Jul 2026· Italian National Conference on Sensors· Vol 26, pp. 4718· 0 citations· 31 references
Medicine
TL;DR
This study provides an efficient joint optimization scheme for building high-capacity, wide-coverage, and long-lifespan complex Internet of Things (IoT) networks.
Abstract
To address the severe coverage blind spots and concurrent collision bottlenecks faced by LoRa networks in dense deployments and complex three-dimensional (3D) occlusion environments, this paper proposes a distributed cross-layer protocol framework for LoRa ad hoc networks supporting heterogeneous traffic. To break through the limitations of a single star architecture, this framework constructs a 3D penetration loss model at the physical layer and designs a distributed relay deployment algorithm based on hybrid simulated annealing, achieving blind-spot-free connectivity in complex spaces. At the MAC layer, a non-preemptive priority access mechanism based on symbol energy detection is introduced. Through differentiated backoff windows with time-domain isolation, it precisely guarantees the quality of service (QoS) requirements of heterogeneous traffic and significantly suppresses concurrent collisions. At the network layer, the CAM-AODV routing algorithm is proposed, which integrates hop count, link quality, MAC queue congestion, and nodal residual energy to achieve dynamic traffic diversion and network-wide energy balancing under bursty high loads. Simulation results demonstrate that this cross-layer framework effectively breaks the traditional network capacity bottlenecks. In a large-scale, high-density scenario with 300 nodes, CAM-AODV reduces the average end-to-end delay by 19.46% compared to the traditional AODV. Under high-concurrent loads, the packet delivery ratio (PDR) of the proposed framework improves by 16.32% over the traditional protocol, while the system delay is reduced by 13.66%. Furthermore, under the two aforementioned evaluation scenarios, the Energy Balancing Index (EBI) is significantly improved by 11.13% and 10.57%, respectively, compared to the traditional protocol. This study provides an efficient joint optimization scheme for building high-capacity, wide-coverage, and long-lifespan complex Internet of Things (IoT) networks.
To overcome the inherent compromises between proactive and reactive data transmission in Vehicular Ad-hoc Networks (VANETs), this research introduces a novel framework tailored for highly unstable vehicular topologies. The developed system, termed the Dynamic Hybrid Routing Protocol (DHRP), merges the Optimised Link State Routing (OLSR) and Ad-hoc On-Demand Distance Vector (AODV) algorithms. A core feature of this architecture is its cross-layer power management module, which dynamically recalibrates transmission strength and routing paths by analysing real-time vehicle clustering and speed metrics. Comprehensive evaluations conducted via NS-3 and SUMO indicate that the proposed DHRP significantly surpasses both contemporary benchmarks and standard baselines. Notably, the architecture achieves a Packet Delivery Ratio (PDR) exceeding 90%, limits communication latency to well below the critical 40 ms safety boundary, and slashes energy expenditure by up to 90%. By effectively solving the traditional routing dichotomy, DHRP offers a highly scalable and sustainable communication backbone vital for the reliable operation of future Intelligent Transportation Systems (ITS).
For military wireless communications, the MIL-STD-188-220 standard utilizes various Network Access Delay (NAD) mechanisms to efficiently allocate transmission slots within a shared medium. Among these, the random NAD (R-NAD) protocol is widely adopted for dynamic traffic environments. To evaluate the fundamental capacity and performance limits of single-hop ad hoc networks where all nodes operate within a direct radio range, a rigorous analysis under saturation conditions is essential. Despite its critical importance, a comprehensive theoretical framework that analyzes R-NAD performance under saturation and determines the maximum number of retransmissions required to guarantee specific packet delivery targets has been lacking. To address this issue, this paper provides a thorough performance analysis of the R-NAD protocol under saturation conditions, deriving key metrics such as transmission rate, loss probability, and average delay. Based on these analytical results, we propose a practical and simplified formula for determining the minimum value of the maximum retransmission count required to satisfy a specific target loss probability. Extensive simulations demonstrate that our theoretical derivations are exceptionally well-matched with simulation data. Furthermore, we show that selecting the precise maximum number of retransmissions that meets the target loss probability effectively prevents unnecessary average delay while strictly satisfying the network’s loss requirements, thereby providing a practical guideline for effective system configuration.
The proposed framework separates network control from forwarding, maintains a global view of vehicular network state, classifies V2X flows by service criticality, and dynamically selects routes and bandwidth allocations using delay, congestion, handover, and priority constraints.
Swadhin Singh, Swatantra Kumar, Mr. Rahul Kumar· International Journal of Adv...· 0 citations
Wireless Mesh Networks (WMNs) are a key enabling technology for dynamic, infrastructure-limited IoT environments. The routing protocol is the central design choice in any WMN deployment because throughput, end-to-end delay, energy consumption and delivery reliability are directly affected by it. A systematic, simulation-based evaluation of two widely studied WMN routing protocols is presented: the reactive Ad hoc On-Demand Distance Vector (AODV, RFC 3561) protocol and the proactive Destination-Sequenced Distance-Vector (DSDV) protocol. Simulations were conducted in OMNeT++ 6.3 with the INET 4.5 framework across five network densities $(N \in\{10,20,30,40,50\}$ nodes) in a $1000 ~\mathrm{m} \times 1000 ~\mathrm{m}$ IEEE 802.11g area with a many-to-one UDP traffic pattern representative of IoT data collection. A density-dependent crossover was revealed at approximately $N=20$: lower delay was achieved by DSDV in sparse networks, whereas higher throughput, higher delivery reliability and lower energy consumption were achieved by AODV at higher densities. At $N=50, \approx 35 \%$ higher throughput, zero routing failures and $\approx 8 \%$ lower energy consumption are delivered by AODV. It is indicated by the MAC-layer contention behavior that DSDV's high-density degradation is mainly driven by IEEE 802.11 channel saturation rather than by routing-algorithm deficiencies. Deployment guidelines derived from these findings are provided.
Alá F. Khalifeh, Abdulla Ababneh, Iacovos I. Ioannou· IEEE Jordan Conference on Ap...· 0 citations
LPWANs, especially LoRaWAN, are commonly employed in large IoT deployments. The Adaptive Data Rate (ADR) scheme enhances LoRaWAN by modifying SF and transmit power. But ADR usually depends only on the device-specific links and does not consider the effects of collisions or the capture effect at the network layer, making it less effective in dense scenarios. The present paper presents a CA-ADR technique to handle collisions in dense LoRaWAN deployments. In contrast to other ADR schemes, CA-ADR is an algorithm running at the network layer. Parameter selection is formulated as a multi-objective optimisation problem, which minimises cost based on multiple criteria, including collision probabilities and energy consumption. The collision evaluation also incorporates a capture-aware model based on signal-to-interference ratio thresholds, enabling a more realistic assessment of packet reception under overlapping transmissions. The proposed approach is evaluated using an NS-3 LoRaWAN simulation framework. First, Baseline, standard ADR, and default CA-ADR are compared for network sizes from 10 to 500 devices with a 300~s transmission period. Then, 144 CA-ADR weight configurations are explored in the dense 500-device scenario. Results show that CA-ADR provides controllable energy--reliability trade-offs. High-reliability configurations achieve more than 99\% Last 4 PDR with an average transmit power between 13.51 and 13.60~dBm over 10 independent random seeds
Amrane Said, Abdallah Zahidi, Noureddine Ennadi et al.· Engineering Research Express· 0 citations
Objective: This project focuses on simulating a Wireless Local Area Network (WLAN) using NS-2, specifically targeting a peer-to-peer (Ad-hoc) network. Method: By utilising an Independent Basic Service Set (IBSS), we enabled wireless devices to communicate directly with one another without relying on a central access point or base station. A network bridge was also integrated to connect the WLAN to external networks. Our approach began with a thorough examination of wireless simulation types and the key factors that influence network performance. From there, we mapped out a topology modelled after a university campus, strategically spacing out wireless nodes and adjusting their transmission power to ensure full coverage. To evaluate efficiency, we measured key performance metrics—including packet delivery ratio, delay, jitter, and throughput—and analysed how they scaled with traffic volume. Finally, we deployed and compared three routing protocols (AODV, DSR, and DSDV) to find the most efficient fit. Results: Ultimately, this allowed us to design a highly optimised, resource-efficient network layout that maximises performance without wasting bandwidth. Novelty: This project compares the performance of AODV, DSR, and DSDV routing protocols within an IBSS-based WLAN simulation to identify the most efficient protocol for a university campus network topology.
Maab Alaa· Journal for Technology and S...· 0 citations