View this article at: http://www.macnn.com/articles/08/08/28/true.source.of.3g.issues/
Thursday, Aug 28, 2008 10:50am
Source: 3G problems a mix of software, networking
Ongoing 3G connection problems with the iPhone are actually a mix of software and networking issues, a new account indicates. The report from Roughly Drafted cites "an inside source from AT&T," who explains that the trouble originates with how UMTS-based cellular networks function. All devices tapping into a UMTS node demand a certain amount of power, and once a certain threshold is reached, the node can run out of power to share. At this stage a node will begin dropping calls, and graphs are said to demonstrate this exact event coinciding with the release of the iPhone 3G.

Apple's fault in the situation stems from the iPhone 2.0 firmware, which until recently was demanding more downlink power than necessary, affecting the practical capacity of UMTS nodes. The v2.0.2 firmware is meant to fix this error, but is being hampered by the continuing use of v2.0 and v2.0.1, which can "drown out" v2.0.2 devices. The final remedy thus requires as many people as possible switching to v2.0.2, something that AT&T is allegedly encouraging by sending text messages to iPhone customers.

iPhone 3G woes have in the past been blamed on Infineon's 3G chipset, which was thought to have inherent hardware flaws. Subsequent testing, however, has shown this to be unlikely, and Apple itself has stated that the problem is exclusively software-based.