Best on the move GSM,CDMA

Well, unless handoff issues are better with GSM than they were 3 yrs ago, I'd think CDMA would be the preferred for mobility and holding calls.
My exp was with Cing when they just started to roll it out. Most of the time the handset seemed to be on an ATTWS site, but when switching / handing off, more often than not the call would drop.

 

I think GSM is more fragile holding on to calls than even TDMA! Those time slots are too short and too fast (shorter and faster than TDMA) hence it's hard to keep them synchronized when you are constantly changing RF conditions such as distance, reflection, signal strength, interference, etc. CDMA doesn't have to worry about synchronizing time slots and cancels interference better because it uses a much wider channel.

 

Do you think once the Integration is complete & with them adding more towers this will lessen the dropped call issues with Cingular? I know I have very few dropped calls where I am and when I drive I don't seem to have too many either, but they do happen.

 

I know that I have had a couple of calls here in Ohio, on I-71 and I-75 that spaned a distance of over 100 miles each, and more than once. I wonder what the longest distance anyone has been able to hold a call.

 

Yes, it was Verizon.

 

in GSM if the Towers are well Linked
the handoff are seamless,
whether its hard or soft handoff.
This is one of the reason why Cingular
wants more Towers.

 

i mean since the handoff in CDMA is different in GSM,
the GSM towers have to be well linked to prevent drops.

 

Let the games begin. Wait two years, and then lets check back yes?

 

Excuse my ignornace on the matter, but what do you mean by "well linked"?

 

Linked would be referring to the datafill at each site. Each site keeps a database of neighboring sites, and tables indicating at what point a handoff should occur, what power level, what perceived distance, so on and so forth. These tables vary by site, and are usually customized by the carriers performance engineers.

CDMA allows up to six sites to track a mobile simultaneously, and I feel this makes it superior in the mobile environment. Depending on system setup, the handset can even be communicating via all six of these sites simulatneously, though not likely, as 6 neighboring sites will probably never be on the same channel. At any given moment, most CDMA phones are communicating via at least two sites.

 

Generally the more spectrum license/capacity a carrier has the better the handoff.
Since GSM does hard handoffs signal strength is the key,
when it senses it has a stronger signal from another cell site it's
going to hand it off to that site.

Theoretically CDMA handoff can track more sites
but in the real world that's not possible because of the
TOWER SPACING. You can't lock on to a Tower that's out of
signal range.

You can even lock on to one site if you're in DEAD ZONE.

 

I have had good luck with both GSM and CDMA in the past. With CDMA it is very seldom that I have had a hand-off problem.

I used a PDC phone (Japanese TDMA network) on the Tohoku Shinkansen at top speed (over 160 mph). It worked fine.

I used to have similar experiences with my GSM service provider in Taiwan. I have had a continuous conversation on the train between Hsinchu and Taipei for most of the hour long trip.

Sadly, this is no longer the case. There are now so many people on the system, that I can now lose a connection while standing motionless.

 

Most of the time it's only 2 cell sites as you move.
tracking more than 2 in the real world does not happen
because of the cell spacing being too far apart.

in a hard handoff you are first disconnected from cell site A
to get connected to cell site B. (but this happens in millisecs,
faster than you can blink your eye that the
user can't notice it)

in a soft handoff you are are first connected to cell site B
before being disconnected from cell site A.

GSM is Hard Handoff and CDMA is soft Handoff.
GSM even if its Hard Handoff, it may be handed off
to a different frequency. Even if it moves in time slots it
also moves in frequency. GSM is not all TDMA (as what some CDMA
cheerleaders think) it's also FDMA.

Can both calls drop as they Move?
Absolutely.

 

the main topic of this thread is
best on the Move GSM, CDMA.
And when a user is on the move it's all about Handoff.
We're not going out of TOPIC aren't WE?

 

Actually, jones, field test on your Verizon phone and you will notice that your phone often holds on to 2 or more PN offsets, THIS IS THE REAL WORLD!

 

If that was true almost every phone call would drop!

Looking at my field test right now, I can see 7 different control channels. The phone really doesn't show me all the available channels because the screen size limits what can be shown at one time. But there are more than 7 channels available in this area. Those channels I can see come from 3 different towers. In some places where tower placement is tighter, my phone can sometmes monitor up to 6 or 7 different towers. Nokias can display up to 9 different ones, I believe.

There's a small dynamic database in your phone called "Relesection" which is a list of channels your GSM phone can handoff to depending on how network conditions change. While the phone is not actually registered on all those towers, it can still "watch" for them to be able to handoff to them if conditions require it.

 

that's what i said most of the time it's 2 or 3 towers.
you can't receive those signals that are out of range,
depends on where you are.
you can't even receive one if you're in a dead zone.
if you look at t-mobile compass map that's how rf behaves.
Exactly your call will drop if you're moving to a direction where
there's no covearage.

 

You didn't say 2 or 3. This is what you said:

Anyway, particularly in an urban setting, it is very likely that your phone can "see" more than 2 or 3 towers simultaneously.

 

Anyone else lost?

 

I think jones is trying to say that it is possible to drop calls on the move. I think, although I have a tough time deciphering the post.

 

That is not what I meant. Taiwanese GSM runs on 900 and 1800 MHz, whereas their CDMA runs in 800 MHz.

GSM networks there are overwhelmed by way too many GSM users. Taiwan has the highest cell phone penetration in the world at roughly 120%.

In fairness, the CDMA network (APBW) is also overwhelmed many nights after 11 PM when free in network calling begins.

 

Jones may be trying to use blue smoke & mirrors to obscure the fact that CDMA has a better hand-off than GSM.

If you are in areas with low usage, both types of networks will work well when the handset is moving. As the numbers of users increase a GSM network will tend to drop more calls than a CDMA network because of the difference in the hand off. The GSM hard hand-off is more likely to hand you off to a full tower (and thus a lost connection) than is the soft hand-off of a CDMA network.

At saturation, no cellular technology is worth a hoot.

 

This certainly has been my experience also. Living in a much less congested area, urban area than NJ, i.e. in the northwest area of Connecticut, I can see four or five control channels.

BTW to the oringinal poster: you are not planning on moving near or close to the speed of light by any chance are you?