+ /* The Realtek datasheet for the RTL8187B shows that the RX
+ * header contains the following quantities: signal quality,
+ * RSSI, AGC, the received power in dB, and the measured SNR.
+ * In testing, none of these quantities show qualitative
+ * agreement with AP signal strength, except for the AGC,
+ * which is inversely proportional to the strength of the
+ * signal. In the following, the quality and signal strength
+ * are derived from the AGC. The arbitrary scaling constants
+ * are chosen to make the results close to the values obtained
+ * for a BCM4312 using b43 as the driver. The noise is ignored
+ * for now.
+ */