In the wireless world we often think more power is good. The louder the signal surely higher the performance gain. I am sorry to say that is not true in most cases. RF power is like a delicate flower and should be treated with respect. Simply choosing a higher power output and not properly tuning your radios could cause you more pain than you really know. In this quick blog post, I share a pair of static bridges being bench tested 70 feet apart. The only difference in configuration is simply changing the RF power. While I only share the capacity values, the throughput values have been excluded to keep the focus on power.
Example #1 - (HOTTEST)
In this example we pump up the power @ 30 dBm.
(1) Link @ -17 dBm
(2) Modulation at 16 / 64 QAM
(3) TX Power 30 dBm
(4) Capacity Link TX 205, RX 200
Example #2 - (HOT)
In this example we power down to @ 24 dBm.
(1) Link @ -22 dBm
(2) Modulation at 256 / 256 QAM
(3) TX Power 24 dBm
(4) Capacity Link TX 396, RX 391
Example #3 - (PEACHY)
In this example we power down to @ 18 dBm.
(1) Link @ -27 dBm
(2) Modulation at 1024 / 1024 QAM
(3) TX Power 18 dBm
(4) Capacity Link TX 482, RX 469
Modulate Gain: 16 vs 1024 and 64 vs 1024
Capacity Link Gain: TX 205 vs 481, RX 200 vs 469
Why excessive power gain is bad is because it increases noise and distortion at the receiver’s radio. In Example #1, both radios can hear each other at -17 dBm! Think of it this way, imagine having someone in your ear with a megaphone yelling today’s lunch specials at you. You can’t hear so well, can you ? Take away the megaphone and step back a few feet and all is peachy.
My quick less-techy blog post for today!
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.