The key requirements for Wireless M2M Technology are:
Interoperability: devices may use unlicensed bands for short range communications and licensed bands for long range communication to the network.
Real-time Data Acquisition and Analysis: Instrumentation of Analog Sensors, Event ordering, time-stamping, synchronization and signal processing will be required.
Reliability and Robustness: Sensors and other devices must operate with sufficient reliability in harsh industrial environments and with little manual intervention.
| Standard | Bluetooth (Low Energy) | Zigbee | Wi-Fi |
|---|---|---|---|
| IEEE Spec. | 802.15.1 | 802.15.4 | 802.11a/b/g/n |
| Frequency Band | 2.4GHz | 686/915MHz,2.4GHz | 2.4GHz,5GHz |
| Max signal rate | 1Mbps | 250kbps | 54Mbps |
| Nominal Range | 10m | 10-100m | 100m |
| Nominal Tx Power | -10 to 10dBm | -25 to 0dBm | 15 to 20dBm |
| Number of RF Channels | 79 | 1,10,16 | 14 |
| Channel Bandwidth | 1MHz | 0.3MHz,0.6MHz,2MHz | 22MHz |
| Modulation Type | GFSK | BPSK,ASK,O-QPSK | BPSK,QPSK,COFDM,M-QAM |
| Spreading | FHSS | DSSS | DSSS,CCK,OFDM |
| Coexistence | Adaptive frequency hopping | Dynamic Frequency Selection | Dynamic Frequency Selection |
| Network | Piconet | Star | Peer Hub |
| Encryption | E0 stream cipher | AES block cipher | RC4 stream cipher |