It’s easy to blame your–sometimes not favorite–carrier when Internet data speeds on your favorite iPhone smartphone is slow, but it appears that the culprit behind the throttling is Apple and not the carrier. Recently discovered code in the iOS operating system suggests that Apple is limiting the true speed potential of your iPhone when connected to a mobile broadband network.
The code was present for iPhone and iPad models on America’s three largest carriers, including AT&T Mobility, Sprint Nextel, and Verizon Wireless. The iPhone 5, which recently launched on T-Mobile USA this year, seems immune to this phenomenon as the system code to throttle was not present on the iPhone for the country’s fourth largest wireless carrier.
iTweekiOS writer Joseph Brown made the code discovery that limits data speeds when connected to 3G or 4G networks. Users who connect to WiFi won’t be affected as a result.
Throttling is a process by which a carrier or device manufacturer limits the speeds of Internet data access to a device or group of devices. This helps to thwart data hogs from congesting the network. Usually, if a user exceeds a certain amount of data per month, carriers may begin slowing down speeds for that user.
For AT&T, users on the carrier’s HSPA+ network, which is marketed as 4G, won’t get the full 21 Mbps advertised speeds of the network’s theoretical potential. Rather, they’re capped to a 14.4 Mbps network.
“For example, an AT&T iPhone 5 was limited to HSDPA “Category 10,” which tops out at 14.4Mbps,” Apple Insider reported. “The second-largest U.S. carrier’s network is capable of supporting up to HSDPA+ speeds that reach 21.1Mbps.”
CNET reports that Brown found code to restrict 4G LTE speeds on Verizon’s network on the iOS devices, though the carrier denies any culpability in the matter.
“We do not throttle,” Verizon representative Brenda Rainey [sic] told CNET. “For that, you would have to call Apple.”
Apple has so far not commented on the code and if this throttling would affect any meaningful performance when an iPhone is used as a speedtest device in comparison to an Android phone.