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Currently, WBAN-based healthcare systems have attracted increasing interest due to their great potential in improving the quality of healthcare services and changing the way of living (Pramanik and al., 2019). Indeed, thanks to the recent advances in miniaturization of smart biosensors, WBANs have enabled the deployment of innovative healthcare applications that provide continuous monitoring of health status with alerting mechanisms against odd conditions.
To benefit from this type of networks in an intended application, one or more types of miniature sensors have to be placed in the appropriate part(s) of the human body to acquire important data about health status through measuring specific physiological parameters. These data should be gathered by a special control device worn by the user or placed in an accessible location, which may then in turn display the according information on a user interface, or transmit the aggregated vital signs to off-site doctors for diagnostic and therapeutic purposes (Tavera and al., 2021). Therefore, two levels of communications can be distinguished in these networks: intra-WBAN communications taking place between sensor nodes and the control device, and extra-WBAN communications that allow sensory data to be transmitted to off-site destinations (Nabila, 2019b).
In this research, we focus our studies on intra-WBAN communications, and we give a particular attention to the MAC sub-layer, which represents the core level for quality of service (QoS) provisioning. Our aim is to look for a general rule indicating the best MAC technology for WBANs on the basis of sensory data requirements as well as the overall traffic of the deployed system. The remainder of this paper is organized as follows. A motivation behind the work is presented in Section 2 with related works. The functional requirements of the most used physiological sensors in WBANs are studied in Section 3. In Section 4, we propose a classification of WBAN-based healthcare systems and present some examples of the WBAN systems proposed in the last two decades to provide a concrete idea about the use of WBANs in the health field. In Section 5, we propose a classification of WBAN MAC protocols and present a brief overview of the existing MAC solutions. In Section 6, we present a comparative analysis of the most well-known wireless technology candidates from which the majority of WBAN MAC protocols are derived. Finally, Section 6 concludes the paper.
Due to the criticality and sensitivity of sensory data in WBAN-based healthcare applications, some incidents may lead to life threatening situations if the related data are corrupted by any means or are not transmitted to their destination on time (Azdad & el Boukhari, 2019). Hence, reliability and timeliness are two extremely important factors that make the design of a suitable MAC protocol for such networks a challenging task. Furthermore, energy limitations and the unreliable nature of wireless communications make QoS provisioning in such networks a non-trivial research problem.
Based on the literature, the great majority of the Medium Access Control protocols proposed for WBANs are primarily derived from the existing IEEE standards 802.15.4 and 802.15.6 (F. Ullah, Abdullah, Kaiwartya, Kumar, and al., 2017). Hence, it will be of a vital importance to judge their usefulness in this type of networks.
Furthermore, to the best of our knowledge, there is no study that provides indications about the preferred standard for wireless body area networks. As presented in (Nabila, 2019a) and (Nabila & Mohamed, 2019), all the existing works compare the two norms in a tight sense over realistic constraints of specific healthcare scenarios. For example, in (Benmansour and al., 2016), Benmansour and al. Have compared the standards ieee 802.15.4 and ieee 802.15.6 over realistic requirements and constraints of home monitoring of an individual cardiac patient to decide about the best mac technology for such scenario. In (Fourati and al., 2015), Fourati and al. Have studied the possibility of using one of these two norms to implement the body area network (wban) of canet (an innovative ehealth project) scenario according to the nature of the integrated sensors.
In this paper, the performances of IEEE 802.15.4 and IEEE 802.15.6 are analyzed under different network topology configurations in order to find a general rule indicating the most suitable norm for WBANs based on the characteristics of the targeted application.