China cell phone jammer should contain any detail of the research

The research report of  cell phone jammer will be drafted according to the research result.
However, in fact, due to different brands, different models of cell phone RxD, TxD and GND pins are not the same, to find three lines of investigation which is sometimes not an easy task; Moreover, the level of cell phone data port is not RS232 level, nor are TTL level, and from a 5V power supply can not be directly connected to the microcontroller serial port. The most simple and reliable method is to use single-chip cell phone data cable to establish connection with the cell phone's hardware. Cell phone data cable is designed for 9-pin serial port to connect a PC designed, the signal level to RS232 level standard, as long as the microcontroller's serial port is converted to Rs 2 3 2 level, can be easily connected. 9-pin serial port pin definition is fixed, that is 2 feet for the TxD (transmit cell phone), 3 feet for the RxD (cell phone receiver), 5 pin GND. In this way, no matter what type of cell phone connection with the microcontroller into a fixed connection, data port cell phone signals do not need to know the specific definition, the two data lines connected through the circuit shown in Figure 1. The research report of   china cell phone jammer should contain any detail of the research.
SCM software interfaces with the cell phone is actually a single-chip GSM SMS with AT commands to control the cell phone's control, such as cell phones to read the short message content, delete the message content has not been listed in the cell phone's short message read. The function of AT commands described in reference [1,2] contents of the article, not repeat them here. However, the implementation of a directive, some of the information presented is not so simple. In fact, the execution process needs to interact with the cell phone chip complete response, and each time the number of bytes sent or received, there are strict requirements, both of these requirements must be based on data exchange, otherwise, communication is a failure. The author, after repeated testing of several cell phones, summed up some of the rules, as listed in Table 1. The research report of cell phone jammer should be delivered together with  cell phone jammer .
All AT commands command symbols, constants, PDu data packets are transmitted in ASCII code, such as "A" of the ASCII code for the 41H, "T" of the AscII encoded as 54H, the number "0, the AsC Ⅱ encoded 30H, etc. MCU control handset to work, the cell phone must be SMS mode set to PDu format, namely, by command AT + cMGF = O to complete. The research report of   cell phone jammer is meaningful for the production of  cell phone jammer.