Want an AT&T cell tower in your home?

As if the risk of brain cancer weren't bad enough justing using a cellphone, AT&T is contacting some of its customers asking if they'd like to test an in-home extension to its cellular networks powered by a subscriber's own broadband—a femtocell. Femtocells use frequencies licensed by the carrier for data and voice, while handling backhaul through a customer-provided service.

AT&T's new product is a small, security-enabled cellular base station that easily connects to your home DSL or Cable Internet, providing a reliable wireless signal for any 3G phone in every room of your house. The device allows you to have unlimited, nationwide Anytime Minutes for incoming or outgoing calls.

Sprint Nextel has been offering femtocells since last year; the advantage to the carrier is providing fill-in service in the home without deploying more base stations in an area. AT&T has apparently been testing femtocells with its own employees since last year as well.

Femtocells differ from T-Mobile's UMA (unlicensed mobile access) approach, which also puts a specialized device in the home. With UMA, specialized handsets must have both cell and WiFi radios, and the firmware to handle seamless handoffs between the two network types. With a femtocells, the radio side is effectively identical with only the backhaul varying. T-Mobile also offers WiFi routers that feature two increasingly common VoIP-oriented protocols (one for power conservation, the other for packet prioritization).

Carriers pay enormously less to transit and account for voice and data over a customer's own broadband, and thus can offer so-called unlimited voice plans (which have some very high monthly limits). T-Mobile's HotSpot@Home service costs $10 (1 or more lines) per month adding to a minimum $40-per-month voice plan; Sprint charges $15 to $25 per month for the same thing.

Femtocells have few disadvantages for home users because the dedicated frequencies means that any WiFi network they may already have in place isn't degraded by cellular use, and vice versa.

Has the iPhone overloaded the AT&T 3G network?

So I'm sitting here working through technical problems with a vendor tonight, and to my surprise my iPhone with all the reception problems is working great. I haven't had a dropped call or choppy conversations all night.

That's very strange. During the day I can't carry on a 5-minute conversation without dropping a conversation, or at least getting a complaint about the quality of my voice.

But at 1:40AM? No problems. I live in the heart of downtown. My neighborhood is congested during the day with thousands of iPhone users at any given moment. Evenings are normally packed with the bar/restaurant/theater/concert crowd. But at 1:40AM you are taking your last drink and heading home (safely of course - we have mass transit in Denver). The point is that the number of people on their phones is decreased dramatically.

So this got me thinking...

Could it be that the iPhone is overloading the AT&T networks? iPhone users tend to use 30 times as much data as regular cellphone users, consuming 100MB per month on average. Even though the article refers to Germany, that's been my approximate data usage month-to-month as well since last year.

So each iPhone user is equivalent to 30 regular AT&T subscribers.

Doing the math, that means if you sell 6-million iPhones, you've really added the equivalent of 180-million phones worth of traffic to the AT&T 3G network. We know that AT&T's already struggling to catch up with the infrastructure for their 3G network, so maybe this is making the problem worse?

Keep in mind that this is less than a scientific observation, but it is an observation. Has anybody else experienced anything similar?

Infineon chips could be to blame for iPhone 3G woes

I've been doing more research today on the iPhone dropped call and data issue I've been having since upgrading my original iPhone.

Looks like the Infineon Chip that Apple used is being blamed for causing problems in 2-3% of iPhone traffic. Now, I'm not sure if that means 2-3% of iPhones, or 2-3% of calls. I know for a fact that I drop several calls everyday, whereas before I dropped none.

It seems that the Infineon Chip is not properly sensing the 3G signal strength, and is causing major handoff issues between 3G and Edge. I hope Apple can fix this in software, but I would imagine that a hardware fix would be a better solution.

iPhone 3G Dropped Call and Data Issues

I have recently upgraded from the original iPhone to the iPhone 3G. My reasons were twofold. I wanted to take advantage of the increased voice quality afforded by the the 3G network. Additionally, I wanted the ability to load data faster so that I can access my corporate Outlook Web Access with Safari. Currently my IT department does not yet support iPhones, even with the Exchange capability in the 2.0 software, and I refuse to carry another BlackBerry.

I home office in downtown Denver, right in the heart of the city. With the first generation iPhone I had 4-5 bars of service in my building at all times, except inside the elevator. I've found that since upgrading to the 3G iPhone, I consistently register 1-2 bars of 3G strength in our loft. If I disable 3G, then I register 4-5 bars of Edge strength.

After upgrading, I am consistently dropping 5-10 calls per day, whereas beforehand I dropped 4-5 calls a year. There seems to be a major issue with the iPhone 3G that prevents the timely handoff of the phone call from 3G to Edge when you are on the boundary of 3G/Edge service. This problem affects both phone calls and data transfer.

When in a call, the typical symptom is a dropped call. When in data mode, such as accessing Safari web browser, it often takes 30-seconds to a minute to make a connection as the phone bounces between 3G and Edge. All in all, the problem is making the phone unusable as my primary phone.

I've found that by disabling 3G I am achieving less dropped calls in downtown Denver. But I am still experiencing more dropped calls than previously, 2-3 per day. Additionally, since upgrading my wife's original iPhone to software 2.0 (and 2.0.1), she is experiencing similar problems.

Now comes word that the iPhone 3G itself might be flawed in it's connection to the 3G network.

The UMTS chips in the iPhone are supplied by Infineon. Ny Teknik, a Swedish publication, cites another cause, alleging that some specimens have insufficient input sensitivity, failing to comply with the 3G specification, and that the problem sometimes occurs because of defects in mass production. The most likely source, they say, is incorrect or inadequate fine tuning between the antenna and the amplifier.

It looks like Apple knows there is a problem, and even though it might be a problem with the Infineon chipset, they plan to address the issue with a software update, not a hardware recall.

Only time will tell how this saga plays out. But I know for my money, as much as I like the iPhone, if they cannot work out the 3G and connectivity issues, I might be moving on.