of an RLC block according to an embodiment of the present invention. Referring to FIG. 4, the RLC block 400 includes an RLC header 410 including a Fast Retrans field 415, and an RLC data block 420.

When the check result in step S230, the field value of the signal data field 315 is set to '1' (S235: Y), that is, the actual data of the LLC data block 320 is the signaling data including the control information The RLC layer module 9 determines such signaling data as data for which fast retransmission is requested, and sets a field value '1' in the Fast Retrans field 415 included in the RLC header 410 of the RLC block 400. In operation S240, the RLC block 400 is stored in a buffer in a queue manner.

In contrast, when the field value of the signal data field 315 is set to '0' (S235: N), that is, when the actual data of the LLC data block 320 is user data, the RLC layer module 9 A field value '0' is set in the Fast Retrans field 415 (S245), and the RLC block 400 is stored in a buffer in a queue manner.

When the mobile station requests channel assignment for data transmission to the network, and in response to the channel assignment from the network, the RLC layer module 9 transmits a GSM RF to the RLC block stored in the buffer at every radio block frame period. Transfer to the layer module (13).

The GSM RF layer module 13 transmits the RLC block received from the RLC layer module 9 to the network through the assigned channel (S250). At this time, the GSM RF layer module 13 may not transmit the RLC block according to the actual wireless environment, and may have it.

When the actual RLC block is transmitted, the GSM RF layer module 13 transmits the RLC layer module 9 to the RLC layer module 9 by setting a field value of 'Block Sent Indication' to '1'. If this is not transmitted, the field value of 'block cent indication' is set to '0' and transmitted to the RLC layer module 9.

The RLC layer module 9 checks the field value of the 'block cent indication' transmitted from the GSM RF layer module 13 to determine whether the actual RLC block is transmitted through the network. Accordingly, the RLC layer module 9 can determine whether to transmit the next RLC block to the GSM RF layer module 13 or whether to wait for the transmission of the RLC block until the transmission is completed in the GSM RF layer module 13. do.

After the RLC block is transmitted to the network, the mobile station checks whether a packet uplink message, which is a response message, is received from the network (S255). The timing of transmission of a packet uplink message in a network is arbitrarily determined by network criteria.

If a packet uplink message is received from the network (S260: Y), the subsequent process will be described with reference to FIG.

If a packet uplink message is not received from the network (S260: N), the mobile station checks the field value of the Fast Retrans field 415 in the RLC header 410 of the transmitted RLC block 400 (S265).

As a result, the RLC block 400 having the field value of the Fast Retrans field 415 set to '1' retransmits the RLC block 400 to the network until the packet uplink message is received (S270).

Therefore, according to the present invention, the RLC block is retransmitted even before the packet uplink message is received for the RLC block in which the Fast Retrans field is enabled. This can solve the problem of long waiting time.

On the contrary, the RLC block 400 in which the field value of the Fast Retrans field 415 is set to '0' is not retransmitted and enters a standby state until a packet uplink message is received (S275).

5 is a diagram illustrating whether to retransmit an RLC block when the Fast Retrans field of the RLC block transmitted to the network is set to '1' or '0'.

Referring to FIG. 5, an RLC block in which the field value of the Fast Retrans field 415 is set to '1', that is, the Fast Retrans field 415 is enabled in units of four frames every 4.615 msec. Delivered to the network.

Subsequently, two RLC blocks in which the field value of the Fast Retrans field 415 is set to '0', that is, the Fast Retrans field 415 is disabled, are continuously transmitted to the network in units of four frames. .

Thereafter, the RLC block in which the Fast Retrans field 415 is enabled is retransmitted frame by frame until the packet uplink message is received.

FIG. 6 is a flowchart illustrating a process of a mobile terminal when a packet uplink message is received in step S260 of FIG. 2.

When the packet uplink message is received (S610), the mobile station checks the Received Block Bitmap (RBB) in the packet uplink message (S620). The mobile terminal checks the RBB to confirm the RLC block received by Ack and the RLC block received by Nack. Received by Ack means that the RLC block transmitted by the mobile terminal has been received in the network. Received by Nack means that the received RLC block has not been received in the network.

As a result of the RBB check, in the case of the RLC block received with the Ack (S630: Y), the RLC layer module 9 deletes the corresponding RLC block from the buffer (S640).

On the contrary, when the RBB check result is the RLC block received by Nack (S635: Y), the RLC layer module 9 performs step S240 of FIG. 2 (S645). More specifically, the RLC layer module 9 determines the RLC block received by the Nack as data for which fast retransmission is requested, and thus, the Fast Retrans field 415 in the RLC header 410 of the RLC block 400 received by the Nack. Is set to '1' and stored as a queue in the buffer.

That is, in the case of the RLC block received by Nack, the Fast Retrans field is set to '1' like the signaling data including the control information. Therefore, when the RLC block received by the Nack is retransmitted, the RLC block received by the Nack is retransmitted back to the network until a packet uplink message is received in response thereto.

In the above description of the preferred embodiment of the present invention, the present invention is not limited to the above-described specific embodiment, it is common in the art to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and such changes are within the scope of the claims.

As described above, according to an embodiment of the present invention, when the Fast Retrans field of the transmitted RLC data block is enabled, the RLC block is retransmitted until the packet uplink message is received.

Therefore, after transmitting the RLC block to the network as in the prior art, the mobile terminal can be prevented from being put in the standby state until receiving a packet uplink message that is a response from the network.

In addition, the higher the traffic of the actual network, the greater the chance of retransmission of the RLC block as the delay in receiving packet uplink messages from the network is increased. Accordingly, even in a high traffic environment, the probability of receiving a packet uplink message is increased, and a high data transmission rate can be expected.

Claims (7)

Transmitting a Radio Link Control (RLC) block to another system or another terminal to communicate over a network; And When a specific field of the RLC block is enabled and it is determined that the data of the RLC block is signaling data including control information, or a response message indicating that the RLC block has not been received normally is transmitted through the network. Retransmitting the RLC block to the other system or another terminal when it is determined that the reception is received from the other system or another terminal, Received Bitmap Block (RBB) in the response message, Retransmission method of an RLC block in a mobile terminal, characterized in that the RLC block of the RLC block that is normally received by the other system or another terminal, and information about the RLC block that was not normally received by the other system or another terminal. The method of claim 1, wherein the specific field, A Fast Retrans field, and when the Fast Retrans field is set to '1', the specific field is determined to be enabled. The method of claim 1, And retransmitting the RLC block until a time point at which a response message for the RLC block is received from the other system or another terminal is performed. The method of claim 1, wherein when the specific field is disabled, And entering a standby state without performing retransmission of the RLC block until the time when the response message for the RLC block is received from the other system or another terminal. Resend method of. The method of claim 3 or 4, wherein the response message, Retransmission method of an RLC block in a mobile terminal, characterized in that the packet uplink message. delete delete

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