updated 04:38 pm EDT, Wed June 5, 2013
Company looking to keep speeds relatively even between carriers?
Apple and the iPhone's major US carriers are imposing artificial caps on the cellular speeds of the iPhone and iPad, claims Joseph Brown, a developer of hacked carrier updates. Brown notes that by scrapping a line of Apple code in his AT&T update, iPhone 5 and fourth-generation iPad speeds saw "significant and noticeable results." AT&T iPhones are reportedly limited to 14.4Mbps HSDPA, despite the iPhone 5 being capable of 42.2Mbps DC-HSDPA+, and AT&T's 3G network supporting speeds up to 21.1Mbps. The carrier also reportedly limits LTE.
Throttling is said to be taking place on Verizon and Sprint as well, but not T-Mobile; Sprint's throttling happens only with 3G. Brown adds however that Apple has set band preferences for AT&T and T-Mobile that are causing signal issues, yet could easily be solved. The issues are allegedly being investigated by the companies, which could mean that they'll be fixed in a future iOS update.
It's speculated that Apple is restricting bandwidth in order to help carriers cope with the large amounts of data iOS users consume, without the carriers having to improve their infrastructure. Following the launch of the iPhone 3G, many people reported severe congestion on AT&T's network. The carrier has since resolved most serious complaints, but can still find itself overburdened whenever a city hosts a major event, such as SXSW in Austin.