IS-GPS-800A - US Coast Guard Navigation Center

3.5.4.5 Subframe 3, Page 6 – TextSubframe 3, page 6, as depicted in Figure 3.5-7, contains the Text message. The specific contents of text messagewill be at the discretion of the Operating Command. Subframe 3, page 6 can accommodate the transmission of 29eight-bit American Standard Code for Information Interchange (ASCII) characters. The requisite bits shall occupybits 19 through 250 of subframe 3, page 6. The eight-bit ASCII characters shall be limited to the set described inparagraph 20.3.3.5.1.8 of IS-GPS-200.3.5.4.6 Subframe 3, Page 7 – (Reserved)(Reserved)3.5.5 Timing RelationshipsThe following conventions shall apply.3.5.5.1 Paging and CutoversBroadcast sequence of subframe 3 pages is completely arbitrary and, as such, users must not expect a fixed patternof page sequence.Cutovers of subframe 2 data to new data sets will nominally occur on hour boundaries except for the first data set ofa new upload. The first data set of newly uploaded data will cutover on 15 minute boundaries.64 IS-GPS-800A8 June 2010