KR20060028961A - Seamless arq traffic transfer method in the process of hand-over on high-speed portable internet system - Google Patents

Abstract

The present invention relates to a high speed portable Internet system. According to the present invention, when the handover occurs, not only the IP packet but also the corresponding ARQ connection information, IP packet information, and transport block information of the IP packet are transmitted to the new base station. This ensures lossless ARQ traffic transmission and uses efficient radio resources.

High speed mobile internet system, handover, ARQ traffic

Description

Lossless ARV transmission method for handover in high-speed portable Internet system {SEAMLESS ARQ TRAFFIC TRANSFER METHOD IN THE PROCESS OF HAND-OVER ON HIGH-SPEED PORTABLE INTERNET SYSTEM}

1 is a block diagram of a high speed portable Internet system to which the present invention is applied.

FIG. 2 is a structural diagram of the ATS in FIG. 1.

FIG. 3 is a diagram illustrating an inter-block interface of the ATS of FIG. 2.

4 is an ARQ traffic processing diagram to which the present invention is applied.

5 is a diagram illustrating a general IP packet forwarding scheme.

6 is a diagram illustrating an IP packet forwarding scheme according to a first embodiment of the present invention.

7 illustrates an IP packet forwarding scheme according to a second embodiment of the present invention.

8 illustrates an IP packet forwarding scheme according to a third embodiment of the present invention.

9 is a diagram illustrating processing of ARQ traffic in an existing AP during handover in a high-speed portable Internet system according to an embodiment of the present invention.

10 is a diagram illustrating processing of ARQ traffic at a new AP during handover in a high speed portable Internet system according to an embodiment of the present invention.

The present invention relates to a method for efficiently using radio resources in a high speed portable internet system (HPi).

In the current IEEE 802.16 standard specification, an IP packet (SDU in MAC) transmitted from a higher layer is stored in a packet classification block (PCFB). In the automatic repeat request block (ARQB), the automatic repeat request (ARQ) data is divided into block units and stored in a buffer, and the service data unit (SDU) is discarded.

The block data stored in the buffer is composed of a MAC PDU payload by the scheduler, and is transmitted to a packet handling block (PHDB) to be transmitted to the terminal. In this case, the ARQ data block stored in the buffer is not discarded until an acknowledgment character (ACK) is received, and is transmitted back to the terminal according to a retransmission algorithm every time an NACK is provided.

However, in the IEEE 802.16 standard, only the forwarding of traffic data to a target base station to be moved when a handover occurs is defined, but a part of ARQ data traffic having already divided an IP packet into blocks is not defined.

Meanwhile, in the conventional 3GPP asynchronous (UMTS) mobile communication High Speed Downlink Packet Access (HSDPA) system, buffer management of a multiple access control (MAC) layer and a radio link control (RLC) layer is performed in the RLC layer. Buffer management method to support HSDPA system of mobile communication that allows HSDPA system to coexist with existing 3rd generation wireless communication system through efficient buffer management method, especially when MAC buffer and RLC buffer coexist There is this. This technology does not require the separate control information to the BTS because buffer management is performed at the RLC layer when handover between base-station transceiver systems (BTS).

However, since the high-speed portable Internet system manages buffers at individual base stations, when handing over to another base station, not only traffic forwarding but also control information should be forwarded to efficiently manage forwarded IP packets and to improve radio resource efficiency.

An object of the present invention is to provide an ARQ traffic transmission method that can efficiently use radio resources while ensuring lossless ARQ traffic when handover occurs in a high-speed portable Internet system.

ARQ traffic transmission method according to an aspect of the present invention for solving this problem is a method for transmitting ARQ traffic in a high-speed portable Internet system that provides a service to a mobile terminal connected through a base station and a packet access router,

a) the base station receiving and storing the IP packet data; b) dividing the IP packet data into block units and configuring a PDU payload; And c) if a handover occurs when the mobile station moves to a new base station, transmitting the block information and connection information together with the IP packet data to the new base station.

In addition, a high-speed portable Internet system according to an aspect of the present invention is a high-speed portable Internet system for providing a service to a mobile terminal connected through a base station and a packet access router,

The base station,

A base station traffic subsystem for processing traffic between the mobile terminal and controlling transmission and reception of a radio link; And a base station controller subsystem for managing and controlling resources of the mobile terminal.

The base station traffic subsystem,

Receives and stores IP packet data into blocks and transmits the information of the block and the connection information to the new base station together with the IP packet data when the mobile terminal transmits the IP packet data to a new base station to be moved.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

First, a high-speed portable Internet system to which the present invention is applied will be described in detail with reference to FIG. 1.

1 is a structural diagram of a high-speed portable Internet system to which the present invention is applied.

As shown in FIG. 1, the ultra-high speed portable Internet system to which the present invention is applied includes an AT (Access Terminal, 100), an AP (Access Point, 200), and a PAR (Packet Access Router, 300).

The AT 100 is a portable Internet terminal, the AP 200 performs a base station function, and the PAR 300 performs a packet access routing function and an external agent function of mobile IP.

In addition, the AP 200 processes the traffic between the base band subsystem (BBS) 210 performing the wireless section transmission / reception function, the AT 100 and the AP 200, and access traffic control function (ATS) performing the radio link transmission / reception control function. Subsystem 220) and an Access Controller Subsystem 230 (ACS) that manages resources of each AT and controls the AP. The ATS 220 and the ACS 230 are connected to the PAR 300 through an Ethernet switch 240.

2 illustrates the structure of the ATS 220 in the AP 200 in detail.

As shown in FIG. 2, the ATS 220 constructs an Automatic Repeat Request Block (ARQB) 221 for managing ARQ traffic, a Packet Scheduling Block (PSCB) in charge of scheduling, and a MAC PDU to be transmitted in a wireless section. Packet Handling Block (222), which handles MAC PDUs, Packet Classification Block (223), which performs packet classification and Connection IDentification (CID) mapping of incoming packets, and TRMB, which performs cell and traffic management. (Traffic Resource Management Block, 224), DSP (DSP Interface Control Block, 225) for managing the interface with the digital signal processor (DSP), and RNGB (Ranging Control Block, 226) for the radio link control.

According to the present invention, ARQB 221 guarantees lossless ARQ traffic transmission, and forwards to the newly moving AP including not only IP packets transmitted in blocks but also corresponding ARQ connection information, IP packet information, and transport block information of forwarding IP packets. Suggest ways to do it.

Next, the function of the ARQB 221 transmission unit to which the ARQ traffic transmission method according to an embodiment of the present invention is applied will be described in detail with reference to FIG. 3.

As described above, in the high-speed portable Internet system, the ARQB 221 divides an IP packet transmitted from an upper layer into block units to form a payload of a PDU. Accordingly, the PCFB 223 stores the addresses in the block information queue by addressing the buffered IP packets in block units as shown in FIG. 3, and configures the blocks as payloads of the PDU in accordance with the packet configuration of the scheduler. At this time, a direct function call is made after generating a header in the PHDB 222b, and the completed payload is transferred to the PHDB 222b. In addition, parameters and traffic control messages related to the connection are received from the TRMB 224.

4 illustrates a general ARQ data generation, transmission, and retransmission process in a high-speed portable Internet system.

As shown in FIG. 4, when an SDU is transmitted from the PCFB 223, the ARQB 221 divides it into block data having a fixed length. 4 illustrates a case where three SDUs are divided into 10 blocks. At this time, the block data transmitted until ACK or NACK, which is feedback information, is stored for reliable ARQ data transmission. If the block is ACK, the block is discarded. If the block is NACK, the block data is retransmitted.

5 shows a general ARQ traffic processing diagram in a high speed portable Internet system.

As shown in FIG. 5, since the existing base station (old AP) 200a already divides IP packets into blocks and stores them in an internal buffer during handover, the newly moved target base station (new AP, 200b) is stored in the PCFB 223. Only packets are received. Therefore, not only does up to N IP packet losses occur, but also a reset procedure necessarily results in inefficient use of radio resources and does not guarantee lossless handover.

Therefore, in the ARQ traffic processing method according to an embodiment of the present invention, the ARQB 221 transmits not only block data but also all of its own block information and connection information to the target base station 200b so that the existing AP 200a and the target AP ( 200b) has the same ARQ transmission environment.

6 shows an ARQ traffic processing diagram according to the first embodiment of the present invention.

As shown in FIG. 6, in the ARQ traffic processing method according to the first embodiment of the present invention, the ARQB of the existing AP transmits all of its block information, block data, and connection information to the target base station, thereby providing the existing AP 200a. Since the ARQ transmission environment of the target AP 200b and the target AP are the same, there is almost no delay (same as the handover time). Therefore, the reset procedure as shown in FIG. 5 does not occur, and radio resources can be saved because data does not have to be transmitted redundantly.

Meanwhile, the ARQ traffic processing method illustrated in FIG. 5 requires a tunneling interface between base stations in order to deliver information on ARQ blocks stored and managed by the existing AP 200a to the target AP 200b. However, the current high speed portable Internet system specification does not specify this point, which may violate the standard interface. In addition, since the ARQ traffic processing method according to the first embodiment of the present invention shown in FIG. 6 must make the transmission environment of the target AP 200b the same as the ARQ traffic transmission environment operating in the existing AP 200a, the complexity of implementation is complicated. Increases.

Therefore, in order to solve this disadvantage, in the second embodiment of the present invention, as shown in FIG. 7, when the ARQB 221 divides the corresponding IP packets into blocks, virtually divides them, and in fact, only address addressing is performed. When constructing the PDU payload, blocks are copied from the IP packet, and the IP packet is discarded when a feedback message is received that all blocks of the IP packet have been successfully received.

That is, according to the second embodiment of the present invention, since the IP packets stored in the PCFB 223 of the existing AP 200a can be transmitted back to the target AP 200b during handover, the target in the existing AP 200a is targeted. Lossless ARQ traffic can be transmitted even without transmitting ARQ blocks to the AP 200b.

In addition, in the second embodiment of the present invention, since all ARQ blocks receive IP packets when successful reception, if one or more ARQ blocks do not receive a successful reception when a handover occurs, all the corresponding packets are transmitted and the target base station 200b. In the beginning, the IP packet is divided into ARQ blocks for redundant transmission. Therefore, the ARQ transmission method according to the second embodiment of the present invention is much simpler than the ARQ transmission method according to the first embodiment of the present invention shown in FIG. 6 and can guarantee lossless ARQ traffic transmission.

However, in the ARQ transmission method according to the second embodiment of the present invention, IP packets that have been successfully received by the existing AP 200a also have an inefficiency in that the target AP 200b needs to perform duplicate transmissions from the beginning. In addition, if the redundant transmission period becomes longer, it causes the expiration of a timer such as a block life time or a sync loss time set in the block, and thus, there is a risk of entering the reset procedure in the target AP 200b. It is implicated.

Accordingly, the third embodiment of the present invention proposes a hybrid IP forwarding method having minimum implementation complexity and maximum efficiency by combining the ARQ transmission methods of the first and second embodiments of the present invention.

That is, in the third embodiment of the present invention, as in the second embodiment of the present invention, all IP packets are transmitted to the target AP, but as shown in FIG. 8, the lowest block sequence number (BSN) among the transmitted IP packets is transmitted. Branch has the ARQ traffic including the information of the IP packet. When the target AP 200b receives the IP packet data from its own network, the target AP 200b uses the ID information of the IP packet received from the existing AP 200a, that is, transmitted as ARQ traffic, and has not received the successful reception among the corresponding IP packets. Resend from the block with the lower sequence number.

That is, since ARQ traffic has a data characteristic of success or success, due to the characteristics of the wireless MAC standard to which the present invention is applied, it is possible to efficiently use radio resources by sending information on IP packets having the lowest sequence number. In addition, implementation complexity is not high and does not violate the interface of the standard to which the present invention is applied.

9 shows a processing diagram of ARQ traffic in an existing AP in the ARQ transmission method according to an embodiment of the present invention.

As shown in FIG. 9, the ARQB 221 stores block data transmitted until ACK or NACK, which is feedback information, for reliable traffic transmission, discards the block if ACK, and retransmits if NACK ( Transmission data 1) and then, when the third IP packet comes from the upper layer, it is divided into ARQ blocks (transmission data 2). At this time, when handover occurs, the ARQB 221 of the existing AP 200a transmits the packet including the connection information and the corresponding IP packet (in this case, the block with the lowest sequence number (last_ack_bsn + 1) and the ARQ block). IP packet information) and the information of the corresponding block are transmitted to the target AP 200b. In addition, the ATS 220 of the existing AP 200a does not delete the information and the IP packet data until the handover state is completely completed, and when the handover to the target AP 200b is completely completed, the ATS 220 receives the corresponding message. Drop the packet. In this case, the information on the IP packet transmitting the ARQ block is passed to the target AP 200b in order to match the sequence number of the block in the target AP 200b with the existing AP 200a.

10 illustrates an ARQ traffic processing diagram at a target AP in an ARQ transmission method according to an embodiment of the present invention.

As shown in FIG. 10, since the PCFB 223 of the target AP 200b accepts IP packets mixed in the current network and the existing AP 200a due to the characteristics of the IP traffic, the PCFB 223 of the target AP 200b receives the IP packet received from the existing AP 200a. It is necessary to classify the ARQ related IP packets sent from the existing AP 200a with the ID. After that, if the IP packet is received from the newly moved network, the sequence number (arqTx_next_bsn) of the last block BSN transmitted from the previous base station is checked and the block sequence number is assigned, and the IP packet transmitted from the existing AP 200a receives IP packet information. Check and process with block order number. In addition, in case of an IP packet including a block (Last_ack_bsn + 1) having a next sequence number of the ACK BSN most recently received from the previous base station, the block information structure is used to sequentially retransmit the block. Therefore, duplicate blocks are not retransmitted in the corresponding IP packet.

That is, according to an embodiment of the present invention, when the UE is handed over from the existing AP 200a to the target AP 200b at the time of handover, the terminal should be made without loss of data, and in this process, ATS (ATS) can be used efficiently. ARQB 221 in 220 does not discard existing SDUs after splitting into fixed length blocks for SDUs (or IP packets) coming from PCFB 223. In addition, when the handover between the AP 200, the AT 100 not only forwards the IP packet of the existing AP 200a to the target AP 200b but also provides information on blocks that have not yet been acknowledged with respect to the corresponding IP packet. Forwarding includes connection information (TX window start value, next transport block sequence number, etc.) to be handed over.

Although a preferred embodiment of the present invention has been described in detail above, the present invention is not limited thereto, and various other changes and modifications are possible.

As described above, the present invention provides a hybrid IP forwarding scheme that can guarantee lossless ARQ traffic when handover occurs in ARQ traffic transmission / reception in a high-speed portable Internet system system, and does not significantly increase the implementation complexity and improve wireless efficiency. It guarantees lossless ARQ traffic that is not guaranteed by the current high speed portable Internet system specification and enables efficient use of radio resources.

In addition, by forwarding data and control information together, the target AP can classify IP packets coming from the network and IP packets forwarded from the existing AP using control information related to ARQ, and IP packets transmitted from the existing AP. The location of blocks to be transmitted can be known from. Therefore, the loss of ARQ parallel data can be ensured, the radio resources can be efficiently used, and the delay time can be reduced.

Claims (13)

A method for transmitting automatic repeat request (ARQ) traffic in a high speed portable Internet system providing a service to a mobile terminal connected through a base station and a packet access router, a) the base station receiving and storing the IP packet data; b) dividing the IP packet data into block units and configuring a PDU payload; And c) transmitting the block information and the connection information together with the IP packet data to the new base station when a handover occurs when the mobile station moves to a new base station; ARQ traffic transmission method in a high-speed mobile Internet system comprising a. The method of claim 1, In step c), When transmitting the IP packet data to the new base station, information of the IP packet having the lowest block sequence number (BSN) among the IP packet data transmitted to the new base station is transmitted together. ARQ Traffic Transmission Method in High Speed Mobile Internet System. The method of claim 2, In step c), When transmitting the IP packet data to the new base station, the information of the IP packet is transmitted together to match the block sequence number of the new base station traffic subsystem with the block sequence number of the base station traffic subsystem before movement. ARQ Traffic Transmission Method in High Speed Mobile Internet System. The method of claim 2, In step b), Performing only address addressing when dividing the IP packet data into the block, and copying the block data from the stored IP packet data when configuring the PDU payload. ARQ Traffic Transmission Method in High Speed Mobile Internet System. The method of claim 2, In step c), The new base station classifies IP packet data using the received IP packet information and assigns a block order number. ARQ Traffic Transmission Method in High Speed Mobile Internet System. The method of claim 2, In step c), The new base station sequentially retransmits from the block requiring retransmission using the received block information. ARQ Traffic Transmission Method in High Speed Mobile Internet System. A high speed portable Internet system that provides a service to a mobile terminal connected through a base station and a packet access router, The base station, A base station traffic subsystem for processing traffic between the mobile terminal and controlling transmission and reception of a radio link; And A base station controller subsystem for managing and controlling resources of the mobile terminal; The base station traffic subsystem, Receiving and storing the IP packet data divided into blocks, and transmitting the information of the block and the connection information to the new base station with the IP packet data when the mobile terminal transmits the IP packet data to the new base station to be moved. High speed mobile internet system. The method of claim 7, wherein The base station traffic subsystem, When transmitting the IP packet data to the new base station, information of the IP packet having the lowest block sequence number (BSN) among the IP packet data transmitted to the new base station is transmitted together. High speed mobile internet system. The method of claim 7, wherein The base station traffic subsystem, Deleting the IP packet data, the block information, and the connection information after receiving the message that the movement of the mobile terminal to the new base station is completed. High speed mobile internet system. The method of claim 8, The base station traffic subsystem, When transmitting the IP packet data to the new base station, the information of the IP packet is transmitted together to match the block sequence number of the new base station traffic subsystem with the block sequence number of the base station traffic subsystem before movement. High speed mobile internet system. The method according to any one of claims 7 to 10, The base station traffic subsystem, A Packet Classification Block (PCFB) that classifies the received IP packet data and performs Connection IDentification (CID) mapping; Automatic Repeat Request Block (ARQB) for dividing and storing the IP packet data into blocks, reconstructing the block data into a protocol data unit (PDU) payload, and managing retransmission request traffic for the block data; And A packet handling block (PHDB) for receiving the PDU payload and transmitting the PDU payload to the mobile terminal; The ARQB is, Addressing only when partitioning the IP packet data into the block, and copying the block data from the IP packet data stored in the PCFB when configuring the PDU payload High speed mobile internet system. The method of claim 11, The PCFB of the new base station is When the mobile station receives an IP packet from the newly moved network, the mobile station checks the sequence number of the last block BSN transmitted from the previous base station of the IP packet and attaches the block sequence number. When the IP packet is received from the previous base station, the IP packet data is classified using the received IP packet information and a block sequence number is assigned. High speed mobile internet system. The method of claim 12, The new base station, When receiving an IP packet including a block having the next sequence number of the most recently received ACK BSN, the block information is sequentially retransmitted from the corresponding block using the block information. High speed mobile internet system.

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