Femtomorrow? Wi-Fi Regardless.

Have femotocells become the next WiMax (read: lots of pilots, few commercial deployments)?

Like WiMax, there's so much written about this new technology but very little real-world services (so far). I've yet to see any device with WiMax support. But then again, I don't get out too much.

Femtocells are fully featured but very low power mobile phone base stations, connected using standard broadband DSL or cable service into the mobile operator's network (click on diagram). They offer excellent mobile phone coverage at home for both voice and data, but at lower cost than outdoor service.

Nearly every carrier with whom we've spoken (and we know them all) has an interest in or is planning some sort of Femto trial. From a handset perspective, Femtocells provide a clear advantage in that they function just like another cell tower so they can potentially leverage standard mobile roaming (click on diagram).

The femtocells themselves look very much like Wi-Fi broadband modems, and some vendors are planning to incorporate all three features into a single box (Wi-Fi, DSL and Mobile). But many consider Femtocells to be "irrelevant" in many countries.

Unlike Wi-Fi, these devices use licensed radio spectrum, so must be operated and controlled by a mobile phone company. Thus it will work with only one mobile phone operator, and thus encourages all users in a household to switch to the same network operator. But skepticism remains.

This skepticism is accompanied by quite a few challenges:

• Interference - The placement of a femtocell has a critical effect on the performance of the wider network - and this is one of the key issues to be addressed for successful deployment.
• Spectrum planning – Each Femtocell unit will affect the overall spectrum planning of the operator which brings up not only planning but also deployment challenges (e.g. what happens if the Femtocell unit is moved?)
• Timing - When will Femtocell really be ready for mass deployment?
• Device support - (specifically laptops) – Many vendors and operators assume a Wi-Fi interface on their Femtocell device to handle laptops. Not so.
• Scale (management) – Operators will need to scale their backend systems to handle not 1000s of towers but potentially millions... that’s a very different problem to solve.
• Cost
• Business model concerns

But the bigger question burning in the minds of many providers:

What's the relationship between Wi-Fi and other broadband technologies
like Femto, WiMax, and 3G/LTE?

It's our not-so-profound belief that (as you'd expect):

Wi-Fi is the ultimate complement for all these broadband wireless technologies.

Why?

• Wi-Fi is everywhere
• Wi-Fi is supported on nearly everything now
• Wi-Fi is arguably the most economical technology for the last 100 meters
• Wi-Fi helps reduce spectrum planning issues
• Wi-Fi augments coverage holes
• Wi-Fi minimizes huge investments in broadband wireless equipment
• Wi-Fi is ideal for offloading data from overburdened 3G, LTE, WiMax networks

Comments

[Stephen]

Hi

couple of things.

Femto / Nano cells are GSM (at least here), so you dont need a WiFi phone to use them.

WiFi phones in general dont seem to have high battery efficiencies compared to GSM phones - more important most potential users already have a GSM phone.

C&W in the UK are using a separate band for pico cells in businesses - these operate in a different section of the GSM spectrum (one of the guard bands between the main spectrum blocks).
http://www.currentanalysis.com/europe/2008/CableWireless-FMC-26193.asp

(and who comes up with all these silly "cell" name variations anyway)?

GSM users roam to a national provider when not on the in building cell, so any interference has a fallback.

Note the range of an individual cell is only around 100m, so the interference you are worrying about is not a big practical issue, even if applied to home based cells where the range is likely to be less.

and finally - WiFi QoS is even more of a problem than QoS on the Internet.....