Richard Gaywood - PhD in wireless network planning from Cardiff University - has tested the iPhone 4 communications problem. Before he thought there were no problems. Now his conclusion is clear: "The iPhone 4 is a fantastic device but a lousy phone."
Gaywood performed various tests that analysed the network throughput of the device. Basically how fast the iPhone 4 could transfer data measured in megabits per second under different conditions:
• Flat on hand
• Covered grip (using a piece of cloth between the hand and the phone).
• Care grip
He first tested the iPhone 4 in a weak signal area, then in an area with a very strong signal, in direct line of sight with a cell tower.
The resulting data was clear under both situations: there is a performance penalty when you hold your iPhone with your bare hand, independently of the bars displayed. When the signal is very strong, the impact is less noticeable. When the signal is weaker (chart above), the problem could stop communications altogether, like has been demonstrated already for both internet access and voice calls.
Test under strong signal conditions
Gaywood argues that Apple's explanations and solutions are conflicting, and that everyone should be affected by the signal problem:
If you're in a strong signal area, you may not ever see the effect, because even with the attenuation from holding the phone you'll still have plenty of signal left over. But that doesn't mean you aren't going to be affected by the issue unless you are never, ever in a weaker signal area—and the second test above suggests that 3G data transfer rates are still going to be slower anyway.
He also claims that, from his experience, it doesn't feel like a software fault to him. He says that he is waiting for a formal response from Apple, thinking that "there's some deeper problem here". For now, however, Apple keeps denying the problem: While talking to iPhone 4 users, Apple Care support has orders to deny the problem, arguing that all mobile phones experience this problem. While this is technically true, as the empirical evidence from Gaywood and thousands of users shows, it affects the iPhone 4 much more than any other device. The obvious reason that Gaywood points out in his article: The user is, at all times, in contact with the antenna through metal.
Anandtech performed some signal attenuation tests as part of their in-depth analysis of the phone. This shows the differences between the iPhone 4, the iPhone 3GS and the HTC Nexus One:
They also weighed in the whole antenna issue:
The main downside to the iPhone 4 is the obvious lapse in Apple's engineering judgment. The fact that Apple didn't have the foresight to coat the stainless steel antenna band with even a fraction of an ounce worth of non-conductive material either tells us that Apple doesn't care or that it simply doesn't test thoroughly enough. The latter is a message we've seen a few times before with OS X issues, the iPhone 4 simply reinforces it. At the bare minimum Apple should give away its bumper case with every iPhone 4 sold. The best scenario is for Apple to coat the antenna and replace all existing phones with a revised model.The ideal situation is very costly for Apple but it is the right thing to do. Plus it's not like Apple doesn't have the resources to take care of its customers.
Both Anandtech and Gaywood argue that Apple's response to this situation is not good. Their expert testing shows what thousands of you have already denounced. The tests results show that the iPhone 4 suffers from a design problem that affects the core functionality of the phone: make calls and receive data.