Should you’ve been an Apple consumer for a very long time, you most likely keep in mind Antennagate – the drama surrounding mobile reception on the iPhone 4. As many customers complained in regards to the sign dropping significantly relying on how they held the telephone, Apple launched the iOS 4.0.1 replace to deal with a part of this situation.
Years later, designer and engineer Sam Henri Gold reverse-engineered the iOS 4.0.1 code to seek out out precisely what Apple did to alter customers’ notion of the iPhone 4’s antennagate downside. Spoiler alert: your entire patch required solely a 20-byte replace.
Remembering Antennagate
For these unfamiliar with the state of affairs, the iPhone 4 got here with a drastic redesign in comparison with the 3s. As a substitute of a plastic unibody again, the iPhone 4 was made nearly completely of glass with a metal body that additionally functioned as wi-fi antennas for Wi-Fi and mobile.
Shortly after the telephone hit shops, many shoppers observed that the mobile sign dropped if the iPhone was held firmly. It didn’t take lengthy earlier than the time period Antennagate caught on and unfold like wildfire on social media. At one level, Steve Jobs was so fed up with the discourse, he responded to a question from Ars Technica with a curt instruction: “Simply keep away from holding it in that means.”
The iPhone 4’s Antennagate scandal concerned the sign energy of the mobile connection.
Foundry
A couple of weeks after the launch of the iPhone 4, Apple printed a letter to the press discussing the difficulty in additional element. On the time, the corporate blamed the formulation used to calculate what number of sign bars iOS exhibits to symbolize the energy of the sign the telephone was receiving.
“Customers observing a drop of a number of bars once they grip their iPhone in a sure means are most certainly in an space with very weak sign energy, however they don’t understand it as a result of we’re erroneously displaying 4 or 5 bars. Their huge drop in bars is as a result of their excessive bars have been by no means actual within the first place,” Apple wrote.
The corporate additionally mentioned within the letter that it will undertake a brand new formulation advisable by AT&T to calculate sign energy extra precisely. The brand new formulation was launched as a part of iOS 4.0.1.
How iOS 4.0.1 recalibrated sign energy
Regardless of the letter and replace, Apple by no means detailed precisely what modified on this formulation. However now, because of Gold, we all know precisely what Apple did on the time – and surprisingly, the event group solely needed to change a couple of traces of code.
As Gold exhibits in a put up on X, the unique formulation used to calculate and symbolize sign energy in bars resulted in 4 or 5 bars of sign for many conditions. This led customers to imagine they’d nice sign reception once they didn’t.
When the sign was actually weak, the variety of bars proven on iOS would out of the blue drop to 2 or only one. This naturally occurred when customers have been holding the telephone of their palms, which led folks to imagine that there was some form of malfunction with the telephone.
With the up to date formulation, the drop from every bar was a lot smoother and extra correct, in order that customers would not assume they’d glorious sign reception once they truly didn’t. And as such, the drop-off in sign when held a sure means wasn’t almost as drastic.
iOS 4.0.1 adjusted the sign energy formulation for accuracy.
Foundry
You may see a comparability of the 2 formulation within the chart above, with purple representing the bars in iOS 4.0 and blue in iOS 4.0.1 with the brand new formulation. The nearer to zero dBm, the higher the sign.
With iOS 4.0.1, Apple additionally modified the peak of the sign bars proven within the iOS standing bar, a small contact that most likely helped scale back alarmism about weaker sign reception on the iPhone.
Apple’s path to a {hardware} repair
Even so, Steve Jobs needed to make sure that most iPhone 4 shoppers have been pleased with the product, not simply the repair. A couple of days after publishing the letter, Apple held a small press convention during which it shared extra particulars about how the corporate carried out laboratory exams on the iPhone 4 antenna.
To assist scale back rigidity, Apple supplied all iPhone 4 patrons with a free bumper, which prevented customers from instantly holding the telephone close to the antennas and blocking the mobile sign. Apple lately introduced again its bumper case for the iPhone Air, however this time it’s for defense and aesthetics.
A 12 months later with the launch of the iPhone 4s a 12 months later, Apple repositioned the antennas on the chrome steel body, placing an finish to the antennagate downside, which recommended the design was precise an issue. However for hundreds of thousands of iPhone 4 customers, a small little bit of code made all of the distinction.
