What is the time taken by a 200 byte message for transmission in a beacon-enabled network

Question

A message is 200 Byte in an IEEE 802.15.4 beacon-enabled network. How to calculate the time taken by the message to transmit?

I am not clear with this question and how to calculate the time taken for transmission (in air).

Thank you.

Answer 1

Now, data rates of IEEE 802.15.4 are of 3 types-250 kbps, 40 kbps, and 20 kbps and the transmission time varies accordingly. 

Here's the formula if you want to calculate it:

Time(s) = Data(bits) / Rate(bps)

For example, if the rate is 20 kbps, the data(message) is 200 Bytes, the time taken is given by,

(200*8)/(20*1000)=0.08s=80ms

For 250kbps the time taken is 6.4ms.

PS: Actual time may vary as processing time is not taken into account in this formula.