Thank you for a nice article... The “energy per bit” is any day a better indicator of power efficiency than other metrics and this has been raised in other areas like design of high speed motherboards for 100Gb/s ethernet.
One issue that doesn't seem to have been addressed above with respect to power efficiency in a M2M context is the issue of multipath fading...
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.