  In this work, we study how to design uplink transmission with massive machine
type devices in tactile internet, where ultra-short delay and ultra-high
reliability are required. To characterize the transmission reliability
constraint, we employ a two-state transmission model based on the achievable
rate with finite blocklength channel codes. If the channel gain exceeds a
threshold, a short packet can be transmitted with a small error probability;
otherwise there is a packet loss. To exploit frequency diversity, we assign
multiple subchannels to each active device, from which the device selects a
subchannel with channel gain exceeding the threshold for transmission. To show
the total bandwidth required to ensure the reliability, we optimize the number
of subchannels and bandwidth of each subchannel and the threshold for each
device to minimize the total bandwidth of the system with a given number of
antennas at the base station. Numerical results show that with 1000 devices in
one cell, the required bandwidth of the optimized policy is acceptable even for
prevalent cellular systems. Furthermore, we show that by increasing antennas at
the BS, frequency diversity becomes unnecessary, and the required bandwidth is
reduced.
