  In this paper, a new queuing model for the Tactile Internet (TI) is proposed
for the cloud radio access network (C-RAN) architecture of the next generation
wireless networks, e.g., 5G, assisted via orthogonal frequency division
multiple access (OFDMA) technology. This model includes both the radio remote
head (RRH) and baseband processing unit (BBU) queuing delays and reliability
for each end to end (E2E) connection between each pair of tactile users. For
this setup, with the aim to minimize the transmit power of users subject to
guaranteeing tolerable delay of users, and fronthaul and access limitations, we
formulate a resource allocation problem. Since the proposed optimization
problem is highly non-convex, to solve it in an efficient manner, we utilize
diverse transformation techniques such as successive convex approximation (SCA)
and difference of two convex functions (DC). In addition, we propose an
admission control (AC) algorithm to make problem feasible. In our proposed
system model, we dynamically adjust the fronthaul and access links to minimize
the transmit power. Simulation results reveal that by dynamic adjustment of the
access and fronthaul delays, transmit power can be saved compared to the case
of fixed approach per each transmission session. Moreover, the number of
rejected users in the network is significantly reduced and more users are
accepted.
