You’re A Sack Of Potatoes

Ends up, we are all like a lazy sack of potatoes, at least when it comes to RF. Boeing calls it Project SPUDS or rather Synthetic Personnel Using Dielectric Substitution. Apparently they are good substitute for real human bodies when testing wireless networks on planes. Fill the seats with sacks of potatoes and test away.

Nice to know there’s actually a little truth to that old cliché.

iOS 6 Adds Wi-Fi Plus Cellular

A nice little scoop from Apple Insider about iOS 6 shipping with a new setting. Wi-Fi Plus Cellular it will allow your phone to fall back to cellular when a Wi-Fi access point is slow. A rather nice little enhancement.

I’d actually love to see Wi-Fi be geofenced, so that it will automatically enable itself in certain locations. I don’t need Wi-Fi on all the times, but there are certain locations where iOS devices could utilize it. Why should I need to toggle it myself if the device knows where it is? I’d love if my phone knew it had access to Wi-Fi at home and could switch automatically when I’m home. It seems like this would be simple enough to do right. Apple does all the pieces already, it’s just a matter of doing it together.

Wi-Fi Usage Worldwide

From telecompetitor:

Wi-Fi network use will nearly double in homes around the world come 2016, according to new Strategy Analytics research. Already used in some 439 million households worldwide, equivalent to 25% of all households, Wi-Fi home network penetration will expand to 42%, reaching nearly 800 million by 2016, according to the “Broadband and Wi-Fi Households Global Forecast 2012” report.

It also mentions that 61% of US households have Wi-Fi.

Having had Wi-Fi now for a decade (since late 2001), I can’t imagine life without it anymore. It’s liberating being able to put a laptop anywhere and get online at high-speed. Devices like the iPad just make it more so.

Wi-Fi is easy to take for granted. It’s becoming a utility like electricity and water. You just expect it to be there and work when you want it.

Stable WiFi Connections With Mac OS X

I’ve been digging into Mac OS X’s sometimes unstable WiFi connections for a while now, and have come to the conclusion that the Broadcom drivers in Mac OS X 10.6+ are either too fussy or just buggy in particular when dealing with 802.11n.

Apple’s iOS drivers seem to be different as few people see the same issues across Mac OS X and iOS. On the hardware side, the iPad 3 and iPhone 4S use a Broadcom BCM4330, while the slightly older iPhone 4 uses a BCM4750. MacBook, MacBook Pro, Air use a Broadcom BCM4331 these days. Some older ones (pre-2010 I believe) used Atheros AR5008. As you can see the hardware is pretty similar suggesting software as the discrepancy. Despite using a Darwin based OS it makes sense to have slightly different drivers. These devices have very different needs in terms of data usage patterns and power consumption. iOS devices seem to use less power than their OS X based counterparts. That makes perfect sense. The question is how does this impact connectivity and what can we do about it?

Apple has recommendations for iOS. For the most part these are universally good recommendations, however I’ve found a few things to be different:

  • 802.11 a/b/g/n – If you’ve got a broad set of clients, without question seek out a simultaneous dual-band wireless router. Not dual-band, simultaneous dual-band. This will save you a lot of headache and ensure good performance. Two radio’s are better than one.
  • Channel – Apple says to set it to “auto”, however I’ve found if there are several access points on other channels nearby this can be troublesome for OS X based clients on 802.11n in the 5 GHz spectrum. You’re best off setting it to the most open frequency and leaving it if you experience problems. This alone will likely resolve many (if not all) connectivity issues in my experience. 2.4 GHz seems to do better in auto channel. I’m not entirely sure why this is, however I suspect it has to do with power saving strategies employed by the driver. This seems to be even more problematic with 40 MHz channel width, which sort of makes sense given they are related.
  • Set 5 GHz channel width to 20/40… maybe – Apple says to set the 5 GHz channel width to 20/40 MHz if supported because not all devices support 40 MHz, and this is most compatible. If you’ve got simultaneous dual band, you can consider setting it to 5 GHz 802.11n only with 40 MHz channel width and set the other radio set to 802.11b/g 2.4 GHz / 20 MHz serve as adequate backwards compatibility for non-40 MHz devices. I’ve run things both ways, and IMHO either will serve most needs well. Just depends what devices you are supporting.

This is pretty obvious in retrospect. The 5 GHz spectrum seems to have some funny business with channel selection and this can be solved by just being more strategic about your usage. If you’ve got an Apple device being fussy with network connections, this is the first thing to play with.

Israel Lifts iPad Ban

Israel announced that they have lifted the iPad ban.

“The scrutiny conducted by the Ministry technical team vis-à-vis Apple’s team, International laboratory and European counterparts confirmed that the device which could be operated in various standards will be operated in Israel in accordance to the local standards.”

Lets be honest. This had nothing to do with Israeli limitations on wireless communications. This had to do with importing a device that could be resold for significant profit without paying any sort of tax. Israel has more high-tech start-ups per capita than anywhere on earth. Needless to say the number of folks willing to pay a large premium to get their hands on one makes this a profitable market. It also makes the startups extra vulnerable to being extorted.

The truth is the iPad uses a pretty vanilla Broadcom BCM4329 (BCM4329XKUBG to be exact) chip. This is yet another chip in a very popular series of Broadcom chips for wireless communications. It handles Bluetooth and WiFi on one package making it very efficient and battery friendly. The iPhone 3GS uses the BCM4325. Millions of cell phones and laptops have very similar chips in them for the past several years. The radio is nothing new.

Almost every traveler bringing a laptop or smart phone into Israel has a wireless card of equal strength. If they had any real reason to believe that foreign wireless chipsets could be a danger to their infrastructure all laptops would need to be whitelisted before being brought to Israel. Clearly that’s not the case. Yes you can tweak via software to limit the power of a wireless card, but does anyone adjust their laptop when entering another country? Has anyone been checked when entering the country for wireless strength? I’m guessing not.

Now that a few weeks have passed, and the hype is starting to die down, there is no longer a need for the ban. Units will start shipping overseas soon anyway.

This isn’t a bad thing I might add. People who smuggle these devices in and resell them are just opportunistic and taking advantage of the situation.

802.11n Finalized

802.11n, something I was starting to think would never get beyond draft is now approved. Having suffered through “compliant” 802.11b devices I long ago decided wireless networking is fussy enough to warrant stricter standards. As a result I stuck to Wi-Fi Alliance certified 802.11g devices, and the results have been awesome. I’m still of the opinion that the difference between “compliant” and “certified” is gigantic. Certified 802.11n devices should start to appear in the next few months.

Looks like the goals for any 802.11n upgrade are MIMO (obviously) and preferably dual-band (2.4GHz and 5GHz). I can’t see why I would want to do anything otherwise.

Considering most ISP’s don’t yet provide the downstream or upstream bandwidth necessary to take saturate a good 802.11g network, I’m not sure it’s really necessary to upgrade just yet. Thanks to a solid signal I can sustain up to about 19 Mbps over 802.11g even with WPA2 overhead and slight signal degradation. Under 1ms pings as well. ISP currently offers up to 16 Mbps, 12 Mbps plans for mortals. Rarely is that performance actually seen thanks to “the Internets being a series of tubes”. At least for today upgrading would only improve local network performance, not Internet performance. Most traffic is going outside the network anyway. 802.11n would bring capacity up to 130 Mbps, but since the uplink is still 12 Mbps, that really provides no real performance boost.

For anyone who would argue the faster CPU’s on the newer access points would improve performance, I’ve found that my current AP rarely sees more than a 2% load, with rare spikes up to about 40% capacity.

Of course hardware providers, and retail outlets will continue to tell people that downloading will be 6X faster1, but logic and common sense proves otherwise. It’s the equivalent of a Bugatti Veyron stuck behind a funeral procession.

That of course also assumes all devices are connecting via 802.11n. If you have an 802.11g and 802.11n devices connecting over 2.4 GHz, you’re going to be in mixed mode and slow down while 802.11g devices send/receive anyway. As far as I know there’s no way around that.

Then there’s the issue of all the pre-N adapters sold in laptops over the past few years and their compatibility, which is generally pretty good, but not perfect when mixing vendors.

So despite the marketing getting even stronger, I don’t see how it would be really beneficial to upgrade just yet. The actual performance increase for most activity will be virtually non-existent until ISP’s get faster. I’d rather wait until the hardware matures and prices drop more.

1. up to 6X faster, actual results may vary.

How To Be More Secure With Your Data & Identity

It’s amazing how on a daily basis there’s a story about someone’s identity or data being stolen, personal info being misused, or just getting screwed via the Internet. Most of the time it’s due to a complete lack of standards regarding how people treat their digital property and identity. It’s the electronic equivalent of leaving your home and not locking the door. Anyone can come in and take what they want.
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WiFi WPA Encryption Partially Hacked

WPA Encryption, Temporal Key Integrity Protocol (TKIP) has been partially hacked.

To do this, Tews and his co-researcher Martin Beck found a way to break the Temporal Key Integrity Protocol (TKIP) key, used by WPA, in a relatively short amount of time: 12 to 15 minutes, according to Dragos Ruiu, the PacSec conference’s organizer.

They have not, however, managed to crack the encryption keys used to secure data that goes from the PC to the router in this particular attack

The key things to note is:

  1. The TKIP key has been hacked, but they haven’t managed to crack the encryption keys for data…. yet.
  2. This involves WPA, not WPA2 which supports AES.

I personally started using WPA2 and completely disabled support for TKIP a long time ago. I’m sure it will eventually be cracked, but hopefully I’ll be using something else by then.

Another good idea is to always ensure sensitive info is done using HTTPS if you can help it.

Edit [11/8/2008 @ 11:49 AM EST]: More info.

WMM Slowdown

I turned on Wireless Multimedia (WMM) support the other day on my wireless network, figuring QoS for a wireless network would pretty much be a slam dunk. For those who don’t know, the four access categories it uses are:

  • voice
  • video
  • best effort
  • background

I was surprised to find, at least with the Netopia box that this actually resulted in a significant slowdown in http traffic, even when there was no other services being used. To put some numbers out there, we’re talking 10000 kbps with it enabled vs. 17400 kbps when disabled (these aren’t scientific, they are just bandwidth tests). I think the performance hit negated any real benefit, at least in this case. The box doesn’t handle much VoIP, so it really doesn’t do much. Video is more about raw bandwidth these days than latency thanks to CDN’s becoming more common and reducing the bulk of the latency issue. Also interesting is that the CPU hit seems pretty minimal. Daily average increased from 2% to about 4%, it’s double but really nothing serious. With it enabled it never spiked past 50%, and that was only one time.

So after a few days testing, WWM is turned off. Seems QoS at least in this case doesn’t pay. I can’t complain, wireless performance (20Mbps+) and signal strength are fantastic (when the microwave isn’t on) for an 802.11g network. Despite that, there’s always the desire to find ways to make it even better. Next step would be 802.11n, but I have a thing against uncertified gear. Once it’s standardized, I’d strongly consider it, especially if I can find a device that supports Linux firmware.

Experiment complete.