How big (or small) is femto?

A femto is incredibly… infinitesimally… extraordinarily small! It’s actually one quadrillionth of a unit, which, in other terms, is one part of a number that has 15 zeros! Well, the femto that I am going discuss here is not that femto. The one I’m talking about is femtocell, which has lots of buzz around it these days.

Femtocells — or femtos — are your very own, personal base stations that sit in your home or office, providing the best possible network coverage to you. They are being heralded as the provider of the next leap in performance for wireless networks. They provide near peak data rates, and very high capacity. And they put the full capacity of a base station at your disposal.

Since femtocells are usually installed by users, they bring substantial cost savings to operators. They help improve indoor coverage and by off-loading traffic from the macro network, they improve performance for other users in the network as well.

The figure below shows an example of the phenomenal improvements in data rates that can be achieved through femtos. The violet-colored bars indicate the data rates experienced by users before introducing femtocells. The orange-colored bars indicate data rates after.

  Data rate improvements with femtocells

Example of data rate improvements achieved by introducing femtocells

Going back to the definition of femto, you might ask “is the femtocell really that small?” While it may not be one quadrillionth the size of a macro, it is actually fairly small — similar to the size of typical WiFi router. It’s also smaller than a traditional macro base station. In comparison to the macro base station, it also consumes less power and is easier to deploy. Unlike macros, users install femtos themselves, which saves a substantial amount of time and money for operators in terms of on site acquisition, deployment, back-haul and operational activities.

If this innocent looking small box is that good, should I be worried about my neighbors stealing its magical powers? Does the use of femtos affect non-femto users (macro users) in any way? Will its capacity be impacted if all of my envious neighbors deploy their own femtos? What concerns, if any, do operators have about femtos? Get answers to all those questions in my next blog!

Topics: Femtocell
Prakash Sangam

Prakash Sangam

Senior Manager, Technical Marketing

Comments

Anonymous

September 13, 2010, 2:10 AM

I'm glad someone else has noticed the abuse of SI prefixes! Even if we assume the inverse-square law a 'picocell' is not a millionth of the radius of an ordinary cell and a 'femtocell' is not a thirtieth of that.

Anonymous

September 26, 2010, 5:07 PM

Time for the next part? Please...

Qualcomm Blog Author

October 07, 2010, 2:13 PM

Thanks for the interest. The second part is posted now...

With femtos, improved coverage and near peak data rates are only part of the fun…

Fred Feisullin

December 31, 2010, 1:29 PM

Agreed that smaller radius, indoor cells can provide a superior RF envonment for supporting 64 Quam and lower rate coding for superior data rates, but there is no panacia here. A large increase femto deloyment and traffic would require an exponential increase in backhal expansion costs for service providers to implement the potential gain. Even BYOB "bring your own broad band" subscribers will not allieviate the need for expanding back haul capacity as either the wireless carrier or the back haul provider will have to pay for the expansion. Carrier networks today are not equiped for the increased traffic load.

Qualcomm Blog Author

January 05, 2011, 5:34 PM

Dear Fred,

Thanks for the comment.

Well, femtocells are not the panacea ! However, they definitely are one the many tools that operators have in their arsenal to address the rapid growth in the data demand.

You could read about more operators strategies to meet the data demand on our webpage here: www.qualcomm.com/meet_data_demand

Rusty Cobb

February 28, 2011, 4:53 PM

Dear Prakash, deperately need your help! I am not your basic "Techno". What I need is divine guidance. I live in the 'rural area of Clements, California. Our internet provider is Verizon via the phone line (DSL supposedly).The problem is our download and upload speeds are pathetic. WE, all of our neighbors, need faster speeds which we can not obtain from Verizon. Will the 'femtocells' answer our problems?? Really appreciate any advice you can offer. I would be very willing to offer my home location as a "test station" for 'femtocell' or ?? any product that would solve this problem. Any info you need, please ask and I will respond. Thank you very much for your guidance. Rusty

Qualcomm Blog Author

March 01, 2011, 11:29 AM

Rusty,

Thanks for the question.

Femtocells are a way to increase coverage and data speeds of 3G wireless network/service. They, in fact, use DSL or the cable internet connection on the backend and connect to the mobile devices such as smartphones on the front end.

So, unfortunately, femotos cannot help you, if your DSL speeds are not good.

Did you check what kind of wireless broadband (3G/4G)service Verizon Wireless, AT&T and others offer in your area? That might be one option, if they offer what you are looking for.

Regards,
Ps

Post a comment

The content of this field is kept private and will not be shown publicly.
Image CAPTCHA
Enter the characters shown in the image.

Opinions expressed in the content posted here are the personal opinions of the original authors, and do not necessarily reflect those of Qualcomm Incorporated or its subsidiaries ("Qualcomm"). The content is provided for informational purposes only and is not meant to be an endorsement or representation by Qualcomm or any other party. This site may also provide links or references to non-Qualcomm sites and resources. Qualcomm makes no representations, warranties, or other commitments whatsoever about any non-Qualcomm sites or third-party resources that may be referenced, accessible from, or linked to this site.