MWC: Enter the attocell -- a tiny base station ‘on the go’

There is no dearth of names for cells in this industry. There are macro-cells, pico-cells and femtocells. Some vendors offer microcells. Others offer metro-cells. Starting today we have a new cell to add to the product list: the attocell—pretty much the smallest base station you can imagine.

The attocell reduces the base station down to USB stick, which then emits a low-power radio signal over your phone’s frequencies and uses the laptop’s broadband link to backhaul the connection over the Internet to the operator. Essentially it’s a tiny portable femtocell a customer can take anywhere.
Several vendors are working on attocell technology. At CES this year, Picochip unveiled its conceptual picoXcell, which would shrink all of the capabilities of a 3G base station onto a silicon platform that could fit onto a USB dongle. But today, Ubiquisys announced the first attocell product, which it is calling a personal femtocell.

While it makes sense technically, there are several practical matters Ubiquisys had to overcome in order to make the attocell a reality. The biggest one is interference. Though a femtocell can be installed anywhere, it can only use the airwaves owned by the operator that sold it. That’s why a femtocell owner can’t take it overseas and make calls over it just like he was at home. Overseas, that operator’s PCS or cellular frequencies are licensed to someone else who wouldn’t take kindly to a femtocell blasting out interfering RF on its home turf.

The second consideration is placement; a femtocell needs to know where it is on an operator’s network so it doesn’t interfere with neighboring femtocells or the operator’s macro network. Femtocell makers usually get around this problem with GPS. The femto transmits its location back to the operator, which then makes an adjustment to the cell and its neighbors to mitigate those interference problems.

Ubiquisys circumvents both those problems by using the weakest of radios. Regulators only consider a transmission interference if it exceeds a certain power threshold. Those regulations differ from country to country and band to band, but Ubiquisys is making use of an intelligent radio that adjust the attocell’s radio power to just below licensed levels. In most cases that makes for a pretty small cell. In some countries that would mean a cell edge just 5 mm away from the dongle (In such situations, Ubiquisys doesn’t recommend you jam your ear into your USB port. Rather it suggests you lay the phone on top of the attocell and use a Bluetooth headset for the conversation.) In other countries the cell’s range can extend to an entire room.

Ubiquisys designed the device to work with the iPhone, but it will link to any 3G enabled device. Ubiquisys plans to show off the device for the first time at Mobile World Congress next month, but it said that it already has seen interest from a few operators. Attocells may wind up being a hot topic at MWC. Picochip plans to unveil its next femto platform at MWC, which will scale to devices as small as a USB dongle.