WiFi and baseband

In our iPad 2 preview I speculated that Apple might have moved entirely to Qualcomm for the iPad 2 baseband, and the most likely guess was to the same Qualcomm MDM6x00 used in the Verizon iPhone. Turns out that I was only partially right. Looking at the difference in weight between the Verizon and AT&T models on the Apple website should've been the dead giveaway, but I initially suspected the reason was more area dedicated to power amps for the GSM/UMTS version. 


Black RF window at the top, even on a white iPad.

The Verizon iPad 2 shares the same Qualcomm MDM6600 baseband as the Verizon iPhone 4. The AT&T (GSM/UMTS) iPad 2 on the other hand uses the same Infineon, ...errr Intel X-Gold 618 baseband as the GSM/UMTS iPhone 4. It's interesting to see Apple using two different basebands when one could have covered both CDMA2000/EVDO and GSM/UMTS, and faster HSPA at that rate. The X-Gold 618 just isn't super impressive anymore in a world dominated by HSDPA 14.4 and 21.1 compatible basebands. That said, it's a welcome improvement from the X-Gold 608 shared between the iPhone 3G, 3GS and GSM/UMTS iPad, which lacked HSUPA entirely, and thus had a maximum upstream rate of 384 kbps (UMTS speeds). 

GSM/UMTS (AT&T) iPad 2 - Network Support
GSM/EDGE Support 850 / 900 / 1800 / 1900 MHz
UMTS/HSDPA/HSUPA Support 850 / 900 / 1900 / 2100 MHz
HSDPA/HSUPA Speeds 7.2 Mbps / 5.76 Mbps
Baseband Hardware Infineon/Intel X-GOLD 618

CDMA (Verizon) iPad 2 - Network Support
CDMA2000-1xEV-DO 800 / 1900 MHz
Theoretical Downstream/Upstream 3.1 Mbps / 1.8 Mbps
Baseband Hardware Qualcomm MDM6600

The cellular enabled versions of the iPad 2 still are easily picked out by the black plastic strip at the top which is an RF window. Curiously, the color of the RF window is black even on the white iPad models, which seems a bit un-Apple. Maybe black made more sense since white plastic might eventually show some discoloration. Through testing the window seems to also be used for WiFi in addition to cellular. The GSM/UMTS version has a microSIM slot and comes with a SIM ejector tool in the package.

 

I found the microSIM incredibly difficult to eject on my AT&T iPad 2 compared to every other iDevice. You have to insert the ejector tool normal to the curved surface, which ends up being at an angle of nearly 45 degrees with respect to the back surface. It isn't how I expected things to work, and the tray itself is a bit awkward. 

I carried around the AT&T version of the iPad 2 and ran over 150 speedtests using Ookla's speedtest.net application. I averaged throughput of 2.76 Mbps down and 802 kbps up, with latency of 390 ms. Anand carried around the Verizon version and saw downstream speeds averaging 872 kbps down, 434 kbps up, and latency of 382 ms. 

3G Speed Comparison - Speedtest.net to best host
Provider / Data Verizon - (EVDO) AT&T - (UMTS/HSPA)
Max Downstream 1.679 Mbps 6.135 Mbps
Average Downstream 0.872 Mbps 2.759 Mbps
Max Upstream 0.837 Mbps 1.635 Mbps
Average Upstream 0.434 Mbps 0.802 Mbps
Average Latency 382 ms 390 ms
Minimum Latency 298 ms 239 ms

Pricing between the two providers is interesting. It appears that Verizon was careful to not compete with AT&T at the same data package points, instead targeting data packages other than the two 256 MB and 2 GB bundles AT&T already offers. At the same time, pricing at 3 GB on Verizon is exactly where you'd wind up should you run over 2 GB on AT&T and incur the automatic $10.00 overage charge. Interestingly enough, whereas AT&T bills you automatically when you run over your data caps, Verizon simply stops and lets you add more data before the billing cycle ends. It's an interesting distinction, certainly competition is good. In addition, there doesn't appear to be any activation charge for either AT&T or Verizon. 

3G Enabled USAiPad 2 Data Plan Pricing
Provider Verizon (CDMA2000/EVDO) AT&T (GSM/UMTS)
250 MB NA $14.99 / mo - $14.99 for each additional 250 MB
1 GB $20.00 / mo NA
2 GB NA $25.00 / mo -$10 for each additional GB
3 GB $35.00 / mo NA
5 GB $50.00 / mo NA
10 GB $80.00 / mo NA

So which of the two is the one to get in the US? Ultimately the decision about which is "better" is really a function of local coverage profile, speeds, and how much data you use (which will determine your pricing). If you're an iPad 1 AT&T user and used unlimited, you also have the option of grandfathering it in for some time as well. Unless you’re in an overloaded metropolitan area, AT&T 3G data speeds are undeniably faster. At the same time, Verizon has more EVDO coverage that, while slower, is generally more consistent. Verizon’s pricing also includes heavier data numbers than AT&T does, so if you’re looking for something to completely replace a notebook with and intend to not use WiFi, that’s a fairly big draw. 

Speaking of data use, I find the fact that the “Post PC” era includes implicit data caps (neither Verizon nor AT&T offer any unlimited data iPad packages to new customers) somewhat disturbing. I burned through just shy of 1 GB of my 2 GB AT&T plan in 3 days of use. By the time I got finished writing everything on my review sections, I had already used more than half.

 

Words cannot express my frustration - nay, rage - at the telecom industry's calculated assault on unlimited data plans, first in the mobile space, and now alarmingly with terrestrial DSL. Glass caps on both have always existed (200 or 250 GB for cable, 5 GB for essentially all mobile), but unless you clearly were abusing it, nothing happened. This move to tiered billing is a much more alarming trend. The above screenshot coupled with my use patterns (I have under 37 MB per day for the rest of the month? HA!) is precisely why I can't possibly see myself using the iPad 2 on a day to day basis. I hate watching a meter, but at least I do it. The problem isn't so much the number so much as the psychological effect of knowing you're eventually going to run into the celing. 

WiFi

The iPad 2 uses the exact same 802.11a/b/g/n WiFi + Bluetooth 2.1 EDR stack as its predecessor - the BCM4329. Like the iPad 1, the iPad 2 has 65 Mbps (long guard interval, 20 MHz channel, 1 spatial stream) 802.11n support on both 2.4 GHz and 5 GHz. Essentially WiFi speeds and behavior close to the AP is exactly the same as it was before. I’ve seen other WiFi stacks on mobile devices with “802.11n” support provide short guard interval 20 MHz rates of 72 Mbps, but nothing above, yet, so it’s fair to say that the iPad 2 WiFi authentication rate is about par with the competition. That said, Bluetooth 3.0 is already here on a bunch of other devices. 

WiFi Performance

Unfortunately, WiFi range on the iPad 2 is noticeably less than its predecessor, and throughput slows down much earlier on the iPad 2 than it does on the iPad 1. I tested with a WiFi - 3G (AT&T) model and found that I’m able to make it further away from the AP by a good 10 meters or so, but throughput even after you drop one WiFi bar on the iPad 1 is continually better than on the iPad 2. 

WiFi throughput also tells a similar story, it just isn’t quite as good as its predecessor. It’s a bit unfortunate since Apple certainly could’ve used this refresh opportunity to be the first to introduce a two spatial stream 802.11n device.

For now, the wrap up with regards to the iPad 2’s WiFi performance is that close to the AP, things are just like they used to be. At the edge of WiFi coverage, the iPad 1 edges out the iPad 2 at maintaining higher negotiated throughput and actual speeds. 

 

Apple's foray into iPad cases - Smart Covers Display Analysis
POST A COMMENT

189 Comments

View All Comments

  • Mishera - Wednesday, March 23, 2011 - link

    An and you made an excellent point when you said that tablets don't seem on a path towards perfection.  Right now IPads are somewhat of a novelty.  They're kind of like that thing you see at a museum as a child that make you go "wow" or a concept at a convention that's not fully realized.  The problem is people seem content with the device as it is because it's Apple, and companies are trying the "square in circle" method to put it in schools, businesses, etc.

    Thats what really bothers me. Apple pretty much marches on it's own beat, consumers eat up what they release, and companies desperately try to run behind them and release something with better specs, never questioning if there is a better direction.  As a consumer device it's excellent, its just there are so many more directions tablets can go.  I would almost would say that Microsoft had a better idea of what a tablet should be with their umpc line, except they could never get the ui right, and now it seems like their hardware endeavors are over for so I wonder who could really bring a better concept to market.  To make tablets work it's going to take on os and a hardware so far android can't do it, microsoft won't to it and hp is still a question mark so we just have to be content with whatever apple gives us.  
    Reply
  • Zink - Sunday, March 27, 2011 - link

    Here's a very surprising video showing the flexibility of the glass used in the screen.
    http://www.youtube.com/watch?feature=player_embedd...
    Reply
  • JustinB - Monday, March 28, 2011 - link

    While OEMs are racing to create a competitor to the iPad, it seems like commenters on sites like this are trying to create a competitor to the Reality Distortion Field... Reply
  • NetJunky - Tuesday, April 19, 2011 - link

    Actually Dropbox has its own lack of security. So I wouldn't say, that this is a best example of data sharing via web. Reply
  • Bronx 6 - Tuesday, June 28, 2011 - link

    Apple had touch first congrats.They can keep there not so tech ridiculously rich ppl who buy lesser powerful or frivolous shoppers.xoom is to much with not enough (like ipad) on board no dongle needed ports/hdmi/usb/micro usb like acer.i bought an ipad2 as my first owned apple product just so I could show everyone whata piece crap it is and then return it to the store.The things I get off android apps are sooooooo much better because they arent being ran by the Nazi's (apple).,i like not having to waste money on anything app wise,movie(better than anything I could dream for) and of course free absolutely FREE music mp3s.now I even get artwork on them and they appear just as if I bought them.The music mp3 apps even (some) even include music charts so you know what's new and hot.i dont need cable tv,satelite,nadda I get thousands of channels free from apps which use flash and lemme tell flash is the key to the future and present.i love how developers make the good apps ipad has for honeycomb tabs(splashtop hd remote desktop)-myfav allows me to use all pcs as if I was on it even whem im in another state.the resolution is amazing also the many keyboards u can get-new swype is surreal should be stock on all tabs.tried to ruin acertab with viruses it wont phase it amazing alone.i so love the apps on droid they are made by ppl wno arent like the government and honeycomb keeps getting better asnow 3.1 is so muchbetter and its free.the power.of these tabs are like two ipads and the cameras on ipad2 is patheic like an old boostmobile vga cam.mine has the same quality cameras as iphone4 has another + acer has the best tab for the buck they have a functual full usb port and it connects alot.of useful things like keyboard,flashdrives,ch arging capabilites.i had bought one accessery a case stand that's it had hdmi cords already.the ipad I bought over 8 seperate things totally a money hungry company who designs product too keep you buying shit week after week.itunes is just plain retarded.i get the sameshit they do for free easier than a pc.wide open is free like usa is supposedly.if ur reading this and have a tablet download swype beta for honeycomb.It takes the basic stock keyboard but adds stuff u will love even if you dont swype u type better than the stock more like a real one.i bought 2apps in 2YRS yet ive had more than I can think of.i spent $8 total.i have sold more of these to anyone I show and teach.my old mother has one and now wont use her win7 pc's only thru the tablet-thats including me fixing her old pcs accross the country in california all from my badass acer tablet.apple should stick to ipods.droid tabs are diffently ipad.killers.i hope ppl enjoy wasting their money basically getting raped.so dumb ppl stay apple,smart ppl sick of paying for things that we shouldnt and having the ability to do all n then some on tablets enjoy.ps these flash modified apps on droids I cant praise the quality they look during playback is wow.ive watched more hdtv thru this than I have in years with my hdtv sets pretty crazy,so is the gaming similar to xbox360.buy an galaxy tab first then return it for an acer so you can appreciate getting more for less.send me the difference for enlighting u on values of better things.then again the world is more than 50% ignorant and very rude to ones who help them.take it as grain of salt Reply
  • rampantarmadillo - Thursday, August 18, 2011 - link

    I recommend that you learn to seperate vertex and fragment perf, this would demonstrate you aren't clowns. Reply
  • powchie - Saturday, December 10, 2011 - link

    anand, brian,
    what's that workflow that the iPad cannot fit in?
    Reply
  • ChaoticCupcake - Tuesday, December 27, 2011 - link

    Any word on whether or not a camera can be attached and used as a webcam for FaceTime, Skype, etc.? Reply
  • omkarphatak - Tuesday, February 28, 2012 - link

    Find out why choosing an iPad 2 over a laptop makes no sense... http://www.buzzle.com/articles/which-is-better-ipa... Reply

Log in

Don't have an account? Sign up now