KR101169724B1 - Header Compression Apparatus and Header Compression Method - Google Patents

Abstract

The present invention relates to a header compression apparatus and a method optimized for a radio link, wherein the packet data to be coded and transmitted is determined by the state information of the radio link and the priority information of the packet data to be transmitted. A header compression (HC) determination unit for determining a header compression transmission method based on round trip time (RTT) information; A header compression unit for header compressing the packet data according to the determination of the header compression determination unit; A transmission unit for transmitting the packet data compressed by the header compression unit; Receiving unit for receiving the packet data transmitted from the other side transmission unit when receiving; A header compression determining unit determining a header compression transmission method of the packet data received from the receiving unit; And a header decompression unit for decompressing the received packet data according to the determination of the header compression determination unit.
According to the present invention as described above, by applying the header compression transmission method in accordance with the communication state of the radio link in the packet data communication system, it is possible to improve the bandwidth efficiency and compression efficiency.

Description

Optimized header compression device and method for radio link {Header Compression Apparatus and Header Compression Method}

The present invention relates to a header compression apparatus and method thereof optimized for a radio link, and more particularly, to a header compression apparatus and method for transmitting and receiving packet data by applying an optimized header compression transmission scheme in a packet data communication system. .

Recently, a lot of attention has been focused on multimedia communication services. In particular, IP-based multimedia services using the Internet are increasing their influence. In addition, the existing circuit-switched voice-based communication service is gradually changing to IP-based communication, and its importance is getting stronger with the development of IPv6 replacing the existing IPv4. However, for real-time data streams, IP combines with UDP / RTP to have a large overhead compared to payloads. For example, for VoIP, a 40-byte IP / UDP / RTP header doubles the overhead size relative to the payload size. In addition, if the service is served over IPv6 with a default header size of 40 bytes, the overhead is even greater. As a result, there is a need for a method to provide limited bandwidth more efficiently.

In general, header compression can be applied to many applications using link efficiency. Wide area network (WAN), which can be applied to satellite or cellular network with high error rate and delay rate, PPP network supporting low bandwidth, or general telephone network. It can be applied in the case of

Here, the header compression method is a method of reducing the size of the header by removing fields having a common value or a constant difference value among the header fields. In order to apply the header compression method, each node must have a function of compressing and reassembling the header, and the sender and receiver must share information related to compression.

The header compression apparatus to which the conventional header compressor method is applied includes a header compression unit for header-packing packet data according to a set header compression transmission method, a transmission unit for transmitting header data compressed by the header compression unit, and the other side at the time of reception. And a header decompressing unit which decompresses the header part of the received packet data. In general, the header compression transmission method is a HC (Header Compression) method for transmitting the header compressed packet data, a PHC (Periodic HC) method for transmitting the header compressed packet data periodically, or the header is not compressed There is a NHC (Non-HC) scheme for transmitting unpacked packet data.

However, since the header compression apparatus performs packet transmission and reception according to one set of header compression transmission schemes, the header compression transmission scheme is appropriate according to the characteristic that the throughput changes greatly according to the signal-to-noise ratio (SNR) of the radio link. Did not respond. As a result, the number of discarded packets due to bit errors or packet loss increases, which causes a significant drop in bandwidth efficiency.

The present invention is to solve the above problems, in the packet data communication system by appropriately applying the header compression transmission method according to the communication status of the radio link, the header optimized for the radio link that can improve the bandwidth efficiency and compression efficiency It is an object of the present invention to provide a compression apparatus and a method thereof.

In order to achieve the above object, a header compression device optimized for a radio link according to the present invention is a header compression device optimized for a radio link in a packet data communication system, and transmits packet data to be coded and transmitted (Lind). a header compression (HC) determination unit for determining a header compression transmission method based on state information, priority information of packet data to be transmitted, and round trip time (RTT) information; A header compression unit for header compressing the packet data according to the determination of the header compression determination unit; A transmission unit for transmitting the packet data compressed by the header compression unit; Receiving unit for receiving the packet data transmitted from the other side transmission unit when receiving; A header compression determining unit determining a header compression transmission method of the packet data received from the receiving unit; And a header decompression unit for decompressing the received packet data according to the determination of the header compression determination unit.

Here, the header compression transmission method may include a header compression (HC) method for transmitting header compressed packet data, a PHC (periodic HC) method for transmitting header compressed packet data periodically, and a header uncompressed. Characterized in that any one of the NHC (Non-HC) method for transmitting packet data.

In addition, the state information of the radio link includes low error rate (LER) state information in which the channel characteristics of the link are stable because the error rate is lower than the setting range, and HER in which the channel characteristic of the link is unstable because the error rate is higher than the setting range. (High error rate) state information, and the NER (Normal Error Rate) state information in which the link channel characteristic is a basic state when the error rate is within a setting range, and the priority information includes real time packet information and non-real time ( Non-realtime) any one of the packet information, the round trip time information is characterized in that any one of the first information within the set threshold time and the second information exceeding the set threshold time.

The header compression determining unit may determine the header compression transmission method as the HC method when the round trip time information is the first information and the priority information is the real time packet information. If the LER status information, the header compression transmission method is determined by the HC method, and if the HER status information, the header compression transmission method is determined by the PHC method, and the round trip time information is the first information, and the priority information is the non-real time packet. In the case of the information, the header compression transmission method is determined by the HC method if the NER status information according to the state information of the radio link, the header compression transmission method is determined by the HC method if the LER status information, and the header compression transmission method is the HER status information. Characterized in that the PHC method. Further, when the round trip time information is the second information and the priority information is the real time packet information, if the NER status information is NER status information according to the status information of the radio link, the header compression transmission method is determined by the HC method. The header compression transmission method is determined as the PHC method, and if the HER state information, the header compression transmission method is determined as the NHC method. When the round trip time information is the second information and the priority information is the non-real time packet information, the wireless In case of NER status information, the header compression transmission method is determined by HC method, and in case of LER status information, header compression transmission method is determined by PHC method, and when HER status information, header compression transmission method is determined by NHC method. It is characterized by.

Meanwhile, in order to achieve the above object, a header compression method optimized for a radio link according to the present invention is a header compression method optimized for a radio link in a packet data communication system. Determining a header compression transmission scheme based on the state of the radio link, the priority information of the packet data to be transmitted, and the round trip time (RTT) information; Header compressing, by a header compression unit, the packet data according to a determination of the header compression determination unit; Transmitting, by a transmission unit, packet data compressed by the header compression unit; Receiving, by the receiver, packet data transmitted from the other transmitter; Determining, by a header compression determining unit, a header compression transmission method of packet data received from the receiving unit; And a header decompressing unit decompressing the received packet data according to the determination of the header compression determining unit.

Here, the header compression transmission method may include a header compression (HC) method for transmitting header compressed packet data, a PHC (periodic HC) method for transmitting header compressed packet data periodically, and a header uncompressed. Characterized in that any one of the NHC (Non-HC) method for transmitting packet data.

In addition, the state information of the radio link includes low error rate (LER) state information in which the channel characteristics of the link are stable because the error rate is lower than the setting range, and HER in which the channel characteristic of the link is unstable because the error rate is higher than the setting range. (High error rate) state information, and the NER (Normal Error Rate) state information in which the link channel characteristic is a basic state when the error rate is within a setting range, and the priority information includes real time packet information and non-real time ( Non-realtime) any one of the packet information, the round trip time information is characterized in that any one of the first information within the set threshold time and the second information exceeding the set threshold time.

The determining of the header compression transmission method may include: when the round trip time information is the first information and the priority information is the real time packet information, the header compression transmission method is NER state information according to the state information of the radio link. Is determined by the HC method, and if the LER status information, the header compression transmission method is determined by the HC method, and if the HER status information, the header compression transmission method is determined by the PHC method, the round trip time information is the first information, and the priority If the information is non-real time packet information, the header compression transmission method is determined by the HC method if the NER status information according to the state information of the radio link, and if the LER status information, the header compression transmission method is determined by the HC method, and the HER status information. The header compression transmission method is determined by the PHC method. Further, when the round trip time information is the second information and the priority information is the real time packet information, if the NER status information is NER status information according to the status information of the radio link, the header compression transmission method is determined by the HC method. The header compression transmission method is determined as the PHC method, and if the HER state information, the header compression transmission method is determined as the NHC method. When the round trip time information is the second information and the priority information is the non-real time packet information, the wireless In case of NER status information, the header compression transmission method is determined by HC method, and in case of LER status information, header compression transmission method is determined by PHC method, and when HER status information, header compression transmission method is determined by NHC method. It is characterized by.

According to the present invention as described above, by applying the header compression transmission method in accordance with the communication state of the radio link in the packet data communication system, it is possible to improve the bandwidth efficiency and compression efficiency. In particular, the header compression transmission scheme starts with the intention of efficiently using limited bandwidth resources, which is closely related to the efficient use of radio resources. In the case of a low bandwidth mobile communication network, the use of this technology can provide a multimedia service with sufficient image quality and sound quality in response to user demand. In addition, even in the case of wireless LAN, if security such as WEP or 802.1x is added, in the case of VoIP, the echo and delay may become stronger depending on the distance, and these problems may be solved.

1 is a block diagram of a header compression apparatus applied to a radio link according to the present invention.
2 is a flowchart of a header compression method optimized for a radio link according to the present invention.
3 is a diagram illustrating a header compression environment of a WLAN according to an embodiment of the present invention.
4 is a view showing a state change according to channel status and priority of a radio link according to an embodiment of the present invention.
5 is a block diagram of a transmitting and receiving end according to an embodiment of the present invention.

Hereinafter, 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 the detailed description of related known functions or known configurations or obvious matters to those skilled in the art may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

As shown in FIG. 1, the header compression device optimized for a wireless link according to the present invention is a header compression device 100 optimized for a wireless link in a packet data communication system, and transmits packet data to be coded and transmitted. A header compression determining unit 110 for determining a header compression transmission method based on state information, priority information of packet data to be transmitted, and round trip time (RTT) information; ; A header compression unit 120 for header-packing the packet data according to the determination of the header compression determination unit 110; A transmission unit 130 for transmitting the packet data compressed by the header compression unit 120; Receiving unit 140 for receiving the packet data transmitted from the transmitting unit 230 of the other header compression apparatus 200 when receiving; A header compression determination unit 150 for determining a header compression transmission method of the packet data received from the reception unit 140; The header compression determining unit 150 includes a header decompression unit 160 for decompressing the received packet data.

Here, the header compression transmission method may include a header compression (HC) method for transmitting header compressed packet data, a PHC (periodic HC) method for transmitting header compressed packet data periodically, and a header uncompressed. Characterized in that any one of the NHC (Non-HC) method for transmitting packet data. For reference, there are various types of header compression techniques, including the initial model TCT / IP header compression scheme, header compression scheme applied with Real Time Protocol (RTP), which is a protocol for multimedia streams, ROHC (Roburst Header Compression) technique. According to the present invention, the number of packets discarded according to an error of a link is compensated for the disadvantages of the compressed compression (CRTP) and the enhanced compressed RTP (ECRTP) headers of the existing multimedia streaming protocol RTP. It is possible to maintain stable stream state of packet data by minimizing the number and to use the limited wireless channel bandwidth more efficiently. Here, the period of sending the full header in the PHC method of the header compression transmission method may be designed differently according to the error rate of the channel.

In addition, the state information of the radio link includes low error rate (LER) state information in which the channel characteristics of the link are stable because the error rate is lower than the setting range, and HER in which the channel characteristic of the link is unstable because the error rate is higher than the setting range. (High error rate) status information and the NER (Normal error rate) status information in which the channel characteristics of the link are in a basic state when the error rate is within a setting range.

The priority information may be any one of realtime packet information and non-realtime packet information. Here, the priority information refers to information that is a reference for ordering the tasks when there are several tasks to be processed by a system. For example, packet data to be coded and transmitted through an encoder You can check through

The round trip time information may be one of first information within a set threshold time and second information exceeding a set threshold time. Here, the round trip time is the time from when the packet is transmitted from the transmitting side to the receiving side through any number of intermediate ports or communication networks, and then the response signal reaches the transmitting side again through a plurality of intermediate ports or communication networks. Means.

As an example, as shown in Table 1 below, the header compression determining unit 110 includes the state information of the radio link when the round trip time information is the first information and the priority information is the real time packet information. Therefore, if the NER status information, the header compression transmission method is determined by the HC method, if the LER status information, the header compression transmission method is determined by the HC method, and if the HER status information, the header compression transmission method is determined by the PHC method. In addition, when the round trip time information is the first information and the priority information is the non-real time packet information, the header compression transmission method is determined by the HC method if the NER status information is based on the status information of the radio link, and the header compression is the LER status information. The transmission method is determined by the HC method, and if the HER status information, the header compression transmission method is determined by the PHC method. In addition, when the round trip time information is the second information and the priority information is the real time packet information, the header compression transmission method is determined by the HC method when the NER status information is according to the status information of the radio link, and when the LER status information, the header compression transmission is performed. The method determines the PHC method, and if the HER status information, the header compression transmission method is determined as the NHC method. In addition, when the round trip time information is the second information and the priority information is the non-real time packet information, the header compression transmission method is determined by the HC method if the NER status information is based on the status information of the radio link, and the header compression is the LER status information. The transmission method is determined by the PHC method, and if the HER status information, the header compression transmission method is determined by the NHC method.

Round trip time Priority Status of the link Header compression transmission method

First information (within threshold time)
Realtime NER HC LER HC HER PHC
Non-Realtime NER HC LER HC HER PHC

Secondary information (threshold timeout)
Realtime NER HC LER PHC HER NHC
Non-Realtime NER HC LER PHC HER NHC

(Table 1] shows an embodiment of a header compression transmission method according to a communication state in a wireless link.

The header compression unit 120 is designed to execute all three types of header compression according to the header compression transmission method (HC, PHC, NHC), and performs header compression by the header compression determining unit 110. In addition, the header decompression unit 160 is also operated by the header compression determination unit 150, it is designed to perform all the decompression according to the three header compression schemes.

The present invention is made in the data link layer and the network layer of the OSI (Open Systems Interconnection) 7 layer in the packet data communication system, and the transmitting and receiving ends are each configured to compress and restore (decompress) the header. In addition, there is a classifier (or header compression determining unit) related to header compression, which checks the status of the link and accordingly, checks the priority and round trip time of each packet to determine which header compression transmission scheme. It has the ability to determine if it should be applied.

Currently used IP protocol basically uses Real Time Protocol (RTP) for real time communication such as Transport Control Protocol (TCP), User Datagram Protocol (UDP), and VoIP. For example, for real-time communication for VoIP, the header size is RTP 12 bytes, UDP 8 bytes, and IP 20 bytes. In case of 8Kbps G.729 codec which is widely used in VoIP, payload size is 20 bytes. Considering the overhead to the network layer, the default header size of IP / UDP / RTP for transmitting this G.729 payload is 40 bytes, which is twice the overhead of data. As with most real-time services, the large overhead of services with less data compared to the header causes the bandwidth efficiency of the network to decrease. If the header is larger than the data, the header compression technique can reduce a lot of overhead and can be very helpful in the bandwidth efficiency of the network.

Example 1

As a preferred embodiment, header compression can be applied to various applications using link efficiency, which is the biggest advantage. Wide area network (WAN), which can be applied to satellite or cellular network with high error rate and delay rate, PPP network or general telephone network supporting low bandwidth, and has to consider cost with relatively high bandwidth and large amount of data traffic. May be applied in the case. Consider the case of 802.11 WLAN, which is widely used among these various application networks. In the case of WLAN, the error rate is high and packet loss is significantly larger than that of a wired network. In addition, the bandwidth is fixed, so there is a need to improve efficiency performance for overhead. The use of compressed headers lowers the overhead rate, thereby lowering the error rate and reducing the packet loss rate.

3 is a conceptual diagram illustrating a header compression environment of a WLAN according to an embodiment of the present invention. An example of a voice packet used in voice over IP (VoIP) in an error recovery scheme in an 802.11 WLAN environment as shown in FIG. For example, the packet 312 coming into the last router 310 through various paths has an overhead rate of about 75% compared to the 20-byte payload with 60 bytes in the case of IPv6 / UDP / RTP. . In case of IPv4 / UDP / RTP, the header size is 40 bytes and shows an overhead rate of about 67%. Here, the router 310 may provide a quality of service (QoS) through traffic classes and flow label fields among various fields of the IPv6 field. The received packet 312 is sent to the AP 320 through a queue, and the AP 320 including the header compression function transmits the received packet to a CID (see the context table). Context Identification) is added to the terminal 330 via a wireless channel. Header compression occurs between the compressor and the decompressor, and the AP 320 should have both a compressor and a decompressor function. In addition, like the AP 320, the terminal 330 needs both functions. However, in the case of WLAN, the header compression technique is not easy due to the high error rate and loss rate due to fading or interference. In addition, compared to a wired network, the channel state has a higher probability of change, making it difficult to maintain synchronization between transmitters and receivers. Therefore, in the 802.11 WLAN environment, the compressor and decompressor must maintain strong synchronization against packet error or loss, and if the synchronization maintaining the context is lost, the number of discarded packets should be minimized through fast error recovery. To this end, the error recovery scheme maintains faster error recovery by displaying channel characteristics of the data link layer, and provides a more stable channel environment for prioritized packets through mode conversion of the compressor according to channel characteristics. . Here, since the header compression technique is well known, a detailed description thereof will be omitted.

(Packet priority applied)

In IPv6, basically, QoS of a packet is provided through a traffic class field and a flow label field. Based on this, priority can be applied to apply packet policy to each service of subscriber, and the standard is left to service provider's policy. Here, we will apply two packet characteristics associated with the error rate in the link layer. One is a non-real time packet, which is insensitive to delay or loss, and the other is a high priority packet which is sensitive to delay or packet loss and provides a stable service. To distinguish between these two characteristics, the Traffic Classes field is used in the header field of IPv6. The classifier recognizes information about the characteristics of the channel from the link layer, determines the state of the compressor to be converted by grasping the contents of the traffic class field before compression. Depending on the state of the channel, the compressor will switch between two modes. 4 illustrates two states.

4 is a view showing a state change according to the channel state and priority of the radio link according to an embodiment of the present invention, "LER STATE" is a low error rate state can be said that the channel characteristics are stable, "HER STATE "is a state of High Error Rate which indicates that the characteristics of the channel are high and unstable. The identifier (Classfier) compares the two states with priority information of IPv6, and indicates which mode the compressor should switch to.

(Compressor conversion function)

Existing compressors basically compress the header and store the information about it in the context table. If an error occurs, the context information is used to resynchronize with the decompressor. Compressor can perform both modes, PHC mode and HC mode, the conversion of this mode is determined by the determination of the identifier (Classfier). By default, "LER STATE" supports "HC" mode. This is because the error rate is extremely small and stable service is possible for high priority or real time packets. Furthermore, if possible, it should be operated in "HC" mode by default to get the most out of the bandwidth.

5 is a block diagram of a transmitter / receiver according to an embodiment of the present invention, and shows a state in which a compressor has both a function of an identifier (Classfier), a function of a “PHC” mode and a “HC” mode. If the error rate is high in the case of delay-sensitive real-time packets or high priority packets, the identifier (Classfier) is determined by "HER STATE" and accordingly the mode change is requested to the compressor. The compressor will switch to "PHC" mode to provide more reliable service. At this time, the period of sending the full header may be set differently according to the error rate of the channel.

Meanwhile, as shown in FIG. 2, the header compression method optimized for the radio link according to the present invention is a header compression method optimized for the radio link in a packet data communication system, and the header compression determination unit 110 is coded and transmitted. Determining a header compression transmission method based on the state of the radio link, the priority information of the packet data to be transmitted, and the round trip time (RTT) information Step S10; A header compression unit (120) compressing the packet data according to the determination of the header compression determination unit (110) (S20); Transmitting, by the transmission unit 130, the packet data compressed by the header compression unit 120 (S30); Receiving, by the receiver 140, packet data transmitted from the other transmitter 230 (S40); Determining, by the header compression determining unit 150, a header compression transmission method of the packet data received from the receiving unit (S50); The header decompressing unit 160 decompresses the received packet data according to the determination of the header compression determining unit (S60).

Here, the header compression transmission method may include a header compression (HC) method for transmitting header compressed packet data, a PHC (periodic HC) method for transmitting header compressed packet data periodically, and a header uncompressed. It means any one of the NHC (Non-HC) method of transmitting the packet data.

In addition, the state information of the radio link includes low error rate (LER) state information in which the channel characteristics of the link are stable because the error rate is lower than the setting range, and HER in which the channel characteristic of the link is unstable because the error rate is higher than the setting range. (High error rate) means either one of state information and NER (Normal error rate) state information in which the channel characteristics of the link are in a basic state when the error rate is within a setting range.

The priority information may be any one of realtime packet information and non-realtime packet information, and the round trip time information may include first information within a predetermined threshold time and second information exceeding a predetermined threshold time. It means any one of.

In addition, the step (S10) of determining the header compression transmission scheme, as shown in Table 1, when the round trip time information is the first information, the priority information is the real-time packet information, wireless In case of NER status information, the header compression transmission method is determined by HC method. In case of LER status information, header compression transmission method is determined by HC method. In case of HER status information, header compression transmission method is determined by PH method. . In addition, when the round trip time information is the first information and the priority information is the non-real time packet information, the header compression transmission method is determined by the HC method if the NER status information is based on the status information of the radio link, and the header compression is the LER status information. The transmission method is determined by the HC method, and if the HER status information, the header compression transmission method is determined by the PHC method. In addition, when the round trip time information is the second information and the priority information is the real time packet information, the header compression transmission method is determined by the HC method when the NER status information is according to the status information of the radio link, and when the LER status information, the header compression transmission is performed. The method determines the PHC method, and if the HER status information, the header compression transmission method is determined as the NHC method. Finally, if the round trip time information is the second information and the priority information is the non-real time packet information, the header compression transmission method is determined by the HC method if the NER status information is based on the status information of the radio link, and the header compression is the LER status information. The transmission method is determined by the PHC method, and if the HER status information, the header compression transmission method is determined by the NHC method.

According to the present invention as described above, by applying the header compression transmission method in accordance with the communication state of the radio link in the packet data communication system, it is possible to improve the bandwidth efficiency and compression efficiency. In particular, the header compression transmission scheme starts with the intention of efficiently using limited bandwidth resources, which is closely related to the efficient use of radio resources. In the case of a low bandwidth mobile communication network, the use of this technology can provide a multimedia service with sufficient image quality and sound quality in response to user demand. In addition, even in the case of wireless LAN, if security such as WEP or 802.1x is added, in the case of VoIP, the echo and delay may become stronger depending on the distance, and these problems may be solved.

In the above, the present invention has been described with reference to the drawings and embodiments, but the present invention is not limited to the specific embodiments, and those skilled in the art can make many modifications and variations without departing from the scope of the present invention. I will understand what is possible. In addition, the drawings are shown for the purpose of understanding the invention and should not be understood to limit the scope of the claims.

100, 200: header compressor 110, 210: header compression determiner
120, 220: header compression unit 130, 230: transmission unit
140, 240: receiver 150, 250: header compression determination unit
160, 260: header decompression unit

Claims (10)

delete delete delete A header compression device optimized for a radio link in a packet data communication system,
Based on the state information of the radio link, the priority information of the packet data to be transmitted, and the round trip time (RTT) information, packet compression to be coded and transmitted is transmitted based on header compression. A header compression (HC) determination unit for determining a;
A header compression unit for header compressing the packet data according to the determination of the header compression determination unit;
A transmission unit for transmitting the packet data compressed by the header compression unit;
Receiving unit for receiving the packet data transmitted from the other side transmission unit when receiving;
A header compression determining unit determining a header compression transmission method of the packet data received from the receiving unit;
A header decompression unit for decompressing the received packet data according to the determination of the header compression determination unit;
The header compression transmission method includes a HC (Header Compression) method for transmitting header compressed packet data, a PHC (Periodic HC) method for transmitting a header compressed packet data periodically, and a header uncompressed packet data. It is one of the NHC (Non-HC) method for transmitting a,
The state information of the radio link includes low error rate (LER) state information in which the channel characteristics of the link are stable because the error rate is lower than the setting range, and HER (High) in which the channel characteristic of the link is unstable because the error rate is higher than the setting range. error rate) status information and the NER (Normal Error Rate) status information in which the channel characteristics of the link are in a basic state when the error rate is within a setting range,
The priority information is any one of real time packet information and non-realtime packet information.
The round trip time information is any one of first information within a set threshold time and second information exceeding a set threshold time.
The header compression determiner,
When the round trip time information is the first information and the priority information is the real time packet information, the header compression transmission method is determined by the HC method when the NER status information is based on the status information of the radio link, and when the LER status information, the header compression is performed. The transmission method is determined by the HC method, if the HER status information, the header compression transmission method is determined by the PHC method,
When the round trip time information is the first information and the priority information is the non-real time packet information, the header compression transmission method is determined by the HC method when the NER status information is according to the status information of the radio link, and when the LER status information, the header is determined. And the compression transmission method is determined by the HC method, and the header compression transmission method is determined by the PHC method if the HER state information. A header compression device optimized for a radio link in a packet data communication system,
Based on the state information of the radio link, the priority information of the packet data to be transmitted, and the round trip time (RTT) information, packet compression to be coded and transmitted is transmitted based on header compression. A header compression (HC) determination unit for determining a;
A header compression unit for header compressing the packet data according to the determination of the header compression determination unit;
A transmission unit for transmitting the packet data compressed by the header compression unit;
Receiving unit for receiving the packet data transmitted from the other side transmission unit when receiving;
A header compression determining unit determining a header compression transmission method of the packet data received from the receiving unit;
A header decompression unit for decompressing the received packet data according to the determination of the header compression determination unit;
The header compression transmission method includes a HC (Header Compression) method for transmitting header compressed packet data, a PHC (Periodic HC) method for transmitting a header compressed packet data periodically, and a header uncompressed packet data. It is one of the NHC (Non-HC) method for transmitting a,
The state information of the radio link includes low error rate (LER) state information in which the channel characteristics of the link are stable because the error rate is lower than the setting range, and HER (High) in which the channel characteristic of the link is unstable because the error rate is higher than the setting range. error rate) status information and the NER (Normal Error Rate) status information in which the channel characteristics of the link are in a basic state when the error rate is within a setting range,
The priority information is any one of real time packet information and non-realtime packet information.
The round trip time information is any one of first information within a set threshold time and second information exceeding a set threshold time.
The header compression determiner,
When the round trip time information is the second information and the priority information is the real time packet information, the header compression transmission method is determined by the HC method when the NER status information is based on the state information of the radio link, and when the LER status information, the header compression is performed. The transmission method is determined by the PHC method, if the HER status information, the header compression transmission method is determined by the NHC method,
When the round trip time information is the second information and the priority information is the non-real time packet information, the header compression transmission method is determined by the HC method when the NER status information is according to the status information of the radio link, and when the LER status information, the header is determined. And a compression transmission method is determined by the PHC method, and if the HER state information, the header compression transmission device is optimized for the wireless link, characterized in that for determining the NHC method. delete delete delete A header compression method optimized for a radio link in a packet data communication system,
Based on the state information of the radio link, the priority information of the packet data to be transmitted, and the round trip time (RTT) information, the header compression determining unit is coded to transmit the packet data to be coded. Determining a header compression transmission scheme;
Header compressing, by a header compression unit, the packet data according to a determination of the header compression determination unit;
Transmitting, by a transmission unit, packet data compressed by the header compression unit;
Receiving, by the receiver, packet data transmitted from the other transmitter;
Determining, by a header compression determining unit, a header compression transmission method of packet data received from the receiving unit;
And decompressing, by the header decompression unit, the received packet data according to the determination of the header compression determination unit.
The header compression transmission method includes a HC (Header Compression) method for transmitting header compressed packet data, a PHC (Periodic HC) method for transmitting a header compressed packet data periodically, and a header uncompressed packet data. It is one of the NHC (Non-HC) method for transmitting a,
The state information of the radio link includes low error rate (LER) state information in which the channel characteristics of the link are stable because the error rate is lower than the setting range, and HER (High) in which the channel characteristic of the link is unstable because the error rate is higher than the setting range. error rate) status information and the NER (Normal Error Rate) status information in which the channel characteristics of the link are in a basic state when the error rate is within a setting range,
The priority information is any one of real time packet information and non-realtime packet information.
The round trip time information is any one of first information within a set threshold time and second information exceeding a set threshold time.
Determining the header compression transmission method,
When the round trip time information is the first information and the priority information is the real time packet information, the header compression transmission method is determined by the HC method when the NER status information is based on the status information of the radio link, and when the LER status information, the header compression is performed. The transmission method is determined by the HC method, if the HER status information, the header compression transmission method is determined by the PHC method,
When the round trip time information is the first information and the priority information is the non-real time packet information, the header compression transmission method is determined by the HC method when the NER status information is according to the status information of the radio link, and when the LER status information, the header is determined. The compression compression method is determined by the HC method, and if the HER status information, the header compression method optimized for the radio link, characterized in that for determining the header compression transmission method to the PHC method. A header compression method optimized for a radio link in a packet data communication system,
Based on the state information of the radio link, the priority information of the packet data to be transmitted, and the round trip time (RTT) information, the header compression determining unit is coded to transmit the packet data to be coded. Determining a header compression transmission scheme;
Header compressing, by a header compression unit, the packet data according to a determination of the header compression determination unit;
Transmitting, by a transmission unit, packet data compressed by the header compression unit;
Receiving, by the receiver, packet data transmitted from the other transmitter;
Determining, by a header compression determining unit, a header compression transmission method of packet data received from the receiving unit;
And decompressing, by the header decompression unit, the received packet data according to the determination of the header compression determination unit.
The header compression transmission method includes a HC (Header Compression) method for transmitting header compressed packet data, a PHC (Periodic HC) method for transmitting a header compressed packet data periodically, and a header uncompressed packet data. It is one of the NHC (Non-HC) method for transmitting a,
The state information of the radio link includes low error rate (LER) state information in which the channel characteristics of the link are stable because the error rate is lower than the setting range, and HER (High) in which the channel characteristic of the link is unstable because the error rate is higher than the setting range. error rate) status information and the NER (Normal Error Rate) status information in which the channel characteristics of the link are in a basic state when the error rate is within a setting range,
The priority information is any one of real time packet information and non-realtime packet information.
The round trip time information is any one of first information within a set threshold time and second information exceeding a set threshold time.
Determining the header compression transmission method,
When the round trip time information is the second information and the priority information is the real time packet information, the header compression transmission method is determined by the HC method when the NER status information is based on the state information of the radio link, and when the LER status information, the header compression is performed. The transmission method is determined by the PHC method, if the HER status information, the header compression transmission method is determined by the NHC method,
When the round trip time information is the second information and the priority information is the non-real time packet information, the header compression transmission method is determined by the HC method when the NER status information is according to the status information of the radio link, and when the LER status information, the header is determined. The compression compression method is determined by the PHC method, if the HER status information, the header compression method optimized for the radio link, characterized in that for determining the header compression transmission method to NHC method.

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