 Hi everybody, welcome to CS 2023. I'm Salvo Bonina, Field Application Engineer for ST Microelectronics and today I'm going to present a demo designed around our Blue Energy LP SOC showcasing the LE power control feature. But first of all let me introduce you with a few key concepts that helps understanding how the LE power control algorithm works. So number one, the RSSI is the Received Signal Strength Indicator which is a measure of the power of the signal reaching the receiver. Number two, the SNR is the signal to noise ratio. This is a power ratio between the signal strength and the noise level. And then the golden range, the golden range is a RSSI range where we can guarantee a good link quality between the two pairs of the connection. Then outside the golden range the receiver can still hear the signal but we cannot guarantee good performances in terms of signal quality and part consumption. Then talking about the RSSI, ideally we want to avoid the following two scenarios. Number one, where the signal gets too low and this results in a low SNR. So this could put us in a situation where we cannot reach the sensitivity of the receiver device and so the receiver will not be able to demodulate the packets. The second scenario is on the flip side that says when the auto power is too high, so we are wasting power. So basically we are in a situation where there is some inefficiency in terms of power consumption and the battery lifetime of the transmitter will be shortened. Now, the LE power control is a VLE feature that was introduced with the Bluetooth 5.2 specs and helps minimize the power consumption using a dynamic algorithm that will scale the TX auto power up and down depending on the RF path loss between the two ends of the link. And then let's say you have the RSSI within an optimum range. Now we can have two cases. When the receiver gets a signal that is too low, he can ask the transmitter to increase his auto power in order to have the signal within the golden range. On the flip side, if the signal is too high, here we are wasting power. So the receiver can ask the transmitter to reduce the auto power in order to have again the signal within the golden range. Now for the demo we used two boards implementing the central and peripheral device and this establish a VLE connection. The two boards are connected through an RF attenuator that we used to simulate the longer distance between the two boards. And then we started with an overall path loss of 50 dB. And as you can see, the VLE will estimate the path loss between the two boards and set the auto power to minus 21 dBm on the transmitter side. Now we increase the attenuation and the path loss between the two ends of the link, adding steps of 10 dB each time. And then you can see that the algorithm will update the estimation of the RF path loss between the two and also change the power level on the transmitter side accordingly in order to cover now a link that is increased in term of distance in order to maintain a reliable link between the two. We can increase the attenuation even more to simulate a physical space like an office environment or even more for an industrial environment and see the algorithm keeps estimating the path loss between the two and change the auto power accordingly. So the final goal of this is avoiding any waste power and increase the battery lifetime on the transmitter side and maintain the link reliably. So to summarize, what are the benefits of the VLE power control feature? So number one, we optimize the power consumption and we keep the TXA to power to the minimum possible. Number two, we maintain a reliable link, we maintain the RSSI within the optimal range and then we improve the coexistence between multiple devices communicating in the 2.4 GHz band. Thank you for watching and for more information you can visit the webpage sd.com.com.com.com.