https://www.reuters.com/article/us-oneplus-strategy/chinas-oneplus-backed-by-qualcomm-and-t-mobile-launches-smartphone-in-u-s-idUSKCN1N3125 >A five-year old Chinese smartphone company whose high-end products are little known outside a tech-savvy niche is entering the U.S. market on Monday with the backing of two key local allies: chipmaking giant Qualcomm and mobile operator T-Mobile.