**2.1 Basic method for data reduction in an AMI system**

Among existing methods, the conventional approach is combining the messages sent by multiple meters to reduce either protocol overhead or the frequency of transmission. In this approach of message concatenation, energy consumption data, control signal messages, and firmware update packages are combined. This scheme entails a lower transmission volume because the packet header is reduced, where multiple messages can be sent in a header. However, one issue in this scheme is where messages ought to be concatenated.
