KR20060083751A - Method and apparatus for efficiently transmitting data in a wireless potable internet system - Google Patents

Abstract

An embodiment of the present invention determines the priority to determine which connections to send in the HARQ burst when simultaneous allocation of multi-burst of HARQ and non HARQ. In this case, an embodiment of the present invention first considers the reliability of data required by the connection each time a new connection is created and then determines the priority in consideration of QoS. That is, in the embodiment of the present invention, in the case of a connection that is more critical to packet loss than other connections, the priority of the HARQ burst can be increased.

Connection, HARQ

Description

TECHNICAL AND APPARATUS FOR EFFICIENTLY TRANSMITTING DATA IN A WIRELESS POTABLE INTERNET SYSTEM             

1 is a diagram showing the configuration of a typical wireless mobile Internet system;

2 is a view for explaining a HARQ scheme in a wireless portable Internet system;

3 is a diagram illustrating a message flow for data transmission and reception between a terminal and a base station according to the first embodiment of the present invention;

4 is a view showing priority of each service for HARQ burst according to the present invention;

FIG. 5 is a flowchart illustrating an operation control when HARQ burst and non-HARQ Burst are allocated in response to a resource allocation request from a base station in FIG.

6 is a diagram illustrating a message flow for data transmission and reception between a terminal and a base station according to the second embodiment of the present invention;

7 is a flowchart illustrating an operation control when a HARQ burst and a non-HARQ burst are allocated to a terminal from a base station.

The present invention relates to a method and apparatus for efficient message transmission in a wireless portable Internet system.

1 is a diagram illustrating a configuration of a general wireless portable Internet system. Referring to FIG. 1, each mobile subscriber station (MSS) 10, 12 is generally mobile and is connected to a backbone network 30 through a base station (BS) 20, 22, respectively. The terminals 10 and 12 allow access between the base stations 20 and 22 and the subscribers. Base stations 20 and 22 provide control, management, and connectivity to terminals 10 and 12. The backbone network 30 is connected to an authentication and service authorization server (ASA) 40 for authentication and service authentication of the terminals 10 and 12.

The wireless portable Internet system configured as described above may adopt a hybrid automatic request (HARQ) scheme to ensure data transmission between the base stations 20 and 22 and the terminals 10 and 12. The HARQ scheme is an optional function of a MAC or PHY supporting a wireless portable Internet system and may be performed on a per-terminal basis. The HARQ scheme is a data transmission scheme proposed to have a stronger error correction capability for a data transmission channel by adding forward error correction (FEC) to the conventional automatic repeat request (ARQ) scheme. The HARQ scheme is a mixture of the ARQ scheme for transmitting ACK for data reception and the FEC scheme for inserting an error correction code into the transmitted data. The HARQ scheme enables reliable data transmission and is insensitive to channel conditions. Has

2 is a view for explaining the HARQ scheme in a wireless portable Internet system. Referring to FIG. 2, the base station 20 transmits an HARQ encoder packet to the terminal 10 in step 60. When the terminal 10 receives the HARQ encoder packet, the terminal 10 proceeds to step 62 and attempts to demodulate the HARQ encoder packet. In step 64, the terminal 10 determines whether demodulation of the HARQ encoder packet is successful. If demodulation succeeds, the terminal 10 transmits an ACK to the base station 20 in step 66. However, if demodulation fails, the terminal 10 transmits a NAK to the base station in step 68. When the base station 20 receives the NAK, the base station 20 attempts to transmit a second HARQ to the terminal 10. The base station 20 may repeat the transmission of HARQ until the terminal 10 successfully demodulates the corresponding HARQ encoder packet and transmits an ACK.

In the wireless portable Internet system, there may be a terminal supporting HARQ (Hybrid ARQ) and a terminal not supporting HARQ, and data burst allocation is divided into HARQ burst and non-HARQ burst. A terminal that does not support HARQ can receive only non-HARQ bursts on the downlink, but a terminal that supports HARQ can receive non-HARQ bursts and HARQ bursts. In addition, in the uplink period, only one burst may be allocated to a terminal that does not support HARQ, but a plurality of HARQ and non-HARQ bursts may be allocated to a terminal that supports HARQ. The reason for using the HARQ scheme is that the HARQ has a strong error correction capability against channel state and interference change compared to the conventional ARQ scheme.

That is, the HARQ scheme can improve performance due to the SNR gain and time diversity effects caused by combining the received packet in error state and the retransmitted packet. In this case, in order for the UE to smoothly receive downlink HARQ data from the base station, a memory to be used for combining and a memory to be used for reordering performed to deliver successfully demodulated downlink MAC PDUs to its upper layer in the order of the base station transmission. It must be fully equipped.

The N-channel stop-and-wait HARQ adopted in the wireless portable Internet system is capable of reliable data transmission, but requires a large memory buffer capable of storing N HARQ bursts. . Therefore, in implementation, it is necessary to limit the number of HARQ bursts that can be allocated to one terminal in one frame. In this case, when the amount of data requested for allocation by the UE is larger than the amount of HARQ bursts, the non-HARQ burst may be allocated.

Currently, the 802.16 specification alone does not provide a criterion for determining whether it is effective to send data of which connection to which burst when HARQ burst and non-HARQ burst are simultaneously allocated. For example, if two bursts are simultaneously allocated from the BS, the data carried by the HARQ burst is unlikely to be lost, but the data carried by the non-HARQ burst is likely to be lost. Accordingly, a criterion for distinguishing HARQ bursts and non-HARQ bursts according to data characteristics is required.

Accordingly, the present invention provides a method and apparatus for efficiently allocating HARQ bursts and non-HARQ bursts between a terminal and a base station in a wireless portable Internet system.

According to an embodiment of the present invention, in a method for efficient data transmission in a terminal of a wireless access communication system including a base station, requesting resource allocation for each connection after generating one or more connections capable of transmitting and receiving data with the base station And receiving HARQ bursts and non-HARQ bursts together according to the resource allocation request from the base station, and transmitting priority to determine whether to send the formed one or more connections to the HARQ bursts. Determining and transmitting data on HARQ bursts and non-HARQ bursts according to the determined transmission priority.

In addition, an embodiment of the present invention is a device for efficient data transmission in a terminal of a wireless access communication system including a base station, the transmission priority that can determine whether to send on the HARQ burst of HARQ burst and non-HARQ Burst ( a control unit for determining priority) and a transmission unit for transmitting data by splitting the data into HARQ bursts or non-HARQ bursts according to the determined transmission priority.                     

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

An embodiment of the present invention determines the priority to determine which connections to send in the HARQ burst when simultaneous allocation of multi-burst of HARQ and non HARQ. That is, according to the embodiment of the present invention, each time a new connection is created, the priority is determined first by considering reliability of data required by the connection and then by considering QoS. That is, in the embodiment of the present invention, in the case of a connection that is more critical to packet loss than other connections, the priority of the HARQ burst can be increased.

The present invention is applied to the case of allocating HARQ burst and non-HARQ Burst together. Therefore, the present invention does not apply when only HARQ burst or non-HARQ Burst is allocated.

3 is a diagram illustrating a message flow for data transmission and reception between a terminal and a base station according to the first embodiment of the present invention.

Referring to FIG. 3, the terminal 10 generates one or more connections capable of transmitting and receiving data with the base station 20 in step 110. In step 120, the terminal 10 requests the base station 20 for resource allocation for each connection. The base station 20 allocates HARQ bursts and non-HARQ bursts together in response to the resource allocation request in step 130. In operation 140, the terminal 10 schedules the use of an airlink resource. Specifically, the terminal 10 determines the priority to determine which connections to send on the HARQ burst. The terminal 10 first considers the reliability of data required for each connection. The terminal 10 determines the priority in consideration of the Quality of Service (QoS).

In other words, the terminal 10 relatively determines the priority that can be carried in the HARQ burst when the connection is critical to packet loss compared to other connections. And the terminal 10 is determined in consideration of the priority (priority) of the QoS of the connection. Examples of services in 802.16 will be described. Services in 802.16 may be classified into unsolicited grant services (UGS), real-time polling services (rtPS), non-real-time polling services (nrtPS), and best effort (BE) services. UGS supports Constant Bit Rate (CBR) such as T1 / E1 emulation and Voice Over IP (VoIP) without silence suppression. rtPS supports real-time services that generate variable size data packets on a periodic basis, such as MPEG video or VoIP without silence compression. nrtPS supports non-real-time services that require a variable size data grant burst type on a regular basis. Finally, BE (Best Effort) Services are typically provided by the Internet for web surfing today. Among these services, UGS service such as VoIP and rtPS service such as MPEG video are provided in real time, so even if an error occurs in the currently transmitted data, it is not necessary to correct the error data at the next transmission. Therefore, UGS services such as VoIP and rtPS services such as MPEG video are related to error-tolerant applications, which lowers the priority of sending them to the HARQ burst. The priority related to QoS is that UGS is higher than rtPS, and thus the lowest priority that can be put in HARQ burst for UGS.

In addition, nrtPS and BE are related to error-intolerant applications such as FTP data transfer or Web browsing, so they have higher priority to be sent in HARQ burst. In addition, since the priority related to QoS is nrtPS higher than BE, the priority that can be put in HARQ burst for nrtPS is the highest. That is, when HARQ bursts and non-HARQ bursts are allocated at the same time, the HARQ burst is loaded with nrtPS first, and the non-HARQ burst is best loaded with UGS. The priority of each connection for such HARQ burst is shown in FIG. 4.

The terminal 10 transmits data on the HARQ burst and the non-HARQ burst according to the transmission priority determined in step 150.

Next, an operation in the case where the UE is allocated both a HARQ burst and a non-HARQ burst in response to a resource allocation request from the base station will be described.

Referring to FIG. 5, the terminal 10 determines whether to generate one or more connections capable of transmitting and receiving data with the base station 20 in step 210. If more than one connection is created between the terminal and the base station, the terminal 10 requests resource allocation for each connection in step 220. Subsequently, the terminal 10 determines whether HARQ bursts and non-HARQ bursts are allocated from the base station in step 230. If the HARQ burst and the non-HARQ burst are not allocated together, the terminal 10 proceeds to step 240 and transmits data in the conventional manner.

If the HARQ burst and the non-HARQ burst are allocated together, the terminal 10 proceeds to step 250 to determine a priority for determining which connections to send on the HARQ burst. That is, the terminal 10 determines the priority in consideration of the reliability of the data required for each connection and the Quality of Service (QoS). Subsequently, the terminal 10 transmits data on the HARQ burst and the non-HARQ burst according to the transmission priority determined in step 260.

On the other hand, the present invention can be applied even when transmitting data from the base station to the terminal. 6 is a diagram illustrating a message flow for data transmission and reception between a terminal and a base station according to the second embodiment of the present invention.

Referring to FIG. 6, the base station 20 generates one or more connections capable of transmitting and receiving data with the terminal 10 in step 310. In addition, when the base station 20 allocates the HARQ burst and the non-HARQ burst to the terminal 10 in step 320, the base station 20 determines a priority for determining which connections to send on the HARQ burst. The base station 20 determines the priority in consideration of the reliability of the data required for each connection and the Quality of Service (QoS).

As described above, the base station 20 determines a higher priority that can be carried in the HARQ burst when the connection is critical to packet loss compared to other connections. In addition, the base station 20 determines by considering the priority (priority) of the QoS of the connection. For example, among the services in 802.16, a UGS service such as VoIP and an rtPS service such as MPEG video are provided in real time, so even if an error occurs in the currently transmitted data, it is not necessary to correct the error data at the next transmission. Therefore, UGS service such as VoIP and rtPS service such as MPEG video are related to the error-tolerant application, thereby lowering the priority of the HARQ burst. The priority related to QoS is that UGS is higher than rtPS, and thus the lowest priority that can be put in HARQ burst for UGS. The base station 20 carries data on the HARQ burst and the non-HARQ burst according to the transmission priority determined by the terminal 10 in step 330.

Next, an operation of transmitting a HARQ burst and a non-HARQ burst to the terminal from the base station will be described.

Referring to FIG. 7, the base station 20 determines whether to generate one or more connections capable of transmitting and receiving data with the terminal 10 in step 410. If at least one connection is generated between the terminal and the base station, the base station 20 determines whether the terminal allocates HARQ burst and non-HARQ burst from the terminal in step 420. If the HARQ burst and the non-HARQ Burst are not allocated together, the base station 20 proceeds to step 430 and transmits data in the conventional manner.

If the HARQ burst and the non-HARQ burst are allocated together, the base station 20 proceeds to step 440 to determine the priority for determining which connections to send on the HARQ burst. That is, the base station 20 determines the transmission priority in consideration of the reliability of the data required for each connection and the quality of service (QoS). Subsequently, the base station 20 carries data on the HARQ burst and the non-HARQ burst according to the transmission priority determined in operation 450 and transmits the data.

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the equivalent of claims and claims.

As described above, according to the present invention, when the HARQ and the non-HARQ are simultaneously allocated, the priority for the HARQ burst can be reduced, thereby reducing the number of retransmissions and enabling efficient resource utilization. In addition, the base station has such a priority criterion to efficiently distribute uplink resources, and if the downlink transmits HARQ and non-HARQ bursts to one UE at the same time, the priority for HARQ bursts is used. The number of downlink retransmissions can be reduced.

Claims (13)

A method for efficient data transmission in a terminal of a wireless portable internet system including a base station, Generating at least one connection capable of transmitting and receiving data with the base station and requesting resource allocation for each connection; Receiving HARQ burst and non-HARQ Burst together according to the resource allocation request from the base station; Determining a transmission priority that may determine whether to send the formed one or more connections to the HARQ burst; And transmitting data on a HARQ burst or a non-HARQ burst according to the determined transmission priority. The method of claim 1, wherein the determining of the transmission priority is a step of determining priority in consideration of at least one of reliability and quality of service (QoS) of data required in each of the one or more connections. How to. 3. The method of claim 2, wherein the step of prioritizing transmission comprises determining a priority that can be carried in a HARQ burst when the connection is critical to packet loss. 2. The method of claim 1, wherein the step of determining the transmission priority comprises determining a priority that can be carried in a HARQ burst in the case of an error-tolerant connection. 2. The method of claim 1, wherein the determining prioritization step includes Non-Real-Time Polling Services (nrtPS), Best Effort (BE) Services, Real-Time Polling Services (rtPS), and Unsolicited UGS for services that are in 802.16. And determining a priority that can be transmitted in the HARQ burst in the order of Grant Services. In the method for efficient data transmission in the base station of the wireless portable Internet system comprising a terminal, Generating at least one connection capable of transmitting and receiving data with the terminal and allocating a HARQ burst and a non-HARQ burst to the terminal; Determining a priority to determine whether to send the formed one or more connections to the HARQ burst; And dividing data into HARQ bursts or non-HARQ bursts according to the determined transmission priority. The method of claim 6, wherein the determining of the priority is a step of determining the priority in consideration of at least one of reliability and quality of service (QoS) of data required for each of the one or more connections. How to. 8. The method of claim 7, wherein the prioritizing step includes determining a priority that can be carried in a HARQ burst when the connection is critical to packet loss. 7. The method of claim 6, wherein the prioritizing step includes determining a priority that can be carried in a HARQ burst in the case of an error-tolerant connection. 7. The method of claim 6, wherein the prioritizing step includes Non-Real-Time Polling Services (nrtPS), Best Effort (BE) Services, Real-Time Polling Services (rtPS), and Unsolicited Grant for services that are in 802.16. Determining a priority that can be carried in the HARQ burst in order of services. An apparatus for efficient data transmission in a terminal of a wireless portable internet system including a base station, A control unit for determining a transmission priority for determining whether to transmit the HARQ burst among the HARQ burst and the non-HARQ burst; And a transmitter configured to transmit data by splitting the data into HARQ bursts or non-HARQ bursts according to the determined transmission priority. 12. The apparatus of claim 11, wherein the base station allocates the requested HARQ burst and the non-HARQ burst. 13. The apparatus of claim 12, wherein the terminal is allocated an HARQ burst and a non-HARQ burst.

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