5,233 research outputs found
Distributed Backlog-Aware D2D Communication for Heterogeneous IIoT Applications
Delay and Age-of-Information (AoI) are two crucial performance metrics for
emerging time-sensitive applications in Industrial Internet of Things (IIoT).
In order to achieve optimal performance, studying the inherent interplay
between these two parameters in non-trivial task. In this work, we consider a
Device-to-Device (D2D)-based heterogeneous IIoT network that supports two types
of traffic flows, namely AoI-orientated. First, we introduce a distributed
backlog-aware random access protocol that allows the AoI-orientated nodes to
opportunistically access the channel based on the queue occupancy of the
delay-oriented node. Then, we develop an analytical framework to evaluate the
average delay and the average AoI, and formulate an optimization problem to
minimize the AoI under a given delay constraint. Finally, we provide numerical
results to demonstrate the impact of different network parameters on the
performance in terms of the average delay and the average AoI. We also give the
numerical solutions of the optimal parameters that minimize the AoI subject to
a delay constraint
Delay Performance and Mixing Times in Random-Access Networks
We explore the achievable delay performance in wireless random-access
networks. While relatively simple and inherently distributed in nature,
suitably designed queue-based random-access schemes provide the striking
capability to match the optimal throughput performance of centralized
scheduling mechanisms in a wide range of scenarios. The specific type of
activation rules for which throughput optimality has been established, may
however yield excessive queues and delays.
Motivated by that issue, we examine whether the poor delay performance is
inherent to the basic operation of these schemes, or caused by the specific
kind of activation rules. We derive delay lower bounds for queue-based
activation rules, which offer fundamental insight in the cause of the excessive
delays. For fixed activation rates we obtain lower bounds indicating that
delays and mixing times can grow dramatically with the load in certain
topologies as well
- …