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Thanks
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This work is built upon the efforts made by many people to build knowledge of GSM.
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The most important ancestor of *gr-gsm* (and *gsm-receiver* of *Airprobe* project) was *gsm-tvoid* written by Tvoid.
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*Gr-gsm* wouldn't be also possible without help and inspiration by Harald Welte, Dieter Spaar and Sylvain Munaut.
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Special thanks to Pawel Koszut who lent his precious USRP1 to the author of *gr-gsm* (Piotr Krysik) in 2007-2010.