The official dates of MWC 2015 will be from March 2 to 5 at Barcelona, Spain but they will have a special date this March 1 3 pm Barcelona time (that's 10pm at the same date here).
Various international tech sites have some rumors that a Huawei P8 or probably the succcessor of Ascend Mate 7. I hope that the global brand will provide a livestream (it's best if via Youtube) for the viewing public.