A feature of Apple Inc.'s new iPads could become a thorn in the side for wireless carriers, Barclays Capital telecom analyst Phillip Huang said Monday. The iPad Air 2, released last week, has a software-based SIM card, or soft-SIM, that allows users to switch between multiple carriers directly through the device as well as use different carriers when travelling without incurring roaming charges. Huang said in a research note Monday that the soft-SIM eliminates the need for the carrier-provided SIM card that "operators use to control service access." Huang noted only three U.S. operators, AT&T, T-Mobile US Inc. and Sprint Corp., and one in the U.K., EE Ltd., have so far made their services available through the new iPad's soft-SIM. "Given the wide range...