The document discusses key performance indicators RSRP, RSRQ, and SINR used for measuring cellular network signal quality. It defines RSRQ as the ratio of RSRP to the total received power over a specific number of resource blocks, and SINR as the ratio of signal power to interference plus noise power over the resource blocks allocated to the user equipment. It also notes that without a reference signal power boost and with evenly distributed interference, RSRQ is equal to the inverse of SINR plus the resource block loading percentage, divided by 12.