Note that the battery cover or packaging of the product specification

China Telecom and China Netcom started in PHS (PHS) services on the platform location.
Note that the battery cover or packaging of the product specification should be used to identify the text, the cell name, trademark or brand, model specification, standard voltage, rated capacity, the power of positive and negative as well as warning signs or instructions, manufacturer name or initials and the factory number, the implementation of standards. Note the use of the secondary battery label printing technology, in a certain light, from the side, clearly felt the bar code portion of the darker color than the rest, stickers with the metal surface of the white light at the plan, similar to a pencil across the the traces. Note that the battery case made of special material, very strong, difficult to damage, generally means the battery can not be opened, neat appearance, no extra burr, the outer surface has some roughness and feel comfortable, feel smooth inner surface, the bulb can still see fine vertical scratches. Therefore, it is not suggested normally to do the dynamic testing of cell phone jammer in the calling status. 
Its main purpose is to land, sea and air provide real-time three major areas, weather and global navigation services, and for intelligence gathering, nuclear explosion monitoring and emergency communications and some other military purpose, the United States dominate the global strategy an important component. After 20 years of research and experiments at a cost of $ 30 billion to March 1994, the global coverage of up to 98% of the 24 GPS satellite constellation has been laid to complete. Global Positioning System consists of three parts: (1) ground control segment, by the controller (responsible for managing, coordinating the work of the ground control system), the ground antenna (under the control of the master station to the satellite into the search message), stations (automatic data collection center) and communications support system (data transmission) components; (2) the space segment, consists of 24 satellites distributed in six road plane; (3) user equipment parts, mainly by the GPS receiver and satellite antenna. Multiple cell phone site testing is the rapidest, the most convenient and feasible testing method for cell phone jammer .
The main features of the global positioning system: (1) weather; (2) global coverage; (3) fixed-speed three-dimensional high-precision time; (4) fast time-saving high efficiency: (5) widely used multi-functional. 24 GPS satellites from the ground at 12,000 km altitude on a 12-hour period around the Earth, so at any time, any point on the ground can be simultaneously observed four or more satellites.