1、 ETSI TS 102 550 V1.2.1 (2007-01)Technical Specification Satellite Earth Stations and Systems (SES);Satellite Digital Radio (SDR) Systems;Outer Physical Layer of the Radio InterfaceETSI ETSI TS 102 550 V1.2.1 (2007-01) 2 Reference RTS/SES-00286 Keywords digital, layer 1, radio, satellite ETSI 650 Ro
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5、able at http:/portal.etsi.org/tb/status/status.asp If you find errors in the present document, please send your comment to one of the following services: http:/portal.etsi.org/chaircor/ETSI_support.asp Copyright Notification No part may be reproduced except as authorized by written permission. The c
6、opyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2007. All rights reserved. DECTTM, PLUGTESTSTM and UMTSTM are Trade Marks of ETSI registered for the benefit of its Members. TIPHONTMand the TIPHON logo are Trade Marks current
7、ly being registered by ETSI for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. ETSI ETSI TS 102 550 V1.2.1 (2007-01) 3 Contents Intellectual Property Rights4 Foreword.4 1 Scope 5 2 References 5 3 Symbols a
8、nd abbreviations.5 3.1 Symbols5 3.2 Abbreviations .5 4 Outer physical layer6 4.0 Number format definitions .6 4.0.1 Number format and transmission order 6 4.0.2 SI-Prefix Notation.6 4.1 Overview 6 4.2 Interfacing to Service Layer (SL).8 4.3 S-TS to OPL adaptation layer: S-TS encapsulation .8 4.3.1 P
9、F infoword format for S-TS stream type 0 (dummy packet) 10 4.3.2 PF infoword format for S-TS stream type 1 (transparent) 10 4.3.3 PF infoword format for S-TS stream type 2 (MPEG-TS).10 4.3.4 PF infoword format for S-TS stream type 3 (IP stream).11 4.4 PL FEC: turbo code13 4.4.1 Interface to OPL enca
10、psulation.13 4.4.2 Turbo encoder.13 4.4.3 Turbo code termination.17 4.4.4 Turbo Interleavers.19 4.4.5 Output of turbo encoder20 4.4.6 FEC Parameter signalling .20 4.4.7 Diversity combining .21 4.4.8 FEC Parameters for the signalling pipe 21 4.5 Mixer 21 4.6 Segmenter and Slot demultiplexer22 4.7 Dis
11、perser.23 4.8 Collector.24 4.9 C-TS multiplexer25 4.10 Configuration of the OPL.26 4.10.1 Signalling pipe26 4.10.1.1 Encoding and interleaving of signalling pipe26 4.10.1.2 SOF Preamble .26 4.10.1.3 Format of the signalling pipe infoword.27 4.10.2 Partitioning of the C-TS multiplex .31 4.10.3 S-TS s
12、chedule and slot allocation.31 4.10.4 S-TS re-scheduling and slot re-allocation.32 4.10.5 Birth/death of S-TS.32 4.10.6 S-TS ID.33 4.10.7 Calculation of the disperser profile.33 4.10.8 Configuration of the tail pipe34 4.10.9 Pipe reconfiguration34 Annex A (informative): Time slicing can be achieved
13、on two layers .38 Annex B (informative): Bibliography.39 History 40 ETSI ETSI TS 102 550 V1.2.1 (2007-01) 4 Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publ
14、icly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI
15、 Web server (http:/webapp.etsi.org/IPR/home.asp). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are,
16、or may be, or may become, essential to the present document. Foreword This Technical Specification (TS) has been produced by ETSI Technical Committee Satellite Earth Stations and Systems (SES). TC SES is producing standards and other deliverables for Satellite Digital Radio (SDR) systems. An SDR sys
17、tem enables broadcast to fixed and mobile receivers through satellites and complementary terrestrial transmitters. Functionalities, architecture and technologies of such systems are described in TR 102 525. Several existing and planned ETSI standards specify parts of the SDR system, with the aim of
18、interoperable implementations. The physical layer of the radio interface (air interface) is divided up into the outer physical layer, the inner physical layer with a single carrier transmission, and the inner physical layer with multiple carriers transmission. These parts can be used all together in
19、 SDR compliant equipment, or in conjunction with other existing and future specifications. The present document specifies the outer physical layer. The inner physical layer with single carrier transmission is specified in TS 102 551-1, and with multiple carriers transmission in TS 102 551-2. ETSI ET
20、SI TS 102 550 V1.2.1 (2007-01) 5 1 Scope The present document concerns the radio interface of SDR broadcast receivers. It specifies the functionality of the outer physical layer. It allows implementing this part of the system in an interoperable way. 2 References Void. 3 Symbols and abbreviations 3.
21、1 Symbols For the purposes of the present document, the following symbols apply: R Code rate 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: AWGN Additive White Gaussian Noise BCH Bose, Ray-Chaudhuri, Hocquenghem code CRC Cyclic Redundancy Checksum C-TS
22、 Channel-Transport Stream CU Capacity Unit FEC Forward Error Correction ID IDentifier IP Internet Protocol IPL Inner Physical LayerIU Interleaving Unit LSB Least Significant Bit MPEG-TS MPEG Transport Stream MSB Most Significant Bit MTU Maximum Transfer Unit OPL Outer Physical Layer PF Physical laye
23、r FEC PFIW Physical layer FEC Info Word PL PayLoad QoS Quality of Service RFU Reserved for Future Use SL Service Layer SOF Start Of Frame S-TS Service-TransportStream TS ETSI Technical SpecificationVBR Variable Bit Rate WER Word Error Rate ETSI ETSI TS 102 550 V1.2.1 (2007-01) 6 4 Outer physical lay
24、er 4.0 Number format definitions 4.0.1 Number format and transmission order Unless otherwise stated, all bit/symbol streams and values are transmitted with the following convention: In a stream, bits/symbols with a lower index are transmitted temporally earlier than those with a higher index. A pref
25、ix of a block of bits/symbols is transmitted temporally first, whereas a suffix is transmitted temporally last. Signed integer and signed fixed-point values are stored in twos complement format. If a value is represented by N bits, the Most Significant Bit (MSB), i.e. bit N-1, is transmitted tempora
26、lly first followed by bits N-2 down to bit 0, the Least Significant Bit (LSB). This order is referred to as Big Endian. For Bytes, the MSB, bit 7, is transmitted temporally first and the LSB, bit 0, last. Parity symbols of a BCH, Reed-Solomon or CRC-code are transmitted temporally in the following o
27、rder: the symbol with highest degree in polynomial representation comes first and the symbol with degree 0 comes last. The format of integer and fix-point values are specified in the following way: the first letter is U for unsigned and S for signed values, the following value following that letter
28、states the number of integer bits. In the case of fixed-point values, this value is followed by a dot “.“ and another value, which specifies the number of fractional bits. Examples: U8, S3.2. 4.0.2 SI-Prefix Notation The present document uses the prefix notation as defined by the “Systme Internation
29、al dUnits“, i.e. M (mega) represents 1 000 000 units, k (kilo) represents 1 000 units and m (milli) represents 0,001 units. 4.1 Overview The functionality of the Outer Physical Layer (in the following denoted OPL) is to provide Forward Error Correction and time interleaving for resistance against a
30、variety of transmission channel conditions. Different transport channels are used in the OPL to offer the requested performance for different types of services. These transport channels are called pipes in the scope of the present document. The OPL is configurable in terms of error protection, outag
31、e mitigation in case of signal losses, end-to-end delay, zapping time, payload throughput and receiver complexity. Multiple pipes can be used as described above. Each of them contains FEC, Mixer and Disperser. One special pipe exists whose functionality is to transmit all relevant parameters to deco
32、de the other pipes. The so-called signalling pipe is always transmitted at the lowest coderate which is 1/5. The modulation of the signalling pipe is equal to the modulation of the data pipes. The general block diagram of the OPL functionality is given in Figure 1. ETSI ETSI TS 102 550 V1.2.1 (2007-
33、01) 7 Figure 1: General overview of the OPL functionality ETSI ETSI TS 102 550 V1.2.1 (2007-01) 8 The processing, multiplexing and demultiplexing of the data in the OPL is displayed in Figure 2. Figure 2: Definition of the different blocks involved in the OPL processing 4.2 Interfacing to Service La
34、yer (SL) The interface to the service layer is the so-called Service-Transport Stream (S-TS). For the OPL, each S-TS source is the smallest granularity which can be processed independently. The interface may work synchronously or asynchronously. In the case of asynchronous interface, the PL must be
35、able to accept at least the average data rate that is provided by the SL. Any data buffering shall be done inside the SL, such that no data from the S-TS is lost at this interface. When the PL requests new data for transmission, the SL can either provide the requested data to the PL or it can signal
36、 that no data is currently available. If no data is available for transmission, the PL instead transmits dummy data that is discarded in the receiver. Inside an S-TS, multiplexing and de-multiplexing of information shall be carried out by the service layer. Each pipe provides a different set of tran
37、smission parameters (e.g. FEC code rate and disperser profile), and achieves a different QoS in terms of protection against transmission errors and end-to-end delay. One pipe of the OPL may carry several S-TS, all with the same QoS parameters. If PL time slicing is used, each time slice is associate
38、d with one S-TS. The scheduling of the S-TS, i.e. their start instants and lengths, inside a pipe can be adapted frequently (once per schedule/time slicing period). This opens the possibility of handling Variable Bit Rate (VBR) transmission. The maximum allowed payload throughput per S-TS is 3,2 Mbi
39、t/s (this corresponds to approximately 8 to 10 video services inside one S-TS). This is the throughput that the processing chain inside the receiver (e.g. the turbo decoder) must be able to handle at least. 4.3 S-TS to OPL adaptation layer: S-TS encapsulation The OPL is prepared to transport differe
40、nt types of S-TS, and a mixture of different S-TS types may be transported simultaneously over one C-TS multiplex. ETSI ETSI TS 102 550 V1.2.1 (2007-01) 9 The following parameters have to be determined for each S-TS (for parameters, refer to signalling pipe in clause 4.10.1): S-TS ID: identifier for
41、 the transported S-TS, that is unique for each network operator (i.e. for each Operator_ID); observe that one S-TS may be transported over multiple instances of the PL and still have a single unique S-TS ID; this helps, for example, for diversity combining of one S-TS transmitted over satellite and
42、simultaneously over terrestrial repeaters. Several rules apply for the S-TS: - S-TS ID 0 plays a special role: this is the Service Layer configuration S-TS (the SL can signal its own configuration via this S-TS). - An S-TS may be fed to several C-TS multiplexes. The S-TS IDs in all of these C-TS mul
43、tiplexes are identical. - An S-TS may not be fed to several pipes inside the same C-TS multiplex. - S-TS IDs must be unique over the complete network of one operator except for S-TS ID 0 which is allowed on every C-TS multiplex. - S-TS with an identical Operator_ID and S-TS ID can always be diversit
44、y combined (except for S-TS ID 0). - The length of an S-TS can be configured in a granularity of one PL infoword per C-TS frame. Pipe number that this S-TS is transported over. Moreover, for the ensemble of S-TS contained inside a complete C-TS multiplex, the following parameters have to be fixed (f
45、or parameters, refer also to signalling pipe in clause 4.10.1): Operator_ ID: unique identifier for the network operator. Partitioning of the C-TS multiplex into pipes and scheduling of the S-TS inside the pipes, i.e. what is the data rate of one S-TS and when are the bursts of one S-TS transported.
46、 Each S-TS is partitioned into packets to match the length of the PL FEC information word (PF infoword). The packet size is individual for each type of S-TS. The OPL encapsulation inside the S-TS to OPL adaptation layer adapts the length of the S-TS packets to the PF infoword length by appending a s
47、uffix to the S-TS packet. Table 1 defines the S-TS packet length and the suffix length for different S-TS types. Table 1: Defined S-TS type IDs S-TS Type S-TS Type ID S-TS payload packet Size in bytes Suffix length in bits Comment Dummy packet 0 0 26 Used for asynchronous SL/PL interface. Is discard
48、ed in receiver. Transparent 1 1 532 26 SL has to decide what to do with this data. MPEG-TS 2 1 504 250 Payload packet is 8 MPEG packets of 188 bytes each; additionally, a BCH code of 196 bits is applied. IP stream 3 1 504 250 MTU of IP = 4 095 bytes with 2 bytes additional header per packet. RFU 4 t
49、o 7 Reserved for future S-TS types. The detailed format for the different types of S-TS is given in the following clauses. ETSI ETSI TS 102 550 V1.2.1 (2007-01) 104.3.1 PF infoword format for S-TS stream type 0 (dummy packet) The format of the dummy packet is given in Table 2. The insertion of a dummy packet is performed if no data was available at the instant of processing the actual packet in the OPL. Table 2: PF infoword format for S-TS stream type 0 (dummy packet) Start bit index Parameter Description Wordsize (bits) Format Comment 0 Dummy data To
