KR101459011B1 - Apparatus and method for transmitting/receiving voice packet in broadband wireless access system - Google Patents

Abstract

The present invention relates to an apparatus and a method for transmitting and receiving a voice packet in a broadband wireless access system, and more particularly, to an apparatus and method for transmitting and receiving a voice packet in a broadband wireless access system, in which when a Medium Access Control (MAC) SDU (Service Data Unit) (IP) header and a UDP (User Datagram Protocol) header from the received MAC SDU when the received MAC SDU is a MAC SDU for a voice packet, And transmitting a new MAC SDU to the MAC sublayer, the method comprising: transmitting a new MAC SDU to the MAC sublayer, There is an advantage of reducing by 46%.

WiMAX, Convergence Sublayer (CS), Voice over Internet Protocol (VoIP), Header transmission overhead

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a voice packet transmission / reception apparatus and method in a broadband wireless access system,

The present invention relates to an apparatus and a method for transmitting and receiving a voice packet in a broadband wireless access system. More particularly, in a broadband wireless access system, when a transmitter transmits an RTP (Realtime Transport Protocol) (RTP) header and a Voice over Internet Protocol (VoIP) payload without transmitting the RTP header to the radio section. When a receiver receives the RTP packet in a radio section, And an apparatus and method for generating an IP header and a UDP header.

Generally, a communication system has evolved mainly in voice service, and is gradually evolving into a communication system capable of not only voice but also data service and various multimedia services. However, the voice-oriented communication system has not satisfied the service needs of users who are soaring because the transmission bandwidth is relatively small and the fee for use is high. In addition, due to the development of the telecommunication industry and the increase of users' demand for the internet service, there is a growing need for a communication system capable of efficiently providing the Internet service. Accordingly, the present invention has been introduced to a broadband wireless access system for efficiently providing Internet services with a wide bandwidth sufficient to meet the needs of soaring users.

The broadband wireless access system is a system for integrally supporting not only voice but multimedia application services such as various data services of low speed and high speed and high quality video. Such a broadband wireless access system may be implemented in a mobile or fixed environment based on a wireless medium using broadband such as 2GHz, 5GHz, 26GHz, and 60GHz, a Public Switched Telephone Network (PSTN), a Public Switched Data Network (PSDN) ATM (Asynchronous Transfer Mode) network, and the like, and is capable of supporting a channel transmission rate of 2 Mbps or higher. The broadband wireless access system can be classified into a broadband wireless access network, a broadband mobile access network, and a high-speed wireless LAN (Local Area Network) depending on the mobility (fixed or mobile) of the terminal, the communication environment (indoor or outdoor) .

The WiMAX system, which is one of the broadband wireless access systems, is standardized by the IEEE 802.16 standardization group of the Institute of Electrical and Electronics Engineers . The IEEE 802.16 standard is capable of transmitting a large amount of data in a short time due to a wide bandwidth of data compared to a wireless technology for a conventional voice service, and all users share channels (or resources) It is possible. In addition, quality of service (QoS) is ensured so that users can receive different quality services according to the characteristics of the service.

The IEEE 802.16 protocol used in the WiMAX system provides connectivity of the MAC layer. In the WiMAX system, each service flow (SF) generated between the UE and the BS has a virtual circuit form divided into Connection IDs (CIDs). A Convergence Sublayer (CS) in the IEEE 802.16 protocol hierarchy determines the type of payload of a MAC PDU (Packet Data Unit) An Ethernet CS for transmission of an Ethernet packet, and a ROHC CS for transmission of an IP packet whose header is compressed by a ROHC (RObust Header Compression) method.

Voice over Internet Protocol (VoIP) technology is a communication technology that converts voice packets generated from a voice codec (CODEC) into RTP (Realtime Transport Protocol) packets and transmits the packets to a wireless section. Generally, an RTP packet is composed of [IP header + UDP (User Datagram Protocol) header + RTP header + voice packet]. Using the VoIP technology, a voice packet can be transmitted in real time even in an IP packet exchange communication system such as a WiMAX system. The voice codec used in the VoIP technology is AMR (Adaptive MultiRate), G.711, G.723.1, and G.729.

As described above, in order to transmit a voice packet in real time in the IP packet exchange communication system, an IP header, a UDP header, and an RTP header are added to a voice packet. The IP header has fields such as a source IP address and a destination IP address, and occupies a size of 20 bytes. The UDP header has fields such as a source port number and a destination port number, and occupies 8 bytes. The RTP header has a field such as a sequence number and occupies a size of 12 bytes. The voice packet occupies 20 bytes in the case of a G.729 codec having a bandwidth of 8 kbps and a transmission period of 20 ms. Thus, adding the IP header, UDP header, RTP header size, and voice packet size based on the G.729 voice codec is 60 bytes. Of these, 28 bytes corresponding to the IP header and the UDP header constitute a virtual circuit, and an additional amount of data used for delivering one voice packet to the VoIP application program of the destination host, that is, the header transmission overhead do.

The WiMAX system generally proposes a payload header suppression (PHS) scheme and a ROHC (ROburst Header Compression) scheme in order to reduce the header transmission overhead in forming the virtual circuit. The PHS scheme and the ROHC scheme can be applied to a case where a connection is established between a base station and a mobile station through an appointment, Destination port number field, etc.) is omitted and transmitted. Although the header transmission overhead can be reduced by a certain amount of such a header compression scheme, since fields to be changed for each packet are still transmitted, there is a problem that the size of the header transmission overhead that can be reduced is limited.

An object of the present invention is to provide an apparatus and a method for transmitting and receiving a voice packet in a broadband wireless access system.

It is another object of the present invention to provide an apparatus and method for defining RTP CS for transmission of an RTP packet to a CS in an IEEE 802.16 protocol layer structure in a broadband wireless access system and for transmitting and receiving RTP packets through the defined RTP CS have.

It is another object of the present invention to provide a method and apparatus for transmitting an RTP packet and a VoIP payload in a broadband wireless access system, in which an IP header and a UDP header are transmitted in an RTP header and a VoIP payload, And an apparatus and method for reducing a required bandwidth of a radio section for a mobile station.

It is another object of the present invention to provide a method and apparatus for receiving an RTP packet in a wireless section in a broadband wireless access system, And an apparatus and method for generating a header.

According to an aspect of the present invention, there is provided a method of transmitting a voice packet of a CS in a broadband wireless access system, the method comprising: receiving a MAC SDU from an upper layer; And if the received MAC SDU is a MAC SDU for a voice packet, removes an IP header and a UDP header from the received MAC SDU, and generates a new MAC SDU including an RTP header and a voice payload And transmitting the generated new MAC SDU to the MAC sublayer.

According to an aspect of the present invention, there is provided a method for transmitting a voice packet in a broadband wireless access system, the method comprising: when a CS classifier receives a MAC SDU for a voice packet from an upper layer, The RTP CS removes the IP header and the UDP header from the received MAC SDU to generate a new MAC SDU including an RTP header and a voice payload and transmits the new MAC SDU to the MAC sublayer And a control unit.

According to an aspect of the present invention, in a broadband wireless access system, when a MAC SDU for a voice packet is received from an upper layer, the voice packet transmission apparatus transmits the received MAC SDU to an RTP CS And a RTP CS for removing a IP header and a UDP header from a MAC SDU from the CS classifier to generate a new MAC SDU composed of an RTP header and a voice payload and transmitting the MAC SDU to the MAC sublayer .

According to an aspect of the present invention, there is provided a method of receiving a voice packet of a CS in a broadband wireless access system, the method comprising: generating an IP header and a UDP header when a MAC SDU for a voice packet is received from a MAC sublayer; Generating a new MAC SDU including an IP header, a UDP header, an RTP header, and a voice payload by inserting the generated IP header and UDP header into the received MAC SDU; And transmitting the SDU to an upper layer.

According to an aspect of the present invention, there is provided a method of receiving a voice packet of a CS in a broadband wireless access system, the method comprising the steps of: when a CS classifier receives a MAC SDU for a voice packet from a MAC sublayer, SDU to an RTP CS; generating an IP header and a UDP header by the RTP CS; inserting the generated IP header and a UDP header into the received MAC SDU, Generating a new MAC SDU including a header, a UDP header, an RTP header, and a voice payload; and transmitting the generated new MAC SDU to an upper layer by the RTP CS.

According to one aspect of the present invention, in a broadband wireless access system, when a MAC SDU for a voice packet is received from a MAC sublayer, the voice packet receiving apparatus of the CS transmits the received MAC SDU to an RTP CS A new classifier MAC, which is composed of an IP header, a UDP header, an RTP header, and a voice payload, by inserting the generated IP header and UDP header into the received MAC SDU, SDU, and transmitting the generated new MAC SDU to an upper layer.

According to the present invention, an RTP CS for transmission of an RTP packet is defined in a CS in an IEEE 802.16 protocol layer structure in a broadband wireless access system, and when an RTP packet is transmitted in a wireless section by a transmitter, an IP header and a UDP header are transmitted And transmits only the RTP header and the VoIP payload. When the receiver receives the RTP packet in the radio section, the IP header and the UDP header are generated using the packet classification rule. The required bandwidth of the wireless section for the mobile station can be reduced by about 46%. For example, when an RTP packet is transmitted in a wireless zone using a G.729 codec having a bandwidth of 8 kbps and a transmission interval of 20 ms, when an RTP packet is transmitted using a conventional IP CS, a MAC SDU (Service Data Unit) Header + UDP header + RTP header + voice packet], the size of the MAC SDU becomes 60 bytes (= 20 + 8 + 12 + 20). On the other hand, when the RTP packet is transmitted using the RTP CS as in the present invention, since the MAC SDU is composed of [RTP header + voice packet], the size of the MAC SDU becomes 32 bytes (= 12 + 20).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In the broadband wireless access system, when a transmitter transmits an RTP packet over a radio link, only the RTP header and the VoIP payload are transmitted without transmitting the IP header and the UDP header in the radio interval, The apparatus and method for generating the IP header and the UDP header using the packet classification rule will be described. To this end, the present invention defines an RTP CS for transmission of an RTP packet to a CS in an IEEE 802.16 protocol layer structure.

Meanwhile, the RTP CS type service flow (SF) is generated according to the dynamic service flow generation procedure of the existing WiMAX system. Thus, both terminal-initiated service flow generation and base station-initiated service flow generation are both possible.

In addition, a CS specification TLV (Type / Length / Value) is included in a DSA (Dynamic Service Addition) request and response message transmitted / received to establish a new connection between the BS and the UE. Indicates which CS the flow is for. The value of the CS specification TLV may be set to 14 or 15 to indicate that the service flow for that connection is for the RTP CS according to the present invention.

Hereinafter, a VoIP packet will be described as an RTP packet transmitted using the RTP CS.

In addition, the packet classification rule of the RTP CS represents a virtual circuit for VoIP packet transmission between the BS and the MS as a determination condition for distinguishing a general IP packet from a VoIP packet. The packet classification rule of the RTP CS is composed of the same items as the packet classification rule of the IP CS. However, the RTP CS must include five packet classification rule items as shown in Table 1 below, and the CS priority must always be higher than the IP CS.

Item Explanation example Protocol Transport protocol type UDP → 0x11 IP masked source address Source IP address band
(src, smask) 10.0.17.251/255.255.255.255
→ (0x0A0011FB, 0xFFFFFFFF) IP masked destination address Destination IP address band
(dst, dmask) 203.213.66.74/255.255.255.255
→ (0xcbd5424a, 0xffffffff) Protocol source port range Source port number band
(sportlow, sporthigh) Port 48765
→ (0xbe7d, 0xbe7d) Protocol destination port range Destination port number Bandwidth
(dportlow, dporthigh) Port 50001
→ (0xc351, 0xc351)

As shown in Table 1, the RTP CS includes a protocol, an IP masked source address, an IP masked destination address, a protocol source port range, and a protocol destination port range. Indicates the type of protocol. Also, the IP masked source address indicates a source IP address band, which is represented by an IP source address value (src) and a mask value (smask) of an IP source address. The IP masked destination address indicates a destination IP address band, which is represented by an IP destination address value (dst) and a mask value (dmask) of an IP destination address. The Protocol source port range represents the source port number band, which is represented by the lowest value (sportlow) and the highest value (sporthigh) of the source port number. The Protocol destination port range represents a destination port number band, which is represented by the lowest value (dportlow) and the highest value (dporthigh) of the destination port number.

On the other hand, the CS packet classification rule table is a table that defines CS-specific packet classification rules, for example, as shown in Table 2 below. Here, the five packet classification rule items of the RTP CS are determined in the VoIP call establishment process, and the packet classification rule of the RTP CS is generated according to the determination. That is, the IP masked destination address and the Protocol destination port range among the five packet classification rule items of the RTP CS are subjected to a SIP signaling process (i.e., a transmitting side transmits a session initiation protocol INVITE message to a receiving side to request a voice call setup, (SIP 200 OK) to the sender in response to the request, and the IP masked source address and the Protocol source port range are determined as the IP address and UDP port number of the called party, The IP address and UDP port number of the originating side are determined, and the protocol is determined as 17 because UDP-based RTP is used.

CS type CS
Priority SFID Scheduling method protocol Source IP
address Source port number Destination IP
address Destination port number IP CS 0 0 0x4 BE 0 0.0.0.0/
0.0.0.0 0 0.0.0.0/
0.0.0.0 0 IP CS 1 One 0x67 nrtPS 6 0.0.0.0/
0.0.0.0 0 0.0.0.0/
0.0.0.0 80 RTP CS 0 7 0x109 ertPS 17 10.0.17.251/
255.255.255.255 48765 203.213.66.74/
255.255.255.255 50001

As shown in Table 2, the CS-specific packet classification rule includes a CS priority, a Service Flow ID (SFID), a scheduling method, a protocol, a source IP address, a source port number, a destination IP address, And the like.

1 is a diagram illustrating a configuration of a MAC SDU when a transmitter transmits a VoIP packet in a wireless section in the BWA system according to the present invention.

1, a MAC SDU corresponding to a VoIP packet transmitted from an upper layer to an RTP CS includes [IP header 106 + UDP header 104 + RTP header 102 + VoIP payload 100] . The RTP CS removes the IP header 106 and the UDP header 104 from the MAC SDU received from the upper layer and generates a new MAC SDU including only the RTP header 102 + VoIP payload 100. The IP header 106 includes protocol, source IP address, destination IP address, and the like. In addition, the UDP header 104 includes information about a source port number and a destination port number.

2 is a diagram illustrating a protocol layer structure of a transmitter in a broadband wireless access system according to the present invention.

As shown in the figure, the protocol layer structure of the transmitting side is largely divided into an upper layer 200, a MAC (Medium Access Control) layer, and a PHY layer 240. The MAC layer includes a CS 210 and a MAC And a sub-layer 230. The CS 210 includes a CS classifier 212 and various types of CSs such as an IP CS 214, an RTP CS 216 defined in the present invention, an Ethernet CS 218, an ROHC CS 220).

Referring to FIG. 2, the CS classifier 212 in the CS 210, when receiving a MAC SDU from the upper layer 200, extracts header information extracted from the IP header and UDP header in the received MAC SDU, CS packet classification rules in the CS packet classification rule table, selects a CS corresponding to a matching packet classification rule, and transmits the received MAC SDU to the selected CS. Accordingly, when the MAC SDU for the VoIP packet is received from the upper layer 200, the CS classifier 212 transmits the received MAC SDU to the RTP CS 216. That is, the header information extracted from the IP header and the UDP header in the received MAC SDU, and the information obtained in the VoIP call setup process for transmitting the VoIP packet (which is generated by the RTP CS packet classification rule, And transmits a MAC SDU for the received VoIP packet to the RTP CS 216 according to the comparison result. The CS classifier 212 extracts the SFID from the packet classification rule of the selected CS, determines the CID using the extracted SFID and the SFID-CID mapping table, and transmits the received MAC SDU And transmits the determined CID together.

The Ethernet CS 218 is a CS for transmission of an Ethernet packet, and the ROHC CS 220 transmits an IP packet to the Ethernet Is a CS for transmission of a compressed IP packet. The IP CS 214, the Ethernet CS 218, and the ROHC CS 220 perform the same operations as in the prior art. That is, the IP CS 214, the Ethernet CS 218, and the ROHC CS 220 process the MAC SDUs from the CS classifier 212 and transmit the MAC SDUs to the MAC sublayer 212, together with the CIDs from the CS classifier 212, Lt; / RTI >

The RTP CS 216 according to the present invention is a CS for transmitting a VoIP packet, which removes an IP header and a UDP header from a MAC SDU from the CS classifier 212 and generates a [RTP header + VoIP payload] Generates a new MAC SDU, and transmits the generated new MAC SDU and the CID from the CS classifier 212 to the MAC sublayer 230.

The MAC sublayer 230 generates a MAC header using CIDs from various types of CSs 214 to 220 and inserts the generated MAC header into MAC SDUs from various types of CSs 214 to 220 And transmits the generated MAC PDU to the PHY layer 240 through the wireless section.

3 is a diagram illustrating a protocol layer structure of a receiving side in a broadband wireless access system according to the present invention.

As shown, the protocol layer structure of the receiving side is roughly divided into an upper layer 300, a MAC layer, and a PHY layer 340. The MAC layer includes a CS 310 and a MAC sublayer 330 . The CS 310 includes a CS classifier 312 and various types of CSs such as an IP CS 314, an RTP CS 316 defined in the present invention, an Ethernet CS 318, an ROHC CS 320).

3, the MAC sublayer 330 in the CS 310 extracts a MAC header from a MAC PDU received from a radio section through the PHY layer 340, and obtains a CID from the extracted MAC header do. In addition, the MAC sublayer 330 removes the MAC header from the MAC PDU to generate a MAC SDU, and transmits the generated MAC SDU and the obtained CID to the CS classifier 312.

The CS classifier 312 obtains the SFID using the CID and the SFID-CID mapping table from the MAC sublayer 330, selects a CS including the obtained SFID from the CS packet classification rule table, And transmits a MAC SDU from the MAC sublayer 330 to the selected CS.

The Ethernet CS 318 is a CS for receiving an Ethernet packet, and the ROHC CS 320 transmits the Ethernet packet through the ROHC system Is a CS for receiving a compressed IP packet. The IP CS 314, the Ethernet CS 318, and the ROHC CS 320 perform the same operations as in the prior art. That is, the IP CS 314, the Ethernet CS 318, and the ROHC CS 320 process the MAC SDUs from the CS classifier 312 and transmit them to the upper layer 300.

The RTP CS 316 according to the present invention uses the information obtained in the VoIP call establishment procedure for the VoIP packet transmission (which is generated by the RTP CS packet classification rule and is included in the CS packet classification rule table) IP header and a UDP header, inserts the generated IP header and UDP header into the MAC SDU from the CS classifier 312, and generates a new MAC composed of [IP header + UDP header + RTP header + VoIP payload] SDU, and transmits the generated new MAC SDU to the upper layer 300.

4 is a flowchart illustrating a method of operating a CS classifier on a transmission side for transmitting a VoIP packet in a wireless section in a broadband wireless access system according to an embodiment of the present invention.

Referring to FIG. 4, in step 401, the CS classifier determines whether a MAC SDU is received from an upper layer. Here, the MAC SDU for the VoIP packet received from the upper layer is composed of [IP header + UDP header + RTP header + VoIP payload]. When the MAC SDU is received from the upper layer, the IP header and the UDP header information in the received MAC SDU are extracted in step 403. That is, information on a protocol, a source IP address, and a destination IP address is extracted from the IP header, and information on a source port number and a destination port number is extracted from the UDP header.

Then, the CS classifier selects the highest priority CS in the CS packet classification rule table generated in step 405, and checks whether the extracted packet classification rule of the selected CS matches the extracted header information in step 407 do. If the extracted packet header does not match the packet classification rule of the selected CS, the CS classifier selects CS of the next priority in step 409, and returns to step 407 to repeat the following steps.

If the selected CS packet classification rule matches the extracted header information, the CS classifier extracts the SFID from the packet classification rule of the selected CS at step 411, and at step 413, the SFID- And determines the CID for transmission of the VoIP packet using the table. Here, the SFID-CID mapping table may be configured as shown in Table 3, for example.

SFID CID 0x4 538 0x67 663 0x109 56

In step 415, the CS classifier transmits the determined CID and the received MAC SDU to the selected CS. Accordingly, the MAC SDU for the VoIP packet is transmitted to the RTP CS.

Thereafter, the CS classifier terminates the algorithm according to the present invention.

5 is a flowchart illustrating an operation method of a RTP CS on a transmission side for transmitting a VoIP packet in a wireless zone in a broadband wireless access system according to an embodiment of the present invention.

Referring to FIG. 5, in step 501, the RTP CS checks whether a CID and a MAC SDU are received from the CS classifier. Here, the MAC SDU received from the CS classifier is composed of [IP header + UDP header + RTP header + VoIP payload].

In step 503, the RTP CS removes the IP header and the UDP header from the received MAC SDU, and generates a new MAC SDU including an RTP header and a VoIP payload.

In step 505, the RTP CS transmits the received CID and the generated new MAC SDU to the MAC sublayer.

Thereafter, the RTP CS terminates the algorithm according to the present invention.

6 is a flowchart illustrating a method of operating a CS classifier on a receiving side for receiving a VoIP packet in a wireless section in a broadband wireless access system according to an embodiment of the present invention.

Referring to FIG. 6, in step 601, the CS classifier checks whether a CID and a MAC SDU are received from the MAC sublayer. Here, the MAC SDU for the VoIP packet received from the MAC sublayer is composed of [RTP header + VoIP payload].

When the CID and the MAC SDU are received from the MAC sublayer, the CS classifier obtains the SFID using the received CID and the predefined SFID-CID mapping table in step 603.

In step 605, the CS classifier selects a CS including the SFID from the CS packet classification rule table generated in step 605, and transmits the received MAC SDU to the selected CS in step 607. Accordingly, the MAC SDU for the VoIP packet is transmitted to the RTP CS.

Thereafter, the CS classifier terminates the algorithm according to the present invention.

FIG. 7 is a flowchart illustrating a method of operating a receiving side RTP CS for receiving VoIP packets in a broadband wireless access system according to an exemplary embodiment of the present invention.

Referring to FIG. 7, in step 701, the RTP CS determines whether a MAC SDU is received from the CS classifier. Here, the MAC SDU received from the CS classifier is composed of [RTP header + VoIP payload].

Then, in step 703, the RTP CS generates an IP header and a UDP header that are not transmitted in the radio section using its packet classification rule. That is, the IP header is generated by using a protocol in its packet classification rule, information on a source IP address and a destination IP address, and generates the UDP header using information on a source port number and a destination port number do.

The items included in the IP header, including the protocol, the source IP address, and the destination IP address, are as shown in Table 4 below.

Item Explanation Version version. Since it uses IPv4, it always becomes 4. Header Length The length of the IP header. Since it uses IPv4, it is always 5 (unit, 4 bytes). Type Of Service (TOS) Service type. 0 " or " VoIP " packet. That is, the length of the IP header is 4 bytes * 5 = 20 bytes. Total Length Total length (bytes). [IP header 20 bytes + UDP header 8 bytes + RTP header 12 bytes + VoIP payload]. At this time, the size of the VoIP payload uses the value obtained by subtracting 12 bytes of the RTP header from the size of the MAC SDU received from the CS classifier. When the total length exceeds the maximum length, the data is fragmented and transmitted. Identification IP header delimiter identifier. Since fragmentation is not necessary, set it to 0. Flages Flags associated with fragmentation. Since no fragmentation is required, the DF (Do not Fragmentation) bit, which is a flag indicating that fragmentation is not performed, is set to 1, the MF (More Fragmentation) flag which is a flag to mean fragmentation is set to 0, and the Reserved bit is set to 0. Fragment Offset A flag offset, meaning the relative position value of the fragmented packet, for reassembly when fragmented. Since fragmentation is not necessary, set it to 0. Time To Live (TTL) Effective time. It is set to the normal TTL initial value such as 64 or 128. Protocol Transport protocol. Set to 17 because UDP is used as the transport protocol layer. Header Checksum Header checksum. Calculate according to the IP header checksum calculation method. Source IP address Source IP address. Use the source IP address determined during the VoIP call setup process. Destination IP address Destination IP address. Use the destination IP address determined in the VoIP call setup process.

Next, the items included in the UDP header including information on the source port number and the destination port number are as shown in Table 5 below.

Item Explanation Source Port number Source port number. Use the source port number determined in the VoIP call setup process. Destination Port number Destination port number. Use the destination port number determined in the VoIP call setup process. Length Total length (bytes). [8 bytes of UDP header + 12 bytes of RTP header + VoIP payload]. At this time, the size of the VoIP payload uses the value obtained by subtracting 12 bytes of the RTP header from the size of the MAC SDU received from the CS classifier. Checksum Checksum. Calculate according to the checksum calculation method.

In step 705, the RTP CS inserts the generated IP header and UDP header into the received MAC SDU, and generates a new MAC SDU including [IP header + UDP header + RTP header + VoIP payload].

In step 707, the RTP CS transmits the generated new MAC SDU to an upper layer.

Thereafter, the RTP CS terminates the algorithm according to the present invention.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

1 is a diagram illustrating a configuration of a MAC SDU when a transmitter transmits a VoIP packet in a wireless section in a broadband wireless access system according to the present invention;

2 is a diagram illustrating a protocol layer structure of a transmitter in a broadband wireless access system according to the present invention;

3 is a diagram illustrating a protocol layer structure of a receiving side in a broadband wireless access system according to the present invention;

FIG. 4 is a flowchart illustrating a method of operating a CS classifier on a transmission side for transmitting a VoIP packet in a wireless section in a broadband wireless access system according to an exemplary embodiment of the present invention; FIG.

FIG. 5 is a flowchart illustrating an operation method of a RTP CS on a transmission side for transmitting a VoIP packet in a wireless section in a broadband wireless access system according to an embodiment of the present invention; FIG.

6 is a flowchart illustrating a method of operating a CS classifier on a receiving side for receiving a VoIP packet in a wireless section in a broadband wireless access system according to an embodiment of the present invention;

7 is a flowchart illustrating a method of operating a receiving side RTP CS for receiving a VoIP packet in a wireless section in a broadband wireless access system according to an exemplary embodiment of the present invention.

Claims (30)

A Convergence Sublayer (CS) voice packet transmission method in a broadband wireless access system, Checking whether the received MAC SDU is a MAC SDU for a voice packet when a MAC (Medium Access Control) SDU (Service Data Unit) is received from an upper layer; When the received MAC SDU is a MAC SDU for a voice packet, removes an IP (Internet Protocol) header and a UDP (User Datagram Protocol) header from the received MAC SDU to form a Realtime Transport Protocol (RTP) Generating a new MAC SDU, And transmitting the generated new MAC SDU to the MAC sublayer. The method according to claim 1, The process of checking whether the received MAC SDU is a MAC SDU for a voice packet includes: Comparing header information extracted from at least one of an IP header and a UDP header in the received MAC SDU with information obtained when setting up a voice call for transmission of the voice packet; When the header information extracted from at least one of the IP header and the UDP header in the received MAC SDU matches the information obtained in the voice call setup process for transmitting the voice packet, And determining that the packet is a MAC SDU for a voice packet. 3. The method of claim 2, Wherein the header information extracted from the IP header includes at least one of a protocol, a source IP address, and a destination IP address. 3. The method of claim 2, Wherein the header information extracted from the UDP header includes at least one of a source port number and a destination port number. The method of claim 2, wherein the voice call setting comprises: Wherein the transmitting side transmits a session initiation protocol INVITE message to the receiving side to request a voice communication setting, and the receiving side transmits a session initiation protocol success message (SIP 200 OK) to the transmitting side to respond to the request. A method for transmitting a voice packet in a broadband wireless access system, When a Convergence Sublayer (CS) classifier receives a Medium Access Control (MAC) SDU (Service Data Unit) for a voice packet from an upper layer, the Convergence Sublayer classifies the received MAC SDU into an RTP (Realtime Transport Protocol) CS Transmitting, The RTP CS removes an IP (Internet Protocol) header and a UDP (User Datagram Protocol) header from the received MAC SDU to generate a new MAC SDU composed of a RTP (Realtime Transport Protocol) header and a voice payload, To a MAC sublayer. The method according to claim 6, And the CS classifier transmits the received MAC SDU to the RTP CS, Comparing header information extracted from at least one of an IP header and a UDP header in the received MAC SDU with information obtained in a voice call setup process for transmitting the voice packet; When the header information extracted from at least one of the IP header and the UDP header in the received MAC SDU matches the information obtained in the voice call setup process for transmitting the voice packet, Lt; RTI ID = 0.0 > RTP < / RTI > CS. 8. The method of claim 7, Wherein the header information extracted from the IP header includes at least one of a protocol, a source IP address, and a destination IP address. 8. The method of claim 7, Wherein the header information extracted from the UDP header includes at least one of a source port number and a destination port number. 8. The method of claim 7, wherein the voice call setting comprises: Wherein the transmitting side transmits a session initiation protocol INVITE message to the receiving side to request a voice communication setting, and the receiving side transmits a session initiation protocol success message (SIP 200 OK) to the transmitting side to respond to the request. A voice packet transmission apparatus in a broadband wireless access system, A CS classifier for transmitting the received MAC SDU to a Real Time Transport Protocol (RTP) Convergence Sublayer (CS) when a Medium Access Control (MAC) SDU (Service Data Unit) for a voice packet is received from an upper layer, Wow, A new MAC SDU including an RTP (Realtime Transport Protocol) header and a voice payload is generated by removing an IP (Internet Protocol) header and a UDP (User Datagram Protocol) header from a MAC SDU from the CS classifier, Lt; RTI ID = 0.0 > CS. ≪ / RTI > 12. The apparatus of claim 11, wherein the CS classifier comprises: Means for comparing header information extracted from at least one of an IP header and a UDP header in the received MAC SDU with information obtained in a voice call setup process for transmitting the voice packet; When the header information extracted from at least one of the IP header and the UDP header in the received MAC SDU matches the information obtained in the voice call setup process for transmitting the voice packet, Lt; RTI ID = 0.0 > RTP < / RTI > CS. 13. The method of claim 12, Wherein the header information extracted from the IP header includes at least one of a protocol, a source IP address, and a destination IP address. 13. The method of claim 12, Wherein the header information extracted from the UDP header includes at least one of a source port number and a destination port number. 13. The method of claim 12, wherein the voice call setup comprises: Wherein the transmitting side transmits a session initiation protocol INVITE message to the receiving side to request a voice communication setting, and the receiving side transmits a session initiation protocol success message (SIP 200 OK) to the transmitting side to respond to the request. A method for receiving a voice packet in a Convergence Sublayer (CS) in a broadband wireless access system, Generating an IP (Internet Protocol) header and a UDP (User Datagram Protocol) header when a MAC SDU for a voice packet is received from a MAC (Medium Access Control) sublayer; Generating a new MAC SDU including an IP header, a UDP header, an RTP (Realtime Transport Protocol) header, and a voice payload by inserting the generated IP header and UDP header into the received MAC SDU; And transmitting the generated new MAC SDU to an upper layer. 17. The method of claim 16, Wherein the voice packet is generated using information acquired in a voice call setup process for transmitting the voice packet. 18. The method of claim 17, wherein the voice call setup comprises: Wherein the transmitting side transmits a session initiation protocol INVITE message to the receiving side to request a voice communication setting, and the receiving side transmits a session initiation protocol success message (SIP 200 OK) to the transmitting side to respond to the request. 17. The method of claim 16, Wherein the IP header includes at least one of a protocol, a source IP address, and a destination IP address. 17. The method of claim 16, Wherein the UDP header includes at least one of a source port number and a destination port number. A method for receiving a voice packet in a Convergence Sublayer (CS) in a broadband wireless access system, When a Convergence Sublayer (CS) classifier receives a MAC SDU (Service Data Unit) for a voice packet from a MAC (Medium Access Control) sublayer, the Convergence Sublayer classifies the received MAC SDU into a RTP (Realtime Transport Protocol) CS ; And Generating an IP (Internet Protocol) header and a UDP (User Datagram Protocol) header by the RTP CS; Generating a new MAC SDU including an IP header, a UDP header, an RTP header, and a voice payload by inserting the generated IP header and UDP header into the received MAC SDU; And transmitting the generated new MAC SDU to an upper layer by the RTP CS. 22. The method of claim 21, Wherein the voice packet is generated using information acquired in a voice call setup process for transmitting the voice packet. 23. The method of claim 22, wherein the voice call setup comprises: Wherein the transmitting side transmits a session initiation protocol INVITE message to the receiving side to request a voice communication setting, and the receiving side transmits a session initiation protocol success message (SIP 200 OK) to the transmitting side to respond to the request. 22. The method of claim 21, Wherein the IP header includes at least one of a protocol, a source IP address, and a destination IP address. 22. The method of claim 21, Wherein the UDP header includes at least one of a source port number and a destination port number. In a voice packet receiver of a Convergence Sublayer (CS) in a broadband wireless access system, When receiving a MAC SDU (Service Data Unit) for a voice packet from a MAC (Medium Access Control) sublayer, transmits the received MAC SDU to a Real Time Transport Protocol (RTP) Convergence Sublayer (CS) A classifier, (IP) header and a UDP (User Datagram Protocol) header, inserts the generated IP header and UDP header into the received MAC SDU, and transmits the IP header and the UDP header to the received MAC SDU to form an IP header, a UDP header, an RTP header, And generating the new MAC SDU and transmitting the generated new MAC SDU to an upper layer. The method as claimed in claim 26, And generates the voice call using information acquired in a voice call setup process for transmitting the voice packet. 28. The method of claim 27, wherein the voice call setup comprises: Wherein the transmitting side transmits a session initiation protocol INVITE message to the receiving side to request a voice communication setting, and the receiving side transmits a session initiation protocol success message (SIP 200 OK) to the transmitting side to respond to the request. 27. The method of claim 26, Wherein the IP header includes at least one of a protocol, a source IP address, and a destination IP address. 27. The method of claim 26, Wherein the UDP header includes at least one of a source port number and a destination port number.

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