+/*
+ * Find starting rate for new "search" high-throughput mode of modulation.
+ * Goal is to find lowest expected rate (under perfect conditions) that is
+ * above the current measured throughput of "active" mode, to give new mode
+ * a fair chance to prove itself without too many challenges.
+ *
+ * This gets called when transitioning to more aggressive modulation
+ * (i.e. legacy to SISO or MIMO, or SISO to MIMO), as well as less aggressive
+ * (i.e. MIMO to SISO). When moving to MIMO, bit rate will typically need
+ * to decrease to match "active" throughput. When moving from MIMO to SISO,
+ * bit rate will typically need to increase, but not if performance was bad.
+ */