European GNSS (Galileo) open service (797926), страница 9
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i-iiOS SIS ICD, Issue 1.2, dd.mm 2014Page Content2Ephemeris (1/3) and GST3Ephemeris (2/3) and GST4Ephemeris (3/3), GST-UTC conversion, GST-GPS Conversion and TOW5Almanac for satellite (k+9) and almanac for satellite (k+10) part 11SVID, clock correction, SISA, Ionospheric correction, BGD, Signal health status, GSTand Data validity status2Ephemeris (1/3) and GST3Ephemeris (2/3) and GST4Ephemeris (3/3), GST-UTC conversion, GST-GPS Conversion and TOWtionSVID, clock correction, SISA, Ionospheric correction, BGD, Signal health status, GSTand Data validity statusAFCoTn1Almanac for satellite (k+10) part 2 and almanac for satellite (k+11)1SVID, clock correction, SISA, Ionospheric correction, BGD, Signal health status, GSTand Data validity status2Ephemeris (1/3) and GST3Ephemeris (2/3) and GST4Ephemeris (3/3), GST-UTC conversion, GST-GPS Conversion and TOW5Almanac for satellite (k+12) and almanac for satellite (k+13) part 1sulta61SVID, clock correction, SISA, Ionospheric correction, BGD, Signal health status, GSTand Data validity status2Ephemeris (1/3) and GST3Ephemeris (2/3) and GST4Ephemeris (3/3), GST-UTC conversion, GST-GPS Conversion and TOW6Almanac for satellite (k+13) part 2 and almanac for satellite (k+14)1SVID, clock correction, SISA, Ionospheric correction, BGD, Signal health status, GSTand Data validity status34licub2Ephemeris (1/3) and GSTEphemeris (2/3) and GSTEphemeris (3/3), GST-UTC conversion, GST-GPS Conversion and TOW5Almanac for satellite (k+15) and almanac for satellite (k+16) part 11SVID, clock correction, SISA, Ionospheric correction, BGD, Signal health status, GSTand Data validity statusFoSubframe 12rPSubframe 11Subframe 10DRSubframe 9Subframe 8Subframe 7PageType2Ephemeris (1/3) and GST3Ephemeris (2/3) and GST4Ephemeris (3/3), GST-UTC conversion, GST-GPS Conversion and TOW6Almanac for satellite (k+16) part 2 and almanac for satellite (k+17)Table 26.
F/NAV Frame Layout4.2.4. F/NAV Page ContentsThe following tables specify the contents of the F/NAV pages above allocated (see Chapter5 for a description of the F/NAV pages contents).© European Union 2014Document subject to terms of use and disclaimers p. i-iiOS SIS ICD, Issue 1.2, dd.mm 201427Page Type 1: SVID, Clock correction, SISA, Ionospheric correction, BGD, GST, Signal healthand Data validity statusTailCRCSpareE5aDVSTotal(bits)tionTOWE5aHSWNBGD(E1,E5a)Region 5Region 4Region 3Region 2Region 1ai2af2af1af0GSTIonosphericdisturbance flagAzai0ai1SISA(E1,E5a)Ionospheric correctionIODnavt0cSVIDType=1Clockcorrection6 6 10 14 31 21 6 8 11 11 14 1 1 1 1 1 10 2 12 20 1 26 24 6244Table 27.
Bits Allocation for F/NAV Page Type 1AFCoTnPage Type 2: Ephemeris (1/3) and GST1420Tail12CRCTOW32WNlta32●i32GSTsu24●Ω0A1/232eM06 10ΩIODnavType=2Ephemeris (1/3)24 6Total(bits)244Table 28. Bits Allocation for F/NAV Page Type 2CucCusCrcCrst0eWNTOW321616161616141220Tail∆n32CRCω6 10lici0GSTIODnavType=3Ephemeris (2/3)SpareDRPage Type 3: Ephemeris (2/3) and GST8 24 6Total(bits)244Table 29. Bits Allocation for F/NAV Page Type 38816 12Tail3CRCt0G8Spare∆tLsF8TOWDN8WN0GWNLSF8A1GWN0tA0t0tCis32 24A1Cic16Fo6 10 16GST-GPSConversion∆tLsGST-UTC ConversionA0GubEphemeris(3/3)rPIODnavType=4Page Type 4: Ephemeris (3/3), GST-UTC conversion, GST-GPS conversion and TOW.6 20 5 24 6Total(bits)244Table 30. Bits Allocation for F/NAV Page Type 46 4 2 10 6 13 11 16 11 16 11 16 16 13 2TailCRC(1/2)6 13 11 16 11 4 24 6Table 31.
Bits Allocation for F/NAV Page Type 528δiΩ0ωe∆(A1/2)SVID2E5aHSaf1SVSVID2(1/2)M0af0●ΩΩ0δiωe∆(A1/2)SVID1SVSVID1t0aWNaType=5IODaPage Type 5: Almanac (SVID1 and SVID2(1/2)), Week Number and almanac reference time© European Union 2014Document subject to terms of use and disclaimers p. i-iiOS SIS ICD, Issue 1.2, ?????????? 2014Total(bits)2446 4 12 11 16 16 13 26 13 11 16 11 16 11 16 16 13 2TailCRCSpareE5aHSaf1af0M0●ΩΩ0δiωe∆(A1/2)SVID3SVSVID3E5aHSaf1af0Ω(2/2)●M0SVSVID2(2/2)IODaΩ0Type=6Page Type 6: Almanac (SVID2(2/2) and SVID3)3 24 6Total(bits)2444.2.5.
F/NAV Dummy Page DefinitiontionTable 32. Bits Allocation for F/NAV Page Type 6208TailCRClta6Dummy sequencelic AFCoTnType=63In case no valid F/NAV data is to be transmitted, the satellite generates and downlinks thedummy pages (Page Type 63) replacing the pages in the nominal sequencing, accordingto the format in Table 33. CRC is computed on the Page Type and Dummy sequence fields.24 6Total(bits)2444.3. I/NAV Message DescriptionsuTable 33. Bits Allocation for F/NAV Dummy Page4.3.1. General Description of the I/NAV MessagerPubDRThe I/NAV message structure is presented in Figure 15, where the duration of each entityis indicated.Figure 15. I/NAV Message Structure in the Nominal ModeFoThe I/NAV message structures for the E5b-I and E1-B signals use the same page layoutsince the service provided on these frequencies is a dual frequency service, using frequencydiversity.
Only page sequencing is different, with page swapping between both componentsin order to allow a fast reception of data by a dual frequency receiver. Nevertheless, theframe is designed to allow receivers to work also with a single frequency.4.3.2. I/NAV Page LayoutTwo types of I/NAV pages are defined:●● Nominal pages having a duration of 2 seconds transmitted sequentially in time in twoparts of duration 1 second each on each of the E5b-I and E1-B components according© European Union 2014Document subject to terms of use and disclaimers p.
i-iiOS SIS ICD, Issue 1.2, dd.mm 201429to Table 35. The first part of a page is denoted ‘even’ and the second one is denoted‘odd’.●● Alert pages having a duration of 1 second transmitted in two parts of duration 1second each at the same epoch over the E5b-I and E1-B components according toTable 35. Again, the first part of a page is denoted ‘even’ and the second one isdenoted ‘odd’. This transmission is repeated at the next epoch but switching the twoparts between the components.tionThe I/NAV page part (even or odd) layout is defined in Table 34 for both nominal and alertpage types. This table shows the symbols allocation and bits allocation separately.
Thedifferent fields composing this layout are defined in the sections below.I/NAV Page Part (even or odd) SymbolsTotal (symb)10240250AFCoTnSync.TailTotal (bits)6120ltaI/NAV Page Part (even or odd) Bits114suTable 34. I/NAV Page Part Layout4.3.2.1. Synchronisation PatternThe synchronization pattern allows the receiver to achieve synchronisation to the pageboundary.DRNote: The synchronisation pattern is not encoded. The I/NAV synchronisation pattern is01011000004.3.2.2. Tail BitslicThe tail bits field consists of 6 zero-value bits enabling completion of the FEC decoding ofeach page’s information content in the user receiver.4.3.2.3.
I/NAV Page PartubThe structure of the nominal I/NAV even and odd page parts on E5b-I and E1-B are definedin Table 35. A nominal page is composed by the two page parts (even and odd) transmittedsequentially over the same frequency (“vertical page”).Total (bits)2486120Data k (1/2)Total (bits)Tail12Tail120Reserved 26CRCj840 22Spare16SAR1Reserved 1Page Type1Page TypeEven/odd=1120Even/odd=064 24Total (bits)166Total (bits)1Tail1Data j(2/2)TailPage TypeData i(2/2)E1-BReserved 2112CRCiPage Type1Reserved 1Even/odd=01FoData i (1/2)Even/odd=1rPE5b-I11126120Table 35. I/NAV Nominal Page with Bits Allocation30© European Union 2014Document subject to terms of use and disclaimers p. i-iiOS SIS ICD, Issue 1.2, ?????????? 2014The parameters for the nominal page have the following meaning and related values:●● Even/Odd field (1 bit) to indicate the part of the page (0=even/1=odd) that is broadcast●● Page Type (1 bit) equal to 0 to indicate the nominal page type●● Data field composed of a nominal word (described in 4.3.5) of 128 bits (comprising112 bits of data (1/2) and 16 bits of data (2/2))●● The reserved fields will be published in a future update of this ICD●● SAR data (22 bits) composed of SAR RLM data on E1-B only as defined in 4.3.7tion●● CRC (24 bits) computed on the Even/Odd fields, Page Type fields, Data fields (1/2 and2/2), Spare field, SAR (on E1-B only) and reserved fields (Reserved 1 for E5b-I andReserved 1 for E1-B).
In nominal mode the CRC is computed for the Even and Oddparts of a page of the same frequency (“vertical CRC”) and is always broadcast on thesecond part of the “vertical page”.ltaAFCoTnNote: The Reserved 2 field on E5b-I and the Reserved 2 field on E1-B are notprotected by the CRC.●● Tail bits (2*6 bits) as defined in 4.3.2.2. These fields are not protected by the CRCsuThe structure of the alert I/NAV even and odd page parts on E5b-I and E1-B are defined inTable 36.
An alert page is composed by the two page parts (even and odd) transmitted atthe same epoch over E5b-I and E1-B (“horizontal page”).The parameters for the alert page have the following meaning and related values:DR●● Even/Odd field to indicate the part of the page (0=even/1=odd) that is broadcast61201FoReserved 2TailTotal (bits)802486120Reserved 1 (1/2)Total (bits)Even/odd=081TailTotal (bits)24Reserved 1(2/2)CRCEven/odd=1Tail80Page TypeTotal (bits)Reserved 1(2/2)E1-BPage TypeTail1lic120Reserved 216CRCPage Type1112ubPage Type1Reserved 1 (1/2)rPEven/odd=01Even/odd=1E5b-I11126120Table 36.
I/NAV Alert Page with Bits Allocation●● Page Type (1 bit) equal to 1 to indicate the alert page type●● CRC (24 bits) computed on the Even/Odd fields, Page Type fields and on Reserved 1(1/2 and 2/2). In alert mode the CRC is computed for the Even/ Odd pages of bothfrequencies E5b and E1-B (“horizontal CRC”).●● The Reserved 1 and Reserved 2 fields will be published in a future update of this ICD.Note that the reserved 2 fields are not protected by CRC.●● Tail bits (2*6 bits) as defined in 4.3.2.2.© European Union 2014Document subject to terms of use and disclaimers p.
i-iiOS SIS ICD, Issue 1.2, ?????????? 2014314.3.3. I/NAV Nominal Sub-Frame LayoutIn the nominal mode, the page sequence for I/NAV E5b-I and I/NAV E1-B components inevery sub-frame is according to Table 37 where T0 is synchronized with GST origin modulo30 secondsE5b-I Content0NEven1NOdd2NEven3NOddNEvenNOddNEvenWord 7 or 9 (1/2)*NOddWord 7 orRes CRC Res9 (2/2)*6Word 3 (1/2)Word 3(2/2)Res CRC ResWord 5(2/2)Res CRC ResEvenWord 8 or 10 (1/2)*NOddWord 8 orRes CRC Res10 (2/2)*10NEvenReserved (1/2)11NOddReserved (2/2) CRC Res12NEvenReserved (1/2)13NOddReserved (2/2) CRC ResNEvenReserved (1/2)NOddReserved (2/2) CRC Res914rP15licNub8NEvenReserved (1/2)17NOddReserved (2/2) CRC Res18NEvenReserved (1/2)19NOddReserved (2/2) CRC Res20NEvenWord 2 (1/2)21NOdd22NEven23NOdd24NEvenFo1632Word 2(2/2)Word 2(2/2)Word 4(2/2)Word 4(2/2)Word 6(2/2)Res SAR Spare CRCWord 4 (1/2)Res SAR Spare CRCResWord 6 (1/2)Res SAR Spare CRCWord 7 orRes SAR Spare CRC9 (2/2)*ResResWord 8 or 10 (1/2)*Word 8 orRes SAR Spare CRC10 (2/2)*ResReserved (1/2)Reserved (2/2) SAR Spare CRCResReserved (1/2)Reserved (2/2) SAR Spare CRCResReserved (1/2)Reserved (2/2) SAR Spare CRCResReserved (1/2)Reserved (2/2) SAR Spare CRCResReserved (1/2)Reserved (2/2) SAR Spare CRCResWord 1 (1/2)Word 1(2/2)Res CRC ResWord 6 (1/2)ResWord 7 or 9 (1/2)*Res CRC ResWord 4 (1/2)ResWord 2 (1/2)ltaWord 5 (1/2)DR7Res CRC Ressu5Word 1(2/2)SpareRes SAR Spare CRCWord (2/2)AFCoTn4Word 1 (1/2)E1-B ContentRes SAR Spare CRCResWord 3 (1/2)Word 3(2/2)E1-BPageE1BSubframeIDOddN-1EvenNOddNEvenNOddNEvenNOddNEvenNOddNEvenNOddNEvenNOddNEvenNOddNEvenNOddNEvenNOddNEvenNOddNEvenNOddNEvenNOddNtionT0E5b E5b-I(GST0 Sub Pagesync.) frame(s)IDRes SAR Spare CRC© European Union 2014Document subject to terms of use and disclaimers p.
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