1 research outputs found
Uncoordinated Grant-Free Radio Access via Diversity for Critical and Non-Critical IoT Services
Communication services with heterogeneous performance requirements are
emerging as key use cases for 5G and beyond. This paper deals with the
coexistence of two service classes, i.e., critical service (CS) and
non-critical service (NCS) on a grant-free channel consisting of the radio
access and backhaul segments. On the radio access segment, Internet-of-Things
(IoT) devices send packets to a set of non-cooperative access points (APs)
using slotted ALOHA (SA). The APs then forward correctly received messages to a
base station over a shared wireless backhaul segment adopting SA. The APs hence
play the role of low-complexity relays that improve space diversity and reduce
performance losses caused by interference on the access segment. We study first
a simplified erasure channel model, which is well suited for non-terrestrial
applications. Then, in order to account for terrestrial scenarios, the impact
of fading is considered. Throughput and packet success rate metrics are
derived, and numerical results are provided to assess the performance
trade-offs between CS and NCS. Among the main conclusions, we show that
orthogonal inter-service resource allocation is generally preferred for NCS
devices, while non-orthogonal protocols can improve the throughput and packet
success rate of CS devices for both terrestrial and non-terrestrial scenarios.Comment: arXiv admin note: text overlap with arXiv:1909.1028