It is difficult to define the number of jamming devices that exist, however if there is a frequency should therefore be a countermeasure that allow the jamming of a frequency. However the full spectrum of bands is very large and it is impossible that a jammer can jam itself all the frequencies, in fact cannot be and never will be broad-spectrum jammers that can block all bands. So the jammers use to target the most common communications bands. Since jamming devices have a very high cost of development, and this has led to the jamming devices have specialized in the most common frequencies. Within these bands (most common) are the following:
Cell phone jammers, which focus primarily on the GSM, GPRS, 2G, DCS, 3G and 4G frequencies recently. Those jammers have the function to block or override the audio communications and data transmission through the internet. Often used to avoid a security risk, and to prevent leakage and information theft also help prevent privacy risks, as there are phones that are used to hung the calls automatically to hear the conversations. These frequencies are also common GSM 3G spy or spy cameras and microphones currently 4G, so an inhibitor in these frequencies can deter and eliminate intrusions. Also interesting are the locations to avoid through signal triangulation, with which you can easily locate the telephone user. Also often used so widespread in universities and schools, to avoid the use of spy earpiece or headphones used to cheat on tests.
GPS jammers, about the GPS locators there are many bands, but the best known is the L1 (widespread civil use). There are 4 other bands over GPS frequencies reserved for police, military, government and scientific research. The GPS jammer equipment is primarily used to avoid being tracked by GPS locators, or to avoid being monitored by third party could know our business at all times. Today it is easy to find spy software that can be easily installed on mobile phones, to control the position in real time. The GPS tracking systems allows them to take note of our activities, insurance companies can control the use of the car, your vehicle could be monitored by a vehicle fleet control showing your position all the time, and many other uses related to the control of position and mobile satellite comunications.
Jammers for WIFI or BLUETOOTH and wireless cameras, wifi jammers are focused on avoiding communications devices based on communication in civil 2.4GHz band, although there is also the band 5.6 / 5.8Ghz, increasingly used after saturation of the 2.4Ghz band. These frequencies encompass almost all household devices such as phones, computers, routers, set-top boxes, wireless microphones, most spy cameras micro cameras and devices, etc.
Walkie talkie jammers, are jammers that focus on frequencies of Walkie Talkie because it is widespread, very cheap device and also not being controlled communications (directly) by telephone operators (and in turn by the government) are often used for criminal purposes and can be used for remote activations of artifacts.
Radio Frequency jammers, those devices are used very occasionally as a radio controls, controls, other communication devices, etc. At these frequencies usually only be considered for VIP devices, as they are a very casual or for very technical / professional use, so there is usually a very extensive supply for these frequencies. Within these you will find, radar, microwave telecommunications, specialized microphones, car control and automation controls, etc.