iPhone 3G: UMTS connection problems
Complaints about the iPhone 3G are mounting in online communities as well as in Apple's support forums. According to reports from the USA, Canada, and Japan, among other countries, some iPhones don't keep their connection to the UMTS network and even when connected, are achieving lower rates of throughput than expected from UMTS devices. Other UMTS mobiles operated at the same time and place as the iPhone can apparently maintain a healthy connection, while the problem iPhones don't even display one bar in signal strength. But the problem isn't easy to reproduce.
Apple has not mentioned the problems so far and specialists are divided about the cause. Network operators, initially blamed by users for the malfunction, are passing the buck to Apple. They say the problem is not due to the UMTS networks, but to the iPhone 3G itself. Richard Windsor, an analyst at Nomura Securities, suspects an immature UMTS module or protocol stack. The UMTS chips in the iPhone are supplied by Infineon. Ny Teknik, a Swedish publication, cites another cause, alleging that some specimens have insufficient input sensitivity, failing to comply with the 3G specification, and that the problem sometimes occurs because of defects in mass production. The most likely source, they say, is incorrect or inadequate fine tuning between the antenna and the amplifier.
Mark Siegel, spokesman for AT&T, the mobile network operator, has told US media that there is general satisfaction with the iPhone, and that AT&T has not received a significant number of fault reports. Vodafone Australia, on the other hand, admits there are problems. Jessica Forrest, spokeswoman for the company, has told Australian media that the defects are "device-specific and have nothing to do with the mobile network ... We are aware of the problems with the iPhone 3G and we are working with Apple on a solution".