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. 

 

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  • claytontullos - Saturday, March 19, 2011 - link

    http://technabob.com/blog/2011/03/18/ipad-2-refrig... kind of fun? Reply
  • vol7ron - Saturday, March 19, 2011 - link

    This just goes back to what I've said since the iPad was introduced. It'll be the +1 device that's best for laying around your house. This goes into my review as why it needs to hit the $200-250 price point.

    Sure it's a nice e-Reader and can entertain with some games and even allow for some production work, but it is still clunky and uncomfortable and to be efficient and productive you need the additional hardware, which are going to bring you in a nice laptop range anyhow.

    The 3GS is hitting the $50-100 price point w/ a 2 year contract, which I suggested a year ago. Personally, I still think that should be the price w/o the contract (to be available after-market for gifts/presents), but as long it's available at that point, that's where it needs to be.

    I still think the iPad needs to drop to that $200-250 point. It's the coffee table device, which people should consider having 2-3 spread-out in the home [ maybe one in the bathroom ;) ] - if only they could also self-sync wirelessly. I'm not too sure who buys the base model, but the specs alone would keep me from considering it and when you look at the higher spec'd models, it's not as justified when looking at laptops, or other eReaders.
    Reply
  • solipsism - Sunday, March 20, 2011 - link

    $200 to $250 for a newly released 10” Tablet with an IPS panel? WTF are you smoking? How can you have such an odd mental disconnect between writing that and then writing "The 3GS is hitting the $50-100 price point w/ a 2 year contract”? What part of 2-year contract aren’t you understanding? Do you not realize the carrier is paying Apple more than $200-250 for that 3GS, and you are paying the carrier a lot more than that over 2 years?

    Pray tell, how would this device be $200-250 when the competition with a 2 decade head start still hasn’t been able to compete on price?
    Reply
  • synaesthetic - Sunday, March 20, 2011 - link

    I don't get how they sell so many when they're so useless and clunky... and cost so much.

    Lot of hipsters I guess.
    Reply
  • michael2k - Sunday, March 20, 2011 - link

    The weight, battery life, and cost (altogether) are unparalleled in the computing world.

    Smartphones with similar performance characteristics have far smaller screens and lower battery life.

    PCs with similar battery life cost far more and weigh far more.

    PCs with similar weight (and still double at that) cost far more and have only fraction of the battery life.

    PCs with similar cost weigh far more and have drastically lower battery life.
    Reply
  • Meaker10 - Sunday, March 20, 2011 - link

    A dual core sandy bridge 13" device is going to be far more useful for work and far more powerful. Reply
  • michael2k - Sunday, March 20, 2011 - link

    Who said anything about work? For things like reading Anandtech it would be far heavier, bulkier, and with less battery life. Reply
  • bigboxes - Sunday, March 20, 2011 - link

    Just admit that it's a toy. The authors laid it out for you on how they prefer to use other devices instead of the iPad. It too bulky for portability and underpowered for any productivity tasks.

    So, you're telling me (and everyone else here) that you paid $500+ just to surf AnandTech on your couch? Just wondering.
    Reply
  • Stas - Monday, March 21, 2011 - link

    That's exactly why it cannot cost this much to be a reasonable buy. No, the following purchases are not reasonable: fa- sheep base, soccer moms that buy the latest gadget with most hype for their kids/husbands not even knowing wtf it does, or PR boost in form of including, again, the most hyped device with cars, hotel rooms, air travel, etc (3 categories right there probably account for 90% of all sales). I mean people that understand exactly what the device is, what it's not, and have a clear idea of how they are going to use it. And it doesn't matter how much it costs to make it, how advanced the hardware is, or how "revolutionary" the design is. Given the limited usability of a slim, touchscreen device, I think asking $600+ for one is ballsy. Reply
  • MScrip - Monday, March 21, 2011 - link

    -- "Given the limited usability of a slim, touchscreen device, I think asking $600+ for one is ballsy." --

    That's true about any tablet.

    As great as Honeycomb tablets are... they're still not gonna provide a true computing experience.

    A $600 laptop will always provide far more functionality than a $600 tablet...

    Yet... all these manufacturers are pumping out tablets at an alarming rate.

    Apple took the risk and added a new product to their lineup.

    If tablets were destined to fail... we wouldn't see Motorola, Samsung and even RIM jumping into the tablet game...
    Reply

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