What are the effective data rates?
The gross data rates defined in the IEEE 802.15.4 standard are never reached in practical deployments due to following facts:
- Most often MAC and possibly higher networking layers according to the ISO/OSI are implemented, and the network rarely operates at PHY layer only
- MAC layer uses the CSMA-CA algorithm as channel access method with additional wait lines
- Each layer brings protocol overhead, which reduces the effective payload rate
- Other devices may interfere with the transmission
Experiments have shown that a point-to-point connection can achieve about 4 kBs data throughput. Depending on the configuration and customization, strongly deviating results are possible.
If achievable data rates are key factor in the project, care should be taken at an early stage to select the right basic technology and to consider all influencing factors.