Enabling CSMA for LoRaWAN TR013-1.0.0
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461
SF SF7 SF9 SF12
Airtime for 30 bytes 87.3ms 287.7ms 2138.1ms
Tx energy @14dBm 1091.25 nAh 3596.25 nAh 26726.25 nAh
Tx energy @17dBm 1406.50 nAh 4635.16 nAh 34447.16 nAh
Tx energy @22dBm 2037.00 nAh 6713.00 nAh 49889.00 nAh
CSMA overhead @14dBm
1.56% 1.95% 1.45%
CSMA overhead @17dBm
1.21% 1.51% 1.13%
CSMA overhead @22dBm
0.84% 1.04% 0.78%
Table 5: CSMA overhead for three different transmission power levels 462
Roughly speaking, performing CSMA for a 30-byte payload may impose an approximate 463
overhead ranging from 0.8% - 2% of transmission energy. However, it should be noted that 464
due to a large number of different configurations, values here are presented for illustration 465
purposes only. Nonetheless, smaller values of overhead motivates the use of CSMA for 466
LoRaWAN, which encourages the efficient use of spectrum and eventually optimizes 467
spectrum and battery life through collision avoidance. 468
