Previous trials have used significantly higher frequency bands (e.g. 20-80GHz), which struggle with coverage and penetration through physical objects. By comparison Huawei's network operates in the sub-6GHz frequency band and made use of several new technologies, such as Multi-User MIMO (concurrent connectivity of 24 user devices in the macro-cell environment), Sparse Code Multiple Access (SCMA) and Filtered OFDM (F-OFDM).
Assuming all goes well then Huawei hopes to begin a proper pilot in 2018, with interoperability testing being completed during 2019 and then a commercial launch to follow in 2020. But of course they're not the only team trying to develop a 5G solution.