KR20080019143A - The method and apparatus for transmitting robust header compression feedback message in ieee 802.16 - Google Patents

Abstract

A method and an apparatus for transmitting an ROHC feedback message in a communication system are provided to transmit the ROHC feedback message more efficiently by using a management message or a preset reverse CID, and ensure the minimum transmission rate of the ROHC feedback message through a QoS(Quality of Service) parameter related with the ROHC feedback message transmission. A method for transmitting an ROHC(Robust Header Compression) feedback message in a communication system comprises the following steps of: determining whether the ROHC feedback message is included in received packet data if the packet data in which ROHC compression is performed is received(1400,1410); and if so, mapping a context identifier of the feedback information with a reverse CID(Connection Identifier) which will transmit the feedback message(1415).

Description

Method and Apparatus for Transmitting Robust Header Compression Feedback Message In IEEE 802.16}

1 is a diagram illustrating a general wireless communication system.

2 shows a general MAC PDU.

3 shows a transition between typical ROHC operating modes.

4 is a view illustrating a state transition of a compression unit in a general bidirectional positive mode.

5 is a diagram illustrating a state transition of a compression unit that is a general bidirectional reliable mode.

6 illustrates the format of a typical ROHC feedback message.

7 shows the format of general feedback data.

8 shows the format of a general feedback field 1. FIG.

9 shows the format of a general feedback field 2. FIG.

10 shows an example of general RTP feedback.

11 is a block diagram of a base station according to an embodiment of the present invention.

12 is a block diagram of a terminal according to an embodiment of the present invention.

13A is a table illustrating a format of a ROHC feedback message according to a first embodiment of the present invention.

13B is a table showing a ROHC feedback message description according to the first embodiment of the present invention.

14 is a flowchart illustrating the classification / CID mapping / PHS block operation of a base station or a terminal according to the first embodiment of the present invention.

FIG. 15 is a view illustrating Table 383, which is a service flow encoding parameter table of the IEEE 802.16 standard, according to the second embodiment of the present invention.

16 is a diagram showing a set of service QoS parameters of the IEEE 802.16 standard according to the second embodiment of the present invention.

FIG. 17 illustrates a TLV encoding standard with parameters added according to a second embodiment of the present invention. FIG.

18A is a diagram illustrating QoS parameters of an admission service according to a second embodiment of the present invention.

18B illustrates QoS parameters of a real-time variable rate service according to a second embodiment of the present invention.

FIG. 18C illustrates QoS parameters of a non real-time variable rate service according to a second embodiment of the present invention. FIG.

FIG. 18D illustrates QoS parameters of a best effort service according to a second embodiment of the present invention. FIG.

18E illustrates a confirmed real-time variable rate service QoS parameter according to a second embodiment of the present invention.

19 is a flowchart illustrating operations of the classification / CID mapping / PHS block of a base station or a terminal according to the second embodiment of the present invention.

20 is a flowchart of a scheduler of a terminal and a base station according to the second embodiment of the present invention.

The present invention relates to a method and apparatus for providing a ROHC feedback message in a communication system.

For example, the present invention will be described in the case of an IEEE 802.16 system.

1 illustrates a general wireless communication system.

Referring to FIG. 1, the base station 100 communicates with a terminal # 1 110, a terminal # 2 120, and a terminal # 3 130 through a wireless shared channel. That is, the base station 100 transmits the packet data arriving from the wired network to the corresponding terminal through the wireless shared channel. In addition, the packet data generated by the terminal is transmitted to the base station via a wireless shared channel.

2 is a diagram illustrating a general MAC PDU.

Referring to FIG. 2, the MAC Access Control Protocol Data Unit (hereinafter referred to as 'MAC PDU') includes a MAC header 210, an IP (Internet Protocol) / UDP (User Data Protocol) / RTP (Real). Time Protocol) header 220 and a pay load (230). The payload 230 corresponds to voice data, and the MAC PDU has another type of header such as a transmission control protocol (IP / TCP) header according to the type and protocol of data transmitted and received between the base station and the terminal.

Hereinafter, the present invention will be described based on the IP / UDP / RTP header, but the present invention can be similarly applied to other types of header configurations.

For example, in the case of Voice over Internet Protocol (VoIP) technology, the size of the IP / UDP / RTP 220 header is large compared to the size of the payload 230 so that wireless bandwidth is wasted. Therefore, a method of compressing the header is used to reduce the size of the header. That is, in order to compress the header, the packet sender compresses the IP / UDP / RTP header to reduce the size of the header and transmits the packet. The packet receiver decompresses the received packet and restores the IP / UDP / RTP header before compression. The packet sender includes a compression unit for reducing the size of a packet header, and the packet receiver includes a recovery unit for recovering the compressed header.

One such header compression method is the Robust Header Compression (hereinafter referred to as ROHC) method.

3 is a diagram illustrating a transition between typical ROHC operation modes.

Referring to FIG. 3, the ROHC includes a unidirectional mode (indicated by 'U' in the drawing) 300, a bidirectional optimal mode (indicated by 'O' in the drawing) 310, and bidirectional. It has three operation modes (Bidirectional Reliable Mode, denoted by 'R' in the figure) 320.

The bidirectional positive mode 310 and the bidirectional reliable mode 320 transmit a feedback message for informing whether the received data is properly received to the compression unit. On the other hand, the unidirectional mode 330 does not transmit the feedback message to the compression unit.

Accordingly, the bidirectional positive mode 310 and the bidirectional reliable mode 320 compress the header more reliably and effectively than the single direction mode 300 by transmitting the feedback information to the compression unit.

The compression unit and the reconstruction unit operate in the same operation mode, and transition between the operation modes according to whether a feedback channel is available, an error probability, and a distribution. The transition between the operation modes is started by a feedback message of the restoration unit.

The feedback message includes an acknowledgment (NACK) message, a none acknowledge (NACK) message, and a STATIC-NACK message. The ACK (acknowledge) message means that the header of the packet data received by the decompression unit is successfully restored. That is, the ACK message means that the context of the received packet data has a high probability of being up-to-date information. The NACK message indicates that the dynamic context of the packet data received by the decompression unit has lost synchronization, and that a plurality of consecutive packet data failed to be correctly restored. STATIC-NACK means that the static context of the packet data in the restoration unit is not valid or established.

The feedback message is used not only for transition between operation modes, but also for state transition in each operation mode. The compression unit and the restoration unit operate while transitioning three states in each operation mode.

The compression unit initializes and refreshes (hereinafter referred to as 'IR') state, first order (hereinafter referred to as 'FO') state, and second order (Second Order) state in each operation mode. It is operated with three states, hereinafter referred to as 'SO'. The recovery unit operates in three modes with three contexts: a no context state, a static context state, and a full context state.

As described above, the unidirectional mode operates without a feedback message, but the bidirectional positive mode and the bidirectional reliable mode use the feedback message to transition states in each operation mode.

4 is a diagram illustrating a state transition of a compression unit in a general bidirectional positive mode.

Referring to FIG. 4, the compression unit of the IR state 400 transitions from the restoring unit to the FO state 420 or the SO state 430 using an ACK message (410). The compression unit of the FO state 410 uses the STATIC-NACK message 415 when the transition to the IR state 400, and uses the ACK message 425 when transitioning to the SO state 430. The compression unit of the SO state 430 uses an ACK message 445 when the SO state 430 is maintained, and uses a STATIC-NACK message 440 when transitioning to the IR state 400.

5 is a diagram illustrating a state transition of a compression unit that is a general bidirectional reliable mode.

Referring to FIG. 5, the compression unit of the IR state 500 uses the ACK message 515 when transitioning to the FO state 520 or the SO state 535. The compression unit of the FO state 520 uses the ACK message 525 when transitioning to the SO state 535 and the STATIC-NACK message 520 when transitioning to the IR state 500. The compression unit of the SO state 530 uses an ACK message 535 when maintaining the current state, and uses a STAIC-NACK message 545 when transitioning to the IR state 500.

6 is a diagram illustrating a format of a general ROHC feedback message.

Referring to FIG. 6, the ROHC feedback message starts with a predetermined specific code value “11110” and a code field, and the feedback data is configured after the size field of the feedback data. The feedback data type is represented by an octet value. If the code is '0', it indicates that there is a current octet size, and if the code is '1-7', it indicates the size of the feedback data field. The feedback data includes feedback information and context identifier information of the flow.

7 illustrates a general format of feedback data.

Referring to FIG. 7, the feedback data includes a feedback field next to the context ID information field of the flow.

8 and 9 illustrate the format of a general feedback field.

The feedback field has a form of 'FeedBACK-1' which always means ACK as shown in FIG. 8, an ACK type field indicating ACK, NACK, and STATIC-NACK as shown in FIG. 9, and a mode indicating an operation mode. Field and a 'FeedBACK-2' including a sequence number field.

10 is a diagram illustrating an example of general RTP feedback.

Referring to FIG. 10, when a small CID is used, feedback data has a length of 3 bytes, a context ID of 8, an Ack type of ACK, a mode of bidirectional reliable mode, and an RTP sequence number of 17.

As described above, for effective header compression in the ROHC protocol, it is essential for the demodulator to send feedback messages such as ACK, NACK, and STATIC-NACK to the compression unit in the transition between states and between modes of operation.

Meanwhile, a transport connection identifier (hereinafter referred to as a "transport CID") is defined to transmit traffic in the MAC layer of the communication system. Since the transmission CID is defined only in one direction, in order to perform ROHC compression for traffic transmitted in a specific 'transmission CID', a reverse CID for transmitting the ROHC feedback message is required. In addition, when a reverse transmission connection of a ROHC feedback message is transmitted, the reverse transmission connection should be performing ROHC compression. In addition, in order to smoothly transmit the ROHC feedback message, an appropriate service class and quality of service (hereinafter referred to as 'QoS') parameter definition is required.

However, in the IEEE 802.16 system, the following problems may occur because there is no specification of the reverse connection of the ROHC feedback message, that is, the priority and service class of the feedback message transmission.

First, if there is no transport connection in which the ROHC is operating in the reverse direction, there is no transport connection for delivering the ROHC feedback message. Therefore, when the feedback message cannot be delivered, there is a problem that the ROHC operation is performed only in the unidirectional mode.

Next, even if there is a transport connection in which the ROHC is operating in the reverse direction, if the service class of the transport connection is lower than the service class of the transport connection for the traffic, the feedback message is not desired and system performance is not desired. There was a problem falling.

Accordingly, an object of the present invention, which was devised to solve the problems of the prior art operating as described above, is to provide a method and apparatus for effective transmission of an ROHC feedback message in a communication system.

In accordance with a first aspect of the present invention, a method for providing a robust header compression (ROHC) feedback message in a communication system is provided.

Determining whether the packet data is an ROHC feedback message when receiving packet data on which ROHC compression has been performed;

And if the ROHC feedback message is included in the check result, mapping a context identifier of the feedback information and a reverse link identifier to transmit the feedback message.

The method according to the second embodiment of the present invention, which is designed to achieve the above object, in the method for providing a robust header compression (ROHC) feedback message in a communication system,

Determining whether an ROHC feedback message is included in the packet data when receiving the packet data in which the ROHC compression is performed;

If it is determined that the ROHC feedback message is included, checking connection identifiers capable of transmitting the ROHC feedback message with the context identifier of the ROHC feedback message;

And selecting the same connection identifier as the traffic service class of the received packet data among the service classes of the checked connection identifiers, and mapping the context identifier of the feedback message to the selected connection identifier.

An apparatus according to the first embodiment of the present invention, in the apparatus for providing a robust header compression (ROHC) feedback message in a communication system,

When receiving the packet data in which the ROHC compression is performed, it is determined whether the ROHC feedback message is included in the packet data,

If the test result includes a ROHC feedback message, it characterized in that it comprises a classification block for mapping the context identifier of the feedback information and the reverse link identifier to transmit the feedback message.

According to a second aspect of the present invention, there is provided an apparatus for providing a robust header compression (ROHC) feedback message in a communication system.

When receiving the packet data in which the ROHC compression is performed, it is determined whether the ROHC feedback message is included in the packet data,

If the ROHC feedback message is included as a result of the checking, the connection identifiers capable of transmitting the ROHC feedback message with the context identifier of the ROHC feedback message are examined.

And a classification block for selecting the same connection identifier as the traffic service class of the received packet data from among the service classes of the checked connection identifiers and mapping the context identifier of the feedback message to the selected connection identifier. .

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. Like reference numerals refer to the same elements as shown in the drawings, even though they may be shown on different drawings, and in the following description, detailed descriptions of related well-known functions or configurations are unnecessary. If it is determined that it can be blurred, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

11 is a configuration diagram of a base station according to an embodiment of the present invention.

Referring to FIG. 11, the base station includes a packet transmission / reception block 1100, an ROHC engine 1110 including an ROHC compression unit 1112 and an ROHC recovery unit 1114, and classification / CID mapping / PHS (Payload). Header Suppression block 1120, MAP / PDU / Burst generation block 1130, packet scheduler 1140, ranging / CQI (channel quality ACK) hereinafter, 'CQI A processing block 1160, a PDU / burst processing block 1180, an encoding / modulation block 1190, and a decoding / demodulation block 1195.

First, the operation of each block when the base station receives packet data from the network will be described.

The packet reception / transmission block 1100 receives packet data from a network and transfers the packet data to the ROHC compression unit 1112. The ROHC compression unit 1114 determines whether to apply the ROHC to the packet data. In this case, the packet to which the ROHC is applied is subjected to IP / UDP / RTP header compression based on context information, and then delivered to the classification / CID mapping / PHS block 1120, and the packet to which the ROHC is not applied is a header. Pass to classification / CID mapping / PHS block 1120 without compression. The classification / CID mapping / PHS block 1120 classifies the packet and maps the packet to a corresponding CID, and is responsible for payload, that is, header suppression of a MAC service data unit (SDU). Here, the operation of mapping the CID will be described later in detail.

The MAP / PDU / burst generation block 1130 generates a MAC PDU by attaching a MAC header to the payload of the MAC PDU, and generates a burst composed of one or more MAC PDUs. The MAC header includes CID information. The encoding / modulation block 1190 performs encoding and modulation on the burst and transmits it to a subscriber station.

Next, the case where the base station receives the packet data from the terminal will be described.

The decoding / demodulation block 1195 receives packet data from the terminal, performs decoding and demodulation, and then transfers the packet data to the PDU / burst processing block 1180. The PDU / burst processing block 1180 separates the packet data into a payload and a CID and transfers the packet data to a classification / CID mapping / PHS block 1120. The classification / CID mapping / PHS block 1120 restores the header suppressed in the payload and transfers the header to the ROHC recovery unit 1114. The ROHC decompression unit 1114 determines whether the packet is ROHC compressed, and restores the header if the packet is a compressed header. In this case, the ROHC feedback is transmitted to the ROHC compression unit 1112 during the header restoration process, and the remaining packets except for the ROHC feedback are transmitted to the packet transmission / reception block 1100.

12 is a block diagram of a terminal according to an embodiment of the present invention.

Referring to FIG. 12, the terminal includes a higher layer processing block 1200, a ROHC engine block 1210 including a ROHC compression unit 1212 and a ROHC demodulator 1214, and a classification / CID mapping / PHS block 1220. ), UL scheduler 1230, PDU / burst generation block 1235, ranging / CQI / ACK block 1240, MAP decoder 1245, PDU / burst processing block 1250, encoding / Modulation block 1260 and decoding / demodulation block 1270.

First, the operation when the terminal receives the packet data from the base station will be described.

The decoding / demodulation block 1270 receives a signal from a base station, decodes and demodulates the signal, passes the result to the PDU / burst processing block 1250, and transfers MAP information to the MAP decoder 1245. The MAP decoder 1245 transfers downlink allocation information interpreted from the signal to the decoding / demodulation block 1270 and generates uplink allocation information interpreted from the signal to generate the PDU / burst. Transfer to block 1235 and ranging / CQI / ACK block 1240.

The decoding / demodulation block 1270 decodes / demodulates the received burst with the downlink allocation information. The PDU / burst processing block 1250 separates the MAC SDU from the MAC PDU and transmits the MAC SDU to the classification / CID mapping / PHS block 1220 together with the corresponding CID information. The classification / CID mapping / PHS block 1220 restores the suppressed header of the burst and delivers it to the ROHC demodulator 1214. The ROHC demodulator 1214 demodulates the packet to which the ROHC compression is applied among the MAC PDUs whose headers are recovered. During the demodulation process, the ROHC feedback is transmitted to the ROHC compression unit 1212, and the remaining packets from which the ROHC feedback is removed are transmitted to the upper layer processor 1200.

Next, an operation of processing a packet to be transmitted to the base station by the terminal will be described.

The ROHC compression unit 1212 performs compression when the packet applies the ROHC, and transfers the packet directly to the classification / CID mapping / PHS block 1220 when the ROHC is not applied. The classification / CID mapping / PHS block 1220 classifies MAC SDUs (IP Packets) in the packet and maps them to CIDs, performs payload header suppression, and then maps the MAC SDUs and CID information mapped thereto. Transfer to burst generation block 1255.

The uplink scheduler 1230 is provided with the uplink allocation information received from the MAP decoder 1245 and the uplink packet queue length information for each connection received from the PDU / burst generation block 1255. Based on the PDU size and burst size. Here, the operation of the uplink scheduler 1230 will be described in detail below. The PDU / burst generation block 1255 generates the PDU / burst according to the scheduling result of the UL scheduler 1230. The encoding / modulation block 1260 encodes and modulates the generated burst to generate a signal to be transmitted to a base station.

Hereinafter, the present invention proposes two embodiments of transmitting an ROHC feedback message in the case of an IEEE 802.16 system. It is also possible to use only one embodiment of the two embodiments, or to use both embodiments simultaneously.

Hereinafter, in the first embodiment according to the present invention, a 'basic CID' or a 'primary management CID' for transmitting an ROHC feedback message is defined in a management message and includes the defined CID. The ROHC feedback message is transmitted through the management message. As an example, a case of transmitting a feedback message using a 'priority management CID' will be described. However, the case of a 'basic CID' may be similarly applied.

13A and 13B are tables showing ROHC feedback message formats and descriptions according to the first embodiment of the present invention.

Referring to FIG. 13A, a format of the ROHC feedback message includes a management message type and a ROHC feedback payload.

The ROHC management message type may use a number not currently used in IEEE 802.16, and the ROHC management message type is '50' as an example. Since the ROHC feedback payload, that is, the feedback data is the same as in FIG. 7, description thereof is omitted.

Referring to FIG. 13B, as an example of a description of the ROHC feedback payload, it is added to the MAC management message of 'Table 14' of the IEEE 802.16 standard. Specifically, in the ROHC feedback message format of type '50', the connection is set to 'priority management'.

14 is a flowchart illustrating operations of a classification / CID mapping / PHS block of a terminal and a base station according to the first embodiment of the present invention. Here, since the classification / CID mapping / PHS block 1120 and the classification / CID mapping / PHS block 1220 of the terminal are the same, a case of a base station will be described for convenience.

Referring to FIG. 14, in step 1400, the classification / CID mapping / PHS block 1120 of the base station determines whether the received packet data is data on which ROHC compression is performed. If the ROHC compression is not performed as a result of the checking, in step 1405, the CID is mapped according to a classification rule that is determined in advance, such as an input IP or a port number of a source, that is, a terminal, and then ends. In this case, the terminal terminates after mapping the CID with the input IP or the port number of the destination, that is, the base station.

If the result of the check is ROHC compression data, in step 1410, the classification / CID mapping / PHS block 1120 checks whether a received ROHC feedback message is included in the received packet data. If the check result includes the ROHC feedback message, in step 1415, the classification / CID mapping / PHS block maps the context ID and the priority management CID of the feedback message and ends.

If the check result is not ROHC feedback, in step 1420, the classification / CID mapping / PHS block ends after mapping the context ID and the CID.

Hereinafter, in the second embodiment of the present invention, the ROHC feedback message is transmitted through the reverse transmission CID. For this purpose, the maximum allowed feedback rate (Maximum Sustained Feedback Rate) and the minimum reserved feedback rate (Minimum Reserved Feedback Rate) are additionally defined as QoS parameters.

According to the second embodiment of the present invention, the maximum allowed feedback and the minimum reserved feedback transmission rate added to the IEEE 802.16 standard are defined as follows.

First, 11.13.38 The maximum allowed feedback rate is defined as the maximum rate of feedback information to be conveyed in the corresponding service flow. The feedback information includes a ROHC feedback message. The maximum allowed feedback rate is expressed in bps, and means a payload corresponding to a rate of SDU, that is, voice data, at an input terminal of a convergence sublayer. The maximum allowed feedback rate does not include MAC header of 802.16 such as MAC header or Cyclic Redundancy Check (CRC). Accordingly, feedback traffic between the base station and the terminal is negotiated based on the maximum allowed feedback rate.

If the maximum allowed feedback rate is omitted or set to '0', it means that there is no explicitly allowed maximum allowed feedback rate. It is not meant to be transmitted at the maximum allowed feedback maximum data rate, but merely used as a limitation. Therefore, the description of the algorithm for measuring whether the feedback transmitted in the flow exceeds the maximum allowed feedback rate may vary from vendor to vendor, but this is omitted because it is outside the scope of the present invention. Feedbacks considered to be beyond the maximum allowed feedback rate may be delayed or dropped depending on the operator.

Secondly, 11.13.39 minimum reserved feedback rate represents the minimum feedback rate reserved for that service flow. The minimum reserved feedback rate is expressed in bps and represents the minimum amount of average feedback rate transmitted in the corresponding service flow. That is, the minimum reserved feedback rate is only meaningful if there is enough data to wait for transmission scheduling.

The base station and the terminal may transmit feedback information up to a minimum reserved feedback transmission rate. If there is only feedback data less than the minimum feedback rate, the base station and the terminal may allocate the remaining bandwidth for other purposes than the transmission of the feedback information. Data relating to the minimum reserved feedback rate is measured at the input of the convergence sublayer. The sum of the minimum reserved feedback transmission rates of all service flows may be greater than the amount of available bandwidth. Therefore, if the reserved feedback rate is omitted, the minimum reserved feedback rate is set to '0' bps.

Specifically, the maximum allowed feedback rate and the minimum reserved feedback rate parameter may be defined as follows.

Hereinafter, the parameters defined in FIGS. 15 to 18A to E are applied to the IEEE 802.16 system, and all parts other than the parts where the parameters are defined are well-known technologies of the IEEE 802.16 system, and thus description thereof will be omitted.

FIG. 15 is a diagram illustrating Table 383, which is a service flow encoding parameter table of the IEEE 802.16 standard, according to the second embodiment of the present invention.

Referring to FIG. 15, the maximum allowed feedback rate is mapped to type 10 and the minimum reserved feedback rate is mapped to type 27.

16 is a diagram showing a set of service QoS parameters according to the second embodiment of the present invention.

Referring to FIG. 16, the maximum allowed feedback rate is 11.13.38 and the minimum reserved feedback rate is 11.13.39, which is defined in the QoS parameter set.

17 is the TLV (Type Length Value, hereinafter referred to as 'TLV') encoding for transmission of the maximum allowed feedback rate and the minimum reserved feedback rate parameter according to the second embodiment of the present invention. It is added to the specification.

Referring to FIG. 17, the type of the maximum allowed feedback rate is '[145/146] .10', and the type of the minimum reserved feedback rate is '[145/146] .27'. And value and scope are all the same. The length is '4', the value is a transmission rate in units of bits per second, and the scope is a dynamic service request (hereinafter referred to as DSx-REQ) message and a dynamic service request (Dynamic Service Request). , Hereinafter referred to as 'DSx-RSP' message, Dynamic Service Acknowledgment (hereinafter referred to as 'DSx-REQ') message, and Dynamic Service Request (hereinafter referred to as 'DSx-REQ') Message) and a Registration Request (hereinafter referred to as a REG-RSP) message.

Hereinafter, QoS parameters added to each service class according to the second embodiment of the present invention will be described with reference to FIGS. 18A to 18E.

Referring to FIG. 18A, the minimum reserved feedback rate is defined as 11.13.39 in the Unsolicited Grant Service (hereinafter, referred to as 'UGS') parameters and added as a QoS parameter.

Referring to FIG. 18B, the maximum allowed feedback rate for the Real Time Variable Rate (hereinafter, referred to as 'RT-VR') service parameters is 11.13.38, and the minimum reserved feedback rate is 11.13.39. It is defined as and added as QoS parameter.

Referring to FIG. 18C, the maximum allowed feedback rate for the non real time variable rate service (hereinafter, referred to as 'NRT_VR') service parameter is defined as 11.13.38, and the minimum reserved feedback rate is defined as 11.13.39. Is added as a QoS parameter.

Referring to FIG. 18D, the maximum allowed feedback rate is 11.13.38 and the minimum reserved feedback rate is 11.13.39 for the Best Effort (hereinafter, referred to as 'BE') service parameter. Is added.

Referring to FIG. 18E, the determined extended real time-variable rate (hereinafter, referred to as' ERT-VR) service defines a maximum allowed feedback rate as 11.13.38 and a minimum reserved feedback rate parameter as 11.13.39. Is added as a QoS parameter.

On the other hand, when a specific transmission connection is a connection employing the ROHC, the base station or the terminal creates a reverse transmission connection in order to deliver the corresponding ROHC feedback message. At this time, at least one parameter of the maximum allowed feedback rate or the minimum reserved feedback rate should be exchanged. That is, the base station or the terminal recognizes a connection exchanged with the maximum allowed feedback rate or the minimum reserved feedback rate parameter as a connection capable of ROHC feedback transmission. Accordingly, the bandwidth request operation of the terminal, the scheduling operation of the base station, and the feedback transmission to the downlink are performed based on the exchanged parameters.

There are various methods of calculating the maximum allowed feedback rate and the minimum reserved feedback rate. For example, when the ROHC feedback transmitted to the transmission connection A is transmitted through the transmission connection B in the reverse direction, the maximum allowed feedback rate and the minimum reserved feedback rate of the feedback transmission rate of the connection B may be represented by Equation 1 and Equation 1 below. Is calculated as 2.

(커넥션 B의 최대 허용된 피드백 전송율) = α * (커넥션 A의 최대 허용된 트래픽 전송율(Maximum Sustained Traffic rate of A)),

(Maximum allowed feedback rate of connection B) = α * (Maximum Sustained Traffic rate of A),

(커넥션 B의 최소 예약된 피드백 전송율) = β * (커넥션 A의 최소 예약된 트래픽 전송율(Minimum Reserved Traffic Rate of A)), ()

(Minimum Reserved Traffic Rate of Connection B) = β * (Minimum Reserved Traffic Rate of Connection A), ()

Here, the α and β values may have a value between '0' and '1', wherein α is determined based on an expected maximum amount of feedback data, and β is determined based on an estimated minimum amount of feedback data.

A connection for which the maximum allowed feedback rate or the minimum reserved feedback rate parameter value is set is considered a connection to which ROHC feedback data can be transmitted. Accordingly, the classification / CID mapping / PHS block 1120 of the base station or the classification / CID mapping / PHS block 1220 of the terminal classifies the ROHC feedback message into a connection capable of transmitting ROHC feedback and maps the corresponding CID. . In this case, the classification / CID mapping / PHS blocks 1120 and 1220 select the same service class of the connection through which the traffic and feedback message are transmitted, so that the feedback message can be transmitted more smoothly.

Specifically, in the case of a connection for transmitting downlink and uplink packet schedulers (see FIG. 11) of the base station, the traffic and feedback message agreement transmission rate is 'sum of the minimum reserved traffic transmission rate and the minimum reserved feedback transmission rate'. Rather, the scheduling is limited to not exceed the sum of the maximum allowed traffic rate and the maximum allowed feedback rate.

In addition, for a specific connection in which the packet scheduler of the terminal uplink is used for the ROHC feedback transmission, the uplink such that the transmitted traffic and the feedback message consensus transmission rate are equal to or greater than the sum of the minimum reserved traffic transmission rate and the minimum reserved feedback transmission rate. Perform the transfer. In this case, when the transmission rate of the traffic and feedback message consensus exceeds the sum of the maximum allowed traffic transmission rate and the maximum allowed feedback transmission amount, the corresponding uplink traffic or feedback message may be delayed and transmitted or dropped.

19 is a flowchart illustrating operations of the classification / CID mapping / PHS block 1120 of the base station and the classification / CID mapping / PHS block 1220 of the terminal according to the second embodiment of the present invention. Here, since the operation is the same for the classification / CID mapping / PHS block of the terminal and the base station, the case of the terminal will be described for convenience.

Referring to FIG. 19, in step 1900, the classification / CID mapping / PHS block 1220 determines whether the received packet data is data on which ROHC compression is performed. If ROHC compression is not performed as a result of the checking, in step 1905, the classification / CID mapping / PHS block 1220 maps the CID according to a classification rule already determined with the destination, that is, the IP and port number of the base station. Here, the base station maps the source, that is, the IP and port number of the terminal and the like, and the CID.

If the result of the check is packet data in which ROHC compression is performed, in step 1910, the classification / CID mapping / PHS block 1220 determines whether the packet data is a ROHC feedback message. If the check result is not the ROHC feedback message, the process proceeds to 1920. In step 1920, the classification / CID mapping / PHS block 1220 ends after mapping the context ID and the CID.

If the check result is a ROHC feedback message, in step 1915, the classification / CID mapping / PHS block 1220 checks CIDs capable of transmitting the ROHC feedback message. Here, the CIDs capable of transmitting the ROHC feedback message are CIDs in which at least one or more of a minimum reserved feedback rate and a maximum allowed feedback rate parameter are previously exchanged.

In step 1925, the classification / CID mapping / PHS block 1220 selects the same CID as the traffic service class of packet data corresponding to the received ROHC feedback message among the service classes of the checked CIDs. In step 1930, the classification / CID mapping / PHS block 1220 ends after mapping the context ID of the feedback message and the selected CID.

20 is a flowchart of a scheduler of a terminal and a base station according to the second embodiment of the present invention. Here, since the operations of the scheduler 1140 and the terminal scheduler 1240 of the base station are the same, the case of the terminal scheduler 1240 will be described as an example.

Referring to FIG. 20, in step 2000, the terminal scheduler 1240 checks whether uplink allocation information received from the MAP decoder 1245 is a CID for transmitting a feedback message. In the case of the CID for transmitting the feedback message, in step 2005, the terminal scheduler 1240 is larger than the sum of the minimum reserved traffic rate and the minimum reserved feedback message rate and the maximum allowed traffic rate and the maximum reserved rate. The transmission rate of the CID is scheduled to have a transmission rate less than the sum of the feedback message transmission rates.

As a result of the check, if it is not the CID for transmitting the feedback message, in step 2010, the terminal scheduler 1240 schedules the transmission rate of the CID to have a transmission rate smaller than the maximum allowed traffic transmission rate and higher than the minimum reserved traffic transmission rate.

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

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention can more efficiently transmit a ROHC feedback message using a management message or a preset reverse CID in the IEEE 802.16 system. In addition, the minimum transmission rate of the ROHC feedback message can be guaranteed through QoS parameters related to the ROHC feedback message transmission, and the transmission performance can be improved by preventing the context mismatch through the smooth transmission of the ROHC feedback message. It works.

Claims (39)

A method for providing a robust header compression (ROHC) feedback message in a communication system, the method comprising: Determining whether an ROHC feedback message is included in the packet data when receiving the packet data in which the ROHC compression is performed; And mapping a context identifier of the feedback information with a reverse link identifier to which the feedback message is to be transmitted when the ROHC feedback message is included in the test result. The method of claim 1, If you receive packet data for which no ROHC compression has been performed, And mapping a connection identifier according to an input IP or a port number of the packet data destination according to a classification rule already determined. The method of claim 1, wherein the ROHC feedback message, Method included in the MAC management message of 'Table 14' of the IEEE 802.16 standard is transmitted to the destination. The method of claim 3, wherein the ROHC feedback message, And information indicating whether or not the packet data has been successfully restored. A method for providing a feedback message of robust header compression (ROHC) in a communication system, the method comprising: Determining whether the packet data is an ROHC feedback message when receiving packet data on which ROHC compression has been performed; Checking the connection identifiers capable of transmitting the ROHC feedback message with the context identifier of the ROHC feedback message when the result is the ROHC feedback message; Selecting the same connection identifier as the traffic service class of the packet data corresponding to the received ROHC feedback message among the service classes of the checked connection identifiers, and then mapping the context identifier of the feedback message to the selected connection identifier; Characterized in that. The method of claim 5, wherein the connection identifier, At least one parameter of the minimum reserved feedback rate or the maximum allowed feedback rate parameter is a previously exchanged connection identifier. The method of claim 5, wherein the minimum reserved feedback rate, The maximum transmission rate of the feedback information to be delivered to the service flow, characterized in that defined by the following equation. Equation Maximum allowed feedback rate for reverse transmission connection = α * Maximum allowed traffic rate for transmitting connection Here, α may have a value between '0' and '1', and is determined based on an expected maximum amount of feedback data. The method of claim 7, wherein the feedback information, And the ROHC feedback message. The method of claim 5, wherein the maximum allowed feedback rate is: The maximum threshold value of the average feedback rate that can be transmitted in the corresponding service flow, characterized in that defined by the following equation. Equation Minimum Reserved Feedback Rate on Reverse Transfer Connection = β * Minimum Reserved Traffic Rate on Transfer Connection. Here, the β value may have a value between '0' and '1', wherein β is determined based on an expected minimum amount of feedback data. The method of claim 5, wherein when receiving packet data in which ROHC compression is not performed, And mapping a connection identifier according to an input IP or a port number of the packet data destination according to a classification rule already determined. The method of claim 5, wherein the ROHC feedback message, And information indicating whether or not the packet data has been successfully restored. The method of claim 5, The maximum allowed feedback rate and the minimum reserved feedback rate parameters are included in the DSx-REQ message, the DSx-RSP message, the DSx-REQ message, the DSx-REQ message, and the REG-RSP message. How to feature. A method for providing a robust header compression (ROHC) feedback message in a communication system, the method comprising: Checking whether the uplink allocation information received from the upper layer is a connection identifier for transmitting a feedback message; And in case of the connection identifier for transmitting the feedback message, scheduling a transmission rate of the connection identifier within a predetermined range. The method of claim 13, wherein the range is A transmission rate greater than the sum of the minimum reserved traffic rate and the minimum reserved feedback message rate and less than the sum of the maximum allowed traffic rate and the maximum reserved feedback message rate. The method of claim 13, wherein the connection identifier, At least one parameter of the minimum reserved feedback rate or the maximum allowed feedback rate parameter is a previously exchanged connection identifier. The method of claim 13, wherein the minimum reserved feedback rate is: The maximum transmission rate of the feedback information to be delivered to the service flow, characterized in that defined by the following equation. Equation Maximum allowed feedback rate for reverse transmission connection = α * Maximum allowed traffic rate for transmitting connection Here, α may have a value between '0' and '1', and is determined based on an expected maximum amount of feedback data. The method of claim 16, wherein the feedback information, And the ROHC feedback message. The method of claim 13, wherein the maximum allowed feedback rate is: The maximum threshold value of the average feedback rate that can be transmitted in the corresponding service flow, characterized in that defined by the following equation. Equation Minimum Reserved Feedback Rate on Reverse Transfer Connection = β * Minimum Reserved Traffic Rate on Transfer Connection. Here, the β value may have a value between '0' and '1', wherein β is determined based on an expected minimum amount of feedback data. The method of claim 13, As a result of the check, if the connection identifier for the feedback message transmission is not And schedule a transmission rate of the connection identifier to have a transmission rate that is less than the maximum allowed traffic rate and is equal to or greater than the minimum reserved traffic rate. The method of claim 13, The maximum allowed feedback rate and the minimum reserved feedback rate parameters are included in the DSx-REQ message, the DSx-RSP message, the DSx-REQ message, the DSx-REQ message, and the REG-RSP message. Characterized in that the method. An apparatus for providing robust header compression (ROHC) feedback message in a communication system, the apparatus comprising: When receiving the packet data in which the ROHC compression is performed, it is determined whether the ROHC feedback message is included in the packet data, And a classification block for mapping a context identifier of the feedback information and a reverse link identifier to which the feedback message is to be transmitted when the test result includes the ROHC feedback message. The method of claim 21, wherein the classification block, If you receive packet data for which no ROHC compression has been performed, And a connection identifier is mapped according to a classification rule that is already determined such as an input IP or a port number of the packet data destination. The method of claim 21, wherein the ROHC feedback message, Apparatus characterized in that the MAC management message of the "table 14" of the IEEE 802.16 standard transmitted to the destination. The method of claim 21, wherein the ROHC feedback message, And information indicating whether the packet data has been successfully restored. An apparatus for providing robust header compression (ROHC) feedback message in a communication system, the apparatus comprising: When receiving the packet data subjected to the ROHC compression, it is determined whether the packet data is a ROHC feedback message, If the verification result is a ROHC feedback message, the connection identifiers capable of transmitting the ROHC feedback message with the context identifier of the ROHC feedback message are examined. After selecting the same connection identifier as the traffic service class of the packet data corresponding to the received ROHC feedback message from among the service class of the checked connection identifiers, the classification block for mapping the context identifier of the feedback message and the selected connection identifier; Apparatus comprising a. The method of claim 25, wherein the connection identifier, And at least one of the minimum reserved feedback rate or the maximum allowed feedback rate parameter is a previously exchanged connection identifier. 27. The method of claim 26, wherein the minimum reserved feedback rate is: And a maximum transmission rate of feedback information to be delivered to the corresponding service flow. Equation Maximum allowed feedback rate for reverse transport connection = α * Maximum allowed traffic rate for corresponding connection Here, α may have a value between '0' and '1', and is determined based on an expected maximum amount of feedback data. The method of claim 27, wherein the feedback information, The ROHC feedback message. 27. The method of claim 26, wherein the maximum allowed feedback rate is: The maximum threshold value of the average feedback rate that can be transmitted in the service flow, characterized in that defined by the following equation. Equation Minimum Reserved Feedback Rate on Reverse Transfer Connection = β * Minimum Reserved Traffic Rate on Transfer Connection. Here, the β value may have a value between '0' and '1', wherein β is determined based on an expected minimum amount of feedback data. 27. The method of claim 25, wherein when receiving packet data in which ROHC compression is not performed, And mapping a connection identifier according to an input IP or a port number of the packet data destination according to a classification rule already determined. The method of claim 25, wherein the ROHC feedback message, And information indicating whether the packet data has been successfully restored. The method of claim 26, The maximum allowed feedback rate and the minimum reserved feedback rate parameters are included in the DSx-REQ message, the DSx-RSP message, the DSx-REQ message, the DSx-REQ message, and the REG-RSP message. Characterized in that the device. An apparatus for providing robust header compression (ROHC) feedback message in a communication system, the apparatus comprising: If the uplink allocation information received from the upper layer is a connection identifier for sending feedback messages, it is greater than the sum of the minimum reserved traffic rate and the minimum reserved feedback message rate and the maximum allowed traffic rate and the maximum scheduled feedback message rate. And a scheduler for scheduling a transmission rate of the connection identifier to have a transmission rate less than or equal to the sum of. The method of claim 33, wherein the connection identifier, At least one of the minimum reserved feedback rate and the maximum allowed feedback rate parameters is a previously exchanged connection identifier. 35. The method of claim 34, wherein the minimum reserved feedback rate is: And a maximum transmission rate of feedback information to be delivered to the corresponding service flow. Equation Maximum allowed feedback rate for reverse transmission connection = α * Maximum allowed traffic rate for transmitting connection Here, α may have a value between '0' and '1', and is determined based on an expected maximum amount of feedback data. The method of claim 35, wherein the feedback information, The ROHC feedback message. 35. The method of claim 34, wherein the maximum allowed feedback rate is: The maximum threshold value of the average feedback rate that can be transmitted in the service flow, characterized in that defined by the following equation. Equation Minimum Reserved Feedback Rate on Reverse Transfer Connection = β * Minimum Reserved Traffic Rate on Transfer Connection. Here, the β value may have a value between '0' and '1', wherein β is determined based on an expected minimum amount of feedback data. The method of claim 33, And if it is not determined that the connection identifier is for transmitting the feedback message, scheduling the transmission rate of the connection identifier to have a transmission rate smaller than the maximum allowed traffic transmission rate and equal to or higher than the minimum reserved traffic transmission rate. The method of claim 33, The maximum allowed feedback rate and the minimum reserved feedback rate parameters are included in the DSx-REQ message, the DSx-RSP message, the DSx-REQ message, the DSx-REQ message, and the REG-RSP message. Characterized in that the device.

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