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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  • Jacob Marley - Saturday, August 6, 2011 - link

    On page 3...
    "Marvell 88E6350R 7 port GigE switch, with 5 physical interfaces, all of which support up to 10 KByte jumbo frames."

    So the hardware supports jumbo frames, but does the software?

    I have yet to find a home router that supports and enables jumbo frames at the switch level.

    Jumbo frames make no difference for internet bound traffic but it seems to make a big difference for LAN based large data transfers.
  • jay2901 - Saturday, August 6, 2011 - link


    why do you use a separate box for nat? better firewall? curious as to what that device is...

  • Brian Klug - Sunday, August 7, 2011 - link

    I prefer the wealth of configuration options that going that route provides. Specifically software like Tomato, DD-WRT, or if you're really feeling daring, a FreeBSD based solution with a PHP wrapper like m0n0wall or pfSense.

    Just a ton more options for firewall, reporting, bandwidth tracking, QoS, e.t.c.

  • danacee - Saturday, August 6, 2011 - link

    Use D-link, or if you really have to Netgear.. Although only D-link I know for sure makes 5/2.4ghz N routers that never EVER have to reset and run for years. Netgear I've only seen that sort of reliability with their Wireless G routers

    Linksys is rotten filthy garbage just like everything else Cisco makes, avoid it. They've not made a single wireless router in the past 2 years that doesn't shit itself and need a reset nearly every day.

    -Your helpful networking tech.
  • thingi - Sunday, August 7, 2011 - link

    Apple infuriate me sometimes. It would appear that the 'new' time capsule still can't join a wireless network without it's Ethernet ports becoming being disabled if nothing has changed apart from the wifi card :-(

    My iPhone is my only source of net connection which is 80Gb (yes thats eight-zero gigabytes) of 'fair usage' per month which is oodles for a 3G connection so here's what I want to do:-

    'iPhone Personal Hotspot' > Time Capsule > Airport Express (wifi-to-eth) > xbox

    The trouble is that when a time capsule joins a network it's ethernet ports fall asleep. So instead I have to do the following:-

    'iPhone Personal Hotspot' > Airport Express (wfi-to-eth) > Time Capsule > 2nd Airport Express (wfi-to-eth) > xbox.

    The really stupid thing is that a Time Capsule is more powerful piece of network equipment than an airport express, there is no reason why the ethernet ports should fall asleep just because Apple have deemed that users must connect a Time Capsule directly with an iPhone personal hotspot without crippling it.

    The other slightly annoying thing about this setup is that Apple in their infinite wisdom have deemed to force iPhone personal hotspots to set up a 'g' connection instead of an 'n' one (ok it would still be an 2.4Ghz due to the iPhone radio but that would be better than being stuck at 'g' for no good reason in a totally 'g' saturated neighbourhood!

  • repoman27 - Monday, August 8, 2011 - link

    When you tell an AirPort Express / Extreme or Time Capsule to "Join a wireless network" it becomes a client on that network and ceases to perform as a router. This is really only useful to share attached USB or audio devices wirelessly.

    When you enable Personal Hotspot on an iPhone 4, it creates a wireless network (802.11n (b/g compatible), 2.4 GHz band, single spatial stream, WPA encryption) and provides DHCP and NAT to share your cellular internet connection. 802.11n connections are actually possible according to this article: but if you're in a neighborhood where 2.4 GHz is saturated, as many are, there's not much you can do about it. Not many phones have 5 GHz WiFi radios these days.

    If you just want to provide an internet connection for your Xbox, the simplest solution is to buy a WiFi adapter for it and configure that to connect to your iPhone's Personal Hotspot. In order to bridge your Personal Hotspot to your wired network, you would have to set your Time Capsule's Internet Connection: Connection Sharing setting to "Off (Bridge Mode)", set the Wireless: Wireless Mode setting to "Extend a wireless network", and then choose your Personal Hotspot as the network to extend. For various reasons, I'm going to guess that this will never work though. Besides, the iPhone Personal Hotspot only supports a maximum of 3 (GSM models) or 5 (CDMA models) clients via WiFi, so you can't really have much else on your LAN unless you put it behind yet another router.

    It might be easier to tether your iPhone via USB to a Mac or PC, turn on internet connection sharing over the ethernet adapter, and then connect that to a Time Capsule set to bridge mode.
  • ginghus_khan2000 - Sunday, August 7, 2011 - link

    I was a little surprised you didn't test the wifi and hard drives as a system. I'm sure the wifi is the limiting protocol here but there were a few spots where wifi would be faster than the hard drives.
  • stephenbrooks - Sunday, August 7, 2011 - link

    Can you stack the two Airport Extremes on their side and put the Time Capsule across the top?
  • Brian Klug - Sunday, August 7, 2011 - link

    Wow, that's an awesome idea. I'm going to see if I can set it up ;)

  • deadshort - Sunday, August 7, 2011 - link

    Fantastic: thanks for doing that! Spread the word!

    If the main motherboard and chipset are the same, I guess it stands to reason that a more powerful radio would take a bit more power. ~250 Wh/day, or about 5% of my fairly careless daily consumption, is worth knowing but not worrying about.

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