Inside AT&T’s 83 GB/hour mobile cell tower

[Game_Ender]

To convert to more normal units, that is about 189 Mbits/second. Which sounds a little less impressive considering the peak 4G speed is supposed to be 100 Mbit/second.

[skyebook]

I thought 83 GB/hr seemed like not much capacity, and indeed that really isn't much. I've seen these units (and from other carriers as well, IIRC) before and figured they were bringing massive amounts of extra backhaul to spots with big events.

I'm curious how these figures relate with what 'normal' towers have allocated. I've seen the rough 1 gbps figure before but don't know how accurate that is.

[brokentone]

That's peak hour usage average, but I have to imagine the bursts were much higher. Not to say I disagree, doesn't sound all that impressive

[jnw2]

Doesn't 802.11n theoretically support 300 mbits/sec on a single 40mhz channel, too?

[rgbrenner]

So light on details.. could have mistaken it for a press release. And more amazing, they managed to get some of that wrong. In their graphic, they mislabeled the mobile command post as H, and G in the key... and "AT&T’s network is about 80% iPhones" then link to an article about _smartphone_ sales in _Q4 of 2012_

[w1ntermute]

> could have mistaken it for a press release

I tend to avoid articles on any 3rd party sites with the word "Mac" or "Apple" in their domain names for this exact reason. The effects of the RDF are just too transparent.

[thedrbrian]

Maybe they're taking about people who use the smart bit of their smartphones?

[hncommenter13]

I ran a mobile gaming conference for about 250 people in a major city back when AT&T was the only game in town for the iPhone (~2009). Without calling us or us reaching out to them, AT&T contacted the venue and installed a micro-cell--free of charge--to ensure good coverage throughout the day.

Say what you want about the network or the company, but I was impressed. (It probably didn't hurt that we had some folks from Apple on the attendee list.)

[tumblen]

I help run a conference in Portland, OR and would love to look into this further.

Do you have any contacts still or any idea who I could get in touch with to get more information? Thanks!

[Maven911]

This is pretty surprising that AT&T engineers were the ones to design the antennas. It is usually vendors such as Nokia-Siemens, Alcaltel-Lucent or Ericsson that provide the equipment and that have the antenna/radio know-how while on the operator side the engineers there focus more on optimization and RF planning, rather then the design.

[tfe]

If you watch the video of the two AT&T engineers, they basically say that they just had the idea; their (unnamed) vendor actually did the work to see if it was feasible and designed the antenna.

[packetslave]

When you get to the level of "top 5 customer" (which AT&T almost assuredly is to whomever their equipment vendor is), the customer has quite a bit of input into the design of new products. Especially if the product is going to be sold primarily TO that huge customer.

[quackerhacker]

I have an unlimited ipad data plan on AT&T, and for 1 month straight, I streamed video constantly just to test if they throttled or capped Unlimited Ipad plans. 128GB in 1 month and I was still getting 50+down/15up.

Evidence: My twitter images twitter.com/MichaelLargent

[shawnz]

Leeching 128GB would only take 6 hours at the speeds you describe. I would certainly hope that they don't cap you after a period that could be as short as 6 hours!

[Matsta]

I've been researching something similar for a startup idea for a while now.

There still a couple of problems that still haven't been addressed (or just aren't included in this article)

1. 1 Cell site isn't enough to cover a densely populated area. Although this is running on 850mhz which is much lower than wifi at 2.4ghz, multiple cell sites are usually better than 1 big one. If their peak is only 189mbps, then it should be fine using cat6 cable, however your limited when for range as you will run in trouble if you run cable over 100m without a repeater or booster. The other option is to use fibre, which is rather expensive but it wouldn't be that bad for AT&T considering their size.

2. Limited to the network beyond the cell towers.

This is coming from experience being at large festivals like Coachella, but although you can get signal on your phone most of the time, sms is virtually useless since your txt's are delayed by 4-5 hours. You can make a call after about trying 10 times, but because of the noise, you can never hear what the other person is saying and vice versa. So unless they are running a local relay for text's and transferring calls, their network servers are the ones that need beefing up rather than the towers themselves.

Now I'm guessing people are going to be using data more than anything, but in the past I've found 2g to be much more reliable (3g flatout did not work at the last festival, Big Day Out I was at). We found that Whatsapp became the most reliable way to communicate between our friends as your messages wouldn't get delayed for hours.

[BadCRC]

what do the AT&T vans connect to? I assume that there is no landline available for them to hook into, so how are they providing service?

my guess is satellites or communicating with other cell towers but the latter seems counterproductive as it would push a high load to a different cell tower. but if they used satellites, wouldn't there by high latency and bandwidth limits?

[Matsta]

A few months back we were exploring a abannonded building (scheduled to be demolished), and we found there was a working cell tower ontop of the building. There was a small server room that had all the eqipment to run everything (I think it was shared by the 2 big telco's here in NZ).

From what we would could see, there were a bunch of ancient racks running 2g gear that looked at least 10 years old (all beige), and then a whole 42U rack of 12v batteries for a UPS.

Then there was a quarter-rack which had a bunch of fibre cables going into a few Huawei branded 1u boxes. LTE only got deployed a month ago so it much of been HSPA+.

I think if they had a satellite connection there would be too much latency. And the throughput wouldn't be limiting as well. They could of had one as a backup source though, or just setup as a secondary connection.

[btgeekboy]

The image at the very top of the article mentions they have a microwave backhaul (see "E"), which I'm assuming goes to another ground location (i.e. a central office.)

[quackerhacker]

I've actually wondered this too. I remember hearing about these temp towers at the 2013 inauguration. I understand how they allow more users to get a signal, but as you said.....what is the backhaul actually on? It could be distributed through a cell tower you may not get a signal from is my guess (like 1 that's 1mi away), or ran on a fios network (like voip).

http://www.huffingtonpost.com/2013/01/07/cell-phone-towers-i...

[tomflack]

I've seen line-of-sight microwave used for similar needs, but not in built up areas.

Edit: clicking through and actually reading the link, the picture clearly depicts Microwave backhaul. Probably to a site in the vicinity they have a nice big land-based pipe.

[joosters]

Does anyone know if they do any local web caching? There's nothing mentioned, but you'd think that a small-ish transparent web cache would save them a lot of bandwidth.

[nano111]

Can you feel the heat when you sit next to this antenna?

[ricardobeat]

In the ground probably not, but put your hand right in front of one of those dishes and you get some serious RF burn.

[Matsta]

When I was on a building with one, you could hear a quiet buzzing noise, but you couldn't physically feel anything from memory.

[andymcsherry]

I was at this concert actually, and I have to see it was the most spectacular reception I've ever had an event.