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
Comments Locked


View All Comments

  • Dug - Monday, August 8, 2011 - link

    I wish they would allow some type of iTunes server on the Time Capsule. Then I could stream to everything else such as my Apple TV's without having a computer on.
  • tsanga - Monday, August 8, 2011 - link


    When you took apart your older Airport Extreme, did you notice if the antennas might have been improperly connected? Swapping antenna hookups could result in better 2.4 GHz performance:
  • Brian Klug - Tuesday, August 9, 2011 - link

    I'm not entirely sold on that smallnetbuilder conclusion from a long time ago, to say the absolute least. I suspect the swappage they experienced could be explained in other ways. Everything appears to match the way it should be assembled in the present state.

  • CharonPDX - Monday, August 8, 2011 - link

    I have both a first-generation "square" AirPort Express-n (10/100 Ethernet) and a second generation (that added Gigabit,) both of which are single-band-at-a-time only. (i.e. I have to choose between 2.4 or 5 GHz for my whole network, no mixing.)

    When using either one as the 'primary', if I use my maximum bandwidth and/or lots of open connections (I seed Torrents of Debian install images for alternate architectures, I swear!) it will lock up my internet connection every so often. I know it's not my cable modem or the cable company, because if I direct-connect my server, I have no problems. But through either AirPort, every half hour or so of heavy use, my internet will stall until I reboot the base station.

    Have you performed any such testing? I haven't read any complaints about newer generation ones, but want to make sure.
  • Brian Klug - Tuesday, August 9, 2011 - link

    You're using the device as a router in that configuration? I haven't heard of any such problems on the newer Gen 4 or 5, and I beat on mine pretty hard too and haven't seen it stall/hang.

  • weiran - Tuesday, August 9, 2011 - link

    I have the original N Airport Extreme (100Mb) and I don't suffer the issue you have. I did have problems with using Time Machine with an attached disk over WiFi causing router lockups, I've since disabled it and the AE runs weeks without issues.
  • davolfman - Monday, August 8, 2011 - link

    It's nice to see somebody using the Sheeva SOC's in a shipping product. Too bad the RAM and Flash is so low or it would make a tempting (better designed) Sheevaplug replacement.
  • bbarrera - Tuesday, August 9, 2011 - link

    Great article, however please change "AFS" (whatever that is) to AFP.
  • blueeyesm - Tuesday, August 9, 2011 - link

    I use the "n" Express with a D-Link wireless router and I've had no issues via WDS. It connected and maintained a strong signal through two floors of a house, and through two walls (one of which was a fire-rated wall) of an apartment.
  • pcworth - Tuesday, August 9, 2011 - link

    I was wondering if there are any differences in connection reliability and WIFI speed continuity. I have a Gen4 Extreme that was purchased in February and it seems like I have recently started to get slowdowns on the internal network that are corrected by resetting the unit using the Airport Software.

    I originally owned the b/g spaceship and a b/g express, but when we bought our iPads in April 2010 we noticed that the airport station would stop connecting until the units were restarted. We tried working around this using power timers to restart the units, but in the end we gave up and bought a new Gen4 extreme. This problem has now stopped.

    I have no idea whether the problem is a temporary glitch, a hardware problem, or my imagination. It does seem to affect the AppleTV most, which is at the opposite end of the house, because we find it sometimes takes a long time to start streaming from iTunes. When I go in and reset the unit, it seems to improve.

    I was wondering if there are any measures of speed stability, and connection stability, to determine whether the Gen5 is more reliable than the Gen4 and worth thinking about for an upgrade?


Log in

Don't have an account? Sign up now