Showing papers by "Arzad A. Kherani published in 2020"

End-to-End Delay Jitter in LTE Uplink: Simple Models, Empirical Validation & Applications

Abstract: We address the problem of achieving a target end-to-end per-packet delay jitter for an uplink packet traffic from a mobile device to a central server. We provide simple analytical models for predicting the delay jitter and their empirical validation. The structural dependency of the end-to-end per-packet delay jitter on various Constant Bit Rate (CBR) traffic parameters, namely, burst length and inter-burst time, are then utilized to develop a stochastic approximation algorithm to adapt these parameters to achieve a target end-to-end delay jitter. Initial understanding is simulation-based using Network Simulator (NS3). Further, our model is evaluated against the experimental results obtained on a reported real-world implementation.

A Modular Hybrid Simulator for LoRaWAN

Abstract: Low Power Wide Area Network (LPWAN) is considered as a prime choice for Internet of Things (IoT) connectivity as they provide low power data transmission over a wide range of communication. A simulation analysis gives an idea of how the deployed IoT network is going to behave and what kind of challenges it can face. A simulation-based study to assess the performance before deployment of IoT network is preferable.We have developed a discrete event, scalable, and open-source LoRaWAN network simulator, called Modular Hybrid Simulator for LoRaWAN. The script of the developed simulator is written in Python. The designed simulator consists of multiple modules for the required actions of LoRa communication. These modules are easy to understand and can be adapted to the application requirements. As the developed simulator deals with the IQ (in-phase and quadrature-phase) samples, it gives a better understanding of the LoRaWAN (MAC) and LoRa (PHY) interaction.

On limiting Delay and Jitter characteristics at application-layer of Multi-connected Systems

Abstract: This paper addresses the challenge of limiting the delay and jitter characteristics in a communication system under a multi-connectivity setup. We consider an end-to-end system where the traffic source is connected to the network via multiple wireless interfaces and the application is sensitive to the perceived delay and jitter. We consider both the delay and jitter characteristics for each individual link with a varying degree of channel condition and scheduling requirements. Several challenges are identified for the application responsible for splitting and aggregating the traffic. In this system there is no cellular network coordination for the interface association to different available cellular base stations. The paper provides simulation and empirical results along with analytical models for understanding the implications of jitter and delay parameters in multi-connectivity setup. The work proposes a method to select the received packets such that both delay and jitter are limited in order to improve the overall system performance.

Tracking Performance in LoRaWAN-Like Systems and Equivalence of a Class of Distributed Learning Algorithms

Abstract: Considering a low power wide area random access system (like LoRaWAN) where the individual transmitters are mobile, we 1) propose a way of quantifying the performance of tracking of the mobile devices, and 2) design a distributed algorithm to achieve a target tracking performance. The insights gained are then used to provide an analysis of a family of target-achieving reinforcement-learning algorithms used in the literature to learn the optimal (Nash Equilibrium) random access probabilities. By mapping the payoff function in the equivalent game to the performance metric, we establish that, under some general conditions of inter-node parameter separability, the algorithm convergence is independent of the payoff function used. The mapping from the desired performance metric to the success probability in random access can be used in the algorithm to achieve a target success probability.