KR100790360B1 - Method for Traffic Performance Improvement of Interactive Satellite Communications - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a traffic processing performance improvement method considering QoS in a bidirectional satellite access system.

2. The technical problem to be solved by the invention

The present invention performs an IP packet transmission / retransmission process to be transmitted to a central station or a terminal station from a user terminal connected to a two-way satellite access system or a web server of an external network through a satellite, respectively, on behalf of a web server or a user terminal of an external network. Accordingly, the object of the present invention is to provide a method for improving traffic throughput in consideration of QoS in a two-way satellite access system, which enables users to improve traffic throughput in consideration of quality of service (QoS).

3. Summary of Solution to Invention

According to an aspect of the present invention, there is provided a method for improving traffic processing performance of an IP packet to be transmitted from a user terminal connected to a terminal station of a bidirectional satellite access system to a central station through a satellite, and to receive from the user terminal and transmit the received packet to the central station through the satellite. An IP packet storing step of storing an IP packet; An IP packet response step of transmitting a reception response signal for the stored IP packet on behalf of the central station side to the user terminal before the stored IP packet is transmitted to the central station side; And an IP packet retransmission step of transmitting the stored IP packet to the central station side through the satellite, and retransmitting an IP packet not receiving a response signal in response to a retransmission request from the central station side.

4. Important uses of the invention

The present invention is used for improving traffic processing performance considering QoS in a bidirectional satellite access system.

QoS, VPN, PEP, DPM, DRM, Virtual Private Network, Central Station, Terminal Station, Traffic Classification Unit, Priority, Bidirectional Satellite Access

Description

Method for Traffic Performance Improvement of Interactive Satellite Communications in Consideration of Behavior in Two-way Satellite Access System

1 is a configuration diagram of an embodiment of a bidirectional satellite access system for improving traffic processing performance and security to which the present invention is applied;

2 is a diagram illustrating an embodiment of a traffic classification method for classifying traffic priorities according to the present invention;

3 is a diagram illustrating an embodiment of a terminal station to which a traffic classification method for classifying according to traffic priority according to the present invention is applied;

4 is a diagram illustrating an embodiment of a traffic security method considering QoS in a terminal station according to the present invention.

* Explanation of symbols on the main parts of the drawing

111: central station performance improvement proxy server 112: gateway

113: central station temporary network server 115: network resource management unit

1153: dynamic resource allocation unit 116: central station transmitting unit

117: central station receiving unit 121: data transmitting / receiving unit

1212: data processing unit 125: terminal station temporary network network

126: Proxy station performance proxy server

The present invention relates to a method for improving traffic processing performance considering QoS in a two-way satellite access system, and more particularly, to a central station or a terminal station through a satellite from a user terminal connected to a two-way satellite access system or a web server of an external network. In the bidirectional satellite access system, by performing the transmission / retransmission process of the IP packet to replace the web server or the user terminal of the external network, the traffic processing performance can be improved in consideration of the quality of service (QoS) to the user The present invention relates to a traffic processing performance improvement method considering the QoS of a mobile station.

Conventional two-way satellite access system technology does not use the technology for QoS support, the technology for improving the TCP traffic performance, the encryption technology for the virtual private network (VPN), or even applied independently of each other Situation. Therefore, there is a need for an integrated system using interconnected technologies in the two-way satellite access system. In this situation, the problems with the integrated system are as follows.

In case of applying the technology to support the service quality, the technology to improve the traffic performance, and the encryption technology for the virtual private network in the integrated two-way satellite access system, the encrypted TCP header cannot be read and the priority traffic cannot be classified. Or an implementation problem that prevents processing a spoofing ACK.

First, the SMT (Mobile Satellite Terminal) analyzes the header of the TCP according to the service type for traffic transmitted from the user for quality of service (QoS), and according to the analysis result, the aforementioned Voice over Internet Protocol (VoIP) Break down traffic, pages for web business, games and videos, and other traffic.

On the other hand, when the Internet Protocol security protocol (IPsec) scheme is applied for the virtual private network, the terminal station (SMT) is the first in the payload of the IP because the IP payload including the TCP header is encrypted at the OSI 3 layer. There is a problem in that it is difficult to classify the traffic because the encrypted TCP header located at cannot be read.

In addition, the terminal station (SMT), the performance enhancement proxy server (PEP) for improving the performance of the transmission control protocol (TCP), as in the quality of service (QoS) analyzes the header of TCP along with the IP header for TCP traffic The spoofing ACK needs to be processed. However, since the IP packet is encrypted according to the application of the IPsec technique, it is difficult to read the TCP header.

If a traffic classifier for QoS is deployed on a server, such as a performance-enhanced proxy (PEP) server, the location of the virtual private network (VPN) server with the IPsec technique is located at the front or rear of the traffic classifier and performance-enhanced proxy server. This can be If the location of the virtual private network (VPN) server comes to the front end, it is impossible to perform the functions of the traffic classifier and the performance improvement proxy server due to the data encryption.

On the other hand, when the location of the virtual private network (VPN) server comes to the end, the DPM (Data Processing Module) of the terminal station that needs to classify the traffic classifier and allocate resources to the central station according to the amount of IP data stored in each queue It is processed by the kernel stage of the operating system (for example, Linux) and transmitted to the central station through the link layer in the form of an Asynchronous Transfer Mode (ATM) cell or MPEG2-TS without being delivered to more than three layers, but the virtual private network (VPN) server There is a problem that the IPsec scheme of the present invention cannot be applied because it is provided in three layers.

The present invention has been proposed in order to solve the above problems, the external network for the transmission / retransmission process of the IP packet to be transmitted to the central station or terminal station via the satellite from the web server of the user terminal or the external network connected to the two-way satellite access system By performing on behalf of a web server or a user terminal of the user, to provide a traffic processing performance improvement method considering the QoS in a two-way satellite access system that can improve the traffic processing performance in consideration of the quality of service (QoS). The purpose is.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a method for improving traffic processing performance of an IP packet to be transmitted from a user terminal connected to a terminal station of a two-way satellite access system to a central station through a satellite, and receiving the satellite from the user terminal. An IP packet storing step of storing an IP packet (Internet Protocol packet) to be transmitted to the central station through the network; An IP packet response step of transmitting a reception response signal for the stored IP packet on behalf of the central station side to the user terminal before the stored IP packet is transmitted to the central station side; And an IP packet retransmission step of transmitting the stored IP packet to the central station side through the satellite, but retransmitting an IP packet not receiving a response signal in response to a retransmission request from the central station side.

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On the other hand, the present invention, in the method for improving the traffic processing performance of the IP packet to be transmitted to the terminal station via a satellite from a web server of the external network connected to the central station of the two-way satellite access system, received from the web server of the external network An IP packet storing step of storing an IP packet to be transmitted to the terminal station through a satellite; An IP packet response step of transmitting a reception response signal for the stored IP packet on behalf of the terminal station to the web server of the external network before the stored IP packet is transmitted to the terminal station side; And an IP packet retransmission step of transmitting the stored IP packet to the terminal station through the satellite and retransmitting an IP packet not receiving a response signal in response to a retransmission request from the terminal station.

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The technology for supporting quality of service (QoS) according to the present invention is a technology for transmitting data transmitted from a terminal station to a central station by service, which is a business to which VoIP (Voice over Internet Protocol) and a hypothetical private network (VPN) are applied. By classifying web pages, games and videos, and other traffic, the VoIP traffic that provides voice is the highest priority, followed by web traffic for business, traffic such as games or videos, and other traffic in order. In order to allocate the resource, priority is given to prioritizing traffic by reflecting these processing criteria.

In addition, the encryption technology for the virtual private network according to the present invention is a technique for applying the IPsec technique to the network layer corresponding to three layers of the OSI (Open Systems Interconnection) 7 layer for constructing the temporary private network, which is the payload of the IP header This is to secure IP traffic by encrypting Payload. In this technique, the forward link transmitted to the terminal station through the central station encrypts at the central station and decrypts the encrypted data at the terminal station to encrypt data transmitted through the radio link of satellite communication. By encrypting at the station and decrypting the encrypted data at the central station, it is available in a two-way satellite access system.

In addition, a technique for improving the performance of the traffic according to the present invention includes a geostationary satellite (500 ms round trip time (RTT), having a higher Bit Error Rate (BER) characteristics than the landline network) There is a technique to prevent TCP transmission performance from being degraded due to congestion control. Here, since the steady state transmission rate of TCP (Transmission Control Protocol) is inversely proportional to the transmission delay time and the packet loss rate, the performance is reduced due to heavy congestion control during TCP traffic transmission. To alleviate this deterioration of performance, a performance enhancement proxy server (PEP) is installed between the wired network and the satellite to store data packets, and if retransmission is necessary due to the loss of data link, retransmit to the receiver. This is to prevent the sender from performing congestion control by generating and transmitting a spoofing ACK at the sender. In other words, the congestion control prevention process generates and transmits a spoofing ACK, which reduces the transmission delay time recognized by the transmitting side to the transmission delay time on the wired link. Therefore, the TCP performance limitation factor due to the transmission delay time or the bit error rate is reduced. It is to remove.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration of an embodiment of a two-way satellite access system for improving traffic processing performance and security to which the present invention is applied. As shown in FIG. 1, the bidirectional satellite access system may be used as an extension network from an external terrestrial network.

The bidirectional satellite access system for improving traffic processing performance and security to which the present invention is applied includes a central station 10 and a terminal station 12. The central station 10 and the terminal station 12 exchange IP packets via the satellite network, and the terminal station 12 provides the IP terminal transmitted from the central station 10 to the user terminal 128.

As shown in FIG. 1, the central station 10 may include a central station performance enhancement proxy server (PEP) 111, a gateway 112, and a central station virtual private network (VPN). 113, a hub 114, a network resource management unit (NMM) 115, a central station transmitter 116, and a central station receiver 117. The network resource manager 115 may include a dynamic host configuration protocol / network address translation (DHCP / NAT) 1151, a network management module (NMM) 1152, and an operation resource. An allocation unit (DRM: Dynamic Resource Module) 1153 is included. In addition, the central station transmitter 116 includes an L-band converter (L-band converter) 1161, a DVB-S modulator (MOD) 1162, and a transmission data processor (IP Encap). The central station receiver 117 includes a return link IF module (WIM) 1171, a return link demodulator (RLD) 1172, and return link data. And a processing unit (RDP: Rx Data Processor) 1173.

Hereinafter, each component will be described.

The central station performance improvement proxy server 111 stores an IP packet (Internet Protocol packet) among Internet data transmitted from a web server of an external network. In addition, the central station performance improvement proxy server 111 transmits a spoofing ACK (Acknowledge) to the web server of the external network or retransmits the stored IP packet according to a retransmission request from the terminal station due to a loss of the transmitted link. do. This is to improve the performance of the central station proxy server 111 is located in the middle of the wired network and satellite network to act as a substitute for the retransmission to the receiver, while reducing the performance of TCP traffic due to the long transmission delay time of the satellite network. At this time, the central station performance improvement proxy server 111 passes the User Datagram Protocol (UDP) packet as it is.

The gateway 112 performs a routing function of the IP packet transmitted from the central station performance improvement proxy server 111.

The central station virtual private network server 113 encrypts an IP payload excluding an IP header among IP packets stored in the central station performance enhancing proxy server 111 by applying an IPsec technique. This is to secure traffic by applying IPsec technique to network layer corresponding to layer 3 of OSI 7 layer for VPN configuration.

The central station virtual private network server 113 delivers the encrypted IP packet to the central station transmitter 116 via the hub 114. At this time, since the location of the central station virtual private network server 113 is applied for data protection of the satellite section, it may be located where the analysis of the IP header and the TCP header is completed.

The hub 114 connects the central station virtual private network server 113 and the central station transmitter and transmits IP packets.

The central station transmitter 116 transmits the IP packet encrypted by the central station virtual private network server 113 through the transmission data processor 1161, the DVB-S modulator 1162, and the L-band converter 1163 through the satellite network. Send to the side. The central station receiving unit 117 receives the IP packet from the terminal station side via the return link IF receiving unit 1171, the return link demodulation unit 1172, and the return link data processing unit 1175.

The network resource manager 115 performs network management functions such as dynamic host configuration and network address translation. In particular, the operation resource allocator 1153 allocates the resource of the return link differently according to the resource allocation request for each IP traffic from the terminal station. That is, the operation resource allocator 1153 allocates the resources to the VoIP traffic with the highest priority according to the resource allocation request for each IP traffic, and allocates the resources in the order of web business traffic, game or video traffic, and other traffic which are the next priority.

Meanwhile, the terminal station 12 includes a data transmission / reception unit (SMT: Satellite Mobile Terminal) 121, a network address translation unit (NAT) 124, a terminal station virtual private network server 125, and a terminal station performance. Enhancement proxy server 126, and hub 127. The data transmission / reception unit 121 may include a data transmitter (FRM: Forward link Rx Module (Demodulator & Decoder for Forward Link) 1212), a data processing module 1212, and a data receiver (TTM: TDMA). Tx Module (Modulator & Encoder for Return Link)) 1213. Hereinafter, each component will be described.

The terminal station performance improvement proxy server 126 stores the IP packet in the Internet data transmitted from the user terminal 128 through the hub 127 and describes the type of traffic for each service in the IP header of the stored IP packet. This is to allow the data processing unit 1212 to request different resource allocation for traffic for each service in order to provide quality of service (QoS). Here, the traffic type per service is described in the TOS field of the IP header which is plain text. The TOS field is an 8-bit signal value of an IP datagram header indicating or identifying the priority of an individual packet. The TOS field is used to set the priority of the packet using the TOS field and apply another wait alignment.

In addition, the terminal station performance improvement proxy server 126 analyzes the IP header and the TCP header to the user terminal 128 and transmits a spoofing ACK or resends the stored IP packet according to a retransmission request from the central station. In addition, the terminal station performance improvement proxy server 126 transmits an IP packet in which the type of traffic for each service is described in the IP header to the terminal station virtual private network server 125.

The terminal station virtual private network server 125 receives the IP packet describing the traffic type for each service from the terminal station performance enhancement proxy server 126 and encrypts the same by applying an IPsec technique.

The data transmission / reception unit 121 performs a function of transmitting and receiving an IP packet through a satellite network.

The terminal station virtual private network server 125 decrypts the IP packet received by the data transmission / reception unit 121. The terminal station virtual private network server 125 converts the IP payload encrypted by the central station virtual private network server 113 from the received IP header (plain text) and IP payload (encryption text) into plain text, and then switches the hub 127 to the plain text. Transmit to the user terminal 128 through.

Here, since the terminal station virtual private network server 125 is applied for data protection of the satellite section, the terminal station virtual private network server 125 may be located where the analysis of the IP header and the TCP header is completed.

Although not shown in FIG. 1, the traffic classifier 21 classifies traffic according to priority by analyzing the TOS field of the IP header (plain text) in the encrypted IP packet at the terminal virtual private network server 125. Do this. In addition, the traffic classifying unit 21 classifies whether it is VoIP traffic, traffic for web business, game or video traffic, or other traffic and manages it as a separate queue. This is for the data processing unit 1212 to request resources differently according to queue sizes classified separately according to IP traffic.

The data processing unit 1212 according to the traffic-specific priority classified by the traffic classifying unit 21, that is, the priority of the scheduler 22 (for example, the priority is determined according to the amount of IP data stored in each queue). The central station 10 requests resources for the return link channel.

IP station and IP payload, which are plain texts received from the terminal station performance-enhancing proxy server 126, are converted to cipher text, and the payload except for the IP header is transmitted to the data processing unit 1212 through the terminal station virtual private network server 125. . The data processor 1212 may analyze only the IP header in the plain text. The data processing unit 1212 classifies whether the traffic is VoIP traffic, web business traffic, game or video traffic, or other traffic based on the TOS field of the IP header, and manages it as a separate queue, and the scheduler 22 determined by the operator's policy. As a result, the resource request for the return link channel to the central station (10).

For example, when the IP packet is VoIP traffic, the data processor 1212 classifies it as a priority processing traffic, and requests an allocation of resources that guarantee a certain transmission rate, and sequentially, for other traffic, according to each priority allocation order. Request allocation of resources.

2 is a diagram illustrating an embodiment of a traffic classification method for classifying traffic priorities according to the present invention.

As shown in FIG. 2, the traffic classifying unit 21 classifies the traffic for each service in the terminal station 12 to provide the quality of service (QoS), and schedules the traffic through the scheduler 22 for different queues. That is, the traffic classifier 21 classifies the traffic transmitted from the user terminal 128 to provide QoS, and classifies the traffic into VoIP traffic, traffic for web business, game or video traffic, and the like according to the provided service, respectively, in the corresponding queue. After buffering, the scheduler according to the user's request is driven to request the dynamic resource allocation unit 1153 from the data processing unit 1212 to allocate resources for each traffic.

3 is a diagram illustrating an embodiment of a terminal station to which a traffic classification method classified according to traffic priority according to the present invention is applied.

As shown in FIG. 3, the terminal station 12 includes a terminal station performance improvement proxy server 126, a terminal station virtual private network server 125, and a traffic classification unit 21.

User Internet traffic of the user terminal 128 is transmitted to the data processing unit 1212 through the terminal station performance enhancing proxy server 126, the terminal station virtual private network server 125, and the traffic classification unit 21 through the hub 127. After the resource is requested by the data processor 1212 to the dynamic resource allocator 1153, the data is transmitted to the central station 10 using the allocated resources.

4 is a diagram illustrating an embodiment of a traffic security method considering QoS in a terminal station according to the present invention.

As shown in FIG. 4, a method for processing an IP packet in a terminal station includes: user Internet traffic, an IP packet in a terminal station performance improving proxy server 126, an IP packet in a terminal station virtual private network server 125, And described according to the IP packet in the traffic classification unit 21 as follows.

First, user Internet traffic at the user terminal 128, as shown in FIG. 4, consists of an IP header and an IP payload, which consists of a TCP header and a datagram.

The terminal station performance improvement proxy server 126 stores the IP packet received from the user terminal 128, analyzes the IP header and the TCP header of the stored TCP traffic, and transmits a spoofing ACK to the user terminal 28. In the TOS field of the IP header (plain text), the type of traffic for each service is described.

The terminal station virtual private network server 125 encrypts only an IP payload excluding an IP header among IP packets received from the terminal station performance enhancing proxy server 126.

The data processing unit 21 analyzes the TOS field of the IP header (plain text) in the encrypted IP packet at the terminal virtual private network server 125, classifies it according to traffic priority, manages the classified traffic as a separate queue, and scheduler 22 ), The resource request for the return link channel to the central station 10 according to the priority (for example, priority according to the amount of IP data stored in each queue).

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the present invention provides a transmission / retransmission process of an IP packet to be transmitted to a central station or a terminal station through a satellite from a user terminal or an external network web server connected to a bidirectional satellite access system, respectively. By performing on behalf of the, there is an effect that can improve the traffic processing performance in consideration of the quality of service (QoS) to the user.

That is, the present invention can improve TCP performance degradation due to a long transmission delay time, which is a disadvantage of satellites, and classify traffic for each service to guarantee QoS, thereby allocating resource allocation of return links according to services to the central station. There is an effect that can be requested.

Claims (12)

In the method of improving the traffic processing performance of the IP packet to be transmitted from the user terminal connected to the terminal station of the two-way satellite access system to the central station through the satellite, An IP packet storing step of storing an IP packet to be received from the user terminal and to be transmitted to the central station through the satellite; An IP packet response step of transmitting a reception response signal for the stored IP packet on behalf of the central station side to the user terminal before the stored IP packet is transmitted to the central station side; And An IP packet retransmission step of transmitting the stored IP packet to the central station through the satellite and retransmitting an IP packet not receiving a response signal in response to a retransmission request from the central station; Traffic processing performance improvement method of the IP packet in the terminal station of the bidirectional satellite access system comprising a. The method of claim 1, The IP packet response step, Generating a spoofing ACK, which is a reception response signal for the IP packet received from the user terminal, so that the user terminal does not perform congestion control on the IP packet to be transmitted to the central station; A method for improving the traffic processing performance of an IP packet in a terminal station of a bidirectional satellite access system, characterized in that. delete delete delete In the method of improving the traffic processing performance of the IP packet to be transmitted to the terminal station through a satellite from the web server of the external network connected to the central station of the two-way satellite access system, An IP packet storing step of storing an IP packet to be received from a web server of the external network and to be transmitted to the terminal station through the satellite; An IP packet response step of transmitting a reception response signal for the stored IP packet on behalf of the terminal station to the web server of the external network before the stored IP packet is transmitted to the terminal station side; And An IP packet retransmission step of transmitting the stored IP packet to the terminal station through the satellite and retransmitting an IP packet not receiving a response signal in response to a retransmission request from the terminal station; Traffic processing performance improvement method considering QoS in the central station of the bidirectional satellite access system comprising a. The method of claim 6, The IP packet response step, Generate a spoofing ACK, which is a response signal for an IP packet received from the web server of the external network, so that the web server of the external network does not perform congestion control on the IP packet to be transmitted to the terminal station. Method for improving the traffic processing performance considering the QoS in the central station of the two-way satellite access system, characterized in that for transmitting to the web server of the external network. delete delete delete delete delete

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