Faster or Slower: Convergence of Link Quality Metrics in Wireless Sensor Networks

Link quality estimation plays a vital role in wireless sensor networks, which can improve transmission efficiency and reduce node energy consumption by selecting the links with good quality. Packet Reception Ratio (PRR), Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI) are typical metrics for link quality estimation. However, there is a lack of quantitative analysis on the convergence of these three metrics in existing studies. More specifically, what the size of time window should be used to process these metrics to reflect link quality more accurately? To solve this problem, this paper conducted comprehensive and quantitative analysis on the convergence of PRR, RSSI and LQI through collecting and analyzing large amounts of experimental data. Experimental results show that only about 10 packets are enough for RSSI and LQI to evaluate the link quality accurately, while 50 packets are needed for PRR under the same conditions.