"Microsoft Location Finder" - how is it supposed to work ?

[POSTED TO alt.internet.wireless - REPLY ON USENET PLEASE]

I've seen no evidence of "insistance that users buy A-GPS enabled handsets" by Cingular -- AFAIK current handsets sold by Cingular don't have A-GPS. What am I missing?

Lowest thing I worked with was Decca (CW at four harmonicly related frequencies of roughly 70, 85, 113 and 127 KHz - and at night, it was the pits. There was a thing called Dectra using two of those frequencies to provide position fixes between Northern England and the Maritime provinces of Canada, and Delrac which was down in the

10-20 KHz range, but I never saw any hardware.

Given the wavelength of (nominal) 12.5 KHz is about 24000 meters, the only way you'd see reflections is a distortion analyzer.

Know of the place(s), though I don't ever remember stopping there other than one time there was to be a continuation of a party at the still, but we couldn't even get into the parking lot. I lived a bit further up Central Expressway.

Back then, it was 3000 feet long, but I remember it being only 40 feet wide (compared to 150 foot for the main runways and at Half Moon Bay,

75 foot at Reid Hillview, and San Carlos, 65 foot at Palo Alto). Even though the landing gear track was something like 7.5 to 10.5 feet on most singles (heck, the wing span is usually less than 35 feet), the average student airplane driver had difficulties keeping it on a hard surface only 40 feet wide. As you got more experienced, things got easier, but a goal (though not part of the official Flight Test Guides) was that the aircraft should have the runway centerline stripe between the main gear except when turning off/on the runway.

No, it was definitely the reflection problem - I flew into SJC on a regular basis (instrument proficiency flights), and the VOR indication would be swinging noticeably, while I kept the ILS needles (more or less) centered. As I recall, it was around 800 to 400 feet above the touchdown height - which would put it about 3 to 1.4 miles from the threshold. I don't have the old approach plates, but recall the MDA (minimum decent altitude) was around 560 foot MSL (about 500 feet higher than the runway). This was enough of a concern that they commissioned an NDB 30L approach using the beacon at the middle marker which was on centerline between Hedding and the 17. I hated trying to fly an NDB approach, though the FBO and insurance companies both demanded at least 3 every six months.

At least for now - but I'm sure it will go ahead eventually. Where were they planning to extend 30L? The Southeast end is already limited by highway 17 and the perimeter road (such that touchdown point is displaced

2300 feet to allow clearance over trucks on 17), and the Northwest end is similar over De La Cruz (threshold displaced 1750 feet). I suppose they could add about 600 foot on either end and use it as a stopway. Probably would not be available for takeoff unless they put in a blast fence which might impact the ILS minimums.

Old guy

Well, I might be wrong about that one. One of my sidelines is giving unactivated phones to friends and customers that have lost their cell phones and don't want to pay through the nose for the latest greatest new phone from various providers. So far, Cingular has refused to activate any phone that does not have GPS. This is especially true if you activate a phone online at:

if you bug Cingular support over the phone and keep pounding on them, they will eventually activate the phone. This is as of about 3 months ago, so things may have changed. I can't be sure if the phones offered do or do not have GPS capeabilty because the Cingular web pile doesn't even mention GPS anywhere. I'll call Cingular today and double check.

Activation suggests that these are TDMA phones, in which case resistance isn't surprising, and would have nothing to do with A-GPS -- Cingular is doing its best to discourage TDMA in favor of GSM (which doesn't require activation). Regardless, how about some specific examples of phones that didn't have GPS and that did have GPS?

How then does GPS have anything to do with it?

Waiting with bated breath. :)

Well, that was a waste of time. I called Cingular "Customer Service" which refused to supply tech support unless I already had an account. So, I was transfered to sales. When I asked "Do I need a GPS phone?" she answered "No, you need a GSM" phone. When I asked if a Nokia 3390 will work, they indicated that it would only work if it said "Cingular" on the case and not PacBell. Apparently their policies for activating existing phones is a bit bizarre and may not have anything to do with GPS capeabilities.

I'll bug some of my techy contacts inside Cingular and see if I can get a more sane answer.

Very interesting! Thanks Peter