Faster Throughput on WCDMA

Fixing unintended attenuation is only one part of what’s new however, the other part of the story is faster cellular connectivity for users on WCDMA/UMTS carriers. Users who are using the 4S on CDMA (like Sprint or Verizon) won’t see a performance difference since this is still the same EVDO Rev.A.

The iPhone 4 used an Intel/Infineon X-Gold 618 which supported HSDPA 7.2 and HSUPA 5.76. The MDM6610 inside the 4S supports HSDPA 14.4 and HSUPA 5.76, alongside a number of 3GPP Rel.7 features which are colloquially known as HSPA+. I talked about this extensively in another piece when there was some confusion about whether or not the 4S is HSPA+ - which it is.

iPhone Cellular Speeds
Property iPhone 3G/3GS iPhone 4 (GSM/UMTS) iPhone 4 (CDMA) iPhone 4S
Baseband Infineon X-Gold 608 Infineon X-Gold 618 Qualcomm MDM6600 Qualcomm MDM6610
HSDPA Cat.8 - 7.2 Mbps Cat.8 - 7.2 Mbps N/A Cat.10 - 14.4 Mbps
HSUPA None - 384 Kbps WCDMA only Cat.6 - 5.76 Mbps N/A Cat.6 - 5.76 Mbps
EVDO N/A N/A 1x/EVDO Rev.A 1x/EVDO Rev.A

The previous X-Gold 618 baseband was a nice improvement over the iPhone 3G/3GS’ X-Gold 608, which lacked HSUPA, but in a world where most WCDMA carriers are at least running HSDPA 14.4, it’s nice to finally have an iPhone with something faster than HSDPA 7.2. I’ve done lots of testing inside my Tucson, AZ market (which is “4G” HSPA+ on AT&T’s coverage viewer) with both the 4 and the 4S, and have built a very good feel for the 4’s performance. As a reminder, if you’re in the USA, those dark blue areas represent HSPA+ coverage areas with AT&T’s upgraded backhaul. In practice these are at least HSDPA 14.4.

 
Left: iPhone 4 Limited to ~6.1 Mbps down, Right: iPhone 4S (same location) hitting ~9 Mbps

With line of sight to an AT&T NodeB inside my HSPA+ market I’m used to seeing a maximum downstream throughput on the iPhone 4 of almost exactly ~6.1 Mbps, which is about right for the 4’s HSDPA 7.2 maximum when you include overhead. The nice straight line in that result should clue you in that downstream throughput on the 4 was being gated by the baseband. On the 4S, in this same location, I’ve been able to get 9.9 Mbps when the cell isn’t loaded at night (I didn't grab a screenshot of that one, for some reason). It’s nice to finally not be gated by the baseband anymore on an iDevice. Having a faster baseband is part of the reason the 4S’s cellular performance is much better, the other half is receive diversity which helps the 4S push these high throughput rates, and also dramatically improve performance at cell edge.

I did some drive testing with the 4 and 4S side by side and targeted areas that I know have pretty poor signal strength. The 4S is shown in yellow, the 4 in blue.

You can see how downstream throughput gets a nice shift up, and the average changes as well, from 2.28 Mbps on the 4 to 2.72 Mbps on the 4S. The maximum in this sample increases from 6.25 to 7.62 Mbps as well. It isn’t a huge shift, but subjectively I’ve noticed the 4S going a lot faster in areas that previously were difficult for the 4.

We’ve also run the usual set of standalone tests on the 4S on AT&T in my market of Tucson, AZ, in Anand’s market of Raleigh, NC, and on Verizon in Raleigh, NC. Though we don’t have a Sprint 4S yet, we hope to do a more serious 4S carrier comparison here in the US when we get one. First up is AT&T which is of course HSPA+ in both of our testing markets.

AT&T HSPA+

Verizon EVDO

iPhone 4S Speedtest Comparison
Carrier AT&T Verizon
  Avg Max Min Avg Max Min
Downstream (Mbps) 3.53 9.94 0.24 0.82 2.05 0.07
Upstream (Mbps) 1.17 1.86 0.009 0.38 0.96 0.003
Latency (ms) 137 784 95 177 1383 104
Total Tests 457 150
Air Interface HSPA+
(HSDPA 14.4/HSUPA 5.76)
EVDO Rev.A

For the CDMA carriers, the 4S shouldn’t (and doesn’t) bring any huge improvement to data throughput because the CDMA 4 had both receive diversity and MDM66x0. For users on GSM/UMTS, however, the 4S does make a difference again thanks to the inclusion of those two new features.

One of the things I noticed was absent on the CDMA iPhone 4 was the 3G toggle. It does indeed make some sense to not include this in a CDMA 1x/EVDO scenario since power draw is about the same between the two air interfaces, however, the absence of this toggle has carried over to the 4S regardless of whether the phone is activated on a CDMA2000 or UMTS/GSM network. That’s right, you can go under Settings -> General -> Network, and there’s no longer any 3G Data toggle which you can disable and fall onto EDGE (2G) with now.

 
Left: iPhone 4S (no 3G toggle), Right: iPhone 4 (3G toggle)

It’s likely that this is absent to accommodate the multi-mode nature of the 4S (and thus the lowest common denominator CDMA mode), however the absence of this toggle makes getting connected in congested areas more difficult. In some markets, (I’m looking at you, AT&T in Las Vegas), EDGE is often the only way to get any connectivity, even without a major convention going on. Not having that 3G toggle makes manually selecting that less-used but more reliable connection impossible now, to say nothing of the potential battery savings that this would afford (and that we sadly can’t test now).

There’s one last tangential question about HSPA+ on the 4S, specifically on AT&T. I’ve left this to the end since it doesn’t impact non-US 4S users, but the last question is whether the 4S is actually on HSPA+. For a while, I was concerned that AT&T would continue using the wap.cingular APN on the 4S which seems shaped to around 7.2 Mbps HSDPA. I’m glad to report that AT&T hasn’t continued using wap.cingular on its 4S data plans, instead using “phone” which is a newer APN that allows for HSPA+ (above 7.2 Mbps) rates. You can check this yourself under PDP Context Info on the 4S in field test.

Improved Baseband - No Deathgrip The A5 Architecture & CPU Performance
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  • medi01 - Tuesday, November 08, 2011 - link

    To care about "improved vibration" I have first to be somehow concerned with current "unimproved" vibration. Which I don't. And I don't know any person that is. Reply
  • doobydoo - Friday, December 02, 2011 - link

    You don't have to be concerned with something to care about getting an improved version.

    For example, I may be quite happy to work for a salary of £1,000,000 a year, but that doesn't mean I wouldn't care if my salary was doubled.
    Reply
  • Grandpa - Wednesday, November 09, 2011 - link

    Anyone heard of staticgate yet? How come nobody gives a review about the static issue on the iphone? Reply
  • mymomentummedia - Thursday, November 10, 2011 - link

    Here is a funny iphone 4s review... iphone 4s plus a 50.cal Barret sniper rifle. what do you get?

    http://www.youtube.com/watch?v=RsVEbRt6g94
    Reply
  • chillstatus - Monday, November 14, 2011 - link

    I made sure to switch my dataplan over to the "Unlimited Data Plan for iPhone 4S" and when I run the field test, it still says it's using wap.cingular. I live in Los Angeles, and am wondering how I can get it to use the faster network. Anyone else have this issue? Reply
  • rhch - Sunday, February 05, 2012 - link

    I just found out that my 4S wifi range is not as good as my old iPhone 4 or iPad 2.
    4S gets much earlier "no connection" with Safari, Appstore etc when i take distance to my hotspot.
    Can someone confirm this?
    Reply
  • AlexD - Monday, February 06, 2012 - link

    With this commend I ask for help to find a developer for an iPhone-App that enables to use the 4S for the catching of light below 380nm (UV) and above 780 nm (NIR). The purpose is to identify light emission of materials (inks, plastics) outside the visible range and to visualize it with the smartphone. Even a slight range (e.g. >320nm or <850nm would help me.
    I would also be very greatful if somebody could explain what range of wavelength the 4S camera sensor is catching, if there are filters which can be removed or exchanged or the like to enable the above function. Thanks in advance for your support.
    Reply
  • meace - Sunday, February 12, 2012 - link

    Is the POP memory attachment to the A4 permanent?
    As in... could that pop ddr sdram of 128 *2 be replaced with 256 *2 ?
    I'm guessing there's no way that it's coming apart without damage
    (maybe even in a clean room) but I'll ask.
    Reply
  • Rizi - Tuesday, July 17, 2012 - link

    At first glance <a href="http://cellocean.com/iphone-4s-specifications-2210... phone</a> seems identical to its predecessor, except for the distinctive top-mounted incisions which signifies that a new design of the antenna is lying in wait inside. However, when you switch on the phone you will find that things are different. The 4S does not require activation via the computer except that you are restoring the data from a pre-existing iTunes backup. The phone can be set up as a new phone or restored from an iCloud account. In the event that you do not currently have an Apple ID, there is the option of creating one. A number of iPhone 4 users will ask themselves why they would need the iPhone 4S when the iOS 5 upgrade, which is free of charge, will equip their existing phone with the majority of the new features that are in excess of 200. However, it is important to note that the iPhone 4S is the best phone that Apple has built to date. The A5 dual-core processor, which makes things obviously nippier, is new and it is a feature that is also incorporated in the iPad 2. Web pages load quicker, apps launch faster, multi-tasking is a great deal more fluid and Pages and other resource-hungry apps now permit you to edit documents with no lag. Another great feature of the A5 processor is that it allows you to mirror the content of the iPhone 4S over AirPlay. When operated wirelessly, the iPhone 4S can push out up to 720p to the Apple TV. When connected to HDMI, the number will increase to 1080p. The ease of pushing content of the small screen to the big screen of the fly is an unexpected delight, particularly when you begin to rotate and zoom. In addition, it is something to brag about to owners of iPhone 4; the earlier model just cannot handle with the demands of this technological wizardry. The two antennas that run across the top of the iPhone 4S can both receive and transmit data, enabling quicker 3G connections. Apple has asserted that highest speed of download by way of HSDPA is 14.4Mbps, which is two times as quick as the iPhone 4. A major overhaul has been done to the camera, it now has the capacity to record 1080p video and take eight-megapixel stills. In addition, face detection is an upgrade and it works really well. Reply
  • vitaprimo - Saturday, August 18, 2012 - link

    I don't think it's the phone's fault that much. I have two iPhone 4s (not 4Ss) on different carriers (Telcel and Iusacell) and the never lose signal, no matter how tightly I grip them and I don't use cases. Now, one of the carrier is relatively new in my state and out of the major cities I've had a few dropped calls but they always connect back. I use to have iPhone 4Ss and I noticed no difference; I lost a bag with the phones in it so I'm using my old 4s until the sixth comes out--hopefully in less than two months.

    This whole antenna issue seems to just be affecting carriers in the US--that being AT&T.
    Reply

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