The interference power of the shield is certain, and the shielding radius of the non-blocking space is determined by the path attenuation and the receiving base station signal level. On mobile network to realize mobile phone signal jammer, must ensure that the jammer signal of the field strength is greater than the implementation of mobile signal interference area of field intensity, interfere with the location as close to the base station, the stronger the field intensity, effective jamming area is smaller, conversely, the farther from the base station location, field strength is weak, the greater the effective jamming area.
The Army points to newly developed algorithms that would enable a missile to detect cell phone jammer and determine their location, such as Multiple Signal Classification (MUSIC). These algorithms focus on unique characteristics of jammers. “For example, trackable interference, aka spoofers, likely generate the entire GPS-like constellation and transmit from a common point; thus, these signals generate exogenous constellation-wide delay (i.e., in a bend-pipe versus line-of-sight RF transmission). Other defining characteristics of a malicious interference may include increased energy (i.e., jammers), clock drift/offset coloring, inter-satellite interference, etc.”
Why do jamming devices work
Head of Norway’s military intelligence, Morten Haga Lunde, confirms in an interview with Aftenposten Russia’s jamming during Zapad-2017. «GPS jamming was practiced, electronic warfare. Most likely, this jamming was aimed at interfering Russia’s own forces’ use of GPS. A side-effect, however, affected Widerøe and intercontinental flights that Russia should have seen coming.» In Finnmark, regional airliner Widerøe has commercial daily flights to 11 airports, while SAS flies to Alta and Kirkenes.
Why can the wireless signal jammer interfere with the normal use of the phone? Mobile phones work by receiving and transmitting radio waves. The frequency of the phone is about 1.8GHz. To interfere with cell phone signals, you must have a device that emits the same frequency of radio waves. Cell phone signal jammer is such a device, it will block the mobile phone signal within the scope, the degree of light will seriously affect the call and the quality of the Internet. Generally within a radius of 25 meters, the phone will be strongly disturbed by the jammer. The effective range of 25 meters will also be affected less. The scope of the jammer will also change due to the specific performance and power of each jammer.
In excessive media today, developed communications network impact is not only the university classroom, such as meetings, reunion order of various social routine activities are affected by bow clan brush weibo ‘letter. In the classroom, teachers and students should reach a consensus that the teaching order should not be destroyed, and it is obvious that students playing with mobile phones are illegal.