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In the first half of our iPhone 4 review, we gave a brief historical overview of the iPhone platform since its introduction to the smartphone market in summer 2007, including its booming impact on the global smartphone market over the past three years. We discussed Apple’s design philosophy behind the physical dimensions and aesthetics of the iPhone 4, and we examined the truth behind the much hyped Retina Display. In this half of the review, we will take a look at the real story of the controversy behind the ill-fated antenna design, internal hardware specifications and upgrades from the iPhone 3GS, the improved backside CMOS camera sensor with LED flash and new front-facing VGA camera, battery life with iOS 4 and multitasking, FaceTime chat, and overall market acceptance since launch day.
Antenna design and controversial reception issue Unlike the previous three iPhone generations, the iPhone 4 sports a new antenna design that is meant to improve reception and overall call quality. The antenna is a split stainless steel band that runs around the edge of the phone. The shorter, left strip is used for WiFi, Bluetooth and GPS and the longer, right strip is connected to the UMTS/GSM cellular radio for voice and data. In perspective, the design can be viewed as a return to some of the earliest phone designs from the 90s that featured external antenna poles and could be manually raised for improving reception. During Apple’s WWDC 2010 keynote, Steve Jobs exclusively noted that this was “some brilliant engineering, [where Apple uses] the stainless steel band as part of the antenna system." Now, if the CEO of the company himself is telling his flock of prospective iPhone 4 consumers to “expect brilliance,” we would sure hope that his words resonated a positive marketing image for the new device when launch day came around. Unfortunately, numerous users have discovered that holding the phone in a certain way (noticeably when grasping it in the left hand) appears to degrade signal, and ultimately drops calls and data throughput speeds.Since the issue has become known, many iPhone 4 users have been carefully monitoring their AT&T 3G HSPA reception. In our personal tests with three different iPhone 4’s, we have found that covering the antenna gap on the lower-left of the device does not seem to affect call quality or cause any dropped calls on two of the phones. On the third phone, however, calls are typically dropped with a stronger than normal palm grip over the antenna gap, even in environments where all 5 bars were displayed before the device was gripped.AnandTech’s Brian Klug recently conducted a lengthy scientific analysis of the scenario, where he highlighted the potential for both unintended attenuation and detuning being much greater with an external antenna design than with a conventional internal design. Upon acquiring his iPhone 4, the first thing he attempted was to try and run the hidden Field Test application via the widely documented *3001#12345#* dialer code (it’s a nifty utility, give it a try). Unfortunately, Field Test is completely absent on the iPhone 4’s filesystem applications directory and only works on original iPhone, iPhone 3G and iPhone 3GS devices that have not been updated to run iOS 4 (or higher).
The Wall Street Journal recently ran a report to examine the math behind the number of signal bars displayed on cellphones. Author Carl Bialik explains that some handsets’ formulas can be approximated by using the field test mode, which allows users to see true signal strength numbers on some handsets. But when AnandTech and iPhoneroot.com ran their tests they found that a relative narrow range of power corresponded to the range from one bar to four bars, thus wavering signal strength greatly without an accurate reporting based on environmental conditions.Coming back to AnandTech, Brian Klug explains that iOS reports the quality metric of perceived iPhone signal bars with a compressed, optimistic dynamic range. In perspective, he notes that the best reported signal possible for an AT&T UMTS 3G tower is -51dBm and nothing lower than that number. In Apple’s iOS 4.0, a signal with 4 bars begins at around -99 to -101dBm, a signal with 3 bars sits around -103dBm, a signal with 2 bars sits around -107dBm and a signal with 1 bar extends down to -113dBm. (Update: Signal bar metering has been adjusted with the release of iOS 4.0.1) In other words, -113dBm is the worst possible signal possible before the phone is disconnected from the network entirely. Brian also explains that he happens to live directly across the street from an AT&T UMTS tower and has exceptionally strong signal throughout his house, in most cases around -51dBm and definitely about -65dBm in every room. However, when he squeezes the phone with his left hand and bridges the antenna gap, the result is a 24dB drop in signal degradation, but the iPhone 4 still managed to display the signal at 5 bars. In other words, there is an inherent flaw in the way iOS 4 is reporting signal strength and it is leaving many analysts and pundits in outcry to demand a recall.
Antenna design and controversial reception issue Unlike the previous three iPhone generations, the iPhone 4 sports a new antenna design that is meant to improve reception and overall call quality. The antenna is a split stainless steel band that runs around the edge of the phone. The shorter, left strip is used for WiFi, Bluetooth and GPS and the longer, right strip is connected to the UMTS/GSM cellular radio for voice and data. In perspective, the design can be viewed as a return to some of the earliest phone designs from the 90s that featured external antenna poles and could be manually raised for improving reception. During Apple’s WWDC 2010 keynote, Steve Jobs exclusively noted that this was “some brilliant engineering, [where Apple uses] the stainless steel band as part of the antenna system." Now, if the CEO of the company himself is telling his flock of prospective iPhone 4 consumers to “expect brilliance,” we would sure hope that his words resonated a positive marketing image for the new device when launch day came around. Unfortunately, numerous users have discovered that holding the phone in a certain way (noticeably when grasping it in the left hand) appears to degrade signal, and ultimately drops calls and data throughput speeds.Since the issue has become known, many iPhone 4 users have been carefully monitoring their AT&T 3G HSPA reception. In our personal tests with three different iPhone 4’s, we have found that covering the antenna gap on the lower-left of the device does not seem to affect call quality or cause any dropped calls on two of the phones. On the third phone, however, calls are typically dropped with a stronger than normal palm grip over the antenna gap, even in environments where all 5 bars were displayed before the device was gripped.AnandTech’s Brian Klug recently conducted a lengthy scientific analysis of the scenario, where he highlighted the potential for both unintended attenuation and detuning being much greater with an external antenna design than with a conventional internal design. Upon acquiring his iPhone 4, the first thing he attempted was to try and run the hidden Field Test application via the widely documented *3001#12345#* dialer code (it’s a nifty utility, give it a try). Unfortunately, Field Test is completely absent on the iPhone 4’s filesystem applications directory and only works on original iPhone, iPhone 3G and iPhone 3GS devices that have not been updated to run iOS 4 (or higher).
The Wall Street Journal recently ran a report to examine the math behind the number of signal bars displayed on cellphones. Author Carl Bialik explains that some handsets’ formulas can be approximated by using the field test mode, which allows users to see true signal strength numbers on some handsets. But when AnandTech and iPhoneroot.com ran their tests they found that a relative narrow range of power corresponded to the range from one bar to four bars, thus wavering signal strength greatly without an accurate reporting based on environmental conditions.Coming back to AnandTech, Brian Klug explains that iOS reports the quality metric of perceived iPhone signal bars with a compressed, optimistic dynamic range. In perspective, he notes that the best reported signal possible for an AT&T UMTS 3G tower is -51dBm and nothing lower than that number. In Apple’s iOS 4.0, a signal with 4 bars begins at around -99 to -101dBm, a signal with 3 bars sits around -103dBm, a signal with 2 bars sits around -107dBm and a signal with 1 bar extends down to -113dBm. (Update: Signal bar metering has been adjusted with the release of iOS 4.0.1) In other words, -113dBm is the worst possible signal possible before the phone is disconnected from the network entirely. Brian also explains that he happens to live directly across the street from an AT&T UMTS tower and has exceptionally strong signal throughout his house, in most cases around -51dBm and definitely about -65dBm in every room. However, when he squeezes the phone with his left hand and bridges the antenna gap, the result is a 24dB drop in signal degradation, but the iPhone 4 still managed to display the signal at 5 bars. In other words, there is an inherent flaw in the way iOS 4 is reporting signal strength and it is leaving many analysts and pundits in outcry to demand a recall.
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