Two new iPhone identifiers discovered by ad tracking service, rumored 'iPhone 6C' model in doubt

The firm reported seeing about 150 iPhones carrying identifiers not currently in public circulation, 87 labeled "iphone8,1" and 67 tagged "iphone8,2." For reference, Apple's current iPhone 6 and 6 Plus models are designated "iphone7,2" and "iphone7,1," respectively.

The "iphone8,1" and "iphone8,2" identifiers are thought to be associated with next-gen "iPhone 6s" and "iPhone 6s Plus" hardware, though finalized naming conventions have yet to be announced. Perhaps most apparent in today's data is the absence of a third identifier for a much-rumored "iPhone 6C," which would theoretically carry an "iphone7,3" or "iphone7,4" designation due to its basis on current-generation hardware.

Rumors and speculation have suggested Apple plans to release of three new iPhone models for 2015, with the "6C" potentially marking a return to the 4-inch form factor. Earlier today noted cellphone leaker Evan Blass said he heard Apple was looking to announce all three devices this year, most likely at a special event next month.

Apple's supposed next-gen iPhone test base accounts for only a small fraction of total device impressions that number "in the millions," but Fiksu was able to determine that an overwhelming number of devices connected to data networks within the U.S., with a handful of hits originating in Germany and Brazil.

Apple is expected to unveil its latest smartphone lineup in the coming weeks as part of its annual product refresh cycle. A report last week pegged the date as Sept. 9, adding that an anticipated Apple TV revamp might also make the bill.