On the Benefits of Listen before Talk Scheme for NB-Fi Networks

Area of Science:

• Wireless Communication Technologies
• Low-Power Wide-Area Networks (LPWAN)
• Network Protocol Performance Analysis

Background:

• Narrow Band Fidelity (NB-Fi) is a key protocol for LPWANs, utilizing license-exempt ISM bands.
• NB-Fi devices operate in modes with and without Listen Before Talk (LBT), impacting network efficiency.
• Understanding LBT's role is crucial for optimizing NB-Fi performance in diverse network conditions.

Purpose of the Study:

• To compare NB-Fi network performance with and without Listen Before Talk (LBT).
• To evaluate different LBT implementations under varying network loads and sizes.
• To analyze the impact of LBT on packet loss rate (PLR), delay, energy consumption, and throughput.

Main Methods:

• Extensive simulations were conducted to model NB-Fi network behavior.
• Performance metrics including PLR, delay, energy consumption, and throughput were measured.
• Comparisons were made between NB-Fi networks with and without LBT, and across different LBT strategies (non-persistent CSMA, p-persistent CSMA).

Main Results:

• Listen Before Talk (LBT) significantly improves NB-Fi performance metrics when network load exceeds 40 packets per second.
• For small NB-Fi networks, non-persistent CSMA implementation of LBT yields optimal PLR, delay, and energy consumption.
• In large NB-Fi networks with hidden devices, p-persistent CSMA LBT implementation is superior for improving PLR, delay, throughput, and energy consumption.

Conclusions:

• LBT is essential for optimizing NB-Fi networks, particularly under higher traffic loads.
• The choice of LBT implementation (non-persistent vs. p-persistent CSMA) critically depends on network scale and topology.
• Findings offer practical guidance for deploying efficient and robust NB-Fi based LPWANs.