Calculation of wireless communication distance of Morse radio Calculation method of wireless communication distance during free space propagation: The so-called free space propagation refers to the propagation of radio waves when the antenna is surrounded by an infinite vacuum. When a radio wave travels in free space, its energy is neither absorbed by the obstacle nor reflected or scattered.
Communication distance is related to transmit power, receiving sensitivity and operating frequency [Lfs] (dB) = 32.44 + 20lgd (km) + 20lgf (MHz)
Where Lfs is the transmission loss, d is the transmission distance, and the unit of frequency is calculated in MHz.
It can be seen from the above formula that the radio wave propagation loss (also known as attenuation) in free space is only related to the operating frequency f and the propagation distance d. When f or d doubles, [Lfs] will increase by 6dB, respectively.
The following formula illustrates the loss of radio wave propagation in free space
Los = 32.44 + 20lg d (Km) + 20lg f (MHz)
Los is the propagation loss in dB
d is the distance in Km
f is the operating frequency in MHz
The following illustrates the propagation distance of a system with a working frequency of 433.92MHz, a transmission power of + 10dBm (10mW), and a reception sensitivity of -105dBm in free space:
1. By transmitting power + 10dBm, receiving sensitivity is -105dBm
Los = 115dB
2. by Los, f
Calculated d = 9.7 km
This is the ideal transmission distance. In practical applications, it will be lower than this value. This is because wireless communication is affected by various external factors, such as the loss caused by the atmosphere, obstacles, and multipath. The reference value of is calculated into the above formula, and the approximate communication distance can be calculated.