Apple sent us both a Time Capsule and Airport Extreme which I used for testing, but I also purchased a copy of each to tear down and get to the bottom of the changes internally. Before doing that, however, I hit up the FCC to see what I could glean from comparing the test reports between generations. Apparently I wasn’t alone in doing so, as other people likewise picked up on this avenue for finding out what’s different.

Inside the test reports for both are some nice tables that outline maximum output power for the wireless stack inside the devices. I’ve copied and formatted the data for both the Time Capsule and Airport Extreme.

Airport Extreme—Power Output Comparison
WLAN Mode Gen.4 (BCGA1354) Gen.5 (BCGA1408)
2.4GHz—802.11b 286.42 mW 257.04 mW
2.4GHz—802.11g 143.22 mW 307.61 mW
2.4GHz—802.11n (20 MHz) 130.92 mW 257.63 mW
5GHz—802.11a 202.77 mW 326.59 mW
5GHz—802.11n (20 MHz) 164.82 mW 337.29 mW
5GHz—802.11n (40 MHz) 139.32 mW 392.64 mW

Time Capsule—Power Output Comparison
WLAN Mode Gen.3 (BCGA1355) Gen.4 (BCGA1409)
2.4GHz—802.11b 237.14 mW 257.04 mW
2.4GHz—802.11g 143.22 mW 307.61 mW
2.4GHz—802.11n (20 MHz) 130.92 mW 257.63 mW
5GHz—802.11a 202.77 mW 326.59 mW
5GHz—802.11n (20 MHz) 164.82 mW 337.29 mW
5GHz—802.11n (40 MHz) 139.32 mW 392.64 mW

It’s curious that for the 802.11b category power actually went down on the Airport Extreme, but hopefully nobody will find themselves using 802.11b in the first place. Interestingly enough, the results are almost the same on the Time Capsule, except 802.11b power has gone up accordingly. There are different output powers for each wireless mode, including 20 MHz and 40 MHz channels, but on average power between Airport Extreme generations has increased 135 mW, and 143 mW between Time Capsule generations.

Of course the next logical question is whether antenna gain has changed between the two—after all, having a more powerful output power only goes so far. It turns out that both Airport Extreme generations share the exact same antenna configuration and gain, and likewise with the Time Capsule. Note that two antennas are actually shared among the 2.4GHz and 5GHz RF chains—AP2 and AP3 to be exact.

Airport Extreme—Antenna Gain
Antenna Gen.4 (BCGA1354) Gen.5 (BCGA1408)
  2.4GHz (dBi) 5GHz (dBi) 2.4GHz (dBi) 5GHz (dBi)
AP1 - 1.74 - 1.74
AP2 1.41 2.97 1.41 2.97
AP3 2.33 2.67 2.33 2.67
AP4 1.83 - 1.83 -

Time Capsule—Antenna Gain
Antenna Gen.3 (BCGA1355) Gen.4 (BCGA1409)
  2.4GHz (dBi) 5GHz (dBi) 2.4GHz (dBi) 5GHz (dBi)
AP1 - 4.38 - 4.38
AP2 0.1 0.81 0.1 0.81
AP3 0.27 3.09 0.27 3.09
AP4 4.32 - 4.32 -

I hadn’t looked up the Time Capsule antenna gains until now (having not owned one) but it’s surprising how little gain there is on 2.4GHz with antenna 2. I’m a bit surprised that Apple hasn’t moved over to using the antennas from the Airport Extreme in the Time Capsule. The Airport Extreme has a much more even gain configuration between the three antennas, however as we’ll show later performance is relatively comparable between the two products.

Without even breaking the devices open, we now know that the Airport Extreme and Time Capsule both have substantially increased transmit power, and likely share the same radio given the identical transmit power characteristics.

Introduction and Physical Appearances Disassembling Airport Extremes
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