| Autor: |
Qureshi UM; Department of Computer Science, City University of Hong Kong, Kowloon, 852, Hong Kong, China. umair.qureshi@faculty.muet.edu.pk.; Department of Telecommunication, Mehran University of Engineering and Technology, Jamshoro 76062, Pakistan. umair.qureshi@faculty.muet.edu.pk., Shaikh FK; Department of Telecommunication, Mehran University of Engineering and Technology, Jamshoro 76062, Pakistan. faisal.shaikh@faculty.muet.edu.pk., Aziz Z; Department of Computer Science, City University of Hong Kong, Kowloon, 852, Hong Kong, China. zaziz3-c@my.cityu.edu.hk.; Department of Telecommunication, Mehran University of Engineering and Technology, Jamshoro 76062, Pakistan. zaziz3-c@my.cityu.edu.hk., Shah SM; Department of Telecommunication, Mehran University of Engineering and Technology, Jamshoro 76062, Pakistan. SyedMZ@cs.cardiff.ac.uk.; School of Computer Science & Informatics, Cardiff University, Cardiff CF10 3XQ, UK. SyedMZ@cs.cardiff.ac.uk., Sheikh AA; Science and Technology Unit, Umm Al Qura University, Makkah 24382, Saudi Arabia. aasheikh@uqu.edu.sa., Felemban E; Department of Computer Engineering, Umm Al Qura University, Makkah 24382, Saudi Arabia. eafelemban@uqu.edu.sa., Qaisar SB; CoNNekT Lab, National University of Sciences and Technology, Islamabad 44000, Pakistan. saad.qaisar@seecs.edu.pk. |
| Abstrakt: |
Underwater Wireless Sensor Network (UWSN) communication at high frequencies is extremely challenging. The intricacies presented by the underwater environment are far more compared to the terrestrial environment. The prime reason for such intricacies are the physical characteristics of the underwater environment that have a big impact on electromagnetic (EM) signals. Acoustics signals are by far the most preferred choice for underwater wireless communication. Because high frequency signals have the luxury of large bandwidth (BW) at shorter distances, high frequency EM signals cannot penetrate and propagate deep in underwater environments. The EM properties of water tend to resist their propagation and cause severe attenuation. Accordingly, there are two questions that need to be addressed for underwater environment, first what happens when high frequency EM signals operating at 2.4 GHz are used for communication, and second which factors affect the most to high frequency EM signals. To answer these questions, we present real-time experiments conducted at 2.4 GHz in terrestrial and underwater (fresh water) environments. The obtained results helped in studying the physical characteristics (i.e., EM properties, propagation and absorption loss) of underwater environments. It is observed that high frequency EM signals can propagate in fresh water at a shallow depth only and can be considered for a specific class of applications such as water sports. Furthermore, path loss, velocity of propagation, absorption loss and the rate of signal loss in different underwater environments are also calculated and presented in order to understand why EM signals cannot propagate in sea water and oceanic water environments. An optimal solk6ution for underwater communication in terms of coverage distance, bandwidth and nature of communication is presented, along with possible underwater applications of UWSNs at 2.4 GHz. |
