Aref Hassan Kurd Ali^1,*, Halikul Lenando¹, Slim Chaoui^2,3, Mohamad Alrfaay^1,4, Medhat A. Tawfeek^5,6

CMC-Computers, Materials & Continua, Vol.70, No.2, pp. 4147-4167, 2022, DOI:10.32604/cmc.2022.020659

Abstract Recently, Opportunistic Networks (OppNets) are considered to be one of the most attractive developments of Mobile Ad Hoc Networks that have arisen thanks to the development of intelligent devices. OppNets are characterized by a rough and dynamic topology as well as unpredictable contacts and contact times. Data is forwarded and stored in intermediate nodes until the next opportunity occurs. Therefore, achieving a high delivery ratio in OppNets is a challenging issue. It is imperative that any routing protocol use network resources, as far as they are available, in order to achieve higher network performance. In this article, we introduce the… More >

Puneet Garg^*, Ashutosh Dixit, Preeti Sethi

Computer Systems Science and Engineering, Vol.40, No.2, pp. 703-717, 2022, DOI:10.32604/csse.2022.019557

Abstract Opportunistic Networks (OppNets) is gaining popularity day-by-day due to their various applications in the real-life world. The two major reasons for its popularity are its suitability to be established without any requirement of additional infrastructure and the ability to tolerate long delays during data communication. Opportunistic Network is also considered as a descendant of Mobile Ad hoc Networks (Manets) and Wireless Sensor Networks (WSNs), therefore, it inherits most of the traits from both mentioned networking techniques. Apart from its popularity, Opportunistic Networks are also starting to face challenges nowadays to comply with the emerging issues of the large size of… More >

Cheng Gong^1,2, Xinzhu Yang¹, Wei Huangfu^3,4,*, Qinghua Lu⁵

CMC-Computers, Materials & Continua, Vol.69, No.2, pp. 2445-2457, 2021, DOI:10.32604/cmc.2021.016713

Abstract Communication opportunities among vehicles are important for data transmission over the Internet of Vehicles (IoV). Mixture models are appropriate to describe complex spatial-temporal data. By calculating the expectation of hidden variables in vehicle communication, Expectation Maximization (EM) algorithm solves the maximum likelihood estimation of parameters, and then obtains the mixture model of vehicle communication opportunities. However, the EM algorithm requires multiple iterations and each iteration needs to process all the data. Thus its computational complexity is high. A parameter estimation algorithm with low computational complexity based on Bin Count (BC) and Differential Evolution (DE) (PEBCDE) is proposed. It overcomes the… More >

Jingjian Chen¹, Gang Xu^{1, *}, Fengqi Wei¹, Liqiang He²

CMC-Computers, Materials & Continua, Vol.64, No.3, pp. 1845-1858, 2020, DOI:10.32604/cmc.2020.010010

Abstract Opportunistic networks are self-organizing networks that do not require a complete path between the source node and the destination node as it uses encounter opportunities brought by nodes movement to achieve network communication. Opportunistic networks routing algorithms are numerous and can be roughly divided into four categories based on different forwarding strategies. The Prophet routing algorithm is an important routing algorithm in opportunistic networks. It forwards messages based on the encounter probability between nodes, and has good innovation significance and optimization potential. However, the Prophet routing algorithm does not consider the impact of the historical throughput of the node on… More >

Meihua Liu¹, Xinchen Zhang^2,*, Shuangkui Ge³, Xiaoli Chen¹, Jianbin Wu², Mao Tian¹

CMC-Computers, Materials & Continua, Vol.60, No.2, pp. 559-574, 2019, DOI:10.32604/cmc.2019.04843

Abstract In Opportunistic networks (ONs), buffer management is critical to improve the message exchanging efficiency due to the limited storage space and transmission bandwidth at the wireless edge. Current solutions make message scheduling and drop policy based on assumptions that messages can always been forwarded in a single contact, and all node pairs have the same contact rates. However, such ideal assumptions are invalid for realistic mobility traces of hand-held. Recent studies show that the single contact duration is limited and the mobility of nodes is heterogeneous in reality. In this paper, a buffer management strategy based on contact duration and… More >