Apple iPhone 4S: Thoroughly Reviewed
by Anand Lal Shimpi & Brian Klug on October 31, 2011 7:45 PM EST- Posted in
- Smartphones
- Apple
- Mobile
- iPhone
- iPhone 4S
WiFi Performance
Apple hasn’t spared upgrading WLAN connectivity on the 4S, though the improvement isn’t quite as dramatic as what I was hoping for. The 4S uses BCM4330, Broadcom’s newest WLAN, Bluetooth, and FM combo chip (though the latter still isn’t used). We’ve seen this particular combo chip in the Samsung Galaxy S2, and no doubt BCM4330 will start popping up a lot more in places where its predecessor, BCM4329 was used, which was everything from the 3GS to the 4 and in virtually innumerable Android devices. BCM4330 brings Bluetooth 4.0 support, whereas BCM4329 was previously Bluetooth 2.1, and still includes the same 802.11b/g/n (2.4 GHz, single spatial stream) connectivity as the former, including only tuning 20MHz channels (HT20). I was hoping that the 4S would also include 5 GHz support, after seeing SGS2 include it, however the 4S still is 2.4GHz only.
Encircled in red: The iPhone 4S' 2.4 GHz WiFi+BT Antenna
In addition, the 4S locates the WiFi antenna in the same place as the CDMA iPhone 4. If you missed it back then, and have read the previous cellular connectivity section, you’re probably wondering where the WiFi and Bluetooth antennas went, given the absence of a stainless steel band for them. The answer is inside, printed on a flex board, like virtually everyone else does for their cellular antennas. It’s noted on the FCC-submitted schematic, but I also opened up the 4S I purchased and grabbed a picture.
Left: iPhone 4S with WiFi RSSI circled, Right: iPhone 4
Given the small size of this antenna, you might be led (deceptively) to think it has worse sensitivity or isotropy. It’s interesting to me that this is actually not the case. Subjectively, I measured slightly better received signal strength on the 4S compared to a 4 side by side, and upon checking the FCC documents learned the 4S’ WLAN antenna has a peak gain of –1.5 dBi compared to –1.89 dBi on the 4, making it better than the previous model. That said, the two devices have approximately the same EIRP (Equivalent Isotropically Radiated Power) for transmit when you actually work the math out.
Moving to a newer WLAN combo chip helps speed WiFi throughput up considerably in our test, though I’m starting to think that the bigger boost is actually thanks in part to a faster SoC. As a reminder, this test consists of a 100MB PDF hosted locally loaded over 802.11n (Airport Extreme Gen.5), throughput is measured on the server. On MobileSafari, the PDF document is loaded in its entirety before being rendered, so we’re really seeing WiFi throughput.
GPS
The iPhone 4 previously used a BCM4750 single chip GPS receiver, and shared the 2.4 GHz WiFi antenna as shown many times in diagrams. We reported with the CDMA iPhone 4 that Qualcomm’s GPS inside MDM6600 was being used in place of some discrete solution, and showed a video demonstrating its improved GPS fix. I suspected at the time that the CDMA iPhone 4 might be using GLONASS from MDM6600 (in fact, the MDM6600 amss actually flashed onto the CDMA iPhone 4 includes many GLONASS references), but never was able to concretely confirm it was actually being used.
MDM6610 inside the 4S inherits the same Qualcomm GNSS (Global Navigation Satellite System) Gen8 support, namely GPS and its Russian equivalent, GLONASS. The two can be used in conjunction at the same time and deliver a more reliable 3D fix onboad MDM6610, which is what the 4S does indeed appear to be using. GPS and GLONASS are functionally very similar, and combined support for GPS and GLONASS at the same time is something most modern receivers do now. There are even receivers which support the EU’s standard, Galileo, though it isn’t completed yet. This time around, Apple is being direct about its inclusion of GLONASS. The GPS inside MDM6610 fully supports standalone mode, and assisted mode from UMTS, GSM, OMA, and gpsOneXTRA.
Just like with the CDMA iPhone 4, I drove around and recorded a video to illustrate GPS performance, since unfortunately iDevices still don’t report direct GPS NMEA data. The 4S has a very constant error radius circle in the Maps application and shows little deviation while traveling, whereas the 4 sometimes wanders, changes horizontal accuracy, and velocity. In addition, the 4S GPS reports the present position in the proper lane the whole time as well, while the 4 is slightly shifted. I don’t think many people complained about the GPS performance on the 4, but both time to fix and overall precision are without a doubt improved over the GSM/UMTS 4. Subjectively, indoor performance seems much improved, and I’ve noticed that the iPhone 4S will report slightly better horizontal accuracy than the 4 (using MotionX-GPS on iOS) indoors. Unfortunately we can’t perform much more analysis since again real NMEA data isn’t presented on iOS, instead location is abstracted away using Apple’s location services APIs.
Noise Cancelation
The iPhone 4 included a discrete Audience noise processor and second microphone for doing some advanced common mode noise rejection. This reduced the amount of background noise audible to other parties when calling from a noisy environment, and is a feature that virtually all of this latest generation of smartphones has included. The 4S still includes that second microphone (up at the top, right next to the headset jack), though the discrete Audience IC is gone. It’s possible that Audience has been integrated into the A5 SoC itself, or elsewhere, or the 4S is using Qualcomm’s Fluence noise cancelation. I spent considerable time digging around and couldn’t find anything conclusive to indicate one possible situation over the other.
We recently started measuring noise rejection by placing a call between a phone under test and another phone connected to line-in on an audio card, then ramping volume up and talking into the handset. The 4S doesn’t get spared this treatment, and I’ve also included the 4 and 3GS (which has no such common mode noise rejection) for comparison.
Subjectively, the 4S has further improved ambient noise rejection over the 4. I ran this test twice to make sure it wasn’t a fluke, and indeed the 4S subjectively has less noticeable ambient noise than the 4 even at absurd volume levels.
We’ve also placed the usual test calls to the local ASOS weather station and recorded the output. I can’t detect any difference in line-out quality of the voice call for better or worse, at least on GSM/UMTS. I’d expect the 4S to offer exactly the same quality on CDMA as the CDMA iPhone 4.
One thing I should note is that there does seem to be a bit more perceptible line noise on the 4S’ earpiece when on phone calls. It isn’t a huge difference, but there is definitely a bit more background noise on the 4S earpiece than the 4 in calls. The original 4S that Anand purchased had a noticeable and distracting amount of background noise, though swapping that unit out seems to have somewhat mitigated the problem (he still complains of audible cracking via the earpiece during calls). I’ve tested enough iPhone 4 handsets (and been through several) to know that there is a huge amount of variance in earpiece quality, (even going through one with an earpiece that sounded saturated/overmodulated at every volume setting), so I wager this might have been what was going on.
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ados_cz - Tuesday, November 1, 2011 - link
I have the 4S now and the problem is gone but once my girlfriend comes with her 4, I will make a video and post it to prove you wrong. People have no problems only in areas where signal is really strong. Why would I possibly want to lie?wonderfield - Tuesday, November 1, 2011 - link
What's of concern here is not whether the issue (signal loss) can be demonstrated but whether the phone is, in Brian's/Anand's words, "usable" with the defect or not. It's certainly possible for the GSM iPhone 4 to be rendered unusable in a low signal strength area with a natural, right-handed grip just as it can be rendered unusable with a death grip. That's not to say the phone will be unusable in most scenarios, however, because in most scenarios the phone should function properly. There are certainly edge cases, and the issue is more significant for those who're left-handed and for those who live/work in very poor coverage areas (where it can become an issue), but, again, that's not the typical use case. It's why I categorize Brian's claim that the GSM 4 is not usable without a case as being disingenuous.Realistically, you don't need a "really strong" signal to have not have any problems with the phone, you only need a signal great enough to overcome any attenuation introduced by making contact with the antenna. The extent of the attenuation, as demonstrated in another Anandtech article to which you might refer, is not as significant as portrayed by some media outlets.
ados_cz - Tuesday, November 1, 2011 - link
As far as the need for good signal went I needed to use the case all the time otherwise I would always have to hold the phone in unnatural way. iPhone 4/S is a really beautiful piece of hardware and It was really upseting that I had to use the case and spoil the desing. My close friend living just 15 miles next to me in Perth does not use the case and when he does not care to not to hold the phone in sensitive area, the call drops. It happend to me with him on the phone on few occasions. Few of my friends at uni need to use the case for iPhone 4 as well. The problem was not overstated. Either learn to hold the phone unnaturaly avoiding joining those two critical antenna strips or use a case. I opted for a case. My friend in the London got on well without case, but he learned to hold it by the to when calling. Anyway, I am glad that I have the 4S now and I think my girlfriend does not mind the case on her (former mine) iPhone 4. It so well made piece of hardware and so affordable here in Britain. You are being ripped off in US. Check the deals for iPhones on www.three.co.uk I got mine iPhone 4 for 69 pounds 5 months ago with two years contract for 35 pounds a month (2000 mins any network, 5000 mins mine network, unlimited 3G data with no fairu user policy). I paid 189 pounds for girlfriends (now mine) 4S for 32GB white version just few days ago and she got the same 35 pounds contract.Tetracycloide - Tuesday, November 1, 2011 - link
"I have hundreds of friends who have iPhone 4's who've never had any issue with signal loss at all."Really? Name them. Numbered from one to at least two hundred if you please.
Overstating the strength of your anecdotal evidence doesn't make you look right it makes you look biased.
For what it's worth, I think you're a huge tool for, well, being such a huge tool.
doobydoo - Wednesday, November 2, 2011 - link
Don't be ridiculous.To label someone a 'tool' for stating that their friends don't have issues with signal loss on a phone, is quite frankly ironic.
To suggest I would list my friends names in a bid to convince such a low level individual is even more ridiculous than the rest of your comment (which is a lot).
If you really need hard evidence, I'd point you in the direction of the millions of iPhone customers who gave the iPhone 4 the highest satisfaction ratings of any phone, full stop. Bit hard to imagine that happening if they cant make calls on it, don't you think?
To claim I'm overstating my quite logical claim doesn't make you look right, it makes you look biased.
Tetracycloide - Wednesday, November 2, 2011 - link
I labeled you a tool because your response to another commenter saying they experienced an issue you and 'your friends' never saw was 'your a liar' or more literally "For what it's worth, I don't believe you anyway." That's where you were a tool, that part right there.Your 'hundreds' comment was absurd and you know it. To obtusely pretend I'm actually asking you for a list of names and act like that's absurd (it was obviously rhetorical) is to miss the point which was: you do not actually have 200+ individual examples from 'friends' to draw from. That's absurd.
Your claim was hardly 'logical' it was an absurdly overblown statistic that, even if it was accurate, would still be anecdotal. As are you're 'millions of iPhone customers' by the way. The phone looses signal if held incorrectly. That is the objective reality, full stop.
doobydoo - Friday, December 2, 2011 - link
How ironic that your justification for calling me a tool, is that I essentially disbelieved someone else, after that's all your comments to me are based on.Not only that, but how ridiculous and illogical to say someone is a tool for not believing something. Grow up?
'Hundreds' is not absurd at all, perhaps it sounds absurd to a social recluse? But I can actually name at least 200 friends of mine who use iPhones. Sorry if having friends is a strange concept to you. How dare you claim that you 'do not believe' my 200+ friends claim - that makes you a tool (it's a definition handed down to me by someone special).
Even if my claim was anecdotal, so what? Your criticism of my claim wasn't that it was anecdotal, and I never masqueraded it as anything other than what it was?
The 'MILLIONS' of iPhone customers is not anecdotal at all, by the way - they HAVE factually given the iPhone 4 the best user ratings of any phone of all time. That's reality, fact, pure and simple. They wouldn't do this, if they couldn't make phone calls, don't you agree?
I own an iPhone 4, and it doesn't LOSE (wtf is 'looses') signal in any meaningful way (as in, it never affects call quality or causes calls to be dropped) if held in any way I want. Unbelievable that you make such claims then try to define them as 'objective' - exactly the criticism you levy at me.
gcor - Monday, October 31, 2011 - link
Reading the specs on a lead acid 12v battery I have, I discovered that the higher the load in amps, the lower the total amp hours the battery will output. For example, the spec's say that a particular model can deliver a max of 1 amp hour over 20 hours, but only .5 amp hour over 12 hours.I'm guessing this is also true for the batteries in smartphones and laptops. This assumption seems to be supported when looking at the 3D gaming battery life results in the review, where a 10% increase in power consumption on the 4S, resulted in a 25% drop in battery life.
I assume this has implications for the "race to sleep" concept, as an increase in amp draw by the device may reduce the battery efficiency enormously, as well as actually using more power.
Anyway, just a thought to add into the mix when estimating a % speed increase required for a pay off in additional sleep.
Pliablemoose - Monday, October 31, 2011 - link
Your recommendations mirror my own thoughts, picked up 3 iP4's in the last month, 2 ATT models to put on Straight Talk for $499/year each with unlimited talk text and data (yes, I know it's not really unlimited data) for my kids, and a Verizon iP4 for me. I actually replaced a ThunderBolt with an iP4, got tired of the poorly executed radio software and the constant reboots to keep it connected. The ThunderBolt is a heck of a 4G LTE modem, sort of a poor phone, and definitely a brick with the extended battery it needs get me through a day of web surfing and stock trading.Saving my upgrade next year for an iP5, and keeping my fingers crossed for at least a 4" screen.
ltcommanderdata - Monday, October 31, 2011 - link
"Furthermore Apple even seems to be ok with combining a process shrink with a new architecture as we saw with the iPhone 3GS. It's generally thought of as a risky practice to migrate to both a new process technology and a new architecture in the same generation, although if you can pull it off the benefits are wonderful."I don't believe Apple has actually pushed a new process and architecture simultaneously. Up to now, the iPod Touch was generally the test platform for new processes as a shrink on an existing architecture.
The full evolution is:
iPhone 2G/1st gen iPod Touch/iPhone 3G 412MHz ARM11 90nm
2nd gen iPod Touch 533MHz ARM 11 65nm
iPhone 3GS 600MHz Cortex A8 65nm
3rd gen iPod Touch 600MHz Cortex A8 45nm
iPad 1/iPhone 4/4th gen Touch 1GHz/800MHz Cortex A8 45nm
iPad 2/iPhone 4S 1Ghz/800MHz Cortex A9 45nm
It is curious that we haven't seen a shrink of an existing chip as a pilot for a next gen process, either Samsung 32nm or TSMC 28nm, although the iPod Touch not being updated this year didn't leave many options. It would no doubt be too risky to put a new process pilot chip on the iPhone 4S. I believe iFixit did find some different markings on the 2011 iPod Touch, but I haven't heard about any size difference so that makes a large shrink unlikely. Is there any chance the 2011 iPod Touch could be piloting the A4 on a TSMC 40nm process as a means of getting that relationship off the ground? Is there enough commonality in the tools for the 40nm and 28nm processes to make piloting on 40nm a worthwhile interim step?