In 2015, the UK Office of Communications (Ofcom) concluded that 2.4GHz IoT technology only adequately covered 36% of UK houses. The only options available to solve this problem are to increase transmit power or to increase receive sensitivity.
Increasing transmit power (shout louder)
Transmit power at 2.4GHz is limited to 10dBm (10mW) by regulatory standards in most major markets outside of North America. Moreover, semiconductor power amplifiers are inefficient (~20%) and expensive, thereby often making battery operation unfeasible. Worse still, amplified devices and modules get very hot, which reduces the efficiency of the receiver.
Improving receive sensitivity (listen better)
Previous receiver architectures also have limitations on their efficiency, as described in the next section. The only way to overcome this problem is to invent a new, more efficient, radio architecture. Overcoming the limitations of existing receiver architectures is a problem that radio designers have failed to solve in recent decades.
Fundamental obstacle to wider deployment
Since our homes, offices and industrial plants are all set up for the range of WiFi, and since previous 2.4GHz IoT technology cannot achieve such range, the fundamental problem of wider deployment of this technology is range.