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?
>>>>
>>>>
>>>>
>>
>
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