Meaning
Wireless technology platforms specialize in the short range transmission of data while minimizing the electrical current drawn from the system battery. In battery operated sensors and utility meters, low power radio designs utilize highly efficient modulation schemes and rapid sleep wake cycles to extend the operating life of the device to several years. This hardware operates in unlicensed industrial, scientific and medical frequency bands.
It trades high data throughput and long transmission range for extreme energy efficiency.
Energy Conservation
Reducing the energy consumption of the transceiver involves minimizing the time spent in the active state. The system remains in a sleep mode where current draw is limited to microamperes. When transmission occurs, the radio wakes up, transmits, and sleeps.
Receiver Design
The sensitivity of the receiver must be maximized to compensate for the restricted transmit power of these devices. Achieving high sensitivity requires low noise amplifiers with low noise figures, but these circuits typically consume significant current. Designers resolve this trade off by using advanced duty cycled receiver architectures or wake up receivers.
These specialized circuits monitor the channel for a specific activation pattern while consuming less than a fraction of the standard operating current, allowing continuous monitoring without draining the battery.
Regulatory Standard
Compliance with international telecommunication standards limits the maximum output power and duty cycle of these devices. In Europe, the European Telecommunications Standards Institute restricts the effective radiated power in the sub gigahertz bands to protect other users from interference. Similar regulations are enforced by the Federal Communications Commission in the United States.
Meeting these requirements ensures that the radio can operate globally without interfering with neighboring networks.
