Methods and systems are provided for power management and security for wireless modules in “Machine-to-Machine” communications. A wireless module operating in a wireless network and with access to the Internet can efficiently and securely communicate with a server. The wireless network can be a public land mobile network (PLMN) or a wireless local area network (LAN). The wireless module may include a sensor and may be installed next to a monitored unit. The wireless module may utilize active states for collecting and sending data, and sleep states at other times to conserve a battery and/or energy usage. The wireless module minimize the time spent in a radio resource control (RRC) connected state. Messages between the wireless module and server can be transmitted according to a user datagram protocol (UDP). The wireless module and server can utilize public key infrastructure (PKI) for encryption and digital signatures.