M2M connectivity works by providing a link between different sensors and devices in an IoT ecosystem. It allows the devices to communicate, and then helps in transferring the device generated data to the cloud where it is analyzed. Based on the analysis, the results are sent back to the device and appropriate action is triggered. For example, if a thief is discovered by an IoT surveillance system, the visual image is sent to the cloud and analyzed. In response to the event, a sound alarm at the nearest police station is triggered.
M2M connectivity requirements are very different from conventional connectivity requirements. Have a look at some essential requirements, which will give you a clear idea of how M2M connectivity works:
Unique connectivity solutions for different use cases
M2M connectivity solutions need to be suited for a particular use case. Unlike in other scenarios where faster and low-latency connectivity is preferred, M2M connectivity needs to be in line with business requirements. For example, if you are managing a huge parking lot and have visual sensors that measure the time for which the cars are parked, then you really do not need a fast connection. All you need is a stable connection with low speed as it will help in preventing quick sensor discharge (which will save money for the parking space owner). The same way, if you are using IoT in a store to monitor goods, then RFID and Bluetooth connectivity will be better options than high-speed broadband.
Security
As M2M devices operate independently, they are vulnerable to hackers. Hence, there is a need for end-to-end encryption of the signal and individual devices.
Source: M2M Connectivity