Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!uwmcsd1!ig!agate!ucbvax!UDEL.EDU!Mills From: Mills@UDEL.EDU Newsgroups: comp.protocols.tcp-ip Subject: Re: Network Time Message-ID: <8807061117.aa19795@Huey.UDEL.EDU> Date: 6 Jul 88 15:17:00 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 19 Miles, Your network is hardly unique. MCI currently synchronizes about a dozen plesiochronous "islands" in their digital telephone network using LORAN-C, Sprint plans to do the same and AT&T plans eventually to use the Global Positioning Satellite (GPS). LORAN-C provides timing to within some tens of nanoseconds (for things like digital telephone synchronization) and in principle can provide UTC verification to wihtin a couple of milliiseconds. It does not provide a UTC timecode, which must be disambiguated by other means. There are no LORAN-C receivers known to me that are designed expressly for time service, as against position service, although some may be capable of rho-rho navigation, which requires a much more precise local clock than the usual hyperbolic navigation. Most folk are expecting GPS to become the system of choice. I do not know if its designers are sensitive to the time-distribution issue. Dave