Femtocells - A Cellular Technology for Boats

[ActiveCaptain]

There's a new type of hardware available now for mobile phones and it has interesting applicability onboard boats. The generic class of device is called a "femtocell" and is well-described in Wikipedia:
http://en.wikipedia.org/wiki/Femtocell

It is a confusing piece of hardware because it bridges some gaps in existing cellular technology and is difficult to grasp. If you make a lot of voice calls from your mobile phone on your boat (or want to), it's something you should know about.

I recently purchased AT&T's new femtocell product called the "MicroCell". The hardware is extremely well made by Cisco. It requires connection to a broadband internet connection - WiFi is the only thing that makes sense for boating except in a very unusual circumstance that I'll describe below.

When powered on and configured, MicroCell provides a miniature cell tower in your boat. They say it will provide 5,000 square feet of coverage. So as long as you're cruising on something smaller than a 150 ft megayacht, the coverage will be excellent.

Since it's a real cell tower, you get 4-5 bars on your cell phone all the time when you're within proximity. You can tell that you're connected because your phone will say "MicroCell" or "M-Cell" where it usually shows the cell tower being used.

You have to configure which mobile phones are allowed to connect to it. You don't just provide service to everyone in the area. You're allowed to configure 10 phones or devices at a time - more than enough for most cruisers and guests. Only 4 simultaneous calls are allowed, again, more than enough in most cases.

Your mobile phone sends and receives voice calls just like normal. Voice mail including VisualVoice for iPhone, text messages, and everything else works just like you have a 5-bar connection on land. The actual voice data goes through the broadband connection and directly to AT&T though. If a call is received, AT&T knows that your mobile phone is on your personal MicroCell tower and routes the call immediately to you. My wife and I have been using it for all calls and it has worked flawlessly.

The actual MicroCell currently costs $150 but right now there is a $100 rebate. I think they're doing this because no one is buying it because no one understands what it does. Without any extra plan, using the MicroCell is just like using your normal "minutes" voice plan - you just get exceptional service because you have 4-5 bars all the time. The interesting thing happens when you add AT&T's $20/month MicroCell plan. The optional plan provides unlimited voice calls whenever you're connected to the MicroCell. That ends up being a lot less expensive than any other unlimited cellular calling plan available. An important boating feature of the $20/month plan is that it can be turned on and off by the day costing about $0.67/day.

OK, the unusual twisted way to use a MicroCell on your boat while cruising occurs in places where there is very poor AT&T reception, like most of North Carolina. If you have a Verizon broadband device like a MiFi or aircard, the MicroCell would give you an interesting capability. You'd connect the MicroCell to the internet through Verizon's service. That would give you 4-5 bars of AT&T service on the boat allowing you to make normal voice calls for free although it is using your Verizon data plan. If that makes your head explode trying to understand it, just ignore it. It's a very specialized case and has some router configuration complexity too.

Because the MicroCell is a real cell tower, you can start a call on the boat, get in your dinghy without hanging up, and the call will switch to a real AT&T tower just like normal tower switching occurs. Once you switch to a real tower, you're now using real voice minutes on your mobile plan however.

The five people who are still reading this might ask, how is this different than Skype? Skype also uses a broadband connection to allow voice calls to transmit over the internet to normal phone networks. Well there are a few ways that the MicroCell is better:

- You get to use all your normal mobile phone capabilities: address book, voice mail, caller ID, headsets, etc.

- You get to receive calls on your normal mobile phone; Skype has Skype-In which is similar but requires another phone number and just doesn't work very smoothly from my experience. You also need to leave your laptop running Skype all the time in order to receive Skype-In calls.

- You get to hand off calls when you're leaving the boat without having to hang up.

- Comparing to Skype app support on phones, call quality is much better with MicroCell because the data is going directly to AT&T in a completely supported way. Using Skype on a laptop provides good quality voice calls too most of the time but isn't as portable.


As this rolls out and becomes more common, I'd expect to see it being used a lot more for cruising. It all comes down to getting a good internet connection on a boat, something I'd bet on for the future.

[hellosailor]

Femtocells have been around for years. In a lsightly higher power version they are also called picocells, and all they really are, are active repeaters.

If you are in a building where you can't get cellular reception, you put a picocell inside the building and stick the antennas outside the building, a you're hooked up. If the building is very small--you use a femtocell. The only difference is how many square feet they cover. And, that in the last year or two the major carriers have finally started to admit their coverage has holes that can't be plugged any other way, so they are offering the products under their own brands.

The typical femtocell is plugged into a landline or internet connection--and your call WILL be dropped when you go outside its tiny little range, unless there is other coverage. No magic there, and often monthly charges for it.

Just as easy to install a bidirectional booster (i.e. Wilson) and a good antenna.

[ActiveCaptain]

We have multiple cellular amps on our boat too and have written extensively about them and the various issues. There's a big difference between a femtocell and an amp - the amp will only work if there is already an acceptable cellular signal. A femtocell will work where no signal exists at all. It also allows multiple phones to "connect" at the same time which requires a wireless amp otherwise. Wireless amps are known to be problems on boats because they can't provide the necessary separation between antennas. What might work really well in a building or a subway (picocells) won't work well in a boat at all.

The fact is that until AT&T's MicroCell, there weren't femtocells that a normal person could purchase. Mine cost $50 and is working fantastically. It's hardly a repeater. It's a real cell tower and it switches nicely when I leave my house while on the phone. It's not for everyone and it doesn't fit all needs. But there's a few nice things that it does that are quite unique and totally applicable while cruising especially if you're running a business while on the water.

[witzgall]

Jeff;

I think what might be unclear, is what the AT&T product actually does. Here is my take:

It must connect to a broadband connection, and it essentially "converts" your cell call to Voice over IP, and then transmits your voice call over the internet, where at some point, AT&T puts it back onto the phone network.

Chris

[ActiveCaptain]

Sure, that is exactly what it does. It also acts like a full cellular tower though allowing you to use all the tools you have on your mobile phone as if you were sitting next to a real tower along the highway too.

[hellosailor]

"There's a big difference between a femtocell and an amp - the amp will only work if there is already an acceptable cellular signal. A femtocell will work where no signal exists at all. "
You forget to mention the other half of the picture. An amp requires some cellular signal be present, yes. And a femotcell requires some type of internet connection be present! In which case, you don't need the cell phone at all, you can use VOIP directly. The femtocell will require an internet connection, a Wifi access point, a telephone network connection, or some other equipment and network to function.
Making it a convenient way to keep your cell phone connected--but call forwarding and an IP phone will still do that, without the need for the femtocell.

[DotDun]

Jeff,

I'm not sure running the Femtocell over Verizon's 3G service is going to produce the results you would like. Most 3G service provides less than acceptable delay/jitter therefore not very good support for voice calling. I'd be curious what your results are using 3G as the uplink.

Also, does AT&T verify your location? I know the Sprint AirRave contains a GPS and won't work in non-Sprint territory. Just curious as this would certainly restrict the usage to the US. IOW, can't take it to the Bahamas.

[ActiveCaptain]

Two things...

First, I addressed some of the differences between Skype and other VOIP versus MicroCell in the original posting. I've been using Skype for a few years on my boat. I'd really prefer to use my mobile phone(s) instead and the results I'm seeing provide much better features and quality on the phone itself as compared to the phone/Skype. In other words, people who understand where Skype fits are probably the best prospects for using something like a MicroCell. They'll like it better especially if they often receive calls.

Second, yes, the device does have a GPS. E-911 requires it but after a few conversations with AT&T about it, you're right - it's mostly about verifying that the box is located in the US. It will supposedly shut down if it finds itself in the Bahamas. E-911 is routed based on the configured address of the unit no matter what lat/lon the GPS acquires. This means that the address should be re-entered whenever the boat changes location to ensure proper E-911 response. It's a very quick process to do that but I worry that most people won't do it on boats. That's a danger of using the device.

[DotDun]

Jeff,

Another interesting technology is a dual-mode phone (GSM/802.11) from T-Mobile (using the UMA protocol). Functionally, the same as the femtocell, but no additional hardware required. While the femtocell tunnels the GSM/CDMA protocols through IP back to the carrier's network, UMA puts that functionality right into the handset. I think T-Mobile is currently testing some Android handsets now, but I don't have any firsthand knowledge. Also, how they handle location/911 is a mystery at this point.

[ActiveCaptain]

Originally Posted by DotDun

Another interesting technology is a dual-mode phone (GSM/802.11) from T-Mobile (using the UMA protocol).

I agree - very cool stuff. It's a wonderful time to embrace technology! I keep wondering when I won't be as fascinated with all the new stuff.

[SailFastTri]

I have a Verizon "Network Extender" that is a Femtocell made by Samsung. Works great in my home where I have poor cell reception and a reliable cable Internet connection.

I see several drawbacks in using such a device on a boat, the main one being power. The power brick has a rated output of 12v 1.5A and it is using a high percentage of that judging by the heat produced the unit itself. It also requires a wired Ethernet connection, so on a boat that only has WiFi you need to connect it to an Ethernet port on a wireless bridge that's paired to an access point ashore.... not something for the networking novice.

This isn't the kind of device you turn on only when you need it to make a phone call, and you'd want it to be ready when an incoming call happens. It takes a while to start and all the ready lights to come on -- so it would be left powered on when you're aboard and expecting to be able to communicate.

So assuming you can get a good WiFi signal and you don't already have a power budget deficit, it would be nice to have but only if you use a genset and/or have lots of solar/wind generating capacity.

[ActiveCaptain]

Originally Posted by SailFastTri

I see several drawbacks in using such a device on a boat...

All of your points are good one and all should be part of the consideration of using the device. For me (and every boat is different), here's my take:

- The AT&T MicroCell is drawing 1 amp at 12v. We anchor out 85% of the time. A single amp of extra draw won't change anything for me. In fact, I'm an amp ahead once my iPhone anchor alarm is out

- Many cruising boats like mine have extended WiFi range capability that goes into a boat-only WiFi router. Connecting the MicroCell into that router is going to be a trivial thing for me.

- There are many boats that cruise marina-to-marina and have real power almost every night. For those boats, there is obviously no power issue. For them, this is a pretty nice way to get an inexpensive unlimited voice plan.


All of these issues have to be put in context against need too. For many (most?) cruisers, high volume calling isn't that important. But for me, the only reason I'm able to liveaboard my boat and cruise is because I can run my business from the boat. I suspect there are many others who would rather work from their boat too and this might provide just enough of the missing connectivity to get there.

[ActiveCaptain]

I have one onboard. It's definitely not an at-sea type of thing! It's quite nice if you have a good WiFi connection though...

[ActiveCaptain]

There are 2 signals. Assuming you're able to maintain a WiFi connection (which is why it doesn't work while underway), the Femtocell cellular signal is good for about 1,500 feet. That's big enough for any boat I think I'll ever have - house too!

[Hillbillylad]

We can't get cell reception here at the house so I bought a couple of cheap Axim 51v handsets. They have windows mobile 6.5 on them. I installed skype and we use them as a regular handset. They also do gps and a shed load of other stuff. Sure, as a PDA they've been overtaken by the likes of the iphone, but they are cheap and batteries last for hours.