GSM (Global? System? For? Mobile? Communication) network, the Global System for Mobile Communications, also known as "GSM", many companies involved in standards work, because the first to use all of Europe, also known as the European standard, and after most of the Asian countries have a network (900MHz and 1800MHz), the Americas began in the late nineties with PCS (1900MHz). China Mobile 900MHz this standard. mobile phone jammer can effectively block various cell phone signals so that there will be no missed point.
GSM uses a digital modulation technique, the key one time division multiple access technology (in a time slot for each user on the selected carrier frequency and can only receive the information under a specific time), so its voice clear, confidential easy and can provide higher data transmission services. GSM system has several important features: ability to copy good security, network capacity, number of resource-rich, call clarity, stability, strength less susceptible to interference, the information is sensitive, less dead phone, mobile power base and so on. So its voice clear, confidential easy and can provide higher data transmission services. GSM network can support the number of users to simulate network 1.8-2 times. Another outstanding characteristic of Cellular Phone Jammer is the good electromagnetic compatibility.
CDMA (Code Division Multiple Access), the CDMA technology, Qualcomm's wireless communications in this exciting new era of products and services first developed to provide a very clear voice effects of digital technology. Through the use of digital encoding "spread spectrum" radio frequency technology, CDMA wireless technology can provide better than other, lower-cost voice effects, privacy, system capacity and flexibility, and more comprehensive services such as SMS, e -mail, Internet access. CDMA network developed by Qualcomm, a wireless cellular network, better than the GSM frequency of use. U.S. operator Verizon, Sprint, and other first used, but South Korea is faster to use more advanced CDMA 1X standard. Unicom began operations in 2002 of China's only CDMA network. The shielding interval of cell phone jammer  accurately lies in the uplink channel of the cell phone.
Compared to CDMA phones and GSM phones: CDMA mobile phone has the following advantages: CDMA mobile phones using advanced switching technology: the soft switching technology (ie, after the switch is to follow a good break), making CDMA phones and fixed telephone calls can be comparable; use CDMA network, the operator's investment is relatively reduced, which lowered tariffs for CDMA handsets reserved space; to expand due to the use of a frequency communication-based modulation and multiple access communications, capacity 10 times higher than analog technology, about 4 times over the GSM network; CDMA-based broadband technology makes mobile communications possible in video applications, making phone calls and send text from the only information service in the narrow to broadband multimedia applications. The special suppression measures have been carried out for the harmonic wave outside the band and cell phone jammer  will not interfere with other electronic equipments.
GSM digital mobile phone voice is digitized before being sent over the wireless channel, it is not as easy to analog mobile phone interference, so a clear voice call, a small disturbance. However, because transmission is digital voice, there are also some distortion of the shortcomings of voice. Machine simulation of mobile voice distortion is better than the GSM digital machine. Now, the relevant departments are studying the development of more advanced digital voice encoding techniques to reduce the GSM mobile phone voice distortion. The stable and reliable operation is third characteristic of cell phone jammer .