by: hunterk1111 (21/M)
2/12/00 6:12 pm
Msg: 22299 of 22309
It is not the Nokia 51XX phone that is giving the problem(unless it is CDMA-5180), it is the network that you are on. ATT
and Sprint in the phila region have a horrible network. ATT needs more capacity, Sprint also needs capacity, but they are
doing a bad job of engineering it also. I am an RF Engineer at BAM, and have seen the #'s on lost calls/etc, and can tell you
that BAM's network in the Phila region is rated the highest over everyone else's.
As you know, there are only a certain # of channels available(analog) and you can only deploy(for
CDMA-Sprint/BAM)carriers by taking analog channels(1.228 MHz bandwidth) and making a CDMA carrier out of that
bandwidth. Well, when you deploy a carrier, you have to retune all of your cell sites to not have interference. There is a
%Lost calls that is benchmarked against providers. BAM shoots for .5%, while others shoot for 1%,or worse. THis is why
most users on BAM are not complaining about dropped calls/fast busy signals/inaffective dialing attempt/etc.
For AMPS(analog), there is 1 channel/1call.
For TDMA(digital) there is 1 channel/3 calls due to time offset.
For GSM (digital) there is 1 channel/6 calls due to time offset.
For CDMA(digital) there is 41 channels(30 KHz wide)=1.23Mhz of bandwidth. There is not a certain amount of calls that
we are limited to for them 41 channels worth of bandwidth. It works like this: the more users you have, the higher your noise
floor goes up. To keep this simple, once the noise floor gets too high, you start getting a lower call quality, and then you start
getting to the point where there is not enough capacity to support that many users. Thats where the problems stated above
start to happen.
Sprint is trying to get as many customers signed up as possible,(as everyone else)but they are getting to many users than
what their network can handle, so they have poor call quality.
I don't know about GTE, except that BAM is merging w/ them to have a larger footprint. Also BAM just swapped licenses
w/ Alltel so that it will have ~all of PA in its footprint when the dust settles.
I hope this makes some sense to some of you.
If it doesn't, I'm sure you'll be hollering at me:)
HunterK
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