Ultra-Low Latency for 5G - A Lab Trial
  In this paper, we introduce a lab trial that is conducted to study the feasibility of ultra-low latency for 5G. Using a novel frame structure and signaling procedure, a stabilized 1.5 ms hybrid automatic repeat request (HARQ) round trip time (RTT) is observed in lab trial as predicted in theory. The achieved round trip time is around 5 times shorter compared with what is supported by LTE-Advanced standard. 
Peng Guan, Xi Zhang, Guangmei Ren, Tingjian Tian, Anass Benjebbour,   Yuya Saito, Yoshihisa Kishiyama
cs.NI