Gopinath Nithyanandam  Chinnasamy Ambayiram  Bhalaji Natarajan 《International Journal of Communication Systems》2024,37(4):e5680

Vehicular ad hoc networks (VANETs) are the ultimate solution for preventing road accidents, which result in the loss of precious human life worldwide. In this context, effective communication between the vehicular nodes is essential due to the varying network topology and high vehicular mobility inherent with VANETs. Cluster-based routing is identified to be a significant approach for achieving efficient routing and improving communication proficiency in VANETs. In this paper, a beetle colony optimization algorithm–based clustering scheme (BCOACS) is proposed for generating optimized clusters for facilitating reliable data dissemination. This BCOACS algorithm includes two vital strategies such as beetle antenna search (BAS) and swarm intelligence for attaining inter-cluster and intra-cluster communications. In specific, BAS strategy that includes random search attributed toward gradient direction is used for intra-cluster communication without using the complete amount of gradient information. On the other hand, a swarm intelligence strategy that encompasses a collective approach of self-organized and decentralized agents is used for inter-cluster communication with the view to minimize the load on each cluster head (CH) and to extend the clusters' lifetime. The simulation outcomes of the proposed BCOACS scheme confirmed improved performance in optimizing the number of constructed clusters independent of the increase in the network grid size, transmission range, and number of vehicular nodes in the network compared to the benchmarked approaches. The results also confirmed that the proposed BCOACS scheme achieved a maximized throughput of 13.42%, with reduced delay and protocol overhead of 18.96% and 19.45%, better than the benchmarked schemes used for investigation.  相似文献   

    

R. Ruhin Kouser  T. Manikandan 《International Journal of Communication Systems》2023,36(5):e5424

Various opportunities aimed at the employment of delay-sensitive applications in the vehicular environment are presented by the vehicular cloud (VC). Contrary to diverse wireless networks, VC networks possess exceptional features among others, namely, shorter transmission time along with a higher dynamic topology. Although integration with the cloud offers higher storage along with computation capabilities, it as well entails restricted resource availability. The restrictions on the number of resources serve as a challenge in servicing the applications with their necessary quality of service (QoS) guarantees as the number of service requests for applications keeps on augmenting with diverse circumstances. Thus, the need for an effective scheduling methodology arises to decide the sequence of servicing application requests and successful utilization of a broadcast medium, along with data transmission. To do efficient resource scheduling on VC networks, an optimization algorithm, namely, the crossover and mutation (CM)-centered chicken swarm optimization (CSO) is proposed and implemented with the help of a publicly available dataset. Initially, the VC infrastructure is initialized and some vehicle information is extracted as features. Next, the Brownian motion-centered bacteria foraging optimization (BM-BFO) algorithm chooses the essential features. Centered on the chosen features, the vehicles are clustered using the modified K-means algorithm. Next, as for the cloud server's virtual machines (VMs), the resource information is extracted. Lastly, the CM-CSO algorithm carries out the optimal scheduling in the VC by means of the clustered features of vehicles and features of the VM. The proposed techniques' findings are scrutinized and analogized to the other prevailing methodologies to confirm that the proposed work performs effectively and gives optimal resource allocation (RA) to the VC.  相似文献   

    

Jeonggi Yang  Soojeon Lee 《ETRI Journal》2023,45(5):758-767

In this study, we introduce a loosely coupled relative position estimation method that utilizes a decentralized ultrawideband (UWB), Global Navigation Support System and inertial navigation system for flight controllers (FCs). Key obstacles to multidrone collaboration include relative position errors and the absence of communication devices. To address this, we provide an extended Kalman filter-based algorithm and module that correct distance errors by fusing UWB data acquired through random communications. Via simulations, we confirm the feasibility of the algorithm and verify its distance error correction performance according to the amount of communications. Real-world tests confirm the algorithm's effectiveness on FCs and the potential for multidrone collaboration in real environments. This method can be used to correct relative multidrone positions during collaborative transportation and simultaneous localization and mapping applications.  相似文献   

    

Saeid Akhavan Bitaghsir  Ahmad Khonsari 《International Journal of Communication Systems》2018,31(8)

The explosive growth of mobile data traffic has made cellular operators to seek low‐cost alternatives for cellular traffic off‐loading. In this paper, we consider a content delivery network where a vehicular communication network composed of roadside units (RSUs) is integrated into a cellular network to serve as an off‐loading platform. Each RSU subjecting to its storage capacity caches a subset of the contents of the central content server. Allocating the suitable subset of contents in each RSU cache such that maximizes the hit ratio of vehicles requests is a problem of paramount value that is targeted in this study. First, we propose a centralized solution in which, we model the cache content placement problem as a submodular maximization problem and show that it is NP‐hard. Second, we propose a distributed cooperative caching scheme, in which RSUs in an area periodically share information about their contents locally and thus update their cache. To this end, we model the distributed caching problem as a strategic resource allocation game that achieves at least 50% of the optimal solution. Finally, we evaluate our scheme using simulation for urban mobility simulator under realistic conditions. On average, the results show an improvement of 8% in the hit ratio of the proposed method compared with other well‐known cache content placement approaches.  相似文献   

    

《AEUE-International Journal of Electronics and Communications》2018

Reduction in antenna size by using multi-band radiators play a vital role in the miniaturization of present world wireless handheld devices, as dual band behaviour of the antennas result in the integration of more than one communication standard in a single system and thus, saving the installation space required for separate antennas. In this context, this communication presents a shorted-pin dual band metamaterial inspired microstrip patch antenna array. Under the unloaded conditions, the traditional patch antenna array resonates at 5.8 GHz with gain of 9.8 dBi and bandwidth of 540 MHz. However, when each patch of this traditional antenna array is loaded with split ring resonator (SRR) and a metallic via hole is introduced in the patch, the same antenna array produces an additional resonant frequency in IEEE 802.11b/g/n 2.45 GHz Wi-Fi band with bandwidth and gain of 290 MHz and 5.6 dBi, respectively, while the initial resonant frequency (i.e. 5.8 GHz) gets shifted to IEEE 802.11ac 5 GHz Wi-Fi band, providing the gain and bandwidth of 11.4 dBi and 510 MHz, respectively. The proposed antenna array has been fabricated, and the measured results are presented to validate the proposed array. Moreover, the equivalent circuit of the proposed antenna array has been designed and analyzed to validate the simulated, measured and theoretical results. Attainment of dual band characteristics by incorporating the metamaterial with single band traditional patch antenna array makes this structure novel, as this has been achieved without any extra hardware cost, size and loss of structural planarity. Also, both the frequency bands of this proposed metamaterial inspired antenna array possess considerable gain and bandwidth.  相似文献   

    

《AEUE-International Journal of Electronics and Communications》2018

An improved data rate technology from tag to reader in Wi-Fi backscatter systems is proposed. The proposed system applies a power-level modulation to the conventional backscatter communication system. This technology can improve the data rate dramatically. It also adopts the Euclidean distance evaluation during demodulation, which looks for the most similar signal to enhance the BER performance. We analyze the error performance of the proposed decoding method, and the numerical results are presented. The power level is formed ranging from 2-level to 8-level. The performance of the detecting algorithm is compared to the conventional system, which utilizes the received power of selected sub-carriers.  相似文献   

    

《International Journal of Communication Systems》2017,30(6)

Vehicular ad hoc networks (VANETs) have been a research focus in recent years. VANETs are not only used to enhance the road safety and reduce the traffic accidents earlier but also conducted more researches in network value‐added service. As a result, the security requirements of vehicle communication are given more attention. In order to prevent the security threat of VANETs, the security requirements, such as the message integrity, availability, and confidentiality are needed to be guaranteed further. Therefore, a secured and efficient verification scheme for VANETs is proposed to satisfy these requirements and reduce the computational cost by combining the asymmetric and symmetric cryptology, certificate, digital signature, and session key update mechanism. In addition, our proposed scheme can resist malicious attacks or prevent illegal users' access via security and performance analysis. In summary, the proposed scheme is proved to achieve the requirements of resist known attacks, non‐repudiation, authentication, availability, integrity, and confidentiality. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

    

V. Karthik;R. Lakshmi;Salini Abraham;M. Ramkumar; 《International Journal of Network Management》2024,34(3):e2256

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Marius Vochin  Sorin Zoican  Eugen Borcoci 《Concurrency and Computation》2019,31(22)

Navigation assistance systems are aiming to improve safety and provide traffic optimization and have become more and more popular in a modern vehicular technology. The reason is given by the significant traffic increase and numerous congestion events in large cities, large complexity of road infrastructure, and unexpected or hazardous conditions that can be found on roads. This paper proposes an innovative navigation system solution that intelligently gathers traffic data provided by integrated car sensors and/or onboard security systems and uses it to warn other participants. System concepts, architecture, design, implementation, and performance evaluation aspects are presented, and tasks organization for an embedded cost‐effective implementation using a real‐time kernel is illustrated.  相似文献   

    

Syed Adeel Ali Shah  Ejaz Ahmed  Muhammad Ahsan Qureshi  Sadeeq Jan  Rafidah MD Noor 《International Journal of Communication Systems》2019,32(13)

In safety‐critical scenarios, reliable reception of beacons transmitted by a subject vehicle is critical to avoid vehicle collision. According to the employed contention window sizes in IEEE 802.11p, beacons are transmitted with a small contention window size. As a result, multiple vehicles contend for the shared channel access by selecting the same back‐off slot. This is a perfect recipe for synchronous collisions wherein reliable beacon delivery cannot be guaranteed for any vehicle. We consider the problem of selecting the back‐off slots from the current contention window to provide reliable delivery of beacons transmitted by a subject vehicle to its neighbors. Given a safety scenario, we propose a Pseudo‐Random Number Generator (PRNG)‐inspired back‐off selection (PBS) technique. The proposed technique works on the hypothesis that synchronous collisions of beacons transmitted by a subject vehicle can be reduced if all its neighbors select different back‐off slots (ie, not the back‐off slot selected by the subject vehicle). The discrete‐event simulations demonstrate that PBS can increase the overall message reception from a subject vehicle, in comparison with the uniform random probability back‐off selection in IEEE 802.11p.  相似文献