KR100577201B1 - Method for transmitting packet data, and apparatus for the same - Google Patents

Abstract

The present invention relates to a packet data transmission method and apparatus for transmitting a packet data of a forward link by detecting whether an abnormal operation of a mobile terminal and, in particular, scheduling information, in a next generation mobile communication system. The base station monitors the operation of the mobile terminal to detect whether the mobile terminal is abnormally operated, and then the base station uses the detected information for scheduling for forward link packet data transmission, thereby eliminating unnecessary radio resources generated by the mobile terminal. It is an invention that can reduce waste.

Scheduling, Radio Link Protocol (RLP), Forward Link

Description

Method for transmitting packet data and apparatus therefor {Method for transmitting packet data, and apparatus for the same}

1 is a view for explaining a forward link data service method of a 1xEV-DV system.

2 is a diagram of a conventional method for forward link packet data transmission in a 1xEV-DV system.

3 is a diagram illustrating a configuration for forward link packet data transmission according to the present invention;

4 is a flowchart illustrating a procedure for detecting abnormal operation and using the detected information for scheduling in a mobile terminal according to the present invention.

The present invention relates to a communication system, and more particularly, to a packet data transmission method and apparatus for transmitting packet data of a forward link using detection of abnormal operation of a mobile station and scheduling information of the mobile terminal in a next generation mobile communication system. .

Recently, as the importance of packet data service increases in mobile communication system, standardization and product development of new system for efficient data service has been active.

Accordingly, in the late 90's, 1x EV-DO (1x Evolution Data Optimized) system was developed by Qualcomm, USA for data-only service. Data and Voice systems are under development.

Looking at the trend of data services until recently, the two-way data transmission and reception such as the File Transfer Protocol was the main, but recently the explosive demand of the World Wide Web (WWW) and streaming services has increased. . As a result, the unbalance between phenomena is intensifying, while the data link demand of the forward link is rapidly increasing while the link link data service demand is not greatly increased.

Accordingly, international standards for efficient packet data transmission on the forward link are urgently required, and standardization has been completed in 2002. Standardization on the reverse link is currently in progress.

An international standardization work has been completed and the forward link packet data transmission method of the 1xEV-DV system currently being developed is shown in FIG. 1.

Referring to FIG. 1, the mobile station measures the reception sensitivity of the pilot signal transmitted from the base station and reports the forward link channel quality to the base station from the measurement result.

Then, the base station determines the forward data rate to serve the mobile station through the forward link channel quality information received from the mobile station and a mapping table provided in advance.

The base station schedules the transmission packets sequentially in consideration of scheduling priority and the like, and transmits them in the mobile station.

In a general channel environment, packet data transmitted from the base station is lost 1 to 5% in the radio section due to the fading characteristics of the forward link channels.

However, the packet data lost in the radio section is mostly due to the retransmission function of the Radio Link Protocol (hereinafter, RLP) block belonging to the Medium Access Control (MAC) layer. Is restored.

Therefore, reliable packet data transmission is possible by the retransmission function of the RLP block.

FIG. 2 is a diagram of a conventional method for transmitting a forward link packet data in a 1xEV-DV system, and illustrates some components of a base station.

The RLP block 20 receives and transmits data provided from a packet data source, such as the Internet, from a packet data serving node 10 (hereinafter, referred to as PDSN) 10, and wirelessly. It is responsible for retransmission of lost packet data in the section.

The scheduler 40 belonging to the physical layer performs scheduling using channel quality information received from each mobile station. In this case, the channel quality information is quality information about a channel of the forward link.

At this time, the scheduler 40 receives no control or interference other than receiving the transport packet from the RLP block 20 of the base station.

In order to transmit the forward link packet data of the RLP block 20, the mobile station measures and reports the strength (or reception sensitivity) of the pilot signal received from the base station to the base station.

In the above, the mobile station reports the base link quality to the base station. Through this, the mobile station informs the base station of the maximum traffic data rate that the mobile station can receive. The channel used at this time is a channel quality indicator channel (hereinafter, abbreviated as CQICH).

Accordingly, the base station determines the traffic data rate to be transmitted to the mobile station using the forward link channel quality information received from the mobile station through the CQICH.

However, if the amount of retransmission packets is too large compared to the packet to be newly transmitted due to the abnormal operation of the RLP block belonging to the physical layer of the mobile terminal, the mobile terminal does not actually increase the amount of packet data serviced from the higher application side. In the physical layer, a large amount of packet data is transmitted and received by an abnormally increased retransmission packet.

As a result, the amount of packet data serviced between the PDSN and the application of the mobile terminal is not large, but the physical layer of the mobile terminal consumes a lot of forward link resources, resulting in a very low service efficiency. In addition, due to the characteristics of a mobile communication system sharing the forward link resources of all mobile terminals in a specific cell, an excessive increase in the number of retransmission packets for a specific mobile terminal may adversely affect the data processing efficiency of other mobile terminals located in the same cell. do.

SUMMARY OF THE INVENTION An object of the present invention is to provide a packet data transmission method and apparatus therefor suitable for facilitating transmission of packet data of a forward link by using state information of a mobile terminal in scheduling in a communication system. To provide.

Another object of the present invention, in the next generation mobile communication system 1xEV-DV (evolution data and voice) system, the base station monitors the status of the mobile terminal to detect whether the mobile terminal abnormal operation, and then forwards the packet data to the forward link The present invention provides a method and apparatus for transmitting packet data suitable for performing forward link scheduling by using the detected information when transmitting.

A feature of the packet data transmission method according to the present invention for achieving the above object is from the number of retransmission packets to the mobile terminal from the number of packet data coming down per unit time from the Radio Link Protocol (RLP) block of the base station Checking the state of the mobile terminal and adjusting a scheduling priority for packet data transmission to the mobile terminal using the state of the mobile terminal.

The checking of the status of the mobile station may include calculating a ratio value of the number of retransmitted packets and the number of new packets to be newly transmitted to the mobile terminal from the number of packet data descending from the radio link protocol block per unit time, and the calculation And determining whether the mobile terminal receiver is in normal operation by comparing the predetermined ratio value with a first predetermined threshold value.

At this time, when the ratio value is less than the first threshold, the mobile terminal receiver determines that the abnormal operation is performed, thereby lowering the scheduling priority of the retransmission packet by a predetermined unit.

And further calculating a ratio of the number of new packets to be newly transmitted to the mobile terminal to the number of retransmitted packets to be retransmitted to the mobile terminal from the number of packet data descending per unit time from the radio link protocol block after the scheduling priority is lowered. And restoring scheduling priority for the lowered retransmission packet if the further calculated rate value is above the first threshold and exceeds a second predetermined second threshold.

A feature of the packet data transmission apparatus according to the present invention for achieving the above objects is a radio link protocol (RLP) block belonging to the medium access control (MAC) layer of the base station and the radio link protocol block A packet monitoring block for checking a receiver state of the mobile station by monitoring a number of new packet data to be newly transmitted to the mobile station and a retransmitted packet data to be retransmitted to the mobile station, and status information of the receiver provided by the packet monitoring block; It is configured to include a scheduler for adjusting the scheduling priority of the packet data waiting to be transmitted using.

More preferably, the packet monitoring block calculates a ratio value of the number of new packet data to the number of retransmission packet data from the number of packet data descending per unit time from the radio link protocol block.

Here, the packet monitoring block is set to a first threshold value to compare with the calculated ratio value to determine the state of the mobile terminal receiver, the mobile terminal receiver when the calculated ratio value is less than the first threshold value; It is determined that the operation is abnormal, and instructs the scheduler to lower the scheduling priority of the retransmission packet data of the mobile terminal waiting to be transmitted.

Subsequently, the packet monitoring block determines the scheduling priority when the ratio value of the number of new packets to the number of retransmitted packets calculated from the number of packet data coming down from the radio link protocol block in the next unit time exceeds a predetermined level. Instructs the scheduler to recover the scheduling priority for the retransmitted packet data of the mobile station.

More preferably, the packet monitoring block includes a first threshold for comparing with the calculated ratio value to determine the state of the mobile terminal receiver, a second threshold having a value larger than the first threshold, and the radio link protocol. A third threshold is set that compares with the number of packet data coming down from the block, so that the calculated ratio value is less than the first threshold while the number of packet data coming down from the radio link protocol block exceeds the third threshold. The mobile terminal receiver determines that an abnormal operation is performed, and instructs the scheduler to lower the scheduling priority of retransmission packet data of the mobile terminal waiting to be transmitted.

The second threshold is then used to recover the scheduling priority for the lowered packet data for retransmission of the mobile station, whereby the number of retransmitted packets calculated from the number of packet data coming down from the radio link protocol block in the next unit time. When the ratio value of the number of new packets for the value exceeds the second threshold, the packet monitoring block instructs the scheduler to restore the scheduling priority for the retransmission packet data of the mobile station.

Other objects, features and advantages of the invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, a preferred embodiment of a packet data transmission method and apparatus therefor according to the present invention will be described with reference to the accompanying drawings.

3 is a diagram showing a configuration for forward link packet data transmission according to the present invention, and shows a partial configuration of a base station.

The RLP block 200 belonging to the MAC layer is responsible for receiving and transmitting data provided from a packet data source such as the Internet from the PDSN 100 and retransmitting packet data lost in a radio section.

The RLP block 200 sends down a new packet (hereinafter referred to as "new packet") and a retransmission packet to the mobile station.

The queue block 300 includes buffers 310 and 320 for temporarily storing the new packet or the retransmission packet. Here, buffer 1 310 is described for new packets and buffer 2 320 is described for retransmitted packets.

Among the packets stored in the transmission block 300, the retransmission packet has a higher scheduling priority than the new packet. Therefore, since the scheduling priority of the new packet and the retransmission packet is different as described above, the packets are divided and stored in different buffers 310 and 320.

The scheduler 400 first processes the retransmission packet of the buffer 2 320 having a high scheduling priority in a normal operation situation.

However, if an abnormal operation of the mobile station is notified in the packet monitoring block 600, the scheduling priority for the retransmission packet is lowered.

To this end, the packet monitoring block 600 newly provided in the present invention belongs to the MAC layer and checks the state of the corresponding mobile terminal by monitoring packet data coming down from the RLP block 200 in real time. 4 shows an example in which the scheduler 400 adjusts the scheduling priority of packet data waiting to be transmitted to the buffer (especially buffer 2) according to the status check of the mobile terminal by the monitoring operation and the result of the checking.

Summarizing the operation of the packet monitoring block 600, the packet monitoring block 600 monitors the number of new packets and the number of retransmission packets descending from the RLP block 200 in real time. Here, the number of new packets corresponds to the amount of new packets, and the number of retransmission packets also corresponds to the amount of retransmission packets.

Subsequently, it is determined whether the mobile station is in a normal or abnormal state by using the monitored new packets and the retransmitted packets. In more detail, it is determined whether the mobile terminal receiver is operating normally or abnormally using the monitored number of new packets and the number of retransmission packets. The judgment is made using the methods listed below individually or in combination with one or more of the methods listed.

1. Does the number of retransmission packets received from the RLP block 200 per unit time exceed a certain level? If the number of retransmission packets per unit time exceeds a certain level, the mobile station is determined to be abnormal. Otherwise, the mobile station is determined to be normal.

2. If the ratio of the number of new packets to the number of retransmission packets received from the RLP block 200 per unit time is less than a predetermined level, the mobile terminal is determined to be abnormal, otherwise the mobile terminal is determined to be normal.

3. The ratio of the number of new packets to the number of retransmission packets received from the RLP block 200 per unit time is constant while the number of new packets + number of retransmission packets received from the RLP block 200 per unit time exceeds a certain level. If it is below the level, the mobile terminal is determined to be abnormal, otherwise the mobile terminal is determined to be normal. (Described in FIG. 4)

The packet monitoring block 600 monitoring the state of the mobile terminal in the above manner informs the scheduler 400 of the determined result (state information of the mobile terminal), and causes the scheduler 400 to buffer 2 320. To adjust the scheduling priority of the retransmission packet. More preferably, when it is determined that the mobile terminal operates abnormally, the packet monitoring block 600 sends a command signal to the scheduler 400 to lower the scheduling priority for the retransmission packet. On the other hand, when the packet monitoring block 600 determines that the mobile station is operating normally when the scheduling priority for the retransmission packet is not lowered, it is preferable not to send any command to the scheduler 400.

Thereafter, the packet monitoring block 600 continuously monitors the amount of new packets and the amount of retransmission packets coming down from the RLP block 200 to check the state of the mobile terminal.

Accordingly, if it is determined that the mobile terminal state is normal after a certain time, the mobile station sends a command to the scheduler 400 to restore the scheduling priority. In this case, unlike when the scheduling priority of the retransmission packet is not lowered, the scheduling priority of the retransmission packet is already lowered. Therefore, when it is determined that the mobile terminal operates normally, the mobile station determines that the mobile terminal operates normally. Send a recovery priority scheduling command for the retransmission packet

When the scheduler 400 lowers or restores the scheduling priority of the retransmission packet according to the command of the packet monitoring block 600, the scheduler 400 decreases or increases by one step by a predetermined step.

As a result, in the present invention, the status of the mobile station is checked by using the amount of new packets and the amount of retransmission packets that descend from the RLP block 200 to the physical layer for scheduling, and the retransmission packets to be transmitted to the mobile station according to the checked result. Adjust the scheduling priority of the.

Accordingly, the scheduler 400 according to the present invention is controlled to increase or decrease the scheduling priority according to the amount of packets having different characteristics coming down from the RLP block 200 of the base station.

Of course, in the present invention, the mobile station determines the traffic data rate to be transmitted to the mobile station using the forward link channel quality reported to the base station through the CQICH.

4 is a flowchart illustrating an example of detecting abnormal operation and using the detection information in a mobile terminal according to the present invention, and illustrates an operation example of a packet monitoring block 600 newly provided in a base station of the present invention. .

The symbols used first to describe the procedure of FIG. 4 are first defined.

N_total: Total number / transmission packet transmitted from RLP block. N_total = N_new + N_ret

N_new: number / new packet

N_ret: Retransmission packet count / amount

t: timer time

T1: unit time

Sched_Pri_Down_Flag: Scheduling priority lowering flag

Sched_Pri_Down_Flag == 0: Indicates that scheduling priority has not been lowered

Sched_Pri_Down_Flag == 1: Indicates that scheduling priority has been lowered

thresh1: First threshold based on the total number / quantity of packets coming down the RLP block

thresh2, thresh3: second and third thresholds on which the ratio of new packet count / amount to retransmission packet count / amount is based, thresh2 <thresh3

Referring to FIG. 4, parameter values representing the total number of transmission packets / quantity N_total, the number of new packets / quantity N_new and the number of retransmission packets N_ret are initialized, and the timer time t and the scheduling priority are lowered. The parameter values representing the flag Schedule_Pri_Down_Flag are initialized (S10).

Subsequently, parameter values representing the total number of transmission packets / quantity N_total, the number of new packets / quantity N_new, and the number of retransmission packets / number N_ret are updated for a predetermined time T1 (S20). That is, the packet monitoring block monitors all transport packets coming down from the RLP block, and displays the total number of transport packets / quantity and the number / amount of new packets and retransmission packets descending for a predetermined time T1 among the transport packets. Update each parameter value that it represents.

After that, the timer time t is reset and the monitored total number of transport packets / quantity N_total is compared with the first predetermined threshold th1 (S30). If the total number of transmitted packets / quantity N_total monitored at this time does not exceed the first threshold1, the total number of transmitted packets / quantity N_total, the number of new packets / quantity N_new and the number of retransmission packets are again described. Initialize the parameter values indicating the amount / N (ret) (S120), and then the parameter values indicating the total number of packets / amount (N_total) and the number / number of new packets (N_new) and the number / amount of retransmission packets (N_ret) The process (S20) of updating for a predetermined time T1 is restarted.

On the other hand, if the total number of monitored packets / quantity N_total exceeds the first threshold threshold1, the ratio of the number of new packets / quantity N_new to the number of retransmitted packets N / ret is calculated and the ratio value. Is compared with a second threshold (thresh2) (S40). At this time, if the ratio value is not less than the second threshold (thresh2), the ratio value is again compared with the third threshold (thresh3) having a value larger than the second threshold (S50). On the other hand, if the ratio value is less than the second threshold (thresh2), it is checked whether the value of the scheduling priority lowering flag (Sched_Pri_Down_Flag) is "Sched_Pri_Down_Flag == 0" (S60). That is, it is checked whether the scheduling priority of the mobile station retransmission packet has been lowered.

If "Sched_Pri_Down_Flag = 0" indicates that the scheduling priority of the mobile station retransmission packet has not been lowered before, the scheduler lowers the priority of the retransmission packet of the retransmission buffer (buffer 2) (S70). In addition, "Sched_Pri_Down_Flag = 1" indicates that the scheduling priority for the retransmission packet is lowered (S80). However, if "Sched_Pri_Down_Flag == 0" indicates that the scheduling priority of the mobile station retransmission packet has been lowered before, the scheduler does not lower the priority of the retransmission packet of the retransmission buffer (buffer 2).

When the ratio value is compared with the third threshold threshold3 and the ratio value exceeds the third threshold, it is checked whether the value of the scheduling priority lowering flag (Sched_Pri_Down_Flag) is “Sched_Pri_Down_Flag == 1” (S90). . That is, it is checked whether the scheduling priority of the mobile station retransmission packet has been lowered.

If "Sched_Pri_Down_Flag == 1" indicates that the scheduling priority of the mobile station retransmission packet has been lowered before, the priority of the retransmission packet of the retransmission buffer (buffer 2) is increased (S100). In addition, "Sched_Pri_Down_Flag = 0" indicates that the scheduling priority for the retransmission packet is restored (S80).

However, if "Sched_Pri_Down_Flag == 1" indicates that the scheduling priority of the mobile station retransmission packet has not been lowered before, the scheduler does not increase the priority of the retransmission packet of the retransmission buffer (buffer 2).

According to the present invention described above, the conventional communication system is unable to detect and confirm the abnormal operation situation of a specific mobile terminal that causes an excessive increase in the amount of retransmission packets in the physical layer, waste of resources in the physical layer by packet retransmission In the present invention, the base station monitors the operation of the mobile terminal to detect whether the mobile terminal is abnormally operated, and then the base station uses the detected information for scheduling for forward link packet data transmission. Unnecessary waste of radio resources caused by terminal abnormal operation can be reduced.

In addition, in the present invention, when the RLP block of the mobile station is in an abnormal state, the base station detects the state of the mobile station and lowers the scheduling priority for packets to be transmitted to the abnormal mobile station. It can be minimized.

In addition, the system operator who manages the base station and other communication equipment can monitor the current operating state of the mobile terminal, thereby improving the efficiency of system operation.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (18)

Checking the state of the mobile station from the number of retransmission packets to the mobile station from the number of packet data descending per unit time from a radio link protocol (RLP) block of a base station; And adjusting a scheduling priority for packet data transmission of the mobile terminal by using the state of the mobile terminal. The method of claim 1, wherein the checking of the state of the mobile terminal, Calculating a ratio value of the number of retransmitted packets and the number of new packets to be newly transmitted to the mobile station from the number of packet data descending per unit time from the radio link protocol block; And comparing the calculated ratio value with a first predetermined threshold value to determine whether the mobile station receiver is in normal operation. The method of claim 2, wherein when the ratio value is less than the first threshold value, the mobile terminal receiver determines that the mobile terminal is abnormally operated. 4. The method of claim 3, wherein the scheduling priority of the retransmission packet is lowered by a predetermined unit when it is determined that the MS receives abnormal operation. 5. The method of claim 4, wherein the number of new packets to be newly transmitted to the mobile terminal for the number of retransmitted packets to be retransmitted to the mobile terminal in the number of packet data descending per unit time from the radio link protocol block after the scheduling priority is lowered. Calculating more ratio values, Recovering a scheduling priority for the lowered retransmission packet if the further calculated rate value is greater than or equal to the first threshold and exceeds a second predetermined second threshold. Packet data transmission method. 6. The method of claim 5, wherein the second threshold is greater than the first threshold. 4. The method of claim 3, wherein the calculation of the ratio value and the determination of whether the mobile station is in normal operation are performed only when the number of packet data coming down from the radio link protocol block per unit time exceeds a third predetermined threshold. Packet data transmission method. A Radio Link Protocol (RLP) block belonging to a medium access control (MAC) layer of a base station, A packet monitoring block for monitoring the number of new packet data to be newly transmitted to the mobile terminal coming down from the radio link protocol block and the number of retransmitted packet data to be retransmitted to the mobile terminal to check the state of the receiver of the mobile terminal; And a scheduler for adjusting a scheduling priority of packet data waiting to be transmitted by using the state information of the receiver provided in the packet monitoring block. The packet data transmission of claim 8, wherein the packet monitoring block calculates a ratio value of the number of new packet data to the number of retransmission packet data from the number of packet data descending per unit time from the radio link protocol block. Device. 10. The apparatus of claim 9, wherein the packet monitoring block is set with a first threshold value that is compared with the calculated ratio value to determine a state of the mobile terminal receiver. 12. The apparatus of claim 10, wherein the packet monitoring block determines that the mobile terminal receiver is abnormal when the calculated ratio value is less than the first threshold. 12. The method of claim 11, wherein the packet monitoring block instructs the scheduler to lower the scheduling priority of retransmission packet data of the mobile station waiting to be transmitted, when the mobile station receiver determines that the mobile station is abnormally operated. Packet data transmission apparatus. The method of claim 12, wherein the packet monitoring block has a ratio of the number of new packet data to the number of retransmission packet data calculated from the number of packet data coming down from the radio link protocol block at a next unit time exceeds a predetermined level. And instructing the scheduler to recover scheduling priority for retransmission packet data of the mobile station whose scheduling priority is lowered. 10. The apparatus of claim 9, wherein the packet monitoring block comprises: a first threshold for comparing with the calculated ratio value to determine the state of the mobile terminal receiver; a second threshold having a value greater than the first threshold; And a third threshold value is set which is compared with the number of packet data coming down from the link protocol block. 15. The mobile terminal of claim 14, wherein the packet monitoring block comprises: when the calculated ratio value is less than the first threshold while the number of packet data coming down from the radio link protocol block exceeds the third threshold, Packet data transmission apparatus characterized in that it determines to operate abnormally. 16. The method of claim 15, wherein the packet monitoring block instructs the scheduler to lower the scheduling priority of the packet data for retransmission of the mobile station waiting to be transmitted when the mobile station receiver determines that the mobile station is abnormally operated. Packet data transmission apparatus. 17. The apparatus of claim 16, wherein the second threshold is used to recover a scheduling priority for the lowered packet data for retransmission of the mobile station. 18. The method of claim 17, wherein the packet monitoring block has a ratio of the number of new packets to the number of retransmitted packets calculated from the number of packet data descending in the next unit time from the radio link protocol block exceeds the second threshold. And instructing the scheduler to recover a scheduling priority for retransmission packet data of the mobile station.

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