T-Mobile HotSpot @ Home seamlessly integrated GSM/UMA calling

[ontologicalnsite]

T-Mobile USA has these AWESOME handsets that hand calls off automatically between GSM towers and 802.11 wireless networks. We need someone to reverse engineer one of these "HotSpot @ Home" GSM/802.11 handsets, figure out HOW the hardware, firmware &/or software is seamlessly integrated together to do this, and then write us some code so that our iPhones can seamlessly hand calls off between GSM and 802.11 networks too!

This will let us make & receive calls seamlessly through 802.11 networks, and is VITAL for all of us who can't get T-Mobile GSM cell reception at home or work b/c of the weak building penetration strength of the 1900 MHz GSM band T-Mobile uses worldwide. Additionally, you get FREE and unlimited calls over 802.11 wireless networks!

AND this important project is ALSO going to benefit those of you in Europe! Why? B/C T-Mobile will soon be rolling out the same UMA calling system across Europe, based on the "HotSpot @ Home" system developed here in the States. So help us on this project today, and in short order, you'll get to use it in Europe!:D

[jlor]

They've had that in Denmark for a while now, not with T-mobile though but with "Telia".

The way they do it is with VoIP afaik. When you are on wifi it uses VoIP, if you are on GSM it just calls as usual. There's no real firmware thing going on, it just checks if wifi is on and if so it calls using VoIP, if it isn't it calls with GSM.

[squirrelfon]

Actually, maybe the "Hotspot for iPhone" business plan can work for T-Mobile. I promise if they release it soon, I buy a $60 x 2 years contract (right now theirs prepaid). Can anybody hint them about this?

[squirrelfon]

Sorry, I missed that to make the switch seamless, the provider for GSM and VoIP has to be the same. I understand now that's real big opportunity for T-Mobile to cash on.

Now if they simply disclose how their Wifi protocol works, let people do the job of porting it to iPhone, and collect revenues from their voice+$20/m plan everybody wins big (except AT&T who would claim they have exclusivity but what leverage do they have?)

I think you gave an excellent idea, thanks. I guess it's time to find the information about Hotspot@Home -
* Is that technically just VoIP stream between two Internet servers?
* Is the call dropped on GSM or enters some suspended state and can we emulate that on iPhone?
* How does the phone identify itself? Presumably, there could be a hardware key on the phone + key on the SIM. I guess T-Mobile would be happy to hint us this part provided we have their sim ;)

[squirrelfon]

Look like there's a bunch of companies doing this is Europe and the handset part of the protocol is standard. So, it should be possible to implement the protocol from scratch/existing sources even without reverse engeneering.

Sounds amazing.

http://en.wikipedia.org/wiki/Generic_Access_Network

[ontologicalnsite]

Wow everyone, THANKS for reading & responding. Apparently there are 3rd party vendors that supply UMA software, and handset makers incorporate that software into the building of their handsets to make this seamless 802.11/GSM thing work.

I was doing some reading, and I think the way it works is that when you're on 802.11, the carrier's internet web servers translate the call and make it look to the carrier's network like it is just coming from another GSM base (tower), and that's how they integrate the seamless hand-off.

To make this work, I assume that the Phone app on iPhone would have to be re-written, with the UMA software integrated into it. The Phone app would have to know that it should register itself with the carrier's web server over available 802.11 networks first, then register over a GSM tower if that is not available.

Sounds like something that if someone wrote a generic code program, we could simply have a preference pane where end users would type in the network IP or other address of their specific carrier's UMA web server. That way, as this technology is deployed by more carriers around the world, the app would be universal?

I say we need someone to reverse engineer one of these HotSpot @ Home handsets and see how they work. I'm in the States, and I can get one.

[squirrelfon]

This is a hot idea: http://hackint0sh.org/forum/showthread.php?p=57136

There could be some technical obtacles though, and to connect to T-Mobile wifi server we probably need their cooperation. Again, they must be happy to help us. We'll basically sign for the same contract they advertise but they don't have to pay programmers and subsidize our phone. So, can someone hint them?

[squirrelfon]

I was doing some reading, and I think the way it works is that when you're on 802.11, the carrier's internet web servers translate the call and make it look to the carrier's network like it is just coming from another GSM base (tower), and that's how they integrate the seamless hand-off.


Correct, but I don't know if iPhone has enough GSM functions in the library to do the GSM part of this.


To make this work, I assume that the Phone app on iPhone would have to be re-written, with the UMA software integrated into it. The Phone app would have to know that it should register itself with the carrier's web server over available 802.11 networks first, then register over a GSM tower if that is not available.


Yes, but we have to find out how phone authenticates iteslf. Presumably, it uses SIM as a black box with key.


Sounds like something that if someone wrote a generic code program, we could simply have a preference pane where end users would type in the network IP or other address of their specific carrier's UMA web server. That way, as this technology is deployed by more carriers around the world, the app would be universal?

I say we need someone to reverse engineer one of these HotSpot @ Home handsets and see how they work. I'm in the States, and I can get one.

I completely agree that this big.