Lynn said:
Grim, would you happen to know when Verizon is supposed to be going to GSM? All the news I can find says 2008.
When they do, do you think older GSM phones will be compatible with the new (G4?) system?
G3 is UMTS...different animal altogether. Its Wide band CDMA. Some call it 3 gen GSM but its base operating characteristics are really a different then GSM. Its closer to the CDMA tha Verizon has been running with some funky weird stuff like channel hopping and some really in depth logarithmic phase shift key trickery to add capacity and data transfer rates.
Honesty I handle the network gear daily but not as a tech these days and have not studied it they way I did when I was a repair tech for GSM, TDMA and Analog. What I do know about the operating parameters is sort of hard to explain how it works.
Verizon just ran their CDMA platform to the end and now in the same boat as AT&T where they need to add a new platform just like AT&T is doing at the moment. I really don't see Verizon ever making their system support GSM like AT&T has. It would be a step backwards for them at a great financial outlay.
Not sure about Verizon's conversion time line to WCDMA. I'll see if I can track down one of my Buddies that is a Verizon FE and get the inside scoop. Probably working very hard on it right now as they are in the same boat as AT&T and looking to corner the market on Data products like Air cards and Data intensive products like iPhone.
I hear rumors that the UMTS products may be able to support each others system. Sort of a whats old is new again deal. Back in the early days Analog worked on either system. There is one thing now that makes sense that we go back to compatible equipment. Lower product costs and ability to roam where each company has better service. The customer perception would benefit greatly.
The fact is that Band width is at a great premium and products are hard to design that can handle multiple frequencies' There is compromises made in the antennas and transceivers. The narrower the band it has to operate the easier it is to make it efficient on that band as you can tune the antenna to a tighter range greatly improving the sensitivity. When you make a product that can jump form 850 up to 1900 their are reception compromises made to make that product work.
As an example the old Analog 800 products could easily hold a call to -120dB out of the box (db is curved scale so that is some serious ability to hold a call) new products are lucky to hold much better then -106dB. I think current standard is -104dB before it drops the call. 14-16dB of reception is HUGE in this technology. I use to tweak old phones and fine tune them to work better on the part of the spectrum I worked. Old Mil spec Motorola phones could be tweaked up to 4-5 watts output and dialed in to -125dB with the right antenna back "in the day" and still sound pretty good. Back when a major city was covered by 15-20 towers that was a really big deal. Now in a major town a towers spaced more then 1-2 miles apart is pretty uncommon.
Digital can pull your words out of thin air. The "Bit error rate" on digital products of lost data to what it it can not recover and "guess" and still make a reasonably clean sounding call is somewhere around 25%. That means when that signal meter is is showing next to nothing, a 1/4 of what you say never makes it to the other end. The "vocoder" guesses what is missing and puts it back together. That's what makes such a wide spectrum phone possible.
Now that I just went off on a distant tangent LOL
http://www.wirelessadvisor.com/ has a forum and a lot of stuff can be found out there.
It would be a marginal performer in the US without it. It would work but 850 has the biggest foot print for GSM.