Weird... my phone was on 850 yesterday and is on 1900 today. Civic Center area in SF... sometimes the number alternates between 4000's and 9000's... comon ATT,pick one or the other...
Weird... my phone was on 850 yesterday and is on 1900 today. Civic Center area in SF... sometimes the number alternates between 4000's and 9000's... comon ATT,pick one or the other...
I'm not an expert but it seems to be the way it's supposed to work. It only moves on to 850Mhz once it deems that 1900Mhz is weak or over capacity.
My phone hasn't dropped to EDGE even once since the SF upgrade happened! It used to do it all the time.
I'm not an expert but it seems to be the way it's supposed to work. It only moves on to 850Mhz once it deems that 1900Mhz is weak or over capacity.
My phone hasn't dropped to EDGE even once since the SF upgrade happened! It used to do it all the time.
Yeah it's gotten better, but it shouldn't be getting 5 bars on 850 or 5 bars on 1900 and clicking back and forth I wouldn't think. Is there a way to force it to 850? I'm in a highrise so using the lower frequency would really help for elevator reception.
Yeah it's gotten better, but it shouldn't be getting 5 bars on 850 or 5 bars on 1900 and clicking back and forth I wouldn't think. Is there a way to force it to 850? I'm in a highrise so using the lower frequency would really help for elevator reception.
It'll automatically switch to 850Mhz while on your call as you get in the elevator, the only thing you'll probably notice is the call doesn't drop!
It'll automatically switch to 850Mhz while on your call as you get in the elevator, the only thing you'll probably notice is the call doesn't drop!
How can it auto switch between the two frequencies? My understanding of the technology is it cannot do that.... Plus if it did the difference in call quality would be noticeable (highly digital sounding voice at 1900 then more muffled, normal sounding but lacking the clarity at 850). I lived in the midwest before where ATT was 850 and I sure could hear the difference in 1900 when i moved out here.
How can it auto switch between the two frequencies? My understanding of the technology is it cannot do that.... Plus if it did the difference in call quality would be noticeable (highly digital sounding voice at 1900 then more muffled, normal sounding but lacking the clarity at 850). I lived in the midwest before where ATT was 850 and I sure could hear the difference in 1900 when i moved out here.
As it's all digital there should be no difference in the sound you hear on 1900Mhz and 850Mhz I would've thought. I've definitely seen it switch mid call.
Maybe someone with more technical 3G knowledge can answer this?
I know for sure there's a difference in call quality, hence why verizon is muffled and ATT is highly digitized. the benefit of higher frequency (in any radio signal) is higher clarity. The downfall is the higher the frequency the less penetration there is. Aka in building coverage is compromised sooner... this is why they're doing 850...
How can it auto switch between the two frequencies? My understanding of the technology is it cannot do that.... Plus if it did the difference in call quality would be noticeable (highly digital sounding voice at 1900 then more muffled, normal sounding but lacking the clarity at 850). I lived in the midwest before where ATT was 850 and I sure could hear the difference in 1900 when i moved out here.
The call can switch between 3G on 850 and 3G on 1900, and there should be no difference in quality (of course 850 has better range). If you noticed worse quality on 850 or 1900 then that was an issue in that particular area/network.
Yup - I've seen calls go between 3G 850 and 1900 during call, and on GSM between 850 and 1900. Strangely enough, I did notice a few unique things to GSM 1900 here vs GSM 850.
1. GSM 850 showed 'E' on my tilt (in L.A. - dual band market), and GSM 1900 showed 'G'
2. On my older phones, GSM 850 was almost ALWAYS AMR-HR, while 1900 was AMR-FR. I suspect that was their attempt to have 1900MHz work where its weaker.
Just as an FYI, on the Samsung ZX-20, you could pick your specific 'band' and technology.
Eg. You could pick one of the following options:
It is normal to see the phone switch between 1900 and 850. What they implemented is called an overlay, meaning they are using both frequencies to double the capacity. Having everyone move to 850 would defeat the purpose of this. They need to use balance the load between both frequencies. The phone will favor 1900 because that frequency has less range, so the thought is to make the most use of that frequency for people who are in range, then use 850 for those who need the extra boost. As for voice quality, it's a separate but related issue. If a network is overloaded, AT&T will program the tower to run at half the normal bitrate (more compression) to cram more calls in. With the overlay in place, I'd expect them to change this to normal bitrate on both frequencies. How's the voice quality in SF now (I'm no longer there)?
It is normal to see the phone switch between 1900 and 850. What they implemented is called an overlay, meaning they are using both frequencies to double the capacity. Having everyone move to 850 would defeat the purpose of this. They need to use balance the load between both frequencies. The phone will favor 1900 because that frequency has less range, so the thought is to make the most use of that frequency for people who are in range, then use 850 for those who need the extra boost. As for voice quality, it's a separate but related issue. If a network is overloaded, AT&T will program the tower to run at half the normal bitrate (more compression) to cram more calls in. With the overlay in place, I'd expect them to change this to normal bitrate on both frequencies. How's the voice quality in SF now (I'm no longer there)?
When on 3G (almost always now) call quality is crystal clear.
It is normal to see the phone switch between 1900 and 850. What they implemented is called an overlay, meaning they are using both frequencies to double the capacity. Having everyone move to 850 would defeat the purpose of this.
Not really.. they're only using a piece of each spectrum
There's room for 2 carrier channels on 850MHz, and at least 2 on 1900MHz. Currently they're using
10MHz 850, 10MHz 1900 for 3g
15MHz 850, 10MHz 1900 for GSM/EDGE
The only purpose that would be defeated, would be to kill GSM 850.
Originally Posted by redman042
As for voice quality, it's a separate but related issue. If a network is overloaded, AT&T will program the tower to run at half the normal bitrate (more compression) to cram more calls in. With the overlay in place, I'd expect them to change this to normal bitrate on both frequencies. How's the voice quality in SF now (I'm no longer there)?
Voice on 3G will be AMR, regardless. Quality would suffer due to signal quality, not usage. E.g. AMR-half rate (I'm going to assume as the default on 3G), would just end up on a lower data throughput due to FEC bits vs payload / data. On GSM they've been pushing AMR-HR for years. Since 3G doesn't have the concept of frames, and handoffs are soft, garbling won't be an issue. The issue will only occur when the call breaks up due to capacity strain, and your 'packets' litterally don't make it.
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Originally Posted by getyup
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