Weekly Edition
Return to the Development page
| |||||||||||||
|
| |||||||||||||
Harald Welte: In six weeks from bare hardware to receiving BCCHs
Harald Welte writes about progress in creating an open GSM mobile telephone protocol implementation on his blog.
"So, just to be clear on this: Neither OpenEZX, nor gnufiish nor Openmoko were ever about writing Free Software for the GSM baseband processor, i.e. the beast that exchanges messages with the actual GSM operator network. But this is what we're working on right now.
[...]
It's about time, don't you agree? after 19 years of only proprietary software on the baseband chips in billions of phones, it is more than time for bringing the shining light of Freedom into this area of computing."
(Log in to post comments)
Harald Welte: In six weeks from bare hardware to receiving BCCHs Posted Feb 15, 2010 18:12 UTC (Mon) by xav (subscriber, #18536) [Link]
I pretty much like all what this guy is doing.
Harald Welte: In six weeks from bare hardware to receiving BCCHs Posted Feb 15, 2010 18:46 UTC (Mon) by Gollum (subscriber, #25237) [Link]
I have to agree. Harald is a legend.
GPL Violations, GSM, RFID, etc, etc. One almost believes that he is more than one person, the way he codes.
Harald Welte: In six weeks from bare hardware to receiving BCCHs Posted Feb 15, 2010 21:12 UTC (Mon) by paravoid (subscriber, #32869) [Link]
Don't forget netfilter/iptables/... as well. He is indeed a free software legend.
Harald Welte: In six weeks from bare hardware to receiving BCCHs Posted Feb 16, 2010 15:48 UTC (Tue) by njwhite (subscriber, #51848) [Link]
So I don't know much about hardware. When he talks about writing free software for the "GSM baseband processor," is he essentially referring to the firmware on a GSM chip?
And how does this relate to a useful free software stack on a phone? Is the plan that it will be a reasonably generic, well-written firmware which (eventually) can be dropped in to a number of chips quite easily?
Wish I knew more about this stuff, it sounds exciting, but at present I find myself only able to half understand what's happening.
Harald Welte: In six weeks from bare hardware to receiving BCCHs Posted Feb 17, 2010 2:23 UTC (Wed) by pabs (subscriber, #43278) [Link]
Yes, he is referring to the software running on the chip that recieves radio signals from the GSM network.
AFAICT the plan is to stop wasting time reverse engineering stuff and instead just create a free GSM baseband chip from the ground up. I'm hopeful the software running on it will be portable enough to work on other chips too (specs for the OpenMoko FreeRunner GSM chip were leaked).
A free software stack on a phone doesn't necessarily need free software on the baseband chip; for e.g. the OpenMoko runs free software on the CPU but not on the GSM chip (or WiFi/GPS/etc) and can make calls, send SMS, connect to GPRS fine. All a free software stack on a phone needs is standard or documented interfaces/protocols between the GSM chip (or GPS/WiFi) and the CPU. Obviously having free software on the GSM chip would be nice for bugfixing, further optimisation, adding new features like 3G and so on.
Harald Welte: In six weeks from bare hardware to receiving BCCHs Posted Feb 17, 2010 5:37 UTC (Wed) by BrucePerens (subscriber, #2510) [Link] You start out with a USRP (from Ettus Research) and GNURadio, and use that as a GSM transceiver. Then you build the GSM protocol software on top of it. This is the strategy that was used already for the cell-site side. Once you have everything working, you work on making it small and cheap. The USRP is a big, fast DAC/ADC into which you can plug various radio transmitter and receiver cards. It's sort of a large, more general version of a cellular modem.
Harald Welte: In six weeks from bare hardware to receiving BCCHs Posted Feb 18, 2010 12:01 UTC (Thu) by akumria (subscriber, #7773) [Link]
According to Harald's blog he has been using OpenBSC with either the Siemens BS11 microBTS or ip.access nanoBTS hardware.
Whilst I am sure that USRP could be used for this, I do not believe it has been by Harald.
Perhaps you are thinking of someone else?
Harald Welte: In six weeks from bare hardware to receiving BCCHs Posted Feb 17, 2010 14:46 UTC (Wed) by jonth (subscriber, #4008) [Link]
"Obviously having free software on the GSM chip would be nice for bugfixing, further optimisation, adding new features like 3G and so on."
This is a classic "unencumbered by a knowledge of the subject" comment. You make it sound like 3G is a simple bolt-on. It's actually an entirely different modulation scheme and air-interface. It also requires an order of magnitude more processing power than GSM. It's going to be hard enough to do a 2G phone (and I'd be very surprised if a real, commercial phone goes to market using this technology inside 2 years). 3G is another ball-game.
|
|
||||||||||||