Eric L: Since we are into all this stuff now, here is another post which I would appreciate your comments on:
Discusses the discontinuity between GSM and 3rd gen WCDMA.
SI: StockTalk: Communications: The New Qualcomm - a S&P500 company
To: D. Newberry who wrote (10914)
From: Ramsey Su Saturday, May 27, 2000 8:30 PM ET
Reply # of 10926
D. Newberry,
engineer is out of the country and Clark's where abouts are unknown. I am a non-tech but I want to go on record that your post may be in error.
"WCDMA uses a contiguous 5MHZ frequency band. This is an efficient way to achieve the 144K/384K data rates. "
first sentence true, second not.
"WCDMA was designed to allow handover between CDMA and legacy GSM systems"
If you mean the gsm ground network, sure. It also is compatible with the ansi41 ground network used here and elsewhere per the ericsson and operaters harmonization agreements, as well as Q's IPR offer to the ITU. If you are somehow talking about the GSM air interface - NOT - GET THIS STRAIGHT - there is no "migration" from the gsm air interface (the radio's that comprise the base stations and the handsets). Here's the migration - RIP IT OUT AND REPLACE IT. Oh, and tell everyone with a gsm handset to buy a new wcdma handset. Migration? What a joke.
"Keep in mind that a nominal 5MHZ band is required to provide 144K/384Kbps transmission. "
NO, WRONG. cdma20001X-MC accomplishes this same date rate in a 1.25 Mhz channel, which is the standard channel width in IS-95A,B systems. With HDR, which is not a significant upgrade either equipment or expense wise, this can be increased to a max rate of 2.4Meg per sec.
"You might also note from the article below that this is accomplished with a 5 to 10% loss of sprectrum efficiency over WCDMA. "
- well, the article may claim that, but it has yet to be shown in the real world, where loading, handoff, geographies and lots of other things are real real important to actual results. Plus, when IJ says "we think optimizing a 1.25 Mhz channel for data (HDR) makes a lot more sense than trying to combine both, given the different latency and other requirements of voice vs. data, I will believe IJ every time.
I had help with the above so blame ME if it is wrong.
Ramsey |
