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
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  • podperson - Monday, March 21, 2011 - link

    Just admit that most PCs are used as toys. Heck, the whole reason the personal computer took off (in homes) was as a games platform.

    Most of the people I see with PCs are using them to surf the web, watch youtube, update facebook, or mess around with digital media. Where I work there are Macs and PCs available to the public with 27" monitors all open to Facebook (hint, it's a university). Exactly what is this "work" you need to do on PCs? For most people it's a little bit of text editing now.

    For some kinds of things the iPad is markedly superior ergonomically to a PC (or even a tablet computer or WACOM tablet display) — e.g. sketching or various musical apps. For others a PC is markedly superior. For still others one or the other is completely useless.
    Reply
  • michael2k - Monday, March 21, 2011 - link

    Except it isn't bulky nor underpowered for many things.

    I have a 2006 G4 iBook that is lower performance than a 2010 iPad 2. If the iPad 2 is a toy, then so is just about any early 2006 computer, including older Pentium M based laptops.

    It is also far less bulky than self same 4 year old computers, with trivially 2 to 3 times the battery life.

    I paid $500 so that my wife can follow my kids around, but still have a computer she can put in her purse. Without the iPad, she would have indeed settled for an iPod touch, but a netbook with a hinge? Too short a battery life and too hard to manage (Windows XP, Windows Update, AV, etc) for the harried housewife/homemaker
    Reply
  • bigboxes - Monday, March 21, 2011 - link

    Just how big is her purse? As for battery life I think you are looking through rose colored glasses in emphasizing the positive qualities that your device holds. As long as the device lasts until you get home to plug it in (maybe even your vehicle) it will suffice. The iPad is too bulky and not functional enough too do day to day tasks. As I said earlier, the authors point this out.

    As much as we want these cute devices to succeed we find ourselves using other devices that are far more practical. I've made the same mistake myself in the past. Anyone remember the Sony Clie? Another proprietary underpowered overpriced device. I believe I paid $500 for it. It gathered dust for years until I finally put it in a box. There's the cool factor and then there's reality. Do you set it out for your friends' visits or do you actually get x value out of it?

    Also, you are going to be carrying your phone with you already. Why carry both devices with you when one doesn't have more functionality over the other? I would think that the balance for function belongs to the smartphone (phone service is more valuable than screen size).
    Reply
  • michael2k - Monday, March 21, 2011 - link

    Her purse is big enough to hold an iPad, a wallet, another smaller purse, a phone, keys, two Capri Suns, two candy bars, a small bag of chips, and a couple of diapers.

    As for battery life, that's exactly what the iPad is; it lasts as long as it needs to until it gets home to be plugged in. I cannot find a laptop under 2 pounds with similar battery life. The minimum requirement is 6 hours.

    I carry my phone because I am more like Anand than not. She carries the iPad because she isn't like Anand, at all. It would be the equivalent of me driving a Civic and her driving a minivan; surely the very concept of a soccer mom and her requirements being different than a 9-5 commuter isn't lost on you?
    Reply
  • bigboxes - Monday, March 21, 2011 - link

    So, we can officially say this is the official tablet of soccer moms everywhere. Yay.

    She carries it around not because she is unlike Anand. She carries it around because she has a strong back!
    Reply
  • vol7ron - Sunday, March 20, 2011 - link

    A lot of the "sales" are from the retail outlets and not-necessarily the end-user consumer. There's people that buy it to sell to China or other Asian countries that buy it for double it's price; there are a plethora of reviewers these days; there are the people with mass amount of wealth that buy up anything just because they can; and then the hipsters that want to be cool and fit in. It reminds me of the episode of South Park with the smug Prius drivers.

    I'm not saying this isn't a bad device and it's mobility makes it beneficial in many regards. But the price of its mobility does not make it as attractive as it would be at the lower price (~$250). I'm not saying it should go for $100, but you're nearing the $1000 end of the spectrum for these devices and way over that for the necessary apps and accessories.
    Reply
  • crunc - Monday, March 21, 2011 - link

    I don't know why I'm getting into this argument, but all the iPads, including iPad 2's, that I'm seeing out in the world would seem to dispell your notion that no one is actually buying them for their own use. I saw 3 of them within 5 feet of me on the train this morning, for example. In 3 weeks time or so I'll be another one on the train with one, and also using it at home. I don't own a laptop. I wouldn't mind a laptop, but I'd rather have an iPad. It is, for me, far more comfortable to use then a laptop. Even the excellent trackpads on MacBooks don't compare to the entirely touch-based interface of the iPad. Obviously they aren't for everyone, but for some these are a great choice. I don't expect to write a book on it, but I then don't write books. If I ever decide to write a book, maybe I'll get a laptop. Reply
  • Ushio01 - Sunday, March 20, 2011 - link

    It's a fasion accessory just like the iphone, to be with the "in crowd" you have to have apple products that's all there is to it. Everyone on here must know at least someone who bought an iphone and then use it only for calls and texts, I know dozens of people who have done this. Reply
  • crunc - Monday, March 21, 2011 - link

    Actually, no, I don't know anyone who has an iPhone that only uses it for texts and phone calls. Everybody I know who has one uses it for virtually everything, myself included. In fact, I rarely text and only occasionally make phone calls (mostly of the, "should I pick up a pizza?" variety). You go on living in your little dream world, though. I won't stop you. I have an order in for an iPad 2 and I'm really looking forward to it. I love my iPhone and I want something akin to a laptop, but that isn't that, because the iOS interface is fantastic and the devices are more comfortable for me to use. Sure, there's some shortcomings to the platform, but they are overwhelmed by the multitude of positives. Reply
  • sarahtim - Sunday, March 20, 2011 - link

    I think this sort of comment represents a failure of imagination. As iPads sell million after million you have to adjust your idea of how many hipsters there are...
    Other people are different from you.
    Speaking for myself; I find my iPad extremely useful. I use it for a number of hours each day. I don't find it clunky. To me, and this is a very personal thing, the cost was of little consequence. While it is poor taste to blurt out your relative wealth when many folks are having a rough time of it, it is the only way to answer your comment. Further, I consider iPads to be very good value. I bought the bottom of the line iPad 1. It does everything I want. The bulk of its time is spent streaming video via the Air Video app.
    I represent a single data point - as do you. I fully appreciate that an iPad is a useless paperweight to you. No problem. When I use my iPad I do it in private. I don't discuss my ownership with others. I don't think I'm clever or a better person because I have one.
    You would have to look at me for a very long time before you thought of a hipster. Trust me on this. :-)
    Reply

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