Fuzz testing is one of the effective way to find the vulnerabilities. There are already a lot of fuzzing tools for known layer 7 protocol, such as HTTP server, SSL/TLS, FTP server, DNS server, and so on. In this upcoming IoT world, more wireless transmission technique are used for IoT devices, such as WiFi, Bluetooth, ZigBee, Z-Wave, and cellular network (2G/3G/4G). We can fuzz the wireless transmission technique as well, but there are rare fuzzing tools, especially for cellular network. The most difficult part of fuzzing cellular network is building the cellular network environment, not make the corresponding fuzzer. In our representation, we will introduce how to build the 4G LTE environment yourself with limited budget. Afterward, we rewrited the 4G LTE base station and send the malformed LTE message to fuzz your smartphone. After our fuzz testing, we found the vulnerability which could cause your smartphone cannot work as normal and this vulnerability will affect the smartphone which use the specific Qualcomm CPU.