UMA and DD-WRT

Unlicensed Mobile Access, or UMA for short, is basically GSM and GPRS over Wi-Fi. Used by a number of network operators and supported by some phones from Nokia, RIM and others, it's an interesting technology and the basis for VoLGA, a voice over IP solution for LTE that I am quite passionate about. Recently, I stumbled over this website which explains how to configure Wi-Fi Access Points that run the open DD-WRT operating system for the use with UMA phones. Some tips and tricks are given but basically the message is that the Wi-Fi Quality of Service Extensions (WMM) have to be turned on. That also answers one of the questions I had as to whether UMA in practice only runs with access points offered by network operators.  So if you are into the details the link might provide some interesting information for you, too.

Comments

[Stefan Constantinesc]

This is something I've been struggling to understand. With everyone pushing femtocells, trying to drive costs down, blah blah blah, why not just get people to upgrade their WiFi router and make sure that all mobile phones made after today support UMA?

Is it the hand off part that stinks or ... what has stunted the adoption of UMA?

[Kirill]

May be, the main impediment is the inability of operators to control WiFi routers?
What's the benefit for mobile operators if a phone has free access to Internet?

[David Boettger]

Not that I'm a believer in the femtos (no business case, in my opinion), the main advantage of femtos over Wi-Fi/UMA is that femtos work with *all* handsets and don't require any new/special network boxes. Further, they manifest themselves to the network as regular BTSs and thus fit in neatly with the OA&M tools and processes already in-use by the carrier.

That said, the question remains why a consumer would be willing to pay the carrier for the privilege of helping the carrier fill in its own coverage holes.

[Christian von der Ropp]

Stefan: "why not just get people to upgrade their WiFi router and make sure that all mobile phones made after today support UMA?"

Because the 2.4 GHz band is already congested.

David: "That said, the question remains why a consumer would be willing to pay the carrier for the privilege of helping the carrier fill in its own coverage holes."

Because he might get some benefit from a femto. Beyond full signal strength in their home Softbank's customers get a free ADSL-line in return for filling coverage gaps and taking off load from the macro cells: http://www.mobileeurope.co.uk/news_wire/115820/Ubiquisys_enables_Softbank_Mobile_to_offer_free_femtocells_nationwide.html

[David Boettger]

@Martin: This is the first I've seen of femtos being offered for free. This makes a *lot* more sense to me. Thus far, I've only seen offers that require the subscriber both to purchase the femto AND to pay an *additional* charge for unlimited calling from the home. This latter "value proposition" is what I was referring to when I said "pay the carrier for the privilege of filling in its own coverage holes".

[mobilesociety]

Hi David,

looks like there is another move in this direction, this time from AT&T:

http://www.intomobile.com/2010/07/12/att-handing-out-free-microcells-to-select-customers/

Cheers,
Martin