Probability Of Successful Packet Delivery Research Articles

A Link-Layer Synchronization and Medium Access Control Protocol for Terahertz-Band Communication Networks

In this paper, a link-layer synchronization and medium access control (MAC) protocol for very-high-speed wireless communication networks in the Terahertz (THz) band is presented. The protocol relies on a receiver-initiated handshake to guarantee synchronization between transmitter and receiver. Two scenarios are considered, namely, a macroscale scenario, where nodes utilize rotating directional antennas to periodically sweep the space while overcoming the distance problem at THz frequencies, and a nanoscale scenario, where nano-devices require energy harvesting systems to operate. Both scenarios are implemented on a centralized and an ad-hoc network architecture. A carrier-based physical layer is considered for the macro-scenario, whereas the physical layer for the nano-scenario is based on a femtosecond-long pulse-based modulation scheme with packet interleaving. The performance of the proposed MAC protocol is analytically investigated in terms of delay, throughput and probability of successful packet delivery, and compared to that of an adapted Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) with and without handshake. The results are validated by means of extensive simulations with ns-3, in which all the necessary THz elements have been implemented. The results show that the proposed protocol can maximize the successful packet delivery probability without compromising the achievable throughput in THz-band communication networks.

ECP: A Probing-Based Error Control Strategy for THz-Based Nanonetworks With Energy Harvesting

Nanonetworks are comprised of the nano-sized communication devices that can perform simple tasks, such as computation, data storage, and actuation at the nanoscale. However, the error-prone wireless links as a result of severe path loss in the terahertz band (0.1–10.0 THz) and very limited energy storage capacity in nanodevices are challenging the communication in the nanonetworks. Therefore, efficient and effective error control protocols are necessary for the nanonetworks in the THz band. In this paper, first, a novel error control strategy with probing (ECP) mechanism for the nanonetworks powered by energy harvesting is proposed. In particular, each data packet will be transmitted only after the successful communication of one probing packet. Second, the energy state model by considering the energy harvesting-consumption process is presented based on the extended Markov chain approach. Moreover, a probabilistic analysis of the overall network traffic and multiuser interference is used by the proposed energy state model to capture the dynamic network behavior. Third, the impact of the different packets energy of consumption on a state transition and the state probability distribution of nanonodes based on the above-mentioned model is comprehensively investigated. Finally, the performance of the ECP mechanism and the other four different error control strategies, namely, Automatic Repeat reQuest (ARQ), Forward Error Correction (FEC), Error Prevention Codes (EPC) and a hybrid EPC, in terms of the end-to-end successful packet delivery probability, end-to-end packet delay, achievable throughput, and energy consumption are investigated and evaluated. The results show that the proposed ECP mechanism can maximize the end-to-end successful data packet delivery probability than the other four error control schemes, increase the achievable throughput compared with ARQ and EPC schemes, and outperform the ARQ and FEC schemes in terms of energy utilization.

Performance Evaluation of Joint Placement and Sleep Scheduling of Grid-Connected Solar Powered Road Side Units in Vehicular Networks

Ensuring ubiquitous connectivity in vehicular ad hoc networks (VANETs) has gained enormous importance in the research community. In this direction, placing a large number of road side units (RSUs) in the scenario has emerged as a solution. Although placing more RSUs leads to high coverage, it also leads to high deployment cost, operational cost, and total energy consumed. While optimal RSU placement helps to reduce cost, efficient sleep scheduling helps to reduce energy consumption at RSUs. In order to achieve both the benefits, for the first time, we propose joint placement and sleep scheduling of RSUs in a VANET environment. We perform a detailed analysis of the probability of successful packet delivery and expected vehicle-to-RSU delay for a packet by considering the presence of hidden terminals and retransmissions, and by modeling the buffer of a vehicle as an M/M/1 queue. We also formulate an optimization problem which captures the behavior of a realistic scenario and propose an energy efficient candidate location selection algorithm to jointly perform placement and sleep scheduling of grid-connected solar powered RSUs. Our simulation results show that the proposed approach performs better than the uniform placement strategy with and without sleep scheduling of RSUs and exhaustive search without sleep scheduling of RSUs. Also, the results obtained are close to the best case—exhaustive search with sleep scheduling of RSUs. Our analytical results are in good agreement with the simulation results.

AT-MAC: Adaptive MAC-Frame Payload Tuning for Reliable Communication in Wireless Body Area Networks

In wireless sensor networks, adaptive tuning of Medium Access Control (MAC) parameters is necessary in order to assure the QoS requirements. In this paper, we propose an adaptive MAC-frame payload tuning mechanism for wireless body area networks (WBANs) to maximize the probability of successful packet delivery or reliability of the associated sensor nodes based on real-time situation. The enabling algorithm, Adaptively Tuned MAC (AT-MAC), has been proposed to tune the MAC-frame payload of a WBAN sensor node, which is compliant with the IEEE 802.15.4 protocol. AT-MAC prioritizes sensor nodes based on the seriousness of the health parameters that are being measured by the respective sensor nodes. Further, we consider a Markov chain-based analytical approach that acknowledges the slotted CSMA/CA backoff mechanism with retry limits, as described in the IEEE 802.15.4 protocol. We derive expressions for reliability, power consumption, and throughput, which are the key metrics to evaluate the network performance of the proposed protocol, and analyze the impact of MAC parameters on them. Finally, results indicate that the low rate and low power IEEE 802.15.4 can be used effectively in case of WBANs if the payload is tuned properly through the proposed algorithm. The proposed AT-MAC algorithm yields around 70 percent increase in reliability of a critical node in a WBAN.

Joint Energy Harvesting and Communication Analysis for Perpetual Wireless Nanosensor Networks in the Terahertz Band

Wireless nanosensor networks (WNSNs) consist of nanosized communicating devices, which can detect and measure new types of events at the nanoscale. WNSNs are the enabling technology for unique applications such as intrabody drug delivery systems or surveillance networks for chemical attack prevention. One of the major bottlenecks in WNSNs is posed by the very limited energy that can be stored in a nanosensor mote in contrast to the energy that is required by the device to communicate. Recently, novel energy harvesting mechanisms have been proposed to replenish the energy stored in nanodevices. With these mechanisms, WNSNs can overcome their energy bottleneck and even have infinite lifetime (perpetual WNSNs), provided that the energy harvesting and consumption processes are jointly designed. In this paper, an energy model for self-powered nanosensor motes is developed, which successfully captures the correlation between the energy harvesting and the energy consumption processes. The energy harvesting process is realized by means of a piezoelectric nanogenerator, for which a new circuital model is developed that can accurately reproduce existing experimental data. The energy consumption process is due to the communication among nanosensor motes in the terahertz band (0.1-10 THz). The proposed energy model captures the dynamic network behavior by means of a probabilistic analysis of the total network traffic and the multiuser interference. A mathematical framework is developed to obtain the probability distribution of the nanosensor mote energy and to investigate the end-to-end successful packet delivery probability, the end-to-end packet delay, and the achievable throughput of WNSNs. Nanosensor motes have not been built yet and, thus, the development of an analytical energy model is a fundamental step toward the design of WNSNs architectures and protocols.

Reliability Analysis of One-Hop Safety-Critical Broadcast Services in VANETs

Reliability is an important issue for safety-critical broadcast services in vehicular ad hoc networks (VANETs). So far, most investigations of such broadcast networks focus on multihop connectivity, taking all one-hop links for granted. In this paper, four reliability metrics for one-hop broadcast communication in VANETs, including the packet reception rate (PRR), the packet delivery ratio (PDR), the node successful packet delivery probability (PDP), and the effective range (ER), are introduced and evaluated analytically and by simulations. Expressions of these reliability metrics for one-hop broadcast in IEEE-802.11-based 1-D VANETs are derived with consideration of the IEEE 802.11 distributed coordination function (DCF), the hidden terminal problem, and collisions caused by concurrent transmissions. The impacts of network parameters such as distinct transmission, carrier sensing, and interference ranges; the density of nodes in the networks; the distances of receivers to the senders; the message generation rates; the backoff window sizes; and the channel data rates on the reliability of the broadcast communication in VANETs are investigated and discussed. As an example, the proposed model is applied to the evaluation of the dedicated short-range communication (DSRC) safety-critical message propagation in a highway setting. As a result, some important observations to the design and analysis of such communication systems are provided.

Application-driven, energy-efficient communication in wireless sensor networks

Several sensor network applications based on data diffusion and data management can determine the communication transfer rate between two sensors beforehand. In this framework, we consider the problem of energy efficient communication among nodes of a wireless sensor network and propose an application-driven approach that minimizes radio activity intervals and prolongs network lifetime. On the basis of possible communication delays we estimate packet arrival intervals at any intermediate hop of a fixed-rate data path. We study a generic strategy of radio activity minimization wherein each node maintains the radio switched on just in the expected packet arrival intervals and guarantees low communication latency. We define a probabilistic model that allows the evaluation of the packet loss probability that results from the reduced radio activity. The model can be used to optimally choose the radio activity intervals that achieve a certain probability of successful packet delivery for a specific radio activity strategy. Relying on the probabilistic model we also define a cost model that estimates the energy consumption of the proposed strategies, under specific settings. We propose three specific strategies and numerically evaluate the associated costs. We finally validate our work with a simulation made with TOSSIM (the Berkeley motes’ simulator). The simulation results confirm the validity of the approach and the accuracy of the analytic models.