Review: AT&T 3G MicroCell | Hacker News Reader

Review: AT&T 3G MicroCell

paulstamatiou.com

44 pointsPStamatiou39 comments

Maybe I'm missing something, but given that I live in the mission in San Francisco halfway up a hill, it seems pretty poor form for AT&T to expect me to purchase one of these things at my expense.

While I realise that currently they are being offered in rural regions. I'm pretty offended at my surprisingly terrible coverage at home and it seems pretty lame of AT&T to suggest that their customers should a) buy additional hardware to get better cell coverage b) have to provide a free internet connection for their calls

I have to pay AT&T for both my cell connection and my internet connection, and now they think it's appropriate for me to pay to piggy back for free on the internet connection I'm already paying for in order to get decent cell coverage. Uncool in the extreme.

"While I realise that currently they are being offered in rural regions"? I live in midtown Atlanta, not quite rural. (I'm OP) :-)

The main reason for having GPS in these devices isn't to support a phased rollout in US markets. The main reason is so that I can't install one of these outside the country, and still dial/pay like I'm still in the US.

T-mobile offers a number of phones with WiFi that, similarly, connect to the T-mobile network via the internet. I hear they are a great way to get around overseas roaming charges.

But what's the point? Isn't the rationale for roaming charges that it costs more for them to set up (or rent) infrastructure overseas, so you have to pay to make up for it? Seems to me that the MicroCell doesn't cost them anything more if it's on a different continent.

There's no rationale; roaming charges have always been hugely profitable for carriers, and now it's worth putting GPS chips into these femotcells and putting customers through an arduous setup process in order to "protect" that revenue.

Thanks for articulating what I couldn't.

I'm guessing the main reason for having GPS in these devices is that, like other GSM base stations, they probably need access to a very accurate clock. Then, once the hardware's there...

No more accurate than the one in the phone...

Just to confirm. I have a Blackberry 8900 with T-Mobile. Worked just like at home with a wifi connection in Indonesia. They call this service UMA and it's pretty awesome.

That may be one factor, but avoiding lawsuits over broken E911 functionality is another: http://www.lightreading.com/document.asp?doc_id=77368

Correct. That is exactly the reason. The revenue protection is a happy coincidence.

The unit has to know where it is because in different locations AT&T has different wireless licenses. For example, in most parts of North and South Carolina, AT&T owns the PCS B license and so the unit knows its location and knows that it can operate on those frequencies without interfering with another company's spectrum. If the unit was using the wireless spectrum of another company, that company could rightfully sue AT&T for causing interference with their equipment.

And wireless spectrum wasn't sold nationally in this country so AT&T (or Verizon or whomever) has different licenses in different locations and the unit needs to know what it can use. Heck, the AT&T device needs to know what spectrum AT&T has offered for 3G usage in an area so as not to interfere with the GSM/EDGE signals.

The reason you can't use it in another country isn't some plot to make it so you can't use domestic minutes overseas. It's because it would be illegal for AT&T to allow you to operate a wireless transmitter on another company's wireless spectrum.

T-Mobile is a different case because they aren't using micro-cells. They're providing handsets that do WiFi and traditional wireless. As such, they can allow you to set up your WiFi device anywhere because WiFi spectrum isn't licensed.

Sprint similarly has a device (the Airave) which is a micro-cell and uses a GPS unit to determine where you are. The trade-off is that you can only install a micro-cell where a company is licensed to operate, but it works with lots of phones -or- you go with WiFi and can put it anywhere, but you need a special WiFi-enabled phone to use it.

Great review. I have wanted one of these ever since a friend at AT&T shared details about them almost two years ago. I have a mostly stone house with plaster interior walls that is essentially a Faraday cage to wireless devices. I'm just waiting for AT&T to add my city and I'll be first in line to buy one.

If you think about it, it's ironic that I'm looking forward to paying $$ for a device that will extend the coverage of my wireless telephone by using bandwidth provided through my broadband carrier. AT&T should really pay us $20 a month to use them.

If I hadn't noticed the OP was the author of the article, I would have shouted foul play - in the wake of the at&t-verizon battle with 3G. The article is well written enough for me to remark as a viral ploy by at&t to get back to customers. (I didn't know of the 3G micro cell until I read this article; I assumed that this is a new device released)

I know Paul personally and he's a pretty reputable guy. Plus, he used my little Stammy head rating graphic at the end of the post, so how could I not appreciate that :D

It really is a budding market. Sprint has one too, the Airave. Identical.

The GPS requirement seems ridiculous. I understand why they are requiring it, but it really highlights how ridiculous tying services to geographic locations can be when the internet gets involved.

That being said, I'd buy one without hesitation if they were available in Houston.

I wonder if the GPS sync is a one-time requirement, or if it does it periodically to ensure that the device isn't moved.

GPS simulators exist, though they're expensive. I wonder how cheaply you could make a ghetto one yourself?

Would probably be easier to just plug it into a small UPS.

If you were driving, you could very easily transport it hundreds or even thousands of miles without ever worrying about power loss.

From what I can gather it is only during initial setup and it didn't bug me when I moved it afterwards.. but I have to imagine that if it's unplugged for some period of time (ie if you are traveling with it somewhere..) it will try to get another GPS lock before proceeding.

Another friend had to use an external GPS antenna to get it to lock appropriately, so I'm not surprised that you had to put it by the window. I would say this is common in multi-tenant buildings, especially concrete ones.

It would probably violate the TOS, but it seems like it would be pretty simple to circumvent the location restriction.

Very few companies produce GPS chips. Most devices that include GPS capability do not bother to reinvent the wheel, but instead elect to integrate an existing GPS processing chip.

GPS chips usually output various location sentences over standard RS232 (or I2C) a rate of around 1 Hz. It is unlikely that AT&T went through the trouble to design their own GPS processor into the Femtocell ASIC--it's likely connected but separate.

So, if the GPS data line could be isolated, it would be well within the capability of a microcontroller to feed fake GPS NMEA sentences [1] to the Femtocell ASIC using that line. Maintaining an updated time field in the NMEA sentences might require a separate real-time clock chip, but the Femtocell may not even examine the time given by the GPS.

A PIC microcontroller could cost less than $5, not including the cost of a compiler and hardware programmer.

Program a microcontroller to output an artificial location, cut a trace, solder a few leads, and you could make a Femtocell think it is Topeka, even if it is connected to the Internet in Turin.

[1] http://aprs.gids.nl/nmea/

and this is why I love Hacker News

T-Mobile customers can roam onto AT&T... does anyone know if this microcell works with t-mobile phones?

Not only will it not work with T-Mobile phones (which use a completely different 3G frequency), it won't even work with AT&T phones that aren't registered with the device.

It seems like femtocells are are a half way solution. Leveraging a dual mode smartphone would provide much easier solution. Maybe a phone based client that automatically routes through the WiFi to the cellular infrastructure would be a better solution.

I know t-mobile has a solution but that still requires you to get a separate router and it is limited to certain phones. .

I've looked at enterprise solutions like Agito Networks, but the cost seems prohibitively high for non enterprise users..

I have waffling between waiting for this and getting a run of the mill signal booster/amplifier (which should work in my circumstance). I think I'm going for the latter because it doesn't require phones to be manually added and works regardless of carrier. I want visiting phones to work too without hassle.

My apartment gets absolutely no signal of any kind, so why would I be able to get a solid GPS satellite lock? Ridiculous.

I don't understand this complaint. Lack of cell phone signal has nothing to do with GPS signal availability. You just need a reasonable amount of sky to point at.

Yeah I know one is cell signal and one is sat.. I'm just trying to say that my building's construction inadvertently blocks everything. If I whip out my iPhone and press the locate button in the Maps app, that has no idea where I am. Same with my Dash Express if used inside my apartment. Getting the GPS lock required putting the MicroCell right on an open window, almost outside.. not even a few feet from it worked.

Which makes the requirement that it gets a GPS lock before it works that much more ridiculous. GPS gets terrible reception in any indoor situation. It can have trouble with just trees.

Idea: hook your MicroCell through your broadband connection, jailbreak your iPhone, and use it to tether another computer's internet connection through the 3G through the wired broadband connection.

Could you clarify a bit? Is there any use for this when I have Wi-Fi? Unless you are talking about using your connection with someone else's MicroCell, in which they have to add your phone to the authorized list. In which case I see what you mean.. getting access to Internet on your computer when you only have a access to a MicroCell connection. (?)

There's no use for it, I just thought it would be funny.

I guess if you didn't have WiFi, had this, and all your friends had jailbroken iPhones it would be useful.

haha, indeed.

You don't need to jailbreak to tether - there is a carrier file you can download on iPhone 3.0 that will enable it.

Ok, I can't be the only one that wants to get one and hack it to work with any VoIP provider. I haven't been this excited about working on a device since the original iPhone came out.

I missing something. What part would be VoIP?

DO you mean, hack it so that a VoIP phone can pair with it, because those product already exist...

Or do you mean hack it to carry calls over VoIP, which seems like just another monthly-bill layer of abstraction in the transport, since it can already use a "raw" Internet connection to carry the calls.

I'm thinking he's saying he'd like to be able to use a 3G phone via this device without AT&T being in the mix at all.

It does use the "raw" internet to make a VPN-ish connection to AT&T... it would be highly cool if I could make that connection to a VOIP Provider instead.

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