Poor iPhone data coverage in big cities has been one of the major gripes against the iPhone and specifically against its sole US carrier, AT&T. According to AT&T spokesman, Mark Siegel (via Gearlog), they're doing three major things to improve their coverage and speeds, some of which will have a huge positive effect on coverage in cities like New York, San Francisco and Los Angeles.
"3G on 850 Mhz."
In busy cities, some dropped calls and signal problems come because the 1900 Mhz airwaves that AT&T mostly uses for 3G are totally saturated - they're trying to cram too many iPhones into too little space. Across much of the country, though, AT&T also owns big blocks of spectrum in the older 850 band, which was once used for AT&T and its predecessors' older TDMA service. Verizon Wireless is the other big 850 Mhz carrier. AT&T has been refitting their 850 Mhz equipment for 3G. As 3G 850 comes on throughout the rest of this year, the effect will be like going from having 100 people crammed into a conference room, to having the same population in a spacious ballroom.
AT&T is rolling out the 3G on 850 MHz over the next few months and, according to Siegel, "The 850, when it's turned on in individual markets, people notice a big difference."
850Mhz connections are better at penetrating buildings but can't travel as far as 1900MHz.
AT&T already announced its other two initiatives which are improving the line speed to the cell towers by installing fiber and also upgrading the networks to the double speed 7.2 Mbs HSDPA+ equipment. AT&T has a private 7.2Mbs network running in Chicago that isn't yet visible by their customers.
Delicious
Digg
StumbleUpon
Reddit
Facebook
Google
Yahoo
Comments
thank goodness
thank goodness
Actually, 850Mhz travels
Actually, 850Mhz travels further than 1900Mhz for the same amount of transmit power....
Actually, 850Mhz travels
You are right. The bottom line is that lower frequencies go further and higher frequencies have somewhat building penetration. In theory you need up to 4 times more transmitters assuming the same power for twice the frequency (inverse square relationship.)
850Mhz...
it improves band availability 'til also that freq. slots will be statistically full. Unfortunately it will not reliability indoor, as it may drop faster and for sure will require the iPhone a bit more tx power to engage the cell again or to switchover... so... battery squeezed, brain a bit warm...
in Europe we had same problem... while switching from E-TACS to GSM and re-using the old bands...
Fortunately, lower frequncies
Fortunately, lower frequncies traverse walls and other structures more readily. And so 850 MHz will be better in terms of indoor usage than 1900.
Most big cities are already on 850 for 3G, and the legacy Edge service is on 1900. Looks like they're planning to address that in some other regions where, for legacy reasons, they have 3g on 1900. This will make a big difference in those regions in terms of indoor usage.
is true under certain conditions
in terms of physic laws you're right, however, with RF it happens that 850Mhz would require a constant transmission power to have you improving the quality of the signal thru obstacles (eg: indoor, elevators, parking spots, etc.), as I was saying, GSM RF specs set the capability of the tx devices to adapt the power to improve the quality of the phone-call or data stream, on a normal GSM environment and as the tx power changes the rx is not able to get benefits from a "constant" signal even if the freq is lower.
Additionally, UMTS uses a different mechanism to transport voice/data, but honestly I don't know how the frequency change to the lower threshold may help.
While parts of your posts are
While parts of your posts are correct (GSM towers can raise TX power as needed to help weak signals) your message make no sense.
Raising/lowering the trasnmit power is done both on the 850 and 1900 band. 1900 was really developed as a 2ndary band to handle areas of high utilatization and as I said in another post GSM phones will try to use the lower band first.
In US because ATT switched from CDMA to GSM they ended up not being able to use the lower frequency first. That they now can switch part of their legacy network frequencies over to GSM is good for us 3G users.
Why not 900MHz
So this is why iPhone does not support 3G on 900MHz which is the MHz what the rest of the world uses for long distances. Apple use standards, please!
900 isn't available in th US.
900 isn't available in th US. It assigned to the military, and so the FCC allocated 850 instead. No US carrier offers 900.
850 Frequency is good news! Go ATT (for once)
Switching to the 850 band is a big deal. ATT did this in Boston some time ago and it was one of the main reason I switched to them from TMobile. with TMobile I had lousy reception indoor while ATT worked great. This was long before I became an apple convert.
As other people have pointed out using a lower frequency is a great thing. The reason we ended up at 1900 was that all other bands where taken by the time ATT switched over the GSM. I guess they can now convert their old spectrums over to GSM. This should make a noticeable different in number of dropped calls while also providing more total bandwidth.
GSM phones will try to use lower frequencies first and only switched to 1900 when it "has to".
As other have pointed out cell frequencies in USA has nothing to do with Apple and are sold-allocated by the government. They ended up on different bands then europe partly for legacy reasons and partly to support local manufacturers like Motorola etc but today most GSM phones handles all 4 frequency bands used in the world.
I have been using GSM for a long time to be able to bring my phone to Europe.
Great. So it will take even
Great. So it will take even longer to roll out HSPDA while they try and recover basic 3G in the cities.
Well, obviously! They've got
Well, obviously! They've got to make sure everyone on AT&T has good 3G service before rolling out a whole new network!
Why didn't they.....
Why didn't they think of this earlier?
I don't care though. Apple should still tell them that exclusivity is going to end with them next year.
Its going to be AT&T and Verizon for iphones soon.
this is good news.... I was
this is good news.... I was originally with verizon and was going to wait for an iphone to come to them... after getting screwed by big red on a number of different issues, me and my wife happily got a pair of 3GS phones on opening day and I must say the at&t service seems to have gotten better since I had them 3 years ago. This announcement is even better news. In any case, my new iphone walks all over any phone that verizon has (and Ive played with quite a few) and the service so far... cant really tell the difference (in VT, SE PA and Northern/Central FL anyways...been traveling a bit), only dropped call Ive had with the iphone is when the tower got struck by lightning (i actually saw it happen...freaky!)
Insanity at the FCC
I heard all sorts of horror stories about AT&T when I was a Verizon customer. Yeah, I had issues with Verizon, but I _knew_ that AT&T was WAY worse.
Then one day my local Verizon service went way down hill. I called up Verizon, and they said it was because the trees were in blossom. Seriously.
After many months of suffering and dropped calls, I noticed that my girlfriend had no issues with AT&T. So I switched. I found myself much happier with AT&T versus Verizon.
That being said, all mobile providers suck. Charging more than zero for text messaging is crazy - yet they charge for outbound AND inbound messages. That should be regulated immediately. For all I care, charge the sender double and the receiver zero. That seems fair. For me to get charged 20¢ a pop because some dumb kid keeps on texting me instead of her friend is insane. For me to get charged 20¢ a pop for each text message spam is insane.
CONGRESS, where have you BEEN on this one???