What's the 3G Problem? Source Close to AT&T Says iPhone Tower Power Drain

Roughly Drafted is claiming a source close to AT&T has spilled the beans on what's really going on with the iPhone and its 3G connection problems, and what 2.0.2 did to fix it.

In a nutshell? An iPhone 3G running 2.0 or 2.0.1 tries to pull too much power from the network, so when multiple iPhones connect, a tower can actually run out of juice and start dropping calls and losing data.

Why hasn't upgrading to 2.0.2 already fixed the problem? Simple: some people haven't yet upgraded, so their 2.0 and 2.0.1 iPhones keep pulling too much power, causing the same problem even for people who have upgraded but are stuck on the same tower (or same high-density city like San Fran or NY). Only when most users have patched to 2.0.2 will people stuck on high-demand towers see improvements.

Earlier reports and theories have lain blame on everything from the 3G radio and antenna, to the Infineon chipset and Apple firmware, to the carriers themselves. We here at TiPb have long been saying the problems were likely a combination of factors, and firmware that pulls too hard on networks that aren't that hardy seems a far better explanation than any one previously offered. It also goes a long way to explaining why Bluetest didn't find any hardware issues, and why both Apple (via their website) and AT&T (via SMS) have really stepped up the push for this update.

So, do we finally have our answer, or is this just the next "shot in the dark"? Are you still having 3G problems? Is your neighbor still on 2.0 or 2.0.1? Tell them to upgrade now and then let us know if it helps!

Have something to say about this story? Leave a comment! Need help with something else? Ask in our forums!

Rene Ritchie

EiC of iMore, EP of Mobile Nations, Apple analyst, co-host of Debug, Iterate, Vector, Review, and MacBreak Weekly podcasts. Cook, grappler, photon wrangler. Follow him on Twitter and Google+.

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Reader comments

What's the 3G Problem? Source Close to AT&T Says iPhone Tower Power Drain


this actually sounds like a very plausible explanation. i didn't really notice the problem with the first two versions except for when i was at a phillies game in philadelphia (a lot of people in an area pulling off the same network), my only solution was to switch to edge. since i updated to 2.0.2 i noticed the problem in some other areas, but also at another phillies game, even when i have full 3g bars. thinking it was weird that i was in a major city near a tower and couldn't get on the internet and 3g was dropping calls. so the reason that some towers are overloaded, makes a lot of sense. each day it seems to get better, as i guess more people upgrade.

Certainly Apple can count:
How many phones were sold?
How many users have downloaded v2.0.2?
Are we 10% upgraded? 99% upgraded?

This certainly makes sense. It also answers why they are pushing everyone to upgrade by sending txt messages and having a new page on apple.com for 2.0.2.

If this is the problem, wouldn't the other 3G phones also have the same problem since they will also be "starved" out of the 3G signal.

I've noticed the problem with ATT 3G minicell. It is constantly giving me full bars for about two minutes, then quickly starts loosing it's signal. In about another minute or two, the full signal returns. It is very frustrating.

a) the iPhone might have been pulling more 3G signal initially than previous phones, b) did any other previous 3G phone add 1 million handsets to the network over the course of a weekend?

let me see here, a wireless device can draw power from a transmitter over the ether, what universe do you people live in ? The tower power is underengineered.

@dave: absolutely correct. how does the handset have control of the power output of the tower? and WHY does the controller on the tower allow it to fail like this?
If the cell tower has too many users, then they need to erect new cell towers to deal with volume, not coverage. again, still a failure of AT&T not apple. if we were to say that the iPhone has failed due to the fact that it puts out too much power (low battery life), then we can blame apple, but this seems like a tower-based technology issue, or lack thereof.

The iPhone is such a buggy piece of crap. One wonders if they had outsourced it's development to microsoft in some back-room deal.

Yea, other non-iPhone's on AT&T's network had a perfectly good signal since July 11th. If this were really the problem, wouldn't they have buckled too?

Wouldn't the 3G signal be different then the Edge Signal? i'm not a wireless expert but i would assume so.
Also what if they had controllers or towers solely dedicated to broadcasting signals for the iPhone. And for all other mobile phones use different towers/controllers.
just guessing...

So let's say everyone upgrades to 2.0.2, around 99% of the people. That means that the 1% left that is still using older firmware will have 3G working for them a lot faster, since they are using more power?

@ chad:
Your argument sounds like a reasonable one. I haven't heard anyone on AT&T using other 3g phones report problems with dropped calls or slow connection.

I'm don't know if I agree 100% percent with the article.
" An iPhone 3G running 2.0 or 2.0.1 tries to pull too much power from the network, so when multiple iPhones connect, a tower can actually run out of juice and start dropping calls and losing data."- A tower controls it's output's power, not the phone. If a 3G tower starts to get overloaded, it's coverage area starts to shrink, called cell shrinkage, therefore users experience dropped calls and sloooww data speeds. I have never heard of a phone that can control the output power of a UMTS/HSDPA tower.

but it sounds like the phone was constantly polling the tower for power, so it wasn't necessarily using more power, just doing it more often, and if a lot of phones do it more often, then thats more power the tower is pulling out?

My wife just switched from a 3G Blackjack II to an iPhone this weekend and was complaining about poor reception yesterday. Had her upgrade last night. My reception's been fine though.

The article is complete balderdash. The output power from the Tower is a constant and has absolutely nothing to do with what device happens to be listening to the signal. There is no such thing as "Cell Shrinkage", signal Strength fluctuations are a result of variations in atmospheric conditions, ambient environment (you're in a metal box) and movement between cells.
Cell phones are simple "radios", then receive and transmit signals much like a walkie talky but in a more sophisticated way. The key here is the transmit part, since upgrading to 2.0.2, I havent noticed any different in signal strength or quality, but I have noticed that the battery drains faster, and I mean significantly like in the order of 50%. My guess is that they increased the wattage (power) to the iPhone transmitter in the hope that this would prevent call dropping, but in the process the battery now drains faster.

There is such a thing called cell shrinkage, UMTS is based off of a CDMA backbone, and drawbacks are when a UMTS tower gets crowed with calls it will cut back the power that the tower puts out (cell shrinkage), so in result more dropped calls and fluctuating signal. It's real. Ask a cell site engineer.

Here's some more info on cell shrinkage- The performance of CDMA cellular systems over the
air is generally interference-limited. A phenomena arising from
this is the effect of cell-breathing in 3G cellular systems. Cellbreathing
is the expansion or contraction of the effective coverage
of a cell in response to the number of active mobiles (MSs) in a
network. If it is not well controlled, communication failure may
result. With 3G offering different classes of services, planning and
dimensioning of such high-quality radio networks thus requires
extensive planning tools. Despite the progressive rolling out of 3G
systems worldwide, the effects of cell-breathing are not well
understood. In this work, a simulator is set up to study the effect
of cell breathing. Simulation results show how the area where
reliable coverage can be provided by a base station (BS) may
varies as the density of MSs changes within it. Current work
emphasizes on the downlink simulation with a single BS followed
by a similar simulation involving 2 BS. The results demonstrate
how cell-breathing may cause communications failure.

I can't determine whether an arcane cellular networking explanation is true or not. What I do know is that a "bug fixes" patch that actually corrects an error in the cellular networking protocol in a way that patchers suffer and non-patchers continue to have an operational 3G connection is not a "bug fixes" patch. Lacking any known means of updating firmware remotely, Apple should have treated the situation as an EMERGENCY MANDATORY SERVICE RECALL. You can't use the firmware update process to correct a critical error like that. There are plenty of users who not only didn't update to 2.0.2 and now don't have the reason to, but they will wait to update to 2.1 to see what happens then, as well. Those users have no reason to complete or participate in some zany scheme to cover up a critical firmware flaw. You'd have to be a fool to believe that someone in that situation really cares about the networking problems of other people, so to shift blame on them indirectly is ridiculous.

I've found my problems go much deeper. Yes it drops out of 3G - permanently for the psat week but it will also drop from the edge network. After two visits to the store and an hour on the phone with customer service I've given my iPhone back. There have been about 6 days in the three weeks I've had it where I could get no coverage at all - that adds up to a lot of lost business as clients could not make contact with me. Apple should have stayed in computing becuase out thre in mobile services they are not up to it.

This isn't just an iPhone problem. This is a problem with AT&T network and it being oversubscribed in general. The huge influx of yet another round of iPhone users and their associated HUGE volumes of data that they require are only helping to compound the problem. I am not an iPhone user or even a fan - I frankly feel that they are noting more than an expensive toy at this point in time, even with 3G and the half-baked Exchange integration - not a real business tool (no matter what the Apple commercials say). I use an HTC Tilt and within the past 4-6 weeks - not surprisingly just after the latest release of the new iPhones - I have been experiencing excessive numbers of dropped calls, slow data response, mysteriously incomplete calls, etc. This is VERY distressing since I am in sales and dropping/missing calls is a distinct problem. AT&T needs to address this issue by either fixing their network or by stopping the sales of products that are compounding the problems until they can fix their network. If I wasn't tied into a 2-yr contract, I might even consider going back to Verizon or some other carrier.

Me and wife had iphone since January. No problem till now. Cant call out or in and no texts or internet but only when i am at my house. I go one street over and i get connected. Very bad for me since i am in health care and need my phone 24/7. AT&T doesnt really know what to do. I dont know what to do . I thought that "DEAD ZONE " was a joke but now i am in one, and i'm stuck in it with AT&T .

Denis I'm in the same boat AT&T is clueless, they built a tower in the woods on a water tower and guess what the tree's grow and the tower didn't, CLUELESS

All I know is this phone cost me $400. I expect it to work. Is that so much to freakin ask?

The phone works on IP (internet protocol). They will never work in IP because of the way IP travels. IP is an information packet that by definition can have "traffic jams) Hence the damn phones NOT working in areas where there is IP congestion. Look at ATT Uverse it's an all IP network..google ATT Uverse issues) Again, IP does not work on a large scale. Strange...all of these tecom companies want to move to an all IP netork so they can monopolize, gov can trace everything and the damn protocol doesn't even work well for voice/data and video. ATM is used for video NOT IP...no wonder the damn iphones don't work ..they are using the wrong protocol the wrong way. Currently there is a movement to get rid of 3 specialized networks (atm/frame relay and legacy networks) and to run everything through IP and create a new standard called best effort. IT WILL NOT WORK...atm/frame relay,legacy networks and IP are specialized systems that must be subordinate to a switching system or MPLS.
We are in a terrible economy and now they are wanting to put all of telecommunications in IP and drop the quality across the board to best effort. I wish citizens could see that they are being duped an all IP network will not work efficiently. At any given time much of the network will using all IP will lock up. ...Welcome into George Orwell''s 1984 society...an all IP network will allow monopolies and the gov will like it because eveything can be traced (cell phs/email/tv/radio/internet/land lines..etc.) makes a wonderful system for government to spy on people and for the Patriot Act. ..all can be traced but nothing will work efficiently.

I think people tend to forget that social media is really just an extension of our face-to-face relationships. We expect more from it because the potential reach and opportunities for expression are enhanced (like someone's vision is enhanced looking through binoculars or a microscope). But behind the profiles, followers, friends, tweets, likes, etc there are people after all, and the basic rules of communication, relationship building, and doing business with these people still apply. IMO, it's the best "social media" strategy there is.