KR100981823B1 - Method and system for tansmitting/receiving asymmetric two-way packet data - Google Patents

Abstract

The present invention relates to a method and system for transmitting and receiving asymmetric bidirectional packet data. In particular, in a system capable of bidirectional communication for transmitting and receiving a multimedia communication service in UMTS, uplink and downlink operate asymmetrically to efficiently use memory resources. The purpose is to make it available. The present invention for this purpose is the step of transmitting the resource information that the terminal 610 itself can support to the UTRAN 620, and the UTRAN 620 is necessary to use the header compression technology based on the information received from the terminal 610 Determining the resources by separating the uplink and the downlink, transmitting the resource information determined by the UTRAN 620 to the terminal 610, and the resource information transmitted from the UTRAN 620 by the terminal 610. Compressor and decompressor for uplink and downlink are set based on the above, and the UTRAN 620 sets up the decompressor and compressor for uplink and downlink in different forms based on the resources determined above. It is done.

UMTS, Asymmetric, Bidirectional, Data Transmission, Packet, Wireless, Mobile Communication

Description

Asymmetric bidirectional packet data transmission and reception method and system {METHOD AND SYSTEM FOR TANSMITTING / RECEIVING ASYMMETRIC TWO-WAY PACKET DATA}

The present invention relates to a data transmission and reception method in a wireless mobile communication system, and more particularly, to a method and system for transmitting and receiving asymmetric bidirectional packet data in a universal mobile telecommunications system (UMTS).

Wireless mobile communications have made great strides, and wireless mobile phones have become more popular than landline phones. However, in the service of providing a large amount of data communication beyond the general voice call to the wireless mobile phone through the wireless access network, the wireless mobile communication has not yet been able to keep up with the performance of the existing wired communication system. Therefore, a communication system that enables such a large amount of data communication is called IMT-2000, and technology development is promoted in various countries around the world, and cooperation between countries is progressing in standardization.

Universal Mobile Telecommunications System (UMTS), a European-style IMT-2000 system, is a third generation mobile communication system that evolved from the European standard Global System for Mobile Communications (GSM) system.The GSM Core Network and the Wideband Code Division Multiplex Access) It aims to provide better mobile communication service based on access technology.

In December 1998, for the standardization of UMTS, ETSI in Europe, ARIB / TTC in Japan, T1 in the US, and TTA in Korea were referred to as the Third Generation Partnership Project (hereinafter abbreviated as 3GPP). The detailed specification of UMTS is being prepared so far.

In 3GPP, UMTS standardization work is divided into 5 Technical Specification Groups (hereinafter abbreviated as TSG) in consideration of the independence of network components and their operation for the rapid and efficient technology development of UMTS. Doing.

Each TSG is responsible for the development, approval, and management of standards within the relevant areas, among which the Radio Access Network (hereinafter referred to as RAN) group (TSG RAN) supports WCDMA access technology in UMTS. Develops specifications for the functions, requirements and interfaces of the UMTS Terrestrial Radio Access Network (hereinafter referred to as UTRAN).

1 is a block diagram of a general UMTS network.

As shown in FIG. 1, the UMTS system is largely composed of a terminal, a UTRAN 100, and a core network 200.

The UTRAN 100 is composed of one or more Radio Network Sub-systems (RNS) 110, 120.

The wireless network system 110, 120 is a radio network controller (hereinafter referred to as RNC) 111, and one or more Node B (112) (113) managed by the RNC (111) It is composed.

The RNC 111 is responsible for allocating and managing radio resources and serves as an access point with the core network 200.

The Node Bs 112 and 113 serve as access points of the UTRAN 100 to the terminal by receiving information transmitted from the physical layer of the terminal in uplink and transmitting data to the terminal in downlink. do.

The core network 200 includes a Mobile Switching Center (MSC) 210, a Gateway Mobile Switching Center (GMSC) 220 for supporting a circuit switched service, and a Serving GPRS Support Node (SGSN) for supporting a packet switched service ( 230, a Gateway GPRS Support Node (GGSN) 240 is provided.

The services provided to specific terminals are largely divided into circuit-switched services and packet-switched services. For example, general voice telephone services belong to circuit-switched services, and web browsing services through Internet access are classified as packet-switched services.

First, in case of supporting circuit switched service, the RNC 111 is connected with the MSC 210 of the core network 200, and the MSC 210 is connected with the GMSC 220 managing the incoming or outgoing connection from another network. .

For the packet switched service, the service is provided by the SGSN 230 and the GGSN 240 of the core network 200. The SGSN 230 supports packet communication directed to the RNC 111, and the GGSN 240 manages connection to another packet switched network such as the Internet network.

There is an interface (Interface) that can send and receive information for communication between the various network components, the interface between the RNC 111 and the core network 200 is defined as the Iu interface.

When the Iu interface is connected to the packet switched area, it is defined as 'Iu-PS'. When the Iu interface is connected to the circuit switched area, it is defined as 'Iu-CS'.

2 illustrates a structure of a radio access interface protocol between a terminal and the UTRAN 100 based on the 3GPP radio access network standard.

The wireless access interface protocol of FIG. 2 consists of a physical layer, a data link layer, and a network layer horizontally, and vertically, a control plane for transmitting a user plane and a signaling signal for transmitting data information. Control Plane).

The user plane is an area in which traffic information of the user is transmitted, such as voice or IP packet transmission, and the control plane is an area in which control information is transmitted, such as network interface or call maintenance and management.

The protocol layers of FIG. 2 are based on the lower three layers of the Open System Interface (OSI) reference model, which are well known in communication systems, and include L1 (first layer), L2 (second layer), and L3 (first layer). Three layers).

Hereinafter, each layer of FIG. 2 will be described.

The L1 layer, that is, the physical layer, provides an information transfer service to an upper layer by using various wireless transmission technologies. The physical layer is connected to a higher layer by a medium access control layer through a transport channel. Data is transferred between the medium access control layer and the physical layer which is the L1 layer in the transport channel.

The L2 layer includes a medium access control layer (hereinafter referred to as MAC) layer, a radio link control layer (hereinafter referred to as RLC) layer, a packet data convergence protocol (hereinafter referred to as PDCP). There is a hierarchy.

The MAC layer provides a reassignment service of MAC parameters for allocating and reallocating radio resources, and is connected to an RLC layer, which is a higher layer, by a logical channel. Various logical channels are provided according to the type of information to be transmitted. Generally, a control channel is used for transmitting control plane information, and a traffic channel is used for transmitting user plane information. use.

The RLC layer supports reliable data transmission and performs a segmentation and concatenation function of an RLC service data unit (hereinafter, abbreviated as SDU) from an upper layer. The RLC SDU delivered from the upper layer is sized according to the processing capacity in the RLC layer, and then header information is added to the MAC layer in the form of a protocol data unit (hereinafter, abbreviated as PDU). In the RLC layer, there is an RLC buffer for storing RLC SDUs or RLC PDUs from above.

The PDCP layer is located above the RLC layer and allows data transmitted through a network protocol such as IPv4 or IPv6 to be efficiently transmitted over a relatively small bandwidth wireless interface. To this end, the PDCP layer performs a function to reduce unnecessary control information used in a wired network. Such a function is called header compression. The header compression technique may use RFC2507 and RFC3095 (Robust Header Compression: ROHC) defined by the Internet Standardization Group called the Internet Engineering Task Force (IETF). These methods transmit less control information by transmitting only necessary information in the header part of the data, thereby reducing the amount of data to be transmitted.

At the bottom of the L3 layer is a Radio Resource Control (hereinafter, referred to as RRC) layer.

The RRC layer is defined only in the control plane and is responsible for controlling transport channels and physical channels in connection with setting, resetting, and releasing radio bearers. The radio carrier refers to a service provided by the second layer for data transmission between the terminal and the UTRAN. In general, the radio carrier is configured to define characteristics of protocol layers and channels required to provide a specific service, and It means the process of setting specific parameters and operation methods.

For reference, the RLC layer may belong to a user plane or a control plane according to a layer connected to an upper layer. In case of belonging to the control plane, data is transmitted from the RRC layer, and in other cases, it is a user plane.

In addition, as shown in FIG. 2, in the case of the RLC layer and the PDCP layer, several entities may exist in one layer. This is generally because one terminal has several radio carriers and only one RLC entity and PDCP entity are used for one radio carrier.

Hereinafter, an IP header compression method used for header compression in the PDCP layer will be described.

First, the RFC2507 header compression technique, which is an IETF document, will be described.

The RFC2507 header compression technique may use different compressor techniques depending on whether the protocol located above the IP layer is TCP or other protocol. In other words, protocols that do not use TCP, such as UDP / IP, use the method of "Compressed Non-TCP", and when using TCP, "Compressed TCP" and "Compressed TCP" depending on the method of transmitting variable header fields. nodelta ".

The "Compressed TCP" technique is a method of transmitting the difference between packets without sending the entire field value by using the fact that the difference in the variable header field values is not so large between consecutive packets, and the "Compressed TCP nodelta" method. "Is the method of transmitting the entire variable field as it is. In other words, when the "Compressed TCP" technique is used as the header compression technique, the sender first transmits the entire header packet for one packet stream, constructs a context at the sender and the receiver, and then transfers the packet to a later packet. Transmit using a compression header that represents only the difference from the packet. On the other hand, the "Comprssed TCP nodelta" technique transmits the entire variable header field value.

In the case of using the "Compressed Non-TCP" header compression scheme, the sender first transmits the entire header packet to a packet stream to configure a context between the sender and the receiver, and then changes the packet afterwards. Sends the entire header field value composed of fields. However, the "Compressed Non-TCP" header compression technique is available for unidirectional communication and uses the Compression Slow-Start technique to transmit the entire header information at exponentially increasing intervals. As shown in FIG. 3, the compression slow-start technique is a method of frequently transmitting the same total header initially and gradually increasing the transmission interval thereafter when the total header information is changed or a new header compression technique is applied. In FIG. 3, the hatched portion is the entire header packet and the portion without the hatched portion is the compressed header packet.

However, in order to use the RFC2507 header compression technique in the PDCP layer, it is necessary to define parameters configuring the types of the compressor and the decompressor.

Looking at the parameters used in the RFC2507 header compression scheme, the F_MAX_PERIOD parameter tells the number of "compressed non-TCP" header headers that can be transmitted between all header packets transmitted exponentially in the "Compression Slow-Start" scheme. The F_MAX_TIME parameter, which indicates the time at which the compressed header packet can be transmitted after the last header packet is transmitted and before the next header header is transmitted, is used to indicate the repetition period of the entire header packet.

Also, the MAX_HEADER parameter that indicates the maximum header size that can be used for the header compression technique, the TCP_SPACE parameter that indicates the maximum number of contexts that can be used in the "Compressed TCP" technique, and the "Compressed Non-TCP" technique. The NON_TCP_SPACE parameter, which indicates the maximum number of contexts, and the EXPECTED_REORDERING parameter, which indicates whether or not the reordering is supported, are used to configure the compressor and decompressor types in the UE and UTRAN.

First, as can be seen in Figure 4, a series of processes for using the header compression method in the PDCP layer will be described.

Here, the header compression technique is used in the header compression responsible layer, and the header compression responsible layer is included in the PDCP layer.

First, the RRC layer 411 of the terminal 410 informs the RRC layer 421 of the UTRAN 420 of the capability of the parameters that can be supported in using the header compression technique and the RRC of the UTRAN 420. The layer 421 determines the resources required for using the header compression technique based on the information received above. For example, F_MAX_PERIOD is set to '256' and F_MAX_TIME is set to '5' to indicate the repetition period of the entire header packet, and MAX_HEADER, which is the maximum packet size that can be used in the header compression method, is '168' and the use of non-TCP packets. The maximum number of possible contexts is '15'. This step is to determine the size of each parameter.

Thereafter, the RRC layer 421 of the UTRAN 420 transmits a value determined for the parameters to the RRC layer 411 of the terminal 410.

Accordingly, the header compression technique is applied to the header compression responsible layer included in the PDCP layer 412 and 422 by transmitting the parameter values to the respective PDCP layers 412 and 422. Will configure the type of compressor and restorer required to use

In addition, the ROHC (Robust Header Compression) compressor method will be described.

The ROHC compressor method is generally used to reduce header information of a Real-time Transport Protocol (RTP) / User Datagram Protocol (UDP) / Internet Protocol (IP) packet. In this case, the RTP / UDP / IP packet refers to a packet in which data from the upper layer passes through RTP, UDP, and IP, and has associated headers attached thereto, and various header information necessary for data to be transmitted and restored to the destination through the Internet. It includes.

The ROHC compressor method is based on the fact that a field value of each packet header is substantially constant in consecutive packets belonging to one packet stream. Therefore, the ROHC compressor method does not transmit the entire packet header field but transmits a variable field.

For reference, the total header size of the uncompressed RTP / UDP / IP packet is '40' octets for IPv4 (IP version 4) and '60' octets for IPv6 (IP version 6), whereas The size of a pure data portion called a payload is typically '15 -20 'octets. From this, it can be seen that the transmission efficiency is very low because the control information included in the data transmission is much larger than the actual data to be transmitted. Therefore, if the header compression technique is used, the amount of control information can be greatly reduced. In the case of using the ROHC header compression scheme, the reduced header size is usually only about '1' to '3' octets.

In order to use the ROHC compressor method, as with the RFC2507 header compressor method, it is necessary to define the parameters constituting the type of compressor and decompressor.

Looking at the parameters, the Max_CID parameter tells you the maximum number of contexts available to the compressor, and the types of IP packets used in a packet stream, which is a collection of consecutive packets, are RTP / UDP / IP, RTP / IP, and ESP. Profile parameter indicating whether or not IP / IP is divided, Maximum Reconstructed Reception Unit (MRRU) parameter indicating whether the IP packet is segmented, and the maximum size when segmented segments are reassembled in the restorer, and ROHC The Packet_Sized_Allowed parameter indicates the set of compression header packet sizes supported by the compressor method, and the Reverse_Decompression_Depth that determines the number of retries and the number of retries for the compressed packet that failed to be restored by the decompressor. The parameters are defined in RFC3095, the IETF document of the ROHC compressor method.

Similar to the RFC2507 header compression technique, in order to use the ROHC compression technique in the header compression layer included in the PDCP layer, the RRC layer 411 of the terminal 410 has the ability to support the capability of the ROHC compressor technique by UTRAN ( The RRC layer 421 of the 420 is notified, and the RRC layer 421 of the UTRAN 420 determines and configures the resources necessary to use the ROHC compressor method based on this.

Thereafter, the RRC layer 421 of the UTRAN 420 transmits a value determined for the parameters to the RRC layer 411 of the terminal 410. Accordingly, the RRC layers 411 and 421 of the terminal 410 and the UTRAN 420 transmit values for the parameters to the PDCP layers 412 and 422 and include header compression included in the PDCP layer. The responsible layer forms the type of compressor and decompressor required to use the header compression technique.

The configuration of the compressor and the decompressor will be described in detail with reference to FIG. 5.

In order to use the header compression technique in the PDCP layer, the compressor 512 of the terminal 410 and the decompressor 521 of the UTRAN 420 have the same form when communicating in the uplink, and the UTRAN ( The compressor 522 of 420 and the decompressor 511 of the terminal 410 should have the same shape. In fact, the compressor and the decompressor used for the uplink and the downlink are configured to have the same form without distinguishing the current uplink and the downlink.

That is, in the case of the UTRAN 420, the RRC layer 421 transfers parameters related to the header compression technique to the PDCP layer 422. The transmitted parameters are the UTRAN compressor 522 and the UTRAN restoration without distinguishing the uplink and the downlink. The form of the group 521 is comprised.

In addition, in the case of the terminal 410, parameters related to the header compression technique are transmitted from the RRC layer 421 of the UTRAN 420 to the RRC layer 411, and the RRC layer 411 is associated with the header compression technique to the PDCP layer 412. Pass parameters. In this case, the transmitted parameters form the form of the terminal compressor 512 and the terminal restorer 511 without distinguishing between uplink and downlink.

That is, the terminal 410 and the UTRAN 420 configure the compressor and the decompressor in the same form without distinguishing the uplink and the downlink.

As described above, in order to use the RFC2507 header compression method and the ROHC compressor method in the header compression management layer inside the PDCP layer, the terminal 410 and the UTRAN 420 have parameters for configuring the types of the compressor and the decompressor. Regulations must be established. In fact, the current RRC layer is to define the PDCP layer that is in charge of the header compression method in consideration of only the service characterized in that the uplink and downlink has a symmetrical structure, such as Voice over IP (VoIP). Accordingly, since the terminal 410 and the UTRAN 420 are symmetrically configured without distinguishing the uplink and the downlink, the compressor and the decompressor are configured in the same form.

On the other hand, the UMTS system provides not only VoIP service having a symmetrical structure of uplink and downlink but also a streaming service having an asymmetric structure of uplink and downlink. In addition, the UTMS system attempts to use radio resources efficiently by compressing and transmitting existing 40-byte or 60-byte packet headers into 1 to 4 bytes using header compression techniques to efficiently provide VoIP and streaming services. do. In particular, the streaming service is a downlink-oriented service, and the downlink is used to transmit the packet data service that the user wants to receive, and the uplink is used to inform the feedback of the transmitted packet data.

However, in the conventional UMTS, when the streaming service is provided, the header compression handling function is equally applied without distinguishing the uplink and the downlink, so that the data amount of the packet data transmitted in the downlink is transmitted in the uplink. Due to the fact that it is much larger than the amount, the memory of the system and the terminal used in the header compression technique is unnecessarily wasted, which causes a problem of low efficiency of memory resources.

Therefore, in order to improve the conventional problem, in the system capable of bidirectional communication for transmitting and receiving a multimedia communication service in UMTS, an uplink and a downlink operate asymmetrically so that the memory resource can be efficiently used. An object of the present invention is to provide a method and system for transmitting and receiving asymmetric bidirectional packet data.

In order to achieve the object of the present invention as described above, the asymmetric bidirectional packet data transmission and reception method according to the present invention,

In the method for transmitting and receiving packet data in both directions, characterized in that the asymmetric bidirectional communication through the uplink and downlink, including the step of setting up and downlink based on the resources available to support .

Preferably, the uplink / downlink setting step

Determining a parameter value required for the compressor method by distinguishing the uplink and the downlink based on the capability of the supportable parameter;

Receiving the parameter value determined in the above characterized in that the step of setting the form of the compressor for the downlink and the form of the decompressor for the downlink.

In addition, in order to achieve the object of the present invention as described above, the asymmetric bidirectional packet data transmission and reception method according to the present invention,

In the method for transmitting and receiving packet data in both directions,

A first step of transmitting, by the terminal itself, resource information that can be supported to a higher system; and a second of determining a resource necessary for using a header compression technique based on the information received from the terminal by classifying uplink and downlink And a third step of transmitting the resource information determined by the upper system to the terminal, and a fourth step of setting up the compressor and the decompressor for the uplink and the downlink, respectively, based on the resource information determined by the terminal and the upper system. Characterized by comprising a step.

Preferably, the second step is characterized by determining the capacity of the uplink and downlink by determining the uplink capability and the downlink capability of the terminal when determining the resources.

Preferably, the fourth step may include setting different types of compressors and decompressors set in the terminal and the upper system, and setting the same type of compressor and decompressor matched between the terminal and the upper system. Characterized in that.

In addition, in order to achieve the object of the present invention as described above, the asymmetric bidirectional packet data transmission and reception system according to the present invention,

In the system having a bidirectional communication function to transmit and receive packet data,

A radio resource control (RRC) layer that determines the parameter values required for the compressor method by dividing uplink and downlink based on the capability of the supportable parameters;

And a packet data convergence protocol (PDCP) layer configured to receive the determined parameter value and set the type of the compressor for uplink and the type of the decompressor for downlink.

In addition, in order to achieve the object of the present invention as described above, the asymmetric bidirectional packet data transmission and reception system according to the present invention,

In the system having a bidirectional communication function to transmit and receive packet data,

Radio network control means for determining the size of the parameters necessary for the compression method of the packet data into the uplink and downlink, and setting the compressor and the decompressor;

Transmit the capability of the parameters that it can support to the radio network control means;

And a terminal means for setting the compressor and the decompressor based on the uplink and downlink parameter values determined by the radio network control means and configured to perform asymmetric bidirectional communication.

As described in detail above, the present invention is uplinked in the prior art when the PDCP layer supports the transmission of IP multimedia packet data in which uplink and downlink have a symmetrical or asymmetrical structure by using a header compression technique of RFC2507 or ROHC. By improving the method of setting the link and downlink only symmetrically, the asymmetric method is used as a more efficient setting method, which makes it possible to efficiently manage the memory resources required for performing the header compression function in the PDCP layer. have.

The present invention is a system having a bi-directional communication function to transmit and receive packet data in order to achieve the above object, the parameter value required for the compressor method by distinguishing the uplink and downlink based on the capability of the parameters that can be supported in the RRC layer And determining the type of each compressor and the decompressor for uplink and downlink in the PDCP layer by receiving the parameter value determined above, and performing asymmetric bidirectional communication through uplink and downlink. Characterized in that configured to perform.

In addition, in order to achieve the above object, the present invention provides a UTRAN for determining the size of the parameters required for the compression method of the packet data into an uplink and a downlink, setting the compressor and the decompressor, and the capability of the parameters that can be supported. It is characterized in that it is configured to perform asymmetric bidirectional communication comprising a terminal for transmitting to the UTRAN and the compressor and the decompressor based on the uplink and downlink parameter values determined and returned from the UTRAN.

The UTRAN divides parameters necessary for the compression method of packet data into uplink and downlink based on parameter information transmitted from the terminal means, determines the size thereof, and transmits the determined parameter values to the terminal means. ) Layer, and PDCP (Packet Data Convergence Protocol) layer which sets compressor and decompressor based on parameters determined in this RRC layer.

The UE transmits the capability of a parameter that it can support to the UTRAN and receives an uplink and downlink parameter value determined from the UTRAN and an RRC layer, and the compressor and the restoration based on the parameter values received from the RRC layer. It is characterized by comprising a PDCP layer for setting the group.

The PDCP layer is characterized in that it comprises a header compression responsible layer to set up the respective compressor and restorer for uplink and downlink.

The compressor method is characterized in that the RFC2507 compressor method or ROHC compressor method.

Accordingly, the present invention considers not only the case where the UTRAN and the terminal have a symmetrical structure of uplink and downlink like VoIP, but also the case where the uplink and downlink have an asymmetrical structure such as streaming service. The memory resource required for the scheme is configured to be configured differently for uplink and downlink.

That is, according to the present invention, setting the memory resources required for the header compression scheme differently in the uplink and the downlink does not constitute a different form of the peer-to-peer (P2P) compressor and the decompressor. This means that the shapes are configured differently and the shapes of the UTRAN compressor and the UTRAN restorer are configured differently.

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

FIG. 6 is a signal flow diagram illustrating an application process of header compression technique related parameters according to an embodiment of the present invention. As shown in FIG. 6, parameters necessary for the compression method of packet data are classified into uplink and downlink to determine their size. Based on the determined parameters, the UTRAN 620 for setting up a reconstructor for uplink and a compressor for downlink, and transmits the capability of a parameter that can be supported to the UTRAN 620 and is determined from the UTRAN 620. It is configured to perform asymmetric bidirectional communication with a terminal 610 for setting a compressor for uplink and a reconstructor for downlink based on the feedback uplink and downlink parameter values.

The terminal 610 transmits the capability of a parameter that can be supported to the UTRAN 620 and an RRC layer 611 that receives parameter values divided into uplink and downlink determined from the UTRAN 620, and the RRC. The PDCP layer 612 is configured to set a compressor and a restorer based on the parameter values received by the layer 611.

The UTRAN 620 determines the size of the parameters necessary for the compression method of packet data based on the parameter information transmitted from the RRC layer 611 of the terminal 610 into uplink and downlink, and determines the size thereof. RRC layer 621 for transmitting them to the RRC layer 611, and PDCP layer 622 for setting the compressor and the decompressor based on the parameters determined and transmitted by the RRC layer 621.

The compressor and the decompressor set in each of the UTRAN 620 and the terminal 610 are configured in different forms, and the compressor of the UTRAN 620 and the decompressor of the terminal 610 are configured in the same form. The decompressor and the compressor of the terminal 610 are configured in the same form.

Referring to the operation and effect of the embodiment of the present invention configured as described above are as follows.

In the embodiment of the present invention, reference is made to FIG. 5 to describe the configuration of the compressor and the decompressor used in the header compression technique for the terminal 610 and the UTRAN 620.

Operation in the embodiment of the present invention is the same in most of the operations, such as the method of applying the compressor method, the method of determining the parameter value in the prior art described with reference to FIGS.

However, in the embodiment of the present invention, not only the UTRAN 620 and the terminal 610 have a symmetrical structure of uplink and downlink such as VoIP, but also uplink and downlink are asymmetric like a streaming service. In consideration of the structure, the memory resources required for the header compression scheme are set differently for the uplink and the downlink.

As shown in FIG. 6, in the embodiment of the present invention, the RRC layer 661 of the terminal 610 may use the RRC layer 621 of the UTRAN 620 to display the capability of a parameter that it can support in using the header compression technique. The RRC layer 621 of the UTRAN 620 determines the resources required for using the header compression scheme based on the information received above, by dividing the uplink and the downlink. Determine the size of each parameter to set.

Thereafter, the RRC layer 621 of the UTRAN 620 transmits the values determined for the parameters to the RRC layer 611 of the terminal 610.

Accordingly, the header in the header compression responsible layer included in the PDCP layer 612, 622 by the RRC layer 611, 621 transfers the parameter value to each PDCP layer 612, 622. Each type of compressor and decompressor required to use the compressor method will be configured.

To briefly describe this step-by-step, the terminal 610 itself transmits supportable resource information to the UTRAN 620, and the UTRAN 620 uses a header compression technique based on the information received from the terminal 610. Determining the resources necessary to distinguish the uplink and downlink, the step of transmitting the resource information determined by the UTRAN 620 to the terminal 610, and the terminal 610 is transmitted from the UTRAN 620 The compressor and the decompressor for uplink and downlink are set up based on the resource information, and the UTRAN 620 sets up the decompressor and compressor for uplink and downlink based on the resources determined above.

Here, the memory resources required for the header compression scheme are set differently in the uplink and the downlink, which do not form different types of compressors and restorers 512, 521, 522, and 511 of peer-to-peer. This means that the compressor 512 and the decompressor 511 in the 610 are configured differently or the compressor 522 and the decompressor 521 in the UTRAN 620 are configured differently.

That is, in the embodiment of the present invention, the peer-to-peer compressors and restorers 512 and 521, 522 and 511 have the same shape, but the compressors and restorers 512 and 511 in the terminal 610 or the UTRAN 620 are the same. , 522 and 521 are configured differently.

In this case, in applying the RFC2507 header compression method and the ROHC compressor method in FIG. 6, when the RRC layer 621 of the UTRAN 620 transmits the parameters necessary for the header compression method to the RRC layer 611 of the terminal 610. The compressor 512 in which the terminal 610 is used in the uplink by dividing and applying the parameters necessary for configuring the form of the terminal compressor 512 used in the uplink and the terminal restorer 511 used in the downlink to each of them. ) And the shape of the decompressor 511 used for downlink are configured differently.

First, in case of using the RFC2507 header compression scheme, the parameters necessary for configuring the uplink, that is, the terminal compressor 512, include the F_MAX_PERIOD parameter that informs the period of transmitting the entire header packet in relation to the "Compression slow-start" scheme, and the packet. F_MAX_TIME parameter for transmission time, MAX_HEADER parameter for maximum size of compressible header, TCP_SPACE parameter for maximum TCP packet context, and maximum size for non-TCP packet context NON_TCP_SPACE parameters are used. The downlink, that is, the parameters constituting the terminal restorer 511 include a TCP_SPACE parameter for indicating a maximum size of a TCP packet context, a NON_TCP_SPACE parameter for indicating a maximum size of a non-TCP packet context, and a received packet. The EXPECTED_REORDERING parameter is used to indicate whether the array is to be reordered.

In addition, in the case of using the ROHC compressor method, parameters necessary for configuring the form of the uplink, that is, the terminal compressor 512, include a Max_CID parameter indicating a maximum number of contexts used in the header compression method, and an IP packet supported by the decompressor. The Profile parameter that indicates the type of, the MRRU parameter that indicates whether the IP packet segmentation is possible in the compressor, and the Packet_Sized_Allowed parameter that determines the size of the compression header packet available in the compressor. In addition, the parameters necessary for configuring the form of the downlink, that is, the UE restorer 511, include the Max_CID parameter indicating the maximum number of contexts, the Profile parameter indicating the type of the IP packet supported by the decompressor, and the partitioning in the decompressor. MRRU parameter that indicates the maximum size of the combined packets when the segment is combined, and whether to restore retry within the restorer itself when the compressed header packet fails to be restored, and stores the failed packets in the buffer using the retry technique. In this case, the Reverse_Decompression_Depth parameter that indicates the maximum storage buffer size is used.

In the above, the present invention has been described with reference to the embodiments shown in the drawings, but this is merely exemplary, and those skilled in the art may realize various modifications and other equivalent embodiments therefrom. I will understand. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a block diagram of a general UMTS network.

2 is a structural diagram of a radio access interface protocol between a terminal and a UTRAN based on the 3GPP radio access network standard;

3 is an exemplary view illustrating a packet transmission method in a compression slow-start scheme.

4 is a signal flow diagram showing a series of procedures for using the header compression technique in the PDCP layer of the prior art.

5 is a configuration diagram of a compressor and a restorer used in the header compression method in FIG.

Figure 6 is a signal flow diagram showing a series of procedures for using the header compression technique in an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

610: terminal 611, 621: radio resource control (RRC) layer

612,622: Packet Data Convergence Protocol (PDCP) layer

620: UTRAN

Claims (21)

In the method of communicating packet data in a network, Transmitting a message including first header compression information for compressing a header included in data to be transmitted on the uplink, Receiving second header compression information associated with the first header compression information for compressing a header included in data to be transmitted on the uplink; Compressing a header included in data received from an upper layer by using the second header compression information; And Transmitting data including the compressed header to a lower layer, wherein the first header compression information and the second header compression information are independent of header compression used on a link other than the uplink. Packet data communication method. The data of claim 1, wherein the data to be transmitted on the uplink includes: Packet data communication method, characterized in that received from the upper layer. The method of claim 1, wherein the first compression information, Packet data communication method comprising the information related to the size of the header. The method of claim 1, wherein the first compression information, Packet data communication method comprising information about verification related to compression of the header. The method of claim 1, wherein the compressing the header, Removing from the header a portion of the header that is not different between successive headers. In a terminal for communicating packet data in a network, Transmitting first header compression information for compressing a header included in data to be transmitted in an uplink, and compressing a header included in data to be transmitted in the uplink associated with the first header compression information. A transmission and reception layer for receiving header compression information; And A compressor configured to compress a header included in data received from an upper layer by using the second header compression information, and to transmit data including the compressed header to a lower layer, and the first header compression information And the second header compression information is independent of header compression used on a link other than the uplink. The method of claim 6, wherein the data to be transmitted on the uplink, Terminal, characterized in that received from the upper layer. The method of claim 6, wherein the first compression information, And a terminal related to the size of the header. The method of claim 6, wherein the first compression information, And a terminal related to the verification of the compression of the header. The method of claim 6, wherein the compressing the header, And removing a portion in the header from which there is no difference between successive headers. delete delete delete delete delete delete delete delete delete delete delete

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