Abstract:
Ultra-reliable low-latency communication (URLLC),
one of the key component of 5G, provides a set of features
required to support mission-critical applications. Slotted ALOHA
is one of the most popular mechanism to share a channel among
multiple users. However, slotted ALOHA cannot meet high reliability requirements of URLLC when large number of users are
present in the network. In this paper, we propose a preferential
medium access control scheme to match the high reliability
requirement of URLLC. It is ensured by dedicating every Kth slot exclusively for URLLC transmission. We analytically
obtain the packet delay distribution and reliability of both the
URLLC and regular packets. An optimization problem is framed
to maximize the reliability of regular packets subject to meeting
the URLLC reliability constraints. Extensive simulations indicate
that our proposed K-preferential S-ALOHA protocol can meet
the URLLC requirements even when the network traffic is high.
