Modern GPS chipsets do coldstart within 35 seconds with a good view of the sky, and no previous data. This is the main performance gain a GPS chipset with a significant number of 'channels' will get you.
On Tue, Feb 9, 2016 at 2:38 PM, Eric Kuhnke <eric.kuh...@gmail.com> wrote: > Same idea as if you take a handheld dedicated GPS receiver (not one that > partially uses aGPS / cellular location based assistance) from one side of > the world to the other, powered off, and turn it on again... can take > 5-10 minutes to reacquire lock even when on a flat rooftop with view to 12 > satellites. > > On Tue, Feb 9, 2016 at 6:50 AM, Adam Moffett <dmmoff...@gmail.com> wrote: > >> It might not be just a matter of getting the location. If they use the >> 1pps clock from GPS to calibrate an oscillator before they start >> transmitting, then it would legitimately take 20-30 minutes. >> >> Telrad BTS's are like that too. Pisses me off if I ever have to reset >> the power. >> >> >> >> On 2/9/2016 12:12 AM, Jason McKemie wrote: >> >> For whatever reason, the receivers that they use in some of these don't >> seem to be "modern" at all. They frequently take an excessively long time >> to get a lock. >> >> On Monday, February 8, 2016, Eric Kuhnke < <eric.kuh...@gmail.com> >> eric.kuh...@gmail.com> wrote: >> >>> Modern GPS receivers work surprisingly well, if not very accurately, >>> from inside a single floor wood framed house... My oneplus one will pick up >>> 6 satellites while standing in a central hallway 15'+ from any window. >>> Should be accurate enough to get a location within 75'. >>> >>> All bets are off if it is a concrete framed apartment building or >>> something like that. >>> >>> I still find it amazing that anything works at -162 RSL. Thanks to tiny >>> channel size and very basic modulation. >>> On Feb 8, 2016 6:46 PM, "Bill Prince" <part15...@gmail.com> wrote: >>> >>>> Canopy NAT seems to break it with regularity. It might also fail if the >>>> GPS location that it reports is not within a 1/4 mile of where the customer >>>> address is. >>>> >>>> Also requires enough GPS (like near a window) to get a GPS lock. >>>> >>>> bp >>>> <part15sbs{at}gmail{dot}com> >>>> >>>> >>>> On 2/8/2016 3:34 PM, Ken Hohhof wrote: >>>> >>>> What are the typical reasons for these not to work?� >From the user >>>> guide it appears to use IPSEC, so I assume anything that prevents a VPN? >>>> � >>>> Verizon support told the customer they needed a Class A address.� >>>> WTF?� Did they maybe mean it *can't* be a class A address?� >>>> Customer uses 10.x.x.x addresses internally, behind Cisco ASA firewall >>>> (which I don't manage). >>>> � >>>> I do see some udp/500 and udp/4500 packets, I think that means >>>> something is using UDP for IPSEC NAT traversal? >>>> >>>> >>>> >> > -- *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 forre...@imach.com | http://www.packetflux.com <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> <http://twitter.com/@packetflux>