Apple's Signal Strength Display Changes in iOS 4.0.1 and 4.1 Detailed

Late last month, Anandtech detailed the signal strength drop-off experienced by iPhone 4 users when bridging the antenna gap at the lower left corner of the device, mapping how the "bars" of signal strength shown on the device correspond to actual signal levels and how holding the phone in various positions affected that signal under iOS 4.0.

160322 signal strength rescaling

Anandtech has now followed up with a test on Apple's iOS 4.1 beta released yesterday that includes changes to how the visual "bar" indicators correspond to actual signal strength. Anandtech has also confirmed that the changes in today's iOS 4.0.1 update have the same effect.

The results are conclusive - Apple has dramatically changed the signal strength to signal bar mapping in iOS 4.0.1 and the iOS 4.1 beta, making the dynamic range not only much broader, but the range values for each bar much wider. The range of signals that correspond to bars three and four are the same width, and bar two is only slightly less.

The cutoff value for two bars to one bar remains the same, but every other value has increased. The result is that the worst case drop of 24 dBm no longer makes all the signal bars disappear, but rather two.

Notably, Apple has adjusted the bar scale such that the lowest bar remains visible at a signal level down to -121 dBm, significantly lower than the -113 dBm limit in iOS 4.0. Anandtech's report claims that voice and data transmission on the iPhone 4 remained intact all the way down to -121 dBm, bolstering Apple's claims of increased overall sensitivity and reception with the iPhone 4's design.

The report claims that Apple's changes are doing away with a cover-up of AT&T's poor network coverage in many areas and will likely result in some confusion as customers see fewer number of bars than they are used to. The fact that Apple has also increased the heights of the lower bars alongside the change to the mapping of actual signal to bar display appears to be a ploy to somehow makes things appear better than they are, with the subtle, but baseless, suggestion that taller bars imply better signal.

The new signal strength visualization in iOS 4.0.1 is simply going to be more honest with iPhone users. Whether that's going to result in customers confused about why their phone performs "worse" after the update or simply get really mad at AT&T remains to be seen.

Regardless, many observers are expecting to hear more about Apple's response to the signal issue at the company's press conference scheduled for tomorrow. While the company's changes to the signal strength mapping and display may offer a more accurate representation of cellular coverage in a given location, it does not yet address the actual drop in signal seen with the iPhone 4's antenna design.

Related Forum: iPhone

Popular Stories

USB C Over Lightning Feature

EU Passes Law to Switch iPhone to USB-C by End of 2024

Tuesday October 4, 2022 3:30 am PDT by
The European Parliament today voted overwhelmingly in favor of enforcing USB-C as a common charging port across a wide range of consumer electronic devices, including the iPhone and AirPods, by the end of 2024. The proposal, known as a directive, forces all consumer electronics manufacturers who sell their products in Europe to ensure that a wide range of devices feature a USB-C port. This...
ipad pro purple

Five Apple Products You Should Avoid Buying Right Now

Wednesday October 5, 2022 2:12 pm PDT by
Rumors suggest that Apple still has several new devices that are coming before the end of the year, including a range of Macs and iPads. It's not looking like we're going to get an October event in 2022, but refreshes are coming soon, probably via press release. If you're planning to buy a Mac or an iPad, make sure to check out our list to know what's safe to pick up now and what's not. iPad ...
General iOS 16 Feature Yellow

10 New iOS 16 Features Coming Later This Year

Monday October 3, 2022 2:41 pm PDT by
iOS 16 was released to the public three weeks ago with a customizable Lock Screen, the ability to edit iMessages, improvements to Focus modes, and much more. And in the coming months, iPhone and iPad users have even more new features to look forward to. We've rounded up 10 new features coming to the iPhone and iPad later this year, according to Apple. Many of the features are part of iOS...
magsafe charger orange

Apple Releases New MagSafe Charger Firmware

Tuesday October 4, 2022 12:09 pm PDT by
Apple today released updated firmware for the MagSafe Charger that is designed to work with the iPhone 12 and later and the AirPods Pro 2. The new firmware is version 10M1821, up from the prior 10M229 firmware. Note that in the Settings app, you'll see a different version number than the firmware number, with the update displayed as version 255.0.0.0 (the prior firmware was 247.0.0.0). The...
maxresdefault

Video: AirPods Pro 2 vs. Bose QuietComfort II

Monday October 3, 2022 12:50 pm PDT by
Apple on September 23 officially launched the second-generation version of the AirPods Pro, introducing updated Active Noise Cancellation, Adaptive Transparency, improved sound, and more. Right around the same time, Bose introduced new QuietComfort II earbuds with many similar features, so we thought we'd compare the two to see which has the edge. Subscribe to the MacRumors YouTube channel for ...
General iOS 16 Feature Yellow

One of iOS 16's Best Features Drains Battery When Enabled

Thursday October 6, 2022 2:15 am PDT by
One of iOS 16's most praised features comes at the cost of draining battery life, according to recently published Apple support documents. The feature, known as "keyboard haptics," is optional in iOS 16 and allows users to get physical feedback via slight vibrations upon the touch of each key, confirming that it was pressed much like keyboard sounds. The feature is a useful addition to the...
aapl logo banner

No October Apple Event Expected Despite Upcoming Wave of New Devices

Wednesday October 5, 2022 2:33 am PDT by
Apple is no longer expected to host an event this month, despite plans to unveil a host of new devices including new iPad and Mac models, according to recent reports. In recent months, Apple has been expected to hold an event in October to announce a range of products that did not receive any stage time during the company's iPhone 14 unveiling event last month. In a recent newsletter, Bloombe...
iOS 16

Apple Preparing iOS 16.0.3 With More Bug Fixes Following iPhone 14 Launch

Monday October 3, 2022 7:53 am PDT by
iOS 16.0.2 was released last month with several bug fixes for iPhone 14 issues, excessive copy and paste permission prompts, and more. Now, evidence suggests that Apple is planning to release iOS 16.0.3 with additional bug fixes. Evidence of an upcoming iOS 16.0.3 software update has shown up in MacRumors analytics logs, which have been a reliable indicator in the past. There are several...
iOS 16

Apple Seeds New Betas of iOS 16.1 and iPadOS 16.1 to Developers [Update: Public Beta Available]

Tuesday October 4, 2022 10:06 am PDT by
Apple today seeded the fourth beta of iOS 16.1 to developers for testing purposes, with the beta coming one week after the release of the third iOS 16.1 beta. The iOS 16.1 beta is also joined by the fifth beta of iPadOS 16.1, which is on a slightly different schedule as Apple started testing it prior to the launch of iOS 16. Registered developers can download the iOS 16‌ and iPadOS 16...
dynamic island outline 1

iOS 16.1 Beta Adds More Pronounced Gray Border Around Dynamic Island When Using Black Wallpapers or in Dark Mode

Tuesday October 4, 2022 11:58 am PDT by
With the latest iOS 16.1 beta, Apple has tweaked the design of the Dynamic Island on the iPhone 14 Pro and Pro Max to make it more visible on a dark background. When using a darker wallpaper or with the darker interface of Dark Mode activated, there is a light gray border around the outside of the Dynamic Island when the screen is dimmed or when the Dynamic Island is in active use. The...