KR20090055117A - Apparatus and method for header compression in broadband wireless access system - Google Patents

Abstract

A header compression device in a broadband wireless connection system and a compression method thereof are provided to reduce the waste of bandwidth by classifying header compression and a convergence sublayer and communicating the header compressed packet. A classifier(100) classifies an IP(Internet Protocol) packet about a downlink traffic received from a CSN(Core Service Network) according to a classification rule. If the IP packet is a ROHC(Robust Header Compression) SF(Service Flow), the classifier forwards the IP packet to a header compression unit. The header compression unit(108) performs the header compression of the IP packet from the classifier and generates the CS(Convergence Sublayer) PDU(Packet Data Unit). The CS PDU is comprised of the ROHC header and a payload. A data path encapsulator(104) performs the encapsulation by tagging external IP header and a GRE(Generic Routing Encapsulation) header in the CS PDU from the header compression unit and transmits the encapsulated packet to the base station through a data path tunnel.

Description

Header compression apparatus and method in broadband wireless access system {APPARATUS AND METHOD FOR HEADER COMPRESSION IN BROADBAND WIRELESS ACCESS SYSTEM}

The present invention relates to a header compression apparatus and method, and more particularly, to an apparatus and method for performing header compression in a broadband wireless access system.

In general, communication systems have been developed mainly for voice services, and are gradually developing into communication systems capable of not only voice but also data services and various multimedia services. However, the voice-oriented communication system has not satisfied the rapidly increasing user's service needs due to the relatively small transmission bandwidth and high usage fee. In addition, due to the development of the communication industry and increasing user demand for Internet services, there is an increasing need for a communication system capable of efficiently providing Internet services. Accordingly, a broadband wireless access system has been introduced to efficiently provide Internet services with broadband enough to meet the needs of users.

The broadband wireless access system is a system for integrating and supporting not only voice but also various data services such as low and high speeds and multimedia application services such as high definition video. The broadband wireless access system is being standardized by the IEEE 802.16 standardization group of the Institute of Electrical and Electronics Engineers, one of the international standardization organizations. In addition, the network standard for the broadband wireless access system is being standardized in the WiMAX Forum Network Working Group (NWG).

The broadband wireless access system guarantees the quality of service by applying various scheduling according to the service type of data generated in the application layer. The service types include Unsloited Grant Service (UGS), Real-Time Polling Service (rtPS), Extended Real-Time Polling Service (ertPS), Non-Real-Time Polling Service (nrtPS), and Best Effort (BE). .

In addition, the IEEE 802.16 Media Access Control (MAC) layer may have multiple connections of different types. In this case, it is possible to map the connection of the data of the IP (Internet Protocol) layer and the MAC layer, and this function is achieved through a Convergence Sublayer (CS) classification parameter. Parameters used to classify data of the IP layer include a protocol type, a source / destination IP address, and a source / destination port number. These are called 5-tuples.

Meanwhile, various techniques for compressing headers of IP packets have been proposed. The most widely known technique is ROHC (Robust Header Compression). In general, in the case of a wireless link, unlike a wired link, a high error rate is required, and an error in the header portion may cause a fatal result. Therefore, a strong error header processing technique is required. In addition, in the case of a radio link with limited bandwidth, header compression is a necessary technique.

However, according to the network standard (WiMAX Forum NWG) for IEEE 802.16 based broadband wireless access, a structure that does not use header compression is proposed. Due to the high error rate and limited bandwidth of the radio link, header compression is necessary, and therefore, it is necessary to change the network structure of the current WiMAX Forum NWG.

In order to apply header compression to the network structure for broadband wireless access, IP packets should be classified above the IP layer. In other words, an IP packet must be classified into a packet that compresses a header and a packet that does not compress. As described above, the IEEE 802.16 based broadband wireless access system has a function of classifying IP packets to map data of the IP layer to connections of the MAC layer. This IP packet classification function is performed in the convergence sublayer (CS). Therefore, when header compression is applied to a broadband wireless access system as it is, a problem may occur in that classification operations of IP packets are repeatedly performed twice. Since this redundant classification causes unnecessary software and hardware complexity, a more optimized network structure is required when applying header compression.

Accordingly, an object of the present invention is to provide an apparatus and method for performing header compression in a broadband wireless access system.

Another object of the present invention is to provide a base station system for performing header compression and a control method thereof in a broadband wireless access system.

Another object of the present invention is to provide a terminal for performing header compression and a control method thereof in a broadband wireless access system.

Another object of the present invention is to provide an apparatus and method for performing IP packet classification once when performing header compression in a broadband wireless access system.

It is still another object of the present invention to perform header compression and convergence layer (CS) classification in a base station controller in a broadband wireless access system, and to transmit information on service flow identification and terminal identification to a GRE (Generic Routing Encapsulation) key. An apparatus and method for recording and transmitting to a base station is provided.

According to one aspect of the present invention for achieving the above object, in the apparatus for header compression of the base station controller in a broadband wireless access system, IP (for downlink traffic received from a core service network (CSN)) A classifier for classifying packets according to a classification rule and forwarding the IP packet to a header compression unit when the IP packet corresponds to ROHC (Robust Header Compression) Service Flow (SF); The header compression unit generating header convergence sub packet (CS) PDU (Packet Data Unit) by performing header compression on the IP packet of the packet, and the CS PDU is composed of a ROHC header and a payload. Encapsulates by tagging an external IP header and a Generic Routing Encapsulation (GRE) header in a CS PDU, and encapsulates the encapsulated packet in a data path tunnel. It characterized in that it comprises the encapsulator to pass to the base station.

Preferably, the device decapsulates a packet received through a data path tunnel from a base station to obtain a CS PDU, and whether the packet corresponds to a ROHC SF by a key field value in the GRE header of the packet. And a decapsulator for forwarding the CS PDU to the header decompressor, and a header decompressor for decompressing the header of the CS PDU from the decapsulator to obtain an IP packet. It is characterized by including.

According to another aspect of the present invention, in the apparatus for header compression of a terminal in a broadband wireless access system, IP packets generated in the IP layer are classified according to a classification rule, and the IP packet corresponds to a ROHC SF. A classifier for forwarding the packet to the header compression unit, and a header compression on the IP packet from the classifier to generate a CS PDU, and forward the CS PDU to an uplink MAC processor through a MAC-SAP (Service Access Point). The header compression unit and the CS PDU are composed of a ROHC header and a payload, and MAC layer processing of the CS PDU from the header compression unit generates a MAC PDU, and transmits the MAC PDU to a base station through an uplink connection. It characterized in that it comprises the uplink MAC processing unit.

Preferably, the MAC PDU received from the base station MAC layer processing to assemble the CS PDU, if the CS PDU corresponds to the ROHC SF downlink MAC processing unit for forwarding the CS PDU to the header extension through the MAC-SAP And a header extension unit for obtaining an IP packet by extending a header for the CS PDU from the downlink MAC processor.

As described above, the present invention can reduce bandwidth waste by communicating header compressed packets in a broadband wireless access system, and has the advantage of being able to cope with radio link errors strongly. In addition, the structure according to the present invention has the advantage that software and hardware complexity can be reduced because packet classification (service flow classification) is performed only once.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, a scheme for performing header compression in a broadband wireless access system will be described. There are various techniques for the header compression, and the following description will be made using Robust Header Compression (ROHC) as an example.

In the following description, a name of a network entity (NE) is defined according to a corresponding function, and may be changed according to the intention of the standardization group and the operator. For example, the base station may be referred to as an access point (AP), a radio access station (RAS), a node-B, or a base station (BS). In addition, the base station controller may be referred to as a radio network controller (RNC), a base station controller (BSC), an access control router (ACR), or an access service network gateway (ASN-GW). Here, the ASN-GW may perform a router function as well as a base station controller function.

In addition, although an OFDM / OFDMA-based broadband wireless communication system is described below by way of example, the present invention can be easily applied to other wireless communication systems that perform header compression. Further, in the following description, the header compression and decompression function is described as being provided in the base station controller (ASN-GW), but the header compression and decompression function may be provided in the base station.

1 shows a configuration of a base station controller in a broadband wireless access system according to an embodiment of the present invention.

As shown, the base station controller includes a classifier 100, a ROHC function 102, an encapsulation 104 and a data path decapsulation 106. It is configured to include). Here, the ROHC performing unit 102 may include at least one of a header compression unit (ROHC compressor) 108 and a header extension unit (ROHC decompressor) 110. All of the above functional entities may be located at the same location as the anchor data path function of the ASN-GW.

First, looking at downlink, the classifier 100 divides an IP packet for downlink traffic directed to a terminal into a proper service flow. When the IP flow corresponding to the ROHC service flow arrives, the classifier 100 forwards the corresponding IP packet to the ROHC performing unit 102.

The ROHC performing unit 102 may include at least one of the header compression unit 108 and the header extension unit 110. That is, the ROHC performer 102 may have an uplink ROHC SF or a downlink ROHC SF or may include both uplink and downlink. The ROHC performing unit 102 header-compresses the IP packet from the classifier 100 and forwards it to the encapsulator 104.

The encapsulator 104 transmits an outer IP header and a Generic Routing Encapsulation (GRE) header to deliver a header compressed packet from the ROHC execution unit 102 or a feedback packet for uplink to a base station. Tagging In this case, mapping information associated with a service flow identifier and a mobile station identifier (MSID) is set in a destination address field of the external IP header and a key field of a GRE header.

Next, in the uplink, when a packet arrives from a base station through a data path tunnel, the decapsulator 106 decapsulates a received packet and transfers the packet to an upper layer. Forward it. Here, the decapsulation indicates an operation of interpreting an external IP header and a GRE header with respect to the received packet and removing the IP header and the GRE header. At this time, when a packet analysis result of the key of the GRE header belongs to the ROHC SF, the decapsulator 106 forwards the decapsulated packet to the header extension unit 110.

Then, the header decompressor 110 decompresses (decompresses) the header for the packet from the decapsulator 106 and delivers the header to the upper layer.

2 illustrates a configuration of a terminal in a broadband wireless access system according to an embodiment of the present invention.

As shown, the terminal includes a classifier 200, a ROHC function 202, an uplink MAC processor 204, and a downlink MAC processor 206. The ROHC performing unit 202 may include at least one of a header compression unit (ROHC compressor) 208 and a header extension unit (ROHC decompressor) 210.

 First, referring to uplink, the classifier 200 classifies an IP packet for downlink traffic directed to a base station into a proper service flow. If the IP flow corresponds to the ROHC SF, the classifier 200 forwards the packet to the ROHC performer 202.

The ROHC performing unit 202 may include at least one of a header compression unit 208 and a header extension unit 210. That is, the ROHC performing unit 202 may have only one uplink ROHC SF or one downlink ROHC SF or include both uplink and downlink. The ROHC performer 202 compresses the header of the IP packet from the classifier 200 and transmits the header to the uplink MAC processor 204. At this time, the header compressed packet is mapped to a corresponding connection of the MAC layer through a MAC SAP (Service Access Point).

The uplink MAC processor 204 performs a function of a common part sublayer (MAC-CPS) of IEEE 802.16. That is, the uplink MAC processing unit 204 generates a MAC PDU (Packet Data Unit) by splitting or packing a Service Data Unit (SDU) delivered through MAP-SAP, and generates the MAC PDU. Transmit to base station via wireless. At this time, the MAC PDU is transmitted to the base station through an uplink transport connection.

Next, referring to downlink, when the MAC PDU is received from the base station through the radio, the downlink MAC processing unit 206 assembles the SDU with the received MAC PDU and delivers the SDU to the upper layer through the MAC-SAP. . In this case, when the SDU corresponds to the ROHC SF, the downlink MAC processing unit 206 forwards the SDU to the header extension unit 210.

Then, the header decompressor 210 decompresses (decompresses) the header for the packet from the downlink MAC processor 206 and delivers the header to the upper layer (IP layer).

3 is a view for explaining the detailed operation of the ROHC data plane (data plane) of the base station controller according to an embodiment of the present invention.

First, looking at downlink, when an IP packet for downlink traffic is received from a core service network (CSN), the classifier 100 classifies the IP flow according to a packet classification rule. At this time, a service flow (SF) to which ROHC is applied is determined according to the classification rule. If the 5-tuple (protocol type, source / destination IP address, source / destination port number) of the received IP packet belongs to the ROHC SF, the classifier 100 forwards the packet to the ROHC performer 102. do. If the 5-tuple of the received IP packet does not belong to the ROHC SF, the classifier 100 forwards the corresponding IP packet (IPv4 packet or IPv6 packet) to the encapsulator 104.

The header compression unit 108 compresses the packet from the classifier 100 according to a predetermined algorithm (for example, RFC3095). If it does not belong to the profile negotiated with the ROHC peer, the header compression unit 108 discards the corresponding IP packet. The CS PDU generated through the header compression is composed of a ROHC header and a payload, and the CS PDU is forwarded to the encapsulator 104.

The encapsulator 104 encapsulates the CS PDU by a per-flow data path tunnel (eg, a GRE tunnel), and encapsulates the encapsulated packet to a base station via a data path tunnel. To pass. Here, encapsulation indicates an operation of tagging an outer IP header and a GRE header with respect to the CS SDU. In this case, mapping information associated with a service flow identifier and a mobile station identifier (MSID) is set in a destination address field of the external IP header and a key field of a GRE header.

Next, referring to uplink, when the header compressed packet is received from the base station through the data path tunnel, the decapsulator 106 decapsulates the received packet. At this time, the decapsulator 106 checks whether the received packet corresponds to the ROHC SF by the key field value of the GRE header. If the decapsulator 106 corresponds to the ROHC SF, the decapsulator 106 transmits the decapsulated packet to the header extension unit 110. Forward it.

Then, the header decompressor 110 decompresses (decompresses) the header with respect to the packet (CS PDU) from the decapsulator 106 using a ROHC context and delivers it to the CSN.

Next, a method of transmitting a feedback packet for an uplink ROHC channel is as follows.

When it is necessary to send a feedback packet to the terminal during the uplink ROHC SF (ROHC channel) operation, the header extension unit 110 generates a feedback packet and transmits it to the header compression unit 108, and the header compression unit 108 ) Transmits the feedback packet to the base station using the downlink SF. That is, the piggybacked / interspersed ROHC feedback is delivered to the base station through the downlink ROHC SF.

Next, a method of receiving a feedback packet for a downlink ROHC channel is as follows.

If a feedback packet (Piggybacked / Interspersed ROHC feedback packet) is received through the uplink ROHC SF, the header extension unit 110 provides the feedback packet to the header compression unit 108 in the same ROHC performing unit.

4 is a view for explaining the detailed operation of the ROHC data plane (data plane) of the terminal according to an embodiment of the present invention.

First, referring to uplink, when an IP packet for uplink traffic is received from the IP layer of the terminal, the classifier 200 classifies the IP flow according to a packet classification rule. In this case, a service flow SF to which ROHC is applied is determined according to the classification rule. If the 5-tuple (protocol type, source / destination IP address, source / destination port number) of the received IP packet belongs to the ROHC SF, the classifier 200 forwards the packet to the ROHC performer 202. do. If the 5-tuple of the received IP packet does not belong to the ROHC SF, the classifier 200 forwards the corresponding IP packet (IPv4 packet or IPv6 packet) to the uplink MAC processor 204.

The header compressor 208 compresses the packet from the classifier 200 according to a predetermined algorithm (for example, RFC3095). If not belonging to a profile negotiated with the ROHC peer, the header compression unit 208 discards the corresponding IP packet. The Convergence Sublayer (CS) PDU generated by the header compression is composed of a ROHC header and a payload, and the CS PDU is forwarded to the uplink MAC processor 204.

The uplink MAC processor 204 divides or packs the CS PDU to generate a MAC PDU (Packet Data Unit), and transmits the MAC PDU to a base station through the air. At this time, the MAC PDU is transmitted to the base station through the uplink transport connection.

Next, referring to the downlink, when the MAC PDU is received from the base station over the air, the downlink MAC processing unit 206 assembles the CS PDU with the received MAC PDU, and the CS PDU is higher layer through the MAC-SAP. To pass. In this case, when the CS PDU corresponds to the ROHC SF, the downlink MAC processing unit 206 forwards the CS PDU to the header extension unit 210.

Then, the header decompressor 210 decompresses (decompresses) the header for the packet from the downlink MAC processor 206 and delivers the header to the upper IP layer.

Next, a method of transmitting a feedback packet for a downlink ROHC channel is as follows.

When it is necessary to send a feedback packet to a base station controller during a downlink ROHC channel (ROHC channel) operation, the header decompressor 210 transfers the feedback packet to the header compressor 208 and the header compressor 208. The feedback packet transmits the feedback packet to the base station through the uplink ROHC SF. That is, piggybacked / interspersed ROHC feedback is delivered to the base station through the uplink ROHC SF.

Next, a method of receiving a feedback packet for an uplink ROHC channel is as follows.

If a feedback packet (Piggybacked / Interspersed ROHC feedback packet) is received through the downlink ROHC SF, the header extension unit 210 provides the feedback packet to the header compression unit 208 in the same ROHC performing unit.

5 illustrates a network reference model according to the present invention.

As shown, it is assumed that header compression and decompression is performed at the base station controller (ASN-GW). The network may be largely composed of a core service network (CSN), an access service network (ASN), and a terminal. In addition, the ASN may include a base station controller (ASN_GW) and a base station.

Looking at the downlink first, when an IP packet (eg, IPv4, IPv6) for downlink traffic is received from the CSN, the anchor data path function (ADPF) 501 in the base station controller 500 is the IP flow according to the packet classification rule Classify If the 5-tuple of the IP packet belongs to the ROHC SF, the header of the IP packet is compressed to generate a CS PDU. The ADPF 501 encapsulates an external IP header and a GRE header by tagging the CS PDU, and delivers the encapsulated packet to the base station 502.

The base station 502 obtains an SDU by decapsulating the encapsulated packet from the base station controller 500, fragments and packs the SDU to generate a MAC PDU, and generates the MAC. The PDU is physically layered and transmitted to the terminal 504 over the air.

The terminal 504 assembles the MAC PDU received from the base station 502 over the air into an SDU (or CS PDU). In this case, when the CS PDU corresponds to the ROHC SF, the ROHC performing unit 505 decompresses the header of the CS PDU according to the ROHC context and processes the decompressed IP packet.

On the contrary, in the uplink, the terminal 504 classifies the IP packet generated in the IP layer according to the packet classification rule. If the IP packet belongs to the ROHC SF, the ROHC performing unit 505 generates a CS PDU by compressing the IP packet according to a predetermined algorithm (for example, RFC3095). The terminal 504 divides and packs the CS PDU to generate a MAC PDU, and transmits the MAC PDU to a base station through the air. In this case, the MAC PDU is transmitted to the base station through an uplink transport connection.

Then, the base station 502 encapsulates the MAC PDU received over the air into a CS PDU (or SDU), encapsulates an external IP header and a GRE header by tagging the CS PDU, and encapsulates the encapsulated packet. Is transmitted to the base station controller 500 through the data path tunnel (GRE tunnel).

Then, the ADPF 501 in the base station controller 500 decapsulates the packet received through the data path tunnel and checks whether the received packet corresponds to the ROHC SF using the key field value of the GRE header. In the case of the ROHC SF, the ADPF 501 expands the header of the decapsulated packet (CS PDU) using a ROHC context, and delivers the header expanded IP packet (IPv4 or IPv6) to a CSN. .

6 illustrates a downlink traffic processing operation of a base station controller according to an embodiment of the present invention.

Referring to FIG. 6, the base station controller receives an IP packet from a core service network (CSN) in step 601. When the IP packet is received, the base station controller classifies the IP flow according to a packet classification rule in step 603. At this time, the base station controller can classify the IP flow using 5-tuples (protocol type, source / destination IP address, source / destination port number) of the IP packet.

In step 605, the base station controller checks whether the corresponding IP flow belongs to the ROHC SF. If it does not belong to ROHC SF, the base station controller proceeds directly to step 609. On the other hand, if the IP flow belongs to the ROHC SF, the base station controller performs header compression on the IP packet in step 607. For example, the base station controller may compress the header according to the RFC3095 algorithm. If the IP packet does not belong to the profile negotiated with the ROHC peer, the IP packet is discarded. The CS PDU generated through the header compression may be composed of a ROHC header and a payload.

In step 609, the base station controller encapsulates the CS PDU generated through header compression or the IP packet (CS PDU) classified as a flow without header compression by a data path tunnel (GRE tunnel). That is, an external IP header and a GRE header are added to the CS PDU. In this case, mapping information associated with a terminal identifier and a service pull identifier is set in a key field of the GRE header.

In step 611, the base station controller transmits the encapsulated packet to the base station through a data path tunnel.

7 illustrates an uplink traffic processing operation of a base station controller according to an embodiment of the present invention.

Referring to FIG. 7, the base station controller first receives a packet through a data path tunnel (GRE tunnel) from the base station in step 701. When the packet is received from the base station, the base station controller decapsulates the packet received from the base station in step 703. At this time, the base station controller obtains the CS PDU by removing the external IP header and the GRE header from the received packet.

In step 705, the base station controller determines whether the CS PDU belongs to the ROHC SF according to a key field value of the GRE header. If the CS PDU does not belong to the ROHC SF, the base station controller proceeds directly to step 709. On the other hand, if the CS PDU belongs to the ROHC SF, the base station controller proceeds to step 707 to decompress the header of the CS PDU according to the ROHC context.

In step 707, the base station controller delivers the decompressed IP packet or an IP packet of a flow without header compression to a core service network.

8 illustrates an uplink traffic processing operation of a terminal according to an embodiment of the present invention.

Referring to FIG. 8, first, the terminal generates an IP packet to be transmitted in the uplink in step 801. When the IP packet is generated, the terminal classifies the IP flow according to a packet classification rule in step 803. In this case, the terminal may classify the IP flow using 5-tuples (protocol type, source / destination IP address, source / destination port number) of the IP packet.

In step 805, the terminal checks whether the corresponding IP flow belongs to the ROHC SF. If it does not belong to ROHC SF, the terminal proceeds directly to step 809. On the other hand, if the corresponding IP flow belongs to the ROHC SF, the terminal performs header compression on the IP packet in step 807. For example, the terminal may compress the header according to the RFC3095 algorithm. However, if the IP packet does not belong to the profile negotiated with the ROHC peer, the IP packet is discarded. The CS PDU generated through the header compression may be composed of a ROHC header and a payload.

Thereafter, the terminal processes the MAC PDU generated by the header compression or the IP packet (CS PDU) classified as a flow without header compression in step 809 to process the MAC-CPS (Media Access Control-Common Part Sublayer). Create In step 811, the terminal transmits the MAC PDU to the base station through an uplink transport connection.

9 illustrates a downlink traffic processing operation of a terminal according to an embodiment of the present invention.

Referring to FIG. 9, in step 901, a UE receives a MAC PDU through a downlink transport connection. When the MAC PDU is received, the terminal assembles a CS PDU (or SDU) with the received MAC PDU in step 903.

In step 905, the terminal determines whether the CS PDU belongs to the ROHC SF. If the CS PDU does not belong to the ROHC SF, the terminal immediately proceeds to step 909. In contrast, when the CS PDU belongs to the ROHC SF, the UE decompresses the header of the CS PDU according to the ROHC context in step 907.

In step 907, the base station controller protocolizes the decompressed IP packet or an IP packet of a flow without header compression.

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

1 is a diagram illustrating a configuration of a base station controller in a broadband wireless access system according to an embodiment of the present invention.

2 is a diagram illustrating a configuration of a terminal in a broadband wireless access system according to an embodiment of the present invention.

3 is a view for explaining the detailed operation of the ROHC data plane (base plane) of the base station controller according to an embodiment of the present invention.

4 is a view for explaining the detailed operation of the ROHC data plane (data plane) of the terminal according to an embodiment of the present invention.

5 illustrates a Network Reference Model in accordance with the present invention.

6 is a diagram illustrating a downlink traffic processing operation of a base station controller according to an embodiment of the present invention.

7 is a diagram illustrating an uplink traffic processing operation of a base station controller according to an embodiment of the present invention.

8 is a diagram illustrating an uplink traffic processing operation of a terminal according to an embodiment of the present invention.

9 is a diagram illustrating a downlink traffic processing operation of a terminal according to an embodiment of the present invention.

Claims (26)

An apparatus for header compression of a base station controller in a broadband wireless access system, Internet Protocol (IP) packets for downlink traffic received from a Core Service Network (CSN) are classified according to a classification rule, and the IP packets are ROHC (Robust Header Compression) Service Flow (SF). A classifier for forwarding the IP packet to the header compression unit, The header compression unit generates a convergence sublayer (CS) PDU (Packet Data Unit) by performing header compression on the IP packet from the classifier, and the CS PDU includes a ROHC header and a payload. Encapsulates by tagging an external IP header and a Generic Routing Encapsulation (GRE) header to the CS PDU from the header compression unit, and delivers the encapsulated packet to a base station through a data path tunnel. And a radar. The method of claim 1, A CS PDU is obtained by decapsulating a packet received from a base station through a data path tunnel, and confirming whether the packet corresponds to an ROHC SF by using a key field value in the GRE header of the packet. A decapsulator for forwarding the CS PDU to a header extension, if applicable; And decompressing the header of the CS PDU from the decapsulator to obtain an IP packet. The method of claim 1, And the classifier performs packet classification using 5 tuples (protocol type, source / destination address, source / destination port number) of the IP packet. The method of claim 1, And a mapping information associated with a service flow identifier and a terminal identifier is set in a key field of the GRE header. The method of claim 1, And the header compression unit performs header compression according to an RFC3095 algorithm. The method of claim 2, If transmission of a feedback packet for an uplink ROHC channel is required, the header compression unit delivers a feedback packet from the header extension unit to the base station via a downlink ROHC SF. The method of claim 2, And when the feedback packet is received through an uplink ROHC SF, the header extension unit provides the feedback packet to the header compression unit. An apparatus for header compression of a terminal in a broadband wireless access system, A classifier for classifying IP packets generated at an IP layer according to a classification rule, and forwarding the IP packets to a header compression unit when the IP packets correspond to ROHC SFs; Header compression unit to generate a CS PDU by performing header compression on the IP packet from the classifier, and forwards the CS PDU to the uplink MAC processing unit through a MAC-SAP (Service Access Point), and the CS PDU is ROHC Consists of a header and payload, And MAC processing the CS PDU from the header compression unit to generate a MAC PDU, and transmitting the MAC PDU to the base station through an uplink connection. The method of claim 8, MAC layer processing MAC PDU received from the base station to assemble the CS PDU, and if the CS PDU corresponds to the ROHC SF downlink MAC processing unit for forwarding the CS PDU to the header extension through the MAC-SAP; And extending the header of the CS PDU from the downlink MAC processor to obtain an IP packet. The method of claim 8, And the classifier performs packet classification using 5 tuples of IP packets. The method of claim 8, And if the IP packet does not belong to ROHC SF, the classifier forwards the IP packet to the uplink MAC processor. The method of claim 9, And when the feedback packet for the downlink ROHC channel is required, the header compression unit transmits the feedback packet from the header extension unit to the base station through the uplink ROHC SF. The method of claim 9, And when the feedback packet is received through downlink ROHC SF, the header extension unit provides the feedback packet to the header compression unit. A method for header compression of a base station controller in a broadband wireless access system, The classifier classifies an Internet Protocol (IP) packet for downlink traffic received from a Core Service Network (CSN) according to a classification rule, and the IP packet is a Robust Header Compression (ROHC) SF. (Service Flow) is the process of forwarding the IP packet to the header compression unit, and Generating a Convergence Sublayer (CS) PDU (Packet Data Unit) by performing header compression on the IP packet from the classifier, wherein the CS PDU is composed of a ROHC header and a payload, An encapsulator tags and encapsulates an external IP header and a Generic Routing Encapsulation (GRE) header on the CS PDU from the header compression unit, and encapsulates the encapsulated packet through a data path tunnel. Method comprising the step of delivering to. The method of claim 14, The decapsulator obtains a CS PDU by decapsulating a packet received from a base station through a data path tunnel, and confirms whether the packet corresponds to the ROHC SF by using a key field value in the GRE header of the packet. Forwarding the CS PDU to a header extension unit if the ROHC SF corresponds to the ROHC SF; And decompressing the header with respect to the CS PDU from the decapsulator to obtain an IP packet. The method of claim 14, And the classifier performs packet classification using 5 tuples (protocol type, source / destination address, source / destination port number) of the IP packet. The method of claim 14, And mapping information associated with a service flow identifier and a terminal identifier is set in a key field of the GRE header. The method of claim 14, Wherein the header compression unit performs header compression according to an RFC3095 algorithm. The method of claim 15, If the transmission of the feedback packet for the uplink ROHC channel is required, the header compression unit further comprises the step of delivering the feedback packet from the header extension unit to the base station via the downlink ROHC SF. The method of claim 15, And when the feedback packet is received through an uplink ROHC SF, providing the feedback packet to the header compression unit. A method for compressing a header of a terminal in a broadband wireless access system, The classifier classifies the IP packet generated in the IP layer according to a classification rule, and when the IP packet corresponds to ROHC SF, forwarding the IP packet to the header compression unit; Generating a CS PDU by performing header compression on the IP packet from the classifier, and forwarding the CS PDU to an uplink MAC processor through a MAC-SAP (Service Access Point); PDU consists of ROHC header and payload, The uplink MAC processing unit, MAC layer processing the CS PDU from the header compression unit to generate a MAC PDU, and transmitting the MAC PDU to the base station through the uplink connection. The method of claim 21, Downlink MAC processing, MAC layer processing MAC PDU received from the base station to assemble the CS PDU, if the CS PDU corresponds to the ROHC SF forwarding the CS PDU to the header extension through the MAC-SAP; , The header extension unit further comprises the step of obtaining the IP packet by extending the header for the CS PDU from the downlink MAC processing unit. The method of claim 21, And the classifier performs packet classification using 5 tuples of IP packets. The method of claim 21, And if the IP packet does not belong to ROHC SF, the classifier further comprises forwarding the IP packet to the uplink MAC processor. The method of claim 22, If transmission of a feedback packet for a downlink ROHC channel is required, the header compression unit further comprises transmitting a feedback packet from the header extension unit to a base station through an uplink ROHC SF. The method of claim 22, If the feedback packet is received via a downlink ROHC SF, the header extension unit further comprises providing the feedback packet to the header compression unit.

Images