WO2010025685A1 - Device and method for transmitting multicast and broadcast services in wireless communication system - Google Patents

Abstract

A method for providing multicast and broadcast services (MBS) in wireless access network is provided by the present invention. The method includes the following steps: establishing MBS zone which includes multiple base stations and mobile stations; generating MBS control channel (MCCH) information which includes physical layer transmission parameters for each of multiple MBS data pulses; co-encoding the MCCH information; establishing MBS transmission period; transmitting the MCCH information and MBS data in the MBS transmission period, wherein the MCCH information is transmitted at the beginning of the MBS transmission period. The application of the present invention enables the implementation of the MBS with reduced channel overhead and effective coding gain.

Description

 Apparatus and method for transmitting multicast service in a wireless communication system

 The present invention relates generally to the field of wireless communications, and more particularly to a method and system for a Multicast Service (MBS) with reduced channel overhead and efficient coding gain. Background technique

 As with existing television broadcasts and the Internet, a wireless access network can be used to send content. This classification standard has been made public. See IEEE Standards for Rural and Urban Networks - Part 16: Wireless Interface for Fixed and Mobile Broadcast Wireless Access Systems, IEEE New York, NY, February 2006.

 In MBS, a service flow of content is transmitted between a base station (single BS access) or a plurality of base stations (multi-BS access) of multicast communication and an associated mobile station (MS). Multicast communication is a method of sending content to a specific group of users or MSs that receive content or services. In addition, the MS can operate using multiple BS accesses with multiple base stations on a network that covers multicast communications.

 In MBS, content transmitted between one or more BSs and MSs includes signaling information and data transmitted with the carrier. The signaling information is the overhead associated with the data transmitted by the base station and the data received by the mobile station or subscriber station (SS). Other overhead, such as MBS MAP resource allocation information, is provided in the downlink (DL) MAP content sent between the BS and the MS. The amount of overhead information transferred between the BS and the MS is very relevant to the data transmitted in the service flow.

Summary of the invention

 In order to achieve one of the above objects of the present invention, the present invention provides a method for providing a multicast service (MBS) in a radio access network, comprising: creating an MBS area including a plurality of base stations and mobile stations; generating MBS control Channel information, the MBS Control Channel (MCCH) information includes physical layer transmission parameters for each of the plurality of MBS data pulses; co-coding the MBS control channel information; establishing an MBS transmission period; and transmitting in an MBS transmission period The MBS controls channel information and MBS data, wherein the MBS control channel information is transmitted at the beginning of an MBS transmission period.

In addition, the present invention also provides a system, including: a core service network; and an access service network, configured to receive multicast data from the core service network, where the access service network includes: A service controller (MBSC) is used to create a multicast service (MBS) area including a plurality of base stations and mobile stations; and an MBS proxy (MBSA) in each base station for transmitting MBS control channel information in an MBS transmission period And MBS data, wherein the MBS control channel information is sent at the beginning of the MBS transmission period. And a machine-accessible medium for providing instructions, when accessed, causing the access service network to perform the operations of: creating an MBS zone comprising a plurality of base stations and mobile stations; generating MBS control channel information, the MBS control channel The (MCCH) information includes physical layer transmission parameters for each of the plurality of MBS data pulses; co-coding the MBS control channel information; establishing an MBS transmission period; and transmitting MBS control channel information and MBS data in an MBS transmission period, The MBS control channel information is transmitted at the beginning of the MBS transmission period. DRAWINGS

 The subject matter of the invention is particularly pointed out and defined in the appended claims. However, the organization and method of operation, as well as the objects, features, and advantages of the present invention will become more readily understood from

 1 is a broadband wireless access network in accordance with some embodiments of the present invention;

 Figure 2 is a block diagram of one embodiment of a co-coded MBS transmission period of the present invention; Figure 3 is a block diagram of one embodiment of a frame structure of a hybrid carrier including MBS and unicast communication of the present invention;

 4 is a block diagram of an embodiment of a frame structure of a dedicated carrier of the present invention;

 Figure 5 is a block diagram showing another embodiment of a frame structure of a dedicated carrier of the present invention;

 6 is a block diagram of an embodiment of an MBS transmission period in which physical layer parameters are inserted in data according to the present invention;

 7 is a block diagram of an embodiment of a pilot pattern for a plurality of base station accesses having a conventional cell range of the present invention;

 Figure 8 is a block diagram of an embodiment of a pilot pattern for multi-base station access with a large cell range of the present invention;

9 is a flow diagram of one embodiment of a method of transmitting a multicast service in a wireless access network. It is understood that the elements shown in the figures are not necessarily drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to the other elements for clarity. In addition, For convenience, the reference numerals will be repeatedly used in the drawings to indicate the same or similar elements. detailed description

 In the following detailed description, numerous specific features and details of a wireless multicast service are provided for ease of understanding the invention. However, it will be understood by those skilled in the art that the invention may be In other instances, well-known methods, procedures, components, and circuits have not been described in detail to avoid obscuring the invention.

 In the art, a method of reducing the overhead of transmission in a carrier and a method of increasing the coding efficiency of MBS content are advanced. Reducing the channel overhead associated with MBS content can reduce the power associated with the transmission and reception of MBS content. In addition, reducing the overhead associated with MBS content transmission can increase the throughput of desired data, such as electronic files or multimedia streams that are transmitted to one or more access points, subscriber stations, and/or mobile stations in the MBS.

 Referring now to the drawings, Figure 1 shows a broadband wireless access network in accordance with some embodiments of the present invention. The radio access network 100 includes a core serving network (CSN) 110 and an access service network (ASN) 120. The wireless access network 100 can receive content from one or more content servers 112 and provide the content to one or more access points (APs), subscriber stations, or mobile stations (MS) 102, among other things. The ASN 120 may include one or more gateways (GWs) 108, as shown by ASN GW 1 and ASN GW 2 in the figure, and a plurality of base stations (BSs) 104, as shown in BS 1 through BS 7 in the figure. The CSN 110 can include a Authentication, Authorization, and Accounting Server (AAA) 111, where, among other things, access requests can be processed.

Gateway 108 may include a Multicast Service Controller (MBSC) 118, in accordance with an embodiment of the present invention. Each MBSC 118 may create one or more Multicast Service (MBS) zones 106, and each MB S zone 106 may include multiple base stations 104. MBSC 118 may create MBS zone 106 by establishing specific time and frequency parameters to simultaneously perform multicast downlink transmissions to mobile station 102 in a particular one of MBS zones 106. In these embodiments, base station 104 may include an MBS Proxy (MBSA) 114 to direct or instruct base station 104 to simultaneously transmit the same content in the MBS zone of the downlink subframe. Channel information and MBS data, in which MBS control channel information is transmitted at the beginning of the MBS transmission period. The same MBS zone may include multicast content identified by a Multicast Connection Identifier (CID). many The broadcast service can be provided over the wireless access network 100, as will be described in more detail below.

 In some embodiments, the radio access network 100 can operate as a single frequency network (SFN). In these embodiments, base station 104 of normal MBS zone 106 may have downlink and/or uplink subframes synchronized in time and frequency such that mobile station 102 may receive more from any of base stations 104 in a particular MBS zone 106. Broadcast content does not need to perform handover operations in the MBS area. In these embodiments, mobile station 102 may utilize various gains obtained simultaneously from multiple base stations 104 in MBS zone 106, which may result in an improved signal to noise ratio (SNR) at mobile station 102. In these embodiments, the multicast content may be provided in the same MBS field of the downlink subframe such that the mobile station 102 may receive the broadcast content from any one or more of the base stations 104 of the MBS zone 106. In some embodiments, one or more non-single frequency network (non-SFN) base stations (not shown) outside of the MBS zone 106 may transmit multicast data asynchronously, although the scope of the invention is not limited in this respect. .

 2 is a block diagram of some embodiments of a co-coded MBS transmission period 201 of MBS in a wireless access network 100. In this example, the MBS transmission period 201 is the time each MBS is transmitted. In one embodiment, the MBS transmission period 201 is a duration of 500 milliseconds (ms), i.e., a set of 25 20 ms subframes. In other embodiments (not shown), the MBS transmission period 201 is a duration of 20 ms, i.e., one subframe is at a minimum. In a further embodiment, the MBS transmission period 201 can be an integer from 2 to 24 subframes. The advantage of using a longer MBS transmission period 201 is that a longer MBS transmission period 201 can provide better power saving performance for the MS 102.

 In the example where the hybrid carrier is used for MBS transmission, the content can be transmitted through multiple subframes. In this example, each subframe is 20 ms duration and is divided into 4 5 ms radio frames of the same size. The MBS is transmitted in a downlink (DL) subframe, although each subframe can be designated as a DL or can be designated as an uplink (UL) subframe. In one embodiment, each subframe includes six orthogonal frequency division multiplexing (OFDM) symbols, each symbol representing one or more data bits. For a 10 megahertz (MHz) bandwidth, a Fast Fourier Transform (FFT) of 1024 points is used. In other examples, a dedicated carrier is used to transmit the MBS.

For large radius serving cells (e.g., 10 km cell radius), a suitable cyclic prefix (CP) length can be used to correct for delay spread in the composite channel. The size of the FFT can be determined based on the length of the CP to control the CP overhead. For example, in a 10MHz bandwidth environment, support 2048 points of FFT for each Subframes 3 OFDM symbols. In another example, an FFT supporting 4096 points is 3 OFDM symbols per two subframes.

 The embodiment of FIG. 2 further illustrates MBS Control Channel (MCCH) 210 information transmitted or distributed at the beginning of each MBS transmission period 201 in each MBS area 106. The MCCH 210 information includes MBS related control information, such as physical layer transmission parameters for each service that is commonly encoded. As shown in FIG. 2, the MBS control channel 210 transmits MBS related control information in the first data pulse 215, the second data pulse 220, the third data pulse 225, and the nth data pulse 230 of the BMS transmission period T 201 of the BMS service. The MCCH 210 is transmitted in data pulses, such as data pulse 1 215 and data pulse N 230, which is not necessarily decoded in each superframe. Instead, the MCCH can be decoded in each MBS transmission period T 201, which in this example includes a plurality of superframes. As indicated in this embodiment, the MCCH represents the resource allocation for each data pulse (e.g., data pulse 1 215, data pulse 2 220, etc.) in the MBS transmission period 201.

 For the case of mixed carriers, MBS and unicast traffic are sub-frame based time division multiplexing (TMM). In this example, the Secondary Broadcast Channel (SBCH) 205 can provide information related to the MBS zone. In addition, the SBCH 205 can also represent the MCCH 210 physical layer parameters of the MBS transmission period 201.

 3 is a block diagram of one embodiment of a frame structure of a hybrid carrier including MBS and unicast traffic of the MCCH 210 shown in FIG. 2, in which MBS subframes are allocated in a fixed manner in a superframe. In an alternative embodiment (not shown), the MBS subframes may be allocated in a varying manner in the superframe.

 As shown in FIG. 3, a series of superframes including superframe A 301 and superframe n 303 are transmitted in a hybrid carrier. Superframe A 301 includes a synchronization channel (SCH) 305 and/or a preamble and secondary broadcast channel (SBCH) 205 and MBS and/or unicast traffic in frame 1 310. The MBS and/or unicast traffic is also transmitted in frames 2 320, 3330, 4 4, 340 and subsequent superframes in the MBS transmission period 301. In one embodiment, superframe A 301 has a duration of 20 ms and each frame 310 to 340 has a duration of 5 ms. In the present embodiment, the SBCH 205 on the hybrid carrier represents basic information of the dedicated carrier, such as the frequency band and the FFT size.

Each frame may be further divided into a subframe 322 and an MBS Single Frequency Network (MBSFN) subframe 324, each subframe 322 and MBSFN subframe 324 including one or more symbols. In this embodiment, each subframe 322 is designated as a unicast service. Frame 2 320 includes an MBSFN subframe 324, where MBSFN Subframe 324 includes MBS data, which can be distinguished based on information transmitted by SBCH 205. A portion of the MBSFN subframe 324 includes the MBS control channel parameters 210 as described previously in FIG. Frame 3 330 also includes a plurality of subframes 322 and MBSFN subframes 324. In one embodiment, the MBSFN subframe 324 of frame 3 330 includes the MBS control channel parameter 210 starting from the beginning of the MBS transmission period 210, and the MBS control channel parameter 210 is not included in the MBSFN subframe 324 of frame 2 320. . 3 further illustrates 2 of the 4 frames of superframe n 303 (2 frames not shown), which also includes subframe 322 and MBSFN subframe 324 in frame 9 350 and frame 10 360.

 In an alternative embodiment of the MCCH 210 allocation shown in Figure 2, Figure 4 is a block diagram of the frame structure of a dedicated carrier transmitting MBS. In this embodiment, one or more of the mobile stations 102 of FIG. 1 tunes to a dedicated carrier to receive MBS traffic during the MBS transmission period 201. The MBS transmission period 201 represents the time period required to broadcast all or part of the MBS content. The mobile station 102 reads the information in the supplementary broadcast channel 205 of the hybrid carrier and then tunes to the dedicated carrier. In this embodiment, the hybrid subframe 424 of frame 2 420 includes superframe control header 305 and MBS control channel 210 information, and subframe 322 includes MBS traffic on a dedicated carrier.

 Figure 5 is a block diagram of another embodiment of a frame structure for a dedicated carrier transmitting MBS content or traffic. In this embodiment, the Secondary Broadcast Channel (SBCH) 205 on the dedicated carrier transmits or provides the physical layer parameters of the MBS Control Channel (MCCH) 210. If one or more mobile stations 102 are tuned to a dedicated carrier to receive MBS data, the one or more mobile stations 102 can be directly synchronized with the dedicated carrier, in reading the superframe 301 of frames 510 through 560 included in period T 201 The SBCH 205 is read and the MCCH 210 is read before the MBS service of 303. The application of one or more of these embodiments can provide additional coding gain to achieve power efficiency and data traffic enhancement.

6 is a block diagram of an embodiment of inserting an MBS transmission period n 601 and physical layer parameters in an MBS service for a subsequent period n+1 603. Physical layer parameters may be provided by MBS data as an alternative to reading the MBS control channel 210. In one embodiment, a portion of data pulse 1 615 includes a private MAP 610 to provide physical layer parameters to private MAP 1 601 in subsequent cycles n+1 603. Providing physical layer parameter information in the MBS data service enables one or more mobile stations 102 to determine physical layer parameter information without decoding the MCCH 210, which is one way the radio access network 100 saves power. In the present embodiment, the MBS data provided by the private MAP 1 610 in data pulse 1 615 and the private MAP N 620 in data pulse N 625 is captured in cycle n+1 603. For capital In terms of source allocation, the DL distribution configuration can be used for subframe 322, which has the same ranking order as the subcarrier to data recovery unit (DRU) mapping.

 7 is a block diagram of one embodiment of a pilot pattern for multiple base station access in a wireless access network 100. In this embodiment, the first multi-BS pilot symbol 710 and the second multi-BS pilot symbol 720 provide a dual stream pilot pattern for multi-base station 104 communications. The block diagram of Figure 7 shows that the OFDM symbol index increases from left to right along the row and the subcarrier index increases from top to bottom along the column. A two-dimensional grid of time slots is provided in each pilot pattern for the symbols, each symbol representing one or more data bits in a plurality of sub-channels. Pilot symbols, such as first single BS pilot symbol 710 and second single BS pilot symbol 720, are arranged in a non-overlapping mode to provide dual stream channel estimation.

 8 is a block diagram of one embodiment of a pilot pattern of pilot symbols 810 for a dedicated carrier. Figure 8 also shows that the OFDM symbol index increases from left to right in the direction of the row, and the subcarrier index increases from the top to the bottom in the direction of the column. In this embodiment, each subframe is allocated 3 OFDM symbols to provide a pilot scheme with 1/9 pilot overhead.

 9 is a flow chart showing one embodiment of a method of transmitting a multicast service in a wireless access network 100. At step 900, a multicast zone 106 is determined, wherein each multicast zone 106 includes a plurality of base stations 104 and mobile stations 102. The MBS traffic transmitted in each multicast zone 106 can provide the same MBS for each mobile station in the multicast zone 106. The Secondary Broadcast Channel (SBCH) data can be used to indicate or provide information regarding the location of one or more multicast zones 106 and MBS Control Channel (MCCH) information. Unicast data can be sent in unicast transmissions and MCCH information and MBS data or MBS traffic can be sent in MBS transmissions. In addition, MBS transmissions and unicast transmissions can be multiplexed, for example, using time division multiplexing (TDM), utilizing subframe 322. MCCH, MBS data and unicast data can be multiplexed using TMD, Frequency Division Multiplexing (FDM) or other multiplexing algorithms instead.

 In step 910, MBS control channel information is generated, wherein the MBS control channel information includes physical layer transmission parameters. The MBS control channel information is co-encoded in step 920 and an MBS transmission period 201 is established in step 930. Pilot symbols, such as pilot symbols 710 for cells or large cells or pilot symbols 810 for large area cells, may be inserted into the MBS data to form one or more MB S data packets. The pilot symbols can be used to determine quality of service indicators in other channel quality indicators, such as frequency offset prediction and signal to interference and noise ratio (SI R ).

At step 940, MBS control channel information and MBS data are transmitted during the MBS transmission period. Physical layer transmission parameters can be inserted into the MBS data prior to transmission. In this embodiment, MBS control channel information is transmitted at the beginning of the MBS transmission period.

 These embodiments may be described with reference to, for example, instructions, functions, processes, data structures, applications, configurations, and the like. In this specification, for the purposes of disclosure, the term "program" means a broad sense of software components and components, including applications, drivers, procedures, programs, methods, modules, and subroutines. The term "program" can be used to mean a complete compilation unit (i.e., a set of independently compilable instructions), a collection of compilation units, or a portion of compilation units. Moreover, the term "program" can be used to refer to a collection of any instructions that, when executed by the wireless access network 100, perform the required multicast service transmission. A program in the wireless access network 100 can be considered a software environment component.

 The operations discussed herein are typically by embedding in the form of code instructions in the main processor and microcontroller of the radio access network 120, the authentication, authorization and accounting server 111, the content server 112, the base station 104, and/or the mobile station. The firmware or software is executed. Furthermore, embodiments of the invention may include a set of instructions that are executed on some form of processing core or on a machine readable storage medium. A machine-readable storage medium includes a mechanism (e.g., a computer) for storing or transmitting information in a machine readable form. For example, a machine-readable medium can include a manufacturing device, such as a read only memory (ROM), a random access memory (RAM), a disk storage media shield, a disk storage media shield, a flash memory device, and the like. Furthermore, a machine-readable medium can include transmission signals, such as electrical, optical, acoustic, or other forms of communication signals (e.g., carrier waves, infrared signals, digital signals, and the like).

 Although the specific features of the invention have been described in detail, it should be understood that various changes, substitutions, changes, and equivalents are possible. It is to be understood that the appended claims are intended to cover all such changes and modifications.

Claims

Claim  A method for providing a multicast service (MBS) in a wireless access network, comprising: creating an MBS area including a plurality of base stations and mobile stations;  Generating MBS control channel information, the MBS Control Channel (MCCH) information including physical layer transmission parameters for each of the plurality of MBS data pulses;  Co-coding the MBS control channel information;  Establish an MBS transmission cycle;  The MBS control channel information and the MBS data are transmitted during the MBS transmission period, wherein the MBS control channel information is transmitted at the beginning of the MBS transmission period.  The method of claim 1 including transmitting Secondary Broadcast Channel (SBCH) data for indicating MBS zone location and MBS Control Channel Information (MCCH).  3. A method according to claim 2, comprising transmitting unicast data in a unicast transmission and transmitting MBS Control Channel (MCCH) and MBS data in an MBS transmission.  4. The method of claim 3, further comprising utilizing subframe time division multiplexing (TDM) said MBS transmission and unicast transmission.  5. The method of claim 1 further comprising multiplexing MBS control channel information, MBS data, and unicast data.  6. The method of claim 1 further comprising inserting pilot symbols into the MBS data to form MBS data packets.  7. The method of claim 1 further comprising inserting physical layer transmission parameters into the MBS data.  8. A system comprising:  Core service network; and  Accessing a service network for receiving multicast data from the core service network, the access service network comprising:  A Multicast Service Controller (MBSC) is used to create a Multicast Service (MBS) area that includes multiple base stations and mobile stations; An MBS proxy (MBSA) in each base station for transmitting MBS control channel information and MBS data in an MBS transmission period, wherein the MBS control channel information is in an MBS transmission period Start being sent.  9. The system of claim 8 wherein said MBSA sends Secondary Broadcast Channel (SBCH) data for indicating MBS zone location and MBS Control Channel Information (MCCH).  10. The system of claim 9 including transmitting unicast data from the MBSA in a unicast transmission and transmitting MBS Control Channel (MCCH) and MBS data from the MBSA in the MBS transmission.  11. The system of claim 10, further comprising utilizing a main processor time division multiplexing (TDM) of said MBS transmission and unicast transmission in a subframe.  The system of claim 8 further comprising multiplexing MBS control channel information, MBS data, and unicast data using MBSA.  13. The system of claim 8 further comprising inserting pilot symbols into the MBS data using MBSA to form MBS data packets.  The system of claim 8 further comprising inserting physical layer transmission parameters into the MBS data using MBSA.  15. A machine accessible medium for providing instructions that, when accessed, cause an access service network to perform the following operations:  Create an MBS zone comprising a plurality of base stations and mobile stations;  Generating MBS control channel information, the MBS Control Channel (MCCH) information including physical layer transmission parameters for each of the plurality of MBS data pulses;  Co-coding the MBS control channel information;  Establish an MBS transmission cycle;  The MBS control channel information and the MBS data are transmitted during the MBS transmission period, wherein the MBS control channel information is transmitted at the beginning of the MBS transmission period.  16. The machine accessible medium of claim 15 further comprising transmitting secondary broadcast channel (SBCH) data for indicating MBS zone location and MBS Control Channel Information (MCCH).  17. Machine-accessible medium according to claim 16, comprising transmitting unicast data in a unicast transmission and transmitting MBS Control Channel (MCCH) and MBS data in an MBS transmission. 18. The machine accessible medium of claim 17, further comprising utilizing subframe time division multiplexing (TDM) said MBS transmission and unicast transmission. 19. The machine accessible medium of claim 15 further comprising multiplexing MBS control channel information, MBS data, and unicast data.  20. The method of claim 15 further comprising inserting pilot symbols into the MBS data to form MBS data packets.