Alberto Gallegos Ramonet

The IEEE 802.15.6 standard defines wireless body area networks (WBANs) for communication in, on, and around the human body. However, commercially available hardware platforms that support direct experimental validation of IEEE 802.15.6-oriented WBAN studies remain limited. As a result, much WBAN research still relies on simulations or custom-built transceivers, leaving the practical validity of simulation results uncertain. In this study, we evaluated a configurable radio platform for GMSK-based narrowband WBAN PHY validation in the 420–450 MHz band by comparing theoretical calculations, ns-3 simulation results, and hardware measurements. Evaluations covered both on-body and off-body scenarios at transmit powers from −15 to −25 dBm. Our key findings are as follows: (1) lower transmit power consistently decreases the communication range in both simulated and hardware environments; (2) degradation trends in packet success rate are similar for both environments, supporting simulation credibility; and (3) in the off-body scenario, ns-3 simulations overestimate the communication range by approximately 10 m compared to hardware under identical conditions. The publicly available simulation framework facilitates reproducible WBAN research. Our results confirm that our ns-3 implementation can be used effectively to approximate key GMSK-based WBAN PHY behaviors in realistic conditions while identifying specific differences in range estimates.

In recent years, the application of Internet of Things (IoT) technologies has advanced in agriculture, forestry, and fisheries. In this paper, we focus on the hatchery phase of oyster farming and consider a wireless multi-hop network to realize a system that monitors water quality and ambient temperature/humidity in real time using sensors. We design a fully waterproof, integrated device that combines a water quality sensor with a wireless communication module, enabling direct submersion in water for flexible and practical use. However, since radio signals significantly attenuate underwater, we first conduct preliminary experiments using actual hardware to evaluate the affect quantitatively. We then propose to introduce a cylindrical container as a waveguide to improve communication range. Finally, we prototype a wireless multi-hop network and confirm its feasibility.

Energy consumption measurements are crucial for the design of modern computer network devices. They are particularly essential in devices employing batteries as their single source of energy such as those found in wireless sensor networks (WSNs). In this paper, we propose an extension to the capabilities of the energy module of the ns-3 network simulator. The addition of 3 novel battery chemistries is proposed. Moreover, enhancements to reduce the necessary setup time via the introduction of battery presets and the possibility of configuring cell packs are proposed. The proposed model extension was validated via appropriate evaluations, and the results were nearly identical to the battery-discharge curves provided in manufacturer datasheets. The proposed enhancements may enable the identification of the operation limits of communication devices in various environments and thus aid improvements in the energy performance of communication protocols, applications, sensors, and electric vehicles.

The IEEE 802.15.4 is a popular standard used in wireless sensor networks (WSNs) and the Internet of Things (IoT) applications. In these networks, devices are organized into groups formally known as personal area networks (PAN) which require a bootstrap procedure to become operational. Bootstrap plays a key role in the initialization and maintenance of these networks. For this reason, this work presents our implementation and performance analysis for the ns-3 network simulator. Specifically, this bootstrap implementation includes the support of three types of scanning mechanisms (energy scan, passive scan, and active scan) and the complete classic association mechanism described by the standard. Both of these mechanisms can be used independently by higher layers protocols to support network initialization, network joining, and maintenance tasks. Performance evaluation is conducted in total network association time and packet overhead terms. Our source code is documented and publicly available in the latest ns-3 official release.

In vehicle ad hoc networks (VANETs) in urban environments, the presence of many obstacles causes shadowing and interference with radio wave propagation. Despite this, most of the existing opportunistic routing protocols do not consider shadowing in their simulations. In this study, we propose a new opportunistic routing protocol that minimizes the effect of shadowing by actively selecting street intersection nodes as relay nodes. Additionally, we propose a new opportunistic recovery strategy when the local optimum situation occurs. Simulation results show that the proposed scheme improves the packet delivery ratio and overhead.

Mobile ad-hoc networks (MANETs) have limited network resources, such as node battery capacity and wireless frequency band. Therefore, in such networks, it is particularly important to reduce unnecessary packet transfers and to maximize the use of network resources and power, to ensure efficient broadcast communications. Network coding (NC) is a technique that reduces the number of transmitted packets over a network and enables the efficient use of devices and network resources. The packet-reduction benefits obtained using NC depend considerably on the network topology. In this study, we propose an NC method specifically designed for MANETs. In our approach, the nodes switch the type of transmission between an uncoded transmission (simple broadcast) and a coded transmission (NC) based on the estimated neighboring node's proximity. We evaluated the effectiveness of the proposed method using computer simulations. Our evaluations demonstrate that the proposed method can reduce the number of packets in the network without decreasing the packet delivery rate.