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Guy Harris (talk | contribs) →CDMA history: Fix indentation to make it a bit easier to figure out who's saying what. |
Guy Harris (talk | contribs) →CDMA history: The fix needed to involve adding, rather than removing, indentation. |
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::No, it was for the experimental PRNet -- Packet Radio network. It was also funded by DARPA but had nothing to do with the ARPANET, a packet switched network using fixed computers and point-to-point links. An early motivation for what became TCP/IP was to interconnect the ARPANET with the PRNet. [[User:Karn|Karn]] ([[User talk:Karn|talk]]) 08:40, 16 September 2008 (UTC)
:It was proposed and analysed by the GSM as one alternative, and rejected as I say - because it does not have a finite time to deliver: Simple, when the number of users exceed a threshold, the time spend identifying and managing the packets is to high to be able to send everyone, so then you start to retransmit. Put it blunt: What do you consider will happen in a town where every time there was a read light request was issued for every car in the queue to fine a new car to line up for them? Yes - you would very soon run out of street and road space to hold the queue, and after that - run out of cars.
:Yes, Qualcomm has supresses a slight error in their math equation. As long as there are few users, CDMA is a good technology - but once the air gets crowded, the O-residual that they claim is "insignificant" just shows when they fell asleep during Calulus in high school.
<small>—The preceding [[Wikipedia:Sign your posts on talk pages|unsigned]] comment was added by [[User:Khflottorp|Khflottorp]] ([[User talk:Khflottorp|talk]] • [[Special:Contributions/Khflottorp|contribs]]) 12:43, 9 July 2006.</small>
::The above two paragraphs are utter nonsense. <em>Every</em> multiple access system has a capacity limit. That capacity is very well defined with FDMA and TDMA; assign all the frequency or time slots and there aren't any more. The CDMA capacity limit is less well defined but, I emphasize, considerably higher than that of either FDMA or TDMA when used in a cellular telephone network with frequency reuse. Part of this comes from voice activity detection, transmitting only when you have something to say, reducing average interference levels when it would be impractical to reallocate time or frequency slots so rapidly. Most comes from the inherent interference resistance that allows full reuse of frequency channels by all cells instead of allowing only a subset of channels to be used at each cell site to protect its neighbors. The full derivation of the system capacity of CDMA is in <ref> Gilhousen, Jacobs, et al, "On the Capacity of a Cellular CDMA System", IEEE Transactions on Vehicular Technology, May 1991</ref>. Disclaimer: I work for Qualcomm. I dare say we've been pretty successful with CDMA despite having fallen asleep in high school calculus. But <em>don't</em> believe me. Check it all out for yourself. [[User:Karn|Karn]] ([[User talk:Karn|talk]]) 08:40, 16 September 2008 (UTC)
Maybe you have a point but it is lost in words. "What do you consider will happen in a town where every time there was a read light request was issued for every car in the queue to fine a new car to line up for them" - do you understand yourself what you saying?
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