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Technology Stocks : Qualcomm Moderated Thread - please read rules before posting -- Ignore unavailable to you. Want to Upgrade?

To: David E. Taylor who wrote (23180)	5/30/2002 4:45:49 PM
From: rkral	Read Replies (4) \| Respond to of 196646

EOTD .. .. At least Cambridge Positioning Systems didn't try to claim this was new technology .. I think the misunderstood and difficult part of EOTD is the rf part. That's why EOTD still looks like an ill-conceived technology to me. Hopefully you can fill in some blanks. We are talking about EOTD applied to GSM. AFAIK, GSM started with a 4x12 frequency reuse pattern. This means the pattern, with 4 cell sites with 3 sectors per cell site with several frequencies per sector, is repeated again and again (ignoring terrain problems here). (Yes, I have seen data that implies that a 3x9 reuse pattern is the norm today.) Adjacent sectors do not use the same frequency. A 4x12 pattern has a greater distance between sectors using the same frequency, than the 3x9 pattern. Anyway, the point is that rf planning occurs to keep transmissions in one sector from interfering with neighboring, but non-adjacent, sectors using the same frequency. Now that we've physically separated sectors using the same frequency, EOTD needs the mobile to hear 3 BTSs .. at the same time? .. or virtually the same time? Something seems terribly wrong this picture!! (Or do 3 BTSs need to hear the mobile at the same time? I don't think it makes any difference to the dilemma.) A receiver listening to 3 transmitters simultaneously isn't a problem for CDMA. But this is GSM (and GPRS and EDGE) .. TDMA layered on FDMA. To my knowledge, there are no equivalents to CDMA's rake receivers. What am I missing here? Mighty lakers, engineer .. are you out there to lend a hand as well? Ron

To: David E. Taylor who wrote (23180)	5/30/2002 5:02:04 PM
From: Clarksterh	Read Replies (3) \| Respond to of 196646

David - I thought QCOM's SnapTrack GPS approach works on GSM/TDMA as well as CDMA. Is the AWE, Cingular and Voicestream use of EOTD just the result of their resistance to paying QCOM for anything? I would guess that they don't do it because it requires specialized chips which use CDMA technology (GPS is based on CDMA) and no one is producing such chips and the associated software (either basestation or handset). If Qualcomm could have somehow produced a GSM set of SNAPTrak stuff, I suspect it would be a seller. Clark