获得<em>gsm</em><em>信号</em>的指导Abstract: This paper presents current achievements of opensource community developers in the area of
building GSMenabled communication hardware and software. Opensource GPL licensed software makes
constant and very significant contribution to IT industry. Together with so called openhardware, it enables
the cost of some expensive GSM devices, for example bugging devices used by intelligence to be lowered to
the cost of raw electronic components and this can have potentially enormous influence on other branches
of mobile telecommunication industry, similar to the impact opensource exerted on software development
in recent years. Bugging devices can eavesdrop mobile communication based on A5/1 cryptanalysis
achievements and a flaw found in GSM protocol stack.