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

To: mightylakers who wrote (23226)	6/3/2002 12:29:32 PM
From: rkral	Read Replies (1) \| Respond to of 196649

Yes, pretty much, but keep in mind [edit: GSM] mobile does need to scan for the other pilot signals to get ready for handover. Would you please expand on that for me? Expound if you prefer. How and when does the scan happen? Some appropriate 'premises', which might be wrong, so that you know my current level of understanding: (1) GSM is FDD, so the mobile can operate full-duplex. (2) if and when the mobile operates full-duplex, it uses tx-rx frequency pairs with the same frequency separation for all channels. (3) while the mobile is engaged in a voice call, the mobile transmits and receives in one time slot out during a frame of 8 time slots. In other words, let's ignore half-rate. (4) the mobile tx and rx occurs in each and every frame. There are no "holidays". (5) even though the mobile might be able to operate full-duplex, it does not do so during a voice call. The rx and tx physical time slots are separated by 2 (??) slots. (6) if the above is to reduce duplexer costs, the GSM mobile probably never actually operates full-duplex. (Aside: Hmmm. Wonder how that impacts GPRS using multiple slots. Isn't the data link full duplex? Something for later.) (7) the handover is based on some kind of 'better/best signal' algorithm. (8) in order to determine the 'better signal', EITHER the mobile must actually transmit on an alternate channel for a signal measurement at the BTS, OR the mobile must actually receive on an alternate channel to make a signal measurement that it can report to the BTS. The later makes the most sense to me. That's 8 premises .. and at least 8 chances for error .. so hope you don't find TOO many. <gg> Thanks in advance. Ron