KR20090049970A - Apparatus and method for multicast and broadcast service in broadband wireless access system - Google Patents

Abstract

The present invention relates to an apparatus and method for multicast and broadcast services in a broadband wireless access system. In the method for packetizing MBS traffic in a system providing a broadcast service according to the present invention, a process of splitting MBS traffic received from a network for synchronization, and having each of the segmented segments, Generic Routing Encapsulation (B) generating a packet, and at least one of a traffic identifier, an MBS zone identifier, and a broadcast channel identifier indicating whether an MBS is recorded in a header of the GRE packet, and MBS related synchronization information and an MBS synchronization packet in a payload of the GRE packet. A service data unit (SDU) is included, and the process includes transmitting the generated GRE packet to the base station in consideration of the packet period.

Broadcast Service, MBS, Time Synchronization, Packet Synchronization

Description

Apparatus and method for multicast and broadcast service in broadband wireless access system {APPARATUS AND METHOD FOR MULTICAST AND BROADCAST SERVICE IN BROADBAND WIRELESS ACCESS SYSTEM}

The present invention relates to an apparatus and a method for a multicast and broadcast service (MBS) in a broadband wireless access system, and more particularly, to an apparatus and a method for generating an MBS packet for time and packet synchronization. .

In general, communication systems have been developed mainly for voice services, and are gradually developing into communication systems capable of not only voice but also data services and various multimedia services. However, the voice-oriented communication system has not satisfied the rapidly increasing user's service needs due to the relatively small transmission bandwidth and high usage fee. In addition, due to the development of the communication industry and increasing user demand for Internet services, there is an increasing need for a communication system capable of efficiently providing Internet services. As a result, it has been introduced into a broadband wireless access system for efficiently providing Internet services with broadband enough to meet the demands of rapidly increasing users.

The broadband wireless access system is a system for integrating and supporting not only voice but also various low speed and high speed data services and multimedia application services such as high definition video. The broadband wireless access system is based on a wireless medium using broadband such as 2GHz, 5GHz, 26GHz and 60GHz, in a mobile or fixed environment, public switched telephone network (PSTN), public switched data network (PSDN), internet network, IMT2000 network, It is a wireless communication system that can connect ATM (Asynchronous Transfer Mode) network and can support channel rates of 2Mbps or more. The broadband wireless access system may be classified into a broadband wireless subscriber network, a broadband mobile access network, and a high-speed wireless local area network (LAN) according to terminal mobility (fixed or mobile), communication environment (indoor or outdoor), and channel transmission rate. .

The wireless access method of the broadband wireless access system is being standardized by the IEEE 802.16 standardization group of the Institute of Electrical and Electronics Engineers, one of the international standardization organizations.

Compared to the wireless technology for the conventional voice service, the IEEE 802.16 standard has a wider bandwidth of data, which allows a large amount of data to be transmitted in a short time, and enables all users to efficiently use the channel by sharing a channel (or resource). . In addition, quality of service (QoS) is guaranteed so that users can receive different quality services according to the characteristics of the service.

The IEEE 802.16 system has a multicast and broadcast service (MBS) service standard capable of providing multicast and broadcast to a plurality of mobile terminals. In the MBS standard, the same multicast and broadcast service area may be distinguished through different connection identifiers (CIDs) or different security associations (SAs). That is, the MBS zone (MBS_ZONE) is used to indicate that broadcast and multicast service flows are valid through CID and SA. The base station broadcasts MBS_ZONE information through a downlink channel descriptor (DCD) message. In other words, MBS_ZONE may be referred to as a base station group that uses the same CID and SA to transmit content.

The MBS service is divided into a single-BS access and a multi-BS access according to a service access method of a mobile terminal. The single-base station access method is a method in which a mobile terminal receives MBS service from one base station to which it is registered, and the multi-base station access method is a method in which a mobile terminal receives MBS service from two or more base stations simultaneously. 1 is a diagram illustrating a single-base station access method, and FIG. 2 is a diagram showing a multi-base station access method.

As shown in FIG. 2, in the multi-base station access scheme, when a mobile terminal is located at a position where a neighboring cell overlaps with a cell currently being served, a signal of a neighboring cell is not a noise due to interference, but a radio frequency (RF). Frequency) acts as a signal gain by combining. This is the Macro Diversity effect. However, in order to obtain such a macro diversity effect, a signal transmitted from a serving base station and a base station of a neighboring cell must be identical. Therefore, in order to provide MBS, all base stations in MBS_ZONE must transmit the same signal at the same time.

As such, when providing the MBS, a time synchronization scheme is required so that all base stations in the same broadcast zone MBS_ZONE can transmit the same signal at the same time.

In general, the base station generates a media access control (MAC) layer packet data unit (PDU) by segmenting or packing a service data unit (eg, an IP packet) received from a network, and generates the generated MAC. PDUs are collected to generate a physical layer burst, and the physical layer burst is encoded and transmitted at a predetermined Modulation and Coding Scheme (MCS) level. As described above, the reason why the division and packing operation occurs in the base station is that the size of the packet (IP packet) received from the network is variable. In the case of the Multi-BS MBS, the base station should not perform the partitioning and packing operation as described above, and the base station controller or the MBS controller performs this for synchronization, and the base station should bypass.

If base stations belonging to the same broadcast zone separately divide or pack MBS packets received from a network without considering synchronization, MAC PDUs having different sizes may be generated for the same content. There is a problem that can not be transmitted at the correct synchronization time.

In other words, in order to obtain a macro diversity effect on the MBS service, the base station should not generate a split or packet operation on a service data unit (IP packet). On the other hand, the packet received from the network must be accommodated in the MAC PDU in order to prevent the division or packing operation in the base station, but so far has not been proposed for this criterion.

Accordingly, an object of the present invention is to provide an apparatus and a method for all base stations in the same broadcast zone to transmit the same signal at the same time in a broadband wireless access communication system.

Another object of the present invention is to provide an apparatus and method for transmitting MBS packets received from a network without packetization at a base station in a broadband wireless access communication system.

Another object of the present invention is to provide an apparatus and method for generating an MBS packet suitable for a wireless section in a broadband wireless access communication system.

Another object of the present invention is to provide an apparatus and method for determining the size and interval of an MBS packet according to radio section scheduling information in a broadband wireless access communication system.

According to an aspect of the present invention for achieving the above object, an apparatus for packetizing MBS traffic in a system for providing a broadcast service, the packet size and the air size by using the content transmission rate and air section air scheduling information; A control unit for determining a packet period, a division unit for dividing the MBS traffic according to the determined packet size, a GRE packet generation unit for generating a Generic Routing Encapsulation (GRE) packet with each of the segments from the division unit, In the header of the GRE packet, at least one of a traffic identifier, MBS service type, MBS zone identifier, and broadcast channel identifier indicating whether or not MBS is recorded, and the time stamping information corresponding to the absolute broadcast time, packing & Write down whether it is split or not, length of payload, or service data unit (SDU) corresponding to MBS synchronization packet One is included, characterized in that it comprises a communication unit for transmitting the GRE packet from the GRE packet generation unit to the base station in consideration of the packet period.

According to another aspect of the present invention, an apparatus for packetizing MBS traffic in a system for providing a broadcast service, comprising: a divider for dividing MBS traffic received from a network for synchronization, and segments from the divider, respectively A GRE packet generation unit for generating a GRE (Generic Routing Encapsulation) packet, and at least one of a traffic identifier indicating MBS, an MBS service type, an MBS zone identifier, and a broadcast channel identifier is recorded in a header of the GRE packet. The payload of the GRE packet includes at least one of time stamping information corresponding to an absolute broadcast time, packing & splitting information, payload length information, and a service data unit (SDU) corresponding to an MBS synchronization packet. And a communication unit for transmitting the GRE packet from the generation unit to the base station in consideration of the packet period. .

According to still another aspect of the present invention, there is provided a method for packetizing MBS traffic in a system for providing a broadcast service, the method comprising: determining a packet size and a packet period by using content rate and radio interval information, and the MBS traffic; Splitting according to the determined packet size, generating a Generic Routing Encapsulation (GRE) packet with each of the divided segments, a header of the GRE packet, a traffic identifier indicating whether an MBS is present, an MBS service type, At least one of an MBS zone identifier and a broadcast channel identifier is recorded, and the payload of the GRE packet includes time stamping information corresponding to an absolute broadcast time, packing & splitting information, payload length information, and an SDU corresponding to an MBS synchronization packet. And at least one of a Service Data Unit, and the generated GRE packet may be stored in consideration of the packet period. It characterized in that it comprises a process for transmitting to the station.

According to another aspect of the present invention, a method for packetizing MBS traffic in a system for providing a broadcast service, the method comprising the steps of partitioning the MBS traffic received from the network for synchronization, and each of the divided segments Generating a Generic Routing Encapsulation (GRE) packet, and at least one of a traffic identifier indicating MBS, an MBS service type, an MBS zone identifier, and a broadcast channel identifier is recorded in a header of the GRE packet, and the payload of the GRE packet is recorded. Includes at least one of time stamping information corresponding to an absolute broadcast time, packing & splitting information, payload length information, and a service data unit (SDU) corresponding to an MBS synchronization packet, and includes the generated GRE packet in the packet. It is characterized in that it comprises the step of transmitting to the base station in consideration of the period.

According to still another aspect of the present invention, in an apparatus for packetizing MBS traffic in a system providing a broadcast service, a packet size and a packet period are determined by using a content rate and air section air scheduling information. A control unit to divide the MBS traffic according to the determined packet size, a GRE packet generation unit to generate a GRE (Generic Routing Encapsulation) packet from each of the segments from the divider, and the GRE packet The header includes a traffic identifier indicating whether an MBS is present. The GRE payload includes an MBS service type, an MBS zone identifier, a broadcast channel identifier, time stamping information corresponding to an absolute broadcast time, packing & splitting information, and payload length information. And at least one of a service data unit (SDU) corresponding to an MBS synchronization packet, from the GRE packet generation unit. Consider the packet period and the GRE packet is characterized in that it comprises a communication unit for transmitting to the base station.

According to still another aspect of the present invention, in the apparatus for packetizing MBS traffic in a system for providing a broadcast service, determining the packet size and the packet period using the content transmission rate and air section air scheduling information A control unit, a division unit for dividing the MBS traffic according to the determined packet size, a GRE packet generation unit for generating a Generic Routing Encapsulation (GRE) packet with each of the segments from the division unit, and a header of the GRE packet Includes at least one of a traffic identifier indicating the MBS, an MBS zone identifier, an MBS service type, a broadcast channel identifier, packing & splitting information, and the GRE payload includes time stamping information corresponding to an absolute broadcast time and a payload. At least one of the length information and the SDU corresponding to the MBS synchronization packet is included, from the GRE packet generation unit. Considering the GRE packet of the characterized in that it comprises a communication unit for transmitting to the base station.

As described above, the present invention has the advantage that base stations belonging to the same broadcast zone can perform timing synchronization in a broadband wireless access system that provides multicast and broadcast services (MBS). That is, according to the present invention, since the MBS traffic is packetized in advance according to the radio section in the upper system of the base station and transmitted to the base station, that is, since no fragmentation or packing is performed at the base station, broadcasting is performed. There is an advantage that time synchronization can be easily performed for the traffic.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. In addition, terms to be described below are terms defined in consideration of functions in the present invention, and may vary according to the intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, a timing synchronization method for transmitting the same signal by the base stations belonging to the same broadcast zone MBS_ZONE in the same time in a broadband wireless access communication system providing a broadcast service will be described.

In particular, for the time synchronization, the base station should not perform a fragmentation or packing operation on the packet received from the network. That is, the present invention is to packetize the MBS traffic in advance for the radio section in the upper system of the base station to transmit to the base station.

The broadcast service may be referred to as a multicast broadband service (MCBCS), a multicast and broadcast service (MBS), a multi media broadcast and multicast service (MBMS), a broadcast / multicast service (BCMCS), or the like according to a standard group and an operator's intention. have.

In the following description, a name of a network entity (NE) is defined according to a corresponding function, and may be changed according to the intention of the standardization group and the operator. For example, the base station may be called an access point (AP), a radio access station (RAS), a node-B, or a base station (BS). In addition, the base station controller may be referred to as a radio network controller (RNC), a base station controller (BSC), an access control router (ACR), or an access service network gateway (ASN-GW). The GW may perform router functions as well as base station controller functions.

In addition, although an OFDM / OFDMA-based broadband wireless communication system is described below by way of example, the present invention can be easily applied to other wireless communication systems that provide a broadcast service.

3 illustrates a network structure according to an embodiment of the present invention.

As shown, the network structure is largely divided into a part operated by a service provider (SP) and a part operated by a network provider (AP), and the part operated by the network provider is a core service network (SP). It can be divided into CSN: Core Service Network) and Access Service Network (ASN).

The MCBCS Application Server (AS) 30 is operated by a service provider, and generates a service guide for a service area of the service provider and provides it to the MCBCS NS 31. In addition, the MCBCS AS (30) is the service subscription management (subscription management), user authentication and authorization (user authentication & authorization) processing, user group management (user group management), content encryption / decryption key management and distribution (key management & Distribution, content protection, stream / file transmission, user interaction, notification or alert function for notifying emergency broadcasts, etc. are performed. Here, the content serviced by the MCBCS AS 70 may be provided from a content provider (CP) (not shown).

The MCBCS NS 31 is configured in the core service network, collects and transmits MCBCS information (eg, a service guide) from at least one MCBCS AS 30, and performs management for efficient use of network resources. In addition, the MCBCS NS 31 may be configured to manage the MCBCS transmission zone, service guide processing and distribution, stream and file transmission, multicast group management, and reception report management. reception report management) function.

The MCBCS controller 32 is configured in an access service network (eg, a block in the ASN_GW) and performs a packet / time synchronization function for broadcast content. In addition, the MCBCS controller 32 configures an MBS zone by using the reconfigured service guide from the MCBCS NS 31, and divides the service guide into MBS zones and distributes them to base stations of the MBS zone.

As shown, one service area may be configured with at least one MCBCS Tx zone, and one MCBCS Tx zone may be configured with at least one MBS zone. Here, the MCBCS Tx zones may overlap each other, and the overlap region may also be configured of at least one MBS zone.

The base station 33 transmits the broadcast content from the MCBCS controller 32 through a predetermined resource at a predetermined time. Here, base stations belonging to the same MBS zone broadcast the same content at the same time for macro diversity. Meanwhile, the service guide is transmitted to the terminal through the application layer protocol. Accordingly, the terminal may check broadcast channels (or content list) that can be received at the current location through the service guide.

Although not shown, the core service network may include a policy server, an AAA (Authentication, Authorization, Accounting) server, a network management server, and the like.

As described above, one MSB_ZONE consists of a plurality of base stations, and base stations in the same MSB_ZONE transmit the same broadcast signal at the same time. Here, an operation for transmitting the same broadcast signal by the base stations in the same broadcast zone MBS_ZONE at the same time will be described.

In order for base stations belonging to the same broadcast zone to transmit the same broadcast signal, the upper system of the base station packetizes the MBS data for the wireless section, copies the MBS synchronization packet thus generated, and the base stations belonging to the same broadcast zone. Should be sent to. The following description assumes that the packetization is performed in the MCBCS controller 32.

According to the present invention, the MCBCS controller 32 manages a packet size and a packet interval according to broadcast content transmission rate and air duration information (MCS level, MBS burst size) in a mapping table. Therefore, when the transmission rate and the radio section information are obtained, the MCBCS controller 32 may determine the packet size and packet period for generating an MBS synchronization packet by using the information. Here, the transmission rate of the broadcast content may be determined according to the type of content (eg, audio, video, etc.), and the wireless section information may be input by a system operator or received from the base station 33. In addition, the packet period is preferably determined by an integer multiple of the frame length of the radio section. For example, assuming that the frame length is 5ms, the packet period may be determined as 5ms, 10ms, 15ms, 20ms.

As such, when the packet size and the packet period are determined, the MCBCS controller 32 divides MBS data received from the MCBCS NS 31 in consideration of the packet size, and uses the divided data to generate GRE (Generic). Routing Encapsulation) generates a packet. In this case, the header (GRE header) of the GRE packet may include an identifier (traffic identifier), MBS zone identifier, broadcast channel identifier, etc. for identifying a payload traffic. In addition, the payload (GRE payload) of the GRE packet may include synchronization information (time stamp information, packing & splitting information, length information), MBS synchronization packet, and the like.

Meanwhile, the GRE packet is encapsulated into an IP packet, and the IP packet is again encapsulated into an Ethernet packet and multicasted to base stations belonging to the same broadcast zone. Then, the base stations generate the MBS synchronization packet from the MCBCS controller 32 as a MAC PDU (MBS burst) without splitting or packing, and maps the MBS burst to a predetermined resource at a corresponding broadcast time. Thus, base stations belonging to the same broadcast zone can broadcast the corresponding content using the same resources at the same time.

Here, the GRE packet according to the present invention will be described in detail.

Referring to FIG. 4, a GRE packet is largely divided into a GRE header and a GRE payload.

First, look at the GRE header, where the top 5 bits (C / R / K / S / s) are fields for setting whether the option field is included and the next 8 bits are reserved fields for future use. The 3 bits are fields for setting the version, the next 16 bits are fields for setting the protocol type of the payload, and the next 4 bytes are for setting the key for the GRE tunnel. Field, and the next 4 bytes are fields for setting the sequence number of the packet. In addition, the checksum field, an encapsulation count control field, an offset field, and a routing field may be further included according to whether the flag of the upper 5 bits is set.

The present invention records not only information for a GRE tunnel (such as a board and a process block identifier in a BS) but also MBS related information in the key field. Here, the MBS related information may include a traffic identifier for identifying whether the payload traffic is unicast traffic, MBS traffic, or general multicast traffic, and an MBS service type (eg, multi-BS MBS, static transmission single-BS). broadcasting, dynamic transmission single-BS broadcasting, dynamic transmission single-BS multicasting), an MBS zone identifier, and a broadcast channel identifier. Here, the traffic identifier needs only 1 bit to distinguish only unicast traffic and MBS traffic, and needs 2 bits to distinguish three types of traffic. In the case of WiMAX, the MBS zone identifier is 1 byte (the actual 7 bits are used because MSB = 0 is set), and the MAC layer broadcast channel identifier (MCID: Multicast CID) is 12 bits. However, since the MAC layer broadcast channel identifier currently has a range of 0xFEA0 to 0xFEFE (95), a 7-bit may indicate all broadcast channel identifiers. Therefore, if there are at least 14 bits, the MBS zone identifier and the broadcast channel identifier can be displayed.

If a multicast IP address of a backhaul is used instead of the MBS zone identifier, 4 bytes are required for IPv4, and in this case, the multicast IP address is recorded in a payload instead of a key field. Do it.

Next, referring to the GRE payload, an upper predetermined byte (eg, 5 bytes) is a field for setting synchronization information, and the rest is a field for setting an MBS synchronization packet. That is, the synchronization information is recorded in a fixed size immediately after the GRE header. The synchronization information includes absolute time stamping information, information indicating packing & fragmentation, length information indicating the total length of the GRE payload (synchronization information + MBS synchronization packet), and the like. It may include. For example, in case of WiMAX, when using frame number (FN) as time stamping information, 3 bytes are required, packing & splitting information is 2 bits, and length information is byte count. 11 bits are required because they must be 1500 bytes or less. When 3 bits are reserved fields, the field for the synchronization information may be 5 bytes.

Here, an example of a method of displaying packing & splitting information is as follows. '00' indicates that no division / packing operation has been performed, '01' indicates that a packing operation has been performed, '10' indicates that fragmentation and zero padding operations have been performed, and '11' 'Indicates that division and packing operations have been performed.

If the key field is mostly used for purposes other than MBS, an MBS zone identifier and a broadcast channel identifier may also be recorded in the synchronization information field. In this case, the synchronization information field requires a total of 10 bytes or 11 bytes.

4, at least one of a traffic identifier, an MBS service type, an MBS zone identifier, and a broadcast channel identifier is set in a header of the GRE packet, and time stamping information, packing & splitting information, and payload length in a payload. And at least one of MBS synchronization packet (SDU).

In another embodiment, the traffic identifier is set in the header of the GRE packet, the MBS service type, MBS zone identifier, broadcast channel identifier, time stamping information, packing & splitting information, payload length information, and MBS synchronization packet in the payload. At least one of may be set.

In another embodiment, at least one of a traffic identifier, an MBS service type, an MBS zone identifier, a broadcast channel identifier, packing & splitting information is set in a header of the GRE packet, and time stamping information, payload length, and At least one of the MBS synchronization packets may be set.

As such, the classification of the information recorded in the GRE header and the information recorded in the GRE payload may be implemented in various forms. In addition, while the above-described embodiment is described as recording MBS related information in a key field in a GRE header, the MBS related information may include other option fields (eg, protocol type field, sequence number field, Routing fields, etc.).

Meanwhile, although the present invention describes the GRE packet as an example, other tunneling packets may be used. In addition, the terms of the present invention are described on the basis of the WiMAX MBS standard, but it will be apparent that other terms of the same concept may be replaced when the wireless network to be applied is different.

FIG. 5 illustrates a configuration of a network entity NE that performs packetization according to an embodiment of the present invention. The NE performing the packetization may be, for example, one of the MCBCS NS 31 and the base station controller. The following description will be made on the assumption that the NE is performed by the MCBCS controller 32 in the base station controller.

As shown, the MCBCS controller 32 is a control unit 500, wireless section information storage unit 502, mapping table storage unit 504, buffer 506, partition unit 508, GRE packet generation unit 510 ) And a communication unit 516.

Referring to FIG. 5, the controller 500 controls the overall operation of the MCBCS controller 32. The radio section information storage unit 502 manages radio section information for each of the broadcast zones MBS_ZONE. Here, the radio section information may be input by a system operator or received from the base station 33.

The mapping table storage unit 504 manages a packet size and a packet interval according to broadcast content air rate and radio interval information (MCS level, MBS burst size) as a mapping table. For example, the mapping table may be represented as shown in Table 1 below.

 Bit rate [Kbps]  Radio section information (MCS level, burst size)  Packet size [Byte]  Packet period [ms] 600 QPSK, 1/2, 4 Symbols 384 5 (= 1 frame) ... ... ... ... ... ... ... ... ... ... ... ...

The control unit 500 determines the packet size and packet period for generating an MBS synchronization packet by accessing the mapping table with the broadcast content transmission rate and the radio section information. At this time, the control unit 500 determines MBS related information (eg, MBS zone identifier, broadcast channel identifier, time stamping information, packet & split information) to be recorded in each GRE packet. The controller 500 controls the corresponding component in accordance with the determined contents.

The buffer 506 buffers the MBS data received from the MCBCS NS 31 and outputs the MBS data under the control of the controller 500. The divider 508 divides and outputs MBS data from the buffer 506 according to the determined packet size.

The GRE packet generator 510 generates and outputs a GRE packet with each of the divided data from the divider 508. Here, the GRE header generator 512 generates a GRE header as shown in FIG. 4. At least one of a traffic identifier, an MBS zone identifier, and a broadcast channel identifier is recorded in a key field of the GRE header. Meanwhile, the GRE payload generator 514 generates a service data unit (SDU) with the divided data from the divider, and adds MBS related synchronization information to the SDU to generate a GRE payload. The synchronization information may include at least one of time stamping information corresponding to an absolute broadcast time, packing & splitting information, length information of a GRE payload, an MBS zone identifier, and a broadcast channel identifier. The GRE payload generator 514 combines the GRE header and the GRE payload to generate a GRE packet.

The communication unit 516 copies the GRE packets from the GRE packet generation unit 510 according to the number of base stations belonging to the same broadcast zone, and encapsulates the copied GRE packets into IP packets. The communication unit 516 encapsulates the IP packets into layer 2 packets (eg, Ethernet packets), and transmits the Ethernet packets to base stations belonging to the same broadcast zone in consideration of the packet period. In another embodiment, Ethernet packets may be copied according to the number of base stations belonging to the same broadcast zone, and the copied Ethernet packets may be multicasted to base stations belonging to the same broadcast zone.

6 shows a detailed configuration of a base station according to an embodiment of the present invention.

As shown, the base station, the control unit 600, mapping table storage unit 602, MBS SDU storage unit 604, MBS MAC PDU generation unit 606, encoder 608, OFDM modulator 610, CP An adder 612, a DAC 614, and an RF processor 616.

Referring to FIG. 6, first, the mapping table storage unit 602 manages a mapping table as shown in Table 1 above. The controller 600 accesses the mapping table with the broadcast content transmission rate and radio interval information to obtain a packet size and a packet period of the MBS synchronization packet. Here, the broadcast content transmission rate may be determined according to the type of content (eg, audio and video), and the radio section information may be input by a system operator. As such, when the packet size and packet period of the content to be broadcasted later are determined, the controller 600 performs resource scheduling using the same and controls the corresponding component according to the resource scheduling result.

The MBS SDU storage unit 604 buffers MBS synchronization packets (IP packets) received from the network, and outputs each of the buffered MBS synchronization packets at a corresponding time point under the control of the controller 600. The MBS MAC PDU generation unit 606 generates a packet data unit (PDU) of the MAC layer by adding a MAC header to the MBS synchronization packet from the MBS SDU storage unit 606 to generate an encoder of the physical layer. 608). As described above, the present invention configures the packets received from the network as MAC PDUs, and uses the MAC PDUs thus configured as bursts of the physical layer. That is, the packet received from the network is transmitted to the radio section as it is without partitioning or packing.

The encoder 608 codes and modulates the burst (MAC PDU) from the MAC PDU generation unit 606 at a predetermined modulation and coding scheme (MCS) level. The OFDM modulator 610 maps the MBS burst from the encoder 608 to a corresponding resource, and outputs an IFFT (Inverse Fast Fourier Transform) operation. The CP adder 612 adds and outputs a guard interval (eg, Cyclic Prefix) to the sample data from the OFDM modulator 610. The DAC 614 converts the sample data from the CP adder 612 into an analog signal and outputs the analog signal. The RF processor 616 converts the baseband signal from the DAC 614 into a signal of the RF band and transmits the signal through the antenna.

7 illustrates an operation procedure of a network entity that performs packetization according to an embodiment of the present invention. The NE performing the packetization may be, for example, one of the MCBCS NS 31 and the base station controller. The following description will be made on the assumption that the NE is performed by the MCBCS controller 32 in the base station controller.

Referring to FIG. 7, in operation 701, the MCBCS controller 32 checks a transmission rate of broadcast content and radio section information of a corresponding broadcast zone MBS_ZONE. Here, the transmission rate of the broadcast content may be determined according to the type of content (eg, audio, video, etc.), and the wireless section information may be input by a system operator or received from the base station 33.

When the transmission rate and the radio interval information are confirmed, the MCBCS controller 32 accesses a predetermined mapping table (Table 1) with the transmission rate and the radio interval information in step 703 to obtain a packet size and a packet period. In operation 705, the MCBCS controller 32 divides MBS data to be transmitted to the base station 33 according to the packet size.

The MCBCS controller 32 generates a GRE header for the divided data in step 707. In the key field of the GRE header, at least one of a traffic identifier indicating MBS, an MBS zone identifier, and a broadcast channel identifier is recorded.

In operation 709, the MCBCS controller 32 generates an SDU (IP packet) with the divided data, and adds MBS-related synchronization information to the SDU to generate a GRE payload. The synchronization information may include at least one of time stamping information corresponding to an absolute broadcast time, packing & splitting information, length information of a GRE payload, an MBS zone identifier, and a broadcast channel identifier.

In operation 711, the MCBCS controller 32 combines the generated GRE header and the GRE payload to generate a GRE packet. After that, the MCBCS controller 32 copies the generated GRE packet according to the number of base stations belonging to the same broadcast zone in step 713, encapsulates each of the copied GRE packets into an IP packet, and the IP packets. Each is encapsulated as a layer 2 packet (eg, an Ethernet packet) and transmitted to base stations belonging to the same broadcast zone.

8 illustrates an operation procedure of a base station according to an embodiment of the present invention.

Referring to FIG. 8, in step 801, the base station 33 checks transmission rate and radio section information of content to be broadcasted in the future. Here, the transmission rate of the broadcast content may be determined according to content (eg, audio, video, etc.), and the wireless section information may be input by a system operator.

When the transmission rate and the wireless interval information are confirmed, the base station 33 accesses a predetermined mapping table (Table 1) with the transmission rate and the wireless interval information in step 803 to determine the packet size and the packet period. The determined packet size and packet period may be used for resource scheduling.

In step 805, the base station 33 checks whether broadcast content is received from the network. If the reception of the broadcast content is detected, the base station 33 proceeds to step 807 and buffers MBS synchronization packets (SDUs, IP packets) received from the network.

In step 809, the base station 33 checks whether the transmission time according to the packet period has been reached. When the transmission time is reached, the base station 33 generates a packet data unit (PDU) of the MAC layer by adding a media access control (MAC) header to the MBS synchronization packet in step 811. In step 813, the base station 33 codes and modulates the generated MAC PDU (MBS burst) to a predetermined MCS level, and transmits the modulated data by mapping the modulated data to a predetermined resource. The base station 33 then returns to step 809 for the next transmission. As described above, the present invention configures a packet (service data unit) received from the network as it is as a MAC PDU, and transmits the MAC PDU configured as described above as a physical layer burst.

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 determined not only by the scope of the following claims, but also by the equivalents of the claims.

1 is a diagram illustrating a single-base station access scheme in a wireless communication system providing a broadcast service.

2 illustrates a multi-base station access scheme in a wireless communication system providing a broadcast service.

3 illustrates a network structure according to an embodiment of the present invention.

4 is a diagram illustrating a structure of a GRE packet according to an embodiment of the present invention.

5 is a diagram illustrating the configuration of a network entity NE that performs packetization according to an embodiment of the present invention.

6 is a diagram showing a detailed configuration of a base station according to the embodiment of the present invention.

7 is a diagram illustrating an operation procedure of a network entity that performs packetization according to an embodiment of the present invention.

8 illustrates an operation procedure of a base station according to an embodiment of the present invention.

Claims (23)

An apparatus for packetizing MBS traffic in a system providing a broadcast service, A control unit for determining a packet size and a packet period by using content rate and radio section information; A divider for dividing the MBS traffic according to the determined packet size; A GRE packet generation unit generating a GRE (Generic Routing Encapsulation) packet with each of the segments from the division unit; At least one of a traffic identifier, an MBS zone identifier, and a broadcast channel identifier indicating whether an MBS is recorded is recorded in a header of the GRE packet. And a communication unit for transmitting a GRE packet from the GRE packet generation unit to a base station in consideration of the packet period. The method of claim 1, And a storage unit for managing a packet size and a packet period according to the MBS traffic rate and radio section information by using a mapping table. The method of claim 1 The payload of the GRE packet comprises a service data unit (SDU) corresponding to MBS-related synchronization information and MBS synchronization packet. The method of claim 3, The synchronization information may include at least one of time stamping information corresponding to an absolute broadcast time, packing & splitting information, length information of a GRE payload, an MBS zone identifier, and a broadcast channel identifier. The method of claim 1, The radio section information, characterized in that the modulation and coding scheme (MCS) level and MBS burst size. The method of claim 1, The communication unit may copy the GRE packet according to the number of base stations belonging to the same broadcast zone and transmit the copied GRE packets to base stations belonging to the same broadcast zone. An apparatus for packetizing MBS traffic in a system providing a broadcast service, A partition unit for dividing the MBS traffic received from the network for synchronization; A GRE packet generation unit generating a GRE (Generic Routing Encapsulation) packet with each of the segments from the division unit; At least one of a traffic identifier, an MBS zone identifier, and a broadcast channel identifier indicating whether an MBS is recorded is recorded in a header of the GRE packet, and a service data unit corresponding to MBS synchronization information and an MBS synchronization packet is included in a payload of the GRE packet. ), And a communication unit for transmitting the GRE packet from the GRE packet generation unit to a base station. The method of claim 7, wherein The synchronization information may include at least one of time stamping information corresponding to an absolute broadcast time, packing & splitting information, length information of a GRE payload, an MBS zone identifier, and a broadcast channel identifier. The method of claim 7, wherein The communication unit may copy the GRE packet according to the number of base stations belonging to the same broadcast zone and transmit the copied GRE packets to base stations belonging to the same broadcast zone. The method of claim 7, wherein And the dividing unit divides the MBS traffic according to content rate and radio section information. In the method for packetizing MBS traffic in a system providing a broadcast service, Determining a packet size and a packet period using the content rate and the radio section information; Dividing the MBS traffic according to the determined packet size; Generating a Generic Routing Encapsulation (GRE) packet with each of the divided segments; At least one of a traffic identifier, an MBS zone identifier, and a broadcast channel identifier indicating whether an MBS is recorded is recorded in a header of the GRE packet. And transmitting the generated GRE packet to a base station in consideration of the packet period. The method of claim 11, And managing the packet size and the packet period according to the content rate and the radio section information by using a mapping table. The method of claim 11, The payload of the GRE packet comprises a service data unit (SDU) corresponding to MBS-related synchronization information and MBS synchronization packet. The method of claim 13, The synchronization information may include at least one of time stamping information corresponding to an absolute broadcast time, packing & splitting information, length information of a GRE payload, an MBS zone identifier, and a broadcast channel identifier. The method of claim 11, The radio section information is characterized in that the modulation and coding scheme (MCS) level and MBS burst size. The method of claim 11, wherein the transmission process, Copying the GRE packet according to the number of base stations belonging to the same broadcast zone; Transmitting the copied GRE packets to base stations belonging to the same broadcast zone. In the method for packetizing MBS traffic in a system providing a broadcast service, Dividing the MBS traffic received from the network for synchronization; Generating a Generic Routing Encapsulation (GRE) packet with each of the divided segments; At least one of a traffic identifier, an MBS zone identifier, and a broadcast channel identifier indicating whether an MBS is recorded is recorded in a header of the GRE packet, and a service data unit corresponding to MBS synchronization information and an MBS synchronization packet is included in a payload of the GRE packet. ), And transmitting the generated GRE packet to a base station. The method of claim 17, The synchronization information may include at least one of time stamping information corresponding to an absolute broadcast time, packing & splitting information, length information of a GRE payload, an MBS zone identifier, and a broadcast channel identifier. The method of claim 17, wherein the transmission process, Copying the GRE packet according to the number of base stations belonging to the same broadcast zone; Transmitting the copied GRE packets to base stations belonging to the same broadcast zone. The method of claim 17, wherein the dividing process, And dividing the MBS traffic according to content rate and radio segment information. A method for packetizing broadcast traffic in a system providing a broadcast service, Dividing the broadcast traffic received from the network for synchronization; Generating a tunneling packet with each of the divided segments; The header of the tunneling packet includes at least one of a traffic identifier indicating a broadcast status, a broadcast service type, a broadcast zone identifier, and a broadcast channel identifier. The payload of the tunneling packet includes time stamping information corresponding to an absolute broadcast time, packing & At least one of segmentation information, payload length information, and an SDU corresponding to a broadcast synchronization packet; And transmitting the generated tunneling packet to a base station. A method for packetizing broadcast traffic in a system providing a broadcast service, Dividing the broadcast traffic received from the network for synchronization; Generating a tunneling packet with each of the divided segments; In the header of the tunneling packet, a traffic identifier indicating whether to broadcast is recorded, and in the payload of the tunneling packet, a broadcast service type, a broadcast zone identifier, a broadcast channel identifier, time stamping information corresponding to an absolute broadcast time, packing & splitting information, etc. At least one of SDUs corresponding to payload length information and a broadcast synchronization packet, And transmitting the generated tunneling packet to a base station. A method for packetizing broadcast traffic in a system providing a broadcast service, Dividing the broadcast traffic received from the network for synchronization; Generating a tunneling packet with each of the divided segments; The header of the tunneling packet includes at least one of a traffic identifier indicating broadcast or not, a broadcast service type, a broadcast zone identifier, a broadcast channel identifier, and packing & splitting information, and the payload of the tunneling packet corresponds to an absolute broadcast time. At least one of time stamping information, payload length information, and an SDU corresponding to a broadcast synchronization packet; And transmitting the generated tunneling packet to a base station.

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