The adaptive array antenna can form arbitrary beams and point to arbitrary directions. Due to lacking the nulling capability, they may not achieve the optimal concurrent transmission schedules in multi-path-prone environments. SBA can point to several pre-determined directions with pre-defined antenna gain patterns, which can work well without the presence of the multi-path effect (such as in the free-space environment). Recent directional antenna technologies can be categorized into three classes: (1) the switched-beam antenna (SBA) (2) the adaptive array antenna and (3) the Multiple Input Multiple Output (MIMO) array antennas. Since the MEA specified in the standard is assumed to operate over omnidirectional antennas, several operational problems will need to be solved, when it operates over directional antennas. In the literature, rare work studied the performances and challenges of the 802.16(d) mesh CDS-mode network when it uses directional antennas. The performance of MEA has been extensively studied for years (e.g.,, ,, ,, ) however, most of the prior works were based on the use of omnidirectional radios. Because the transmission timing of a control message is controlled by MEA, how MEA influences the network performance of the IEEE 802.16(d) mesh CDS mode is worth studying. The handshake information of THP should be transmitted using control messages. A pair of transmitting and receiving nodes should negotiate a data transmission schedule using a three-way handshake procedure (THP). The data transmission of this network is scheduled in an on-demand manner. Thus, by using MEA each node can schedule collision-free control message transmissions in its one-hop neighborhood. MEA allows a node to know the possible next control message transmission intervals of the nodes in its two-hop neighborhood. The control message transmissions are determined using a distributed pseudo-random algorithm, called the Mesh Election Algorithm (MEA), which employs a unique exponential holdoff design. The transmissions of control messages and data are separated. The 802.16(d) mesh CDS mode uses a TDMA-based Medium Access Control (MAC) layer and OFDM-based physical layer and mainly operates at a single frequency. All rights reserved.The IEEE 802.16(d) mesh coordinated distributed scheduling (CDS) mode is a wireless technology for next-generation fixed broadband relay networks. Although health outcome assessment differed between pesticide studies and agricultural burning studies, similar adverse respiratory health effects were observed across the majority of studies.Īgricultural burning Asthma Children's respiratory health Pesticides.Ĭopyright © 2022 Elsevier B.V. The most frequently studied health outcomes in these publications were acute respiratory symptoms (n = 11 pesticides, n = 3 agricultural burning), followed by asthma (n = 9 pesticides, n = 3 agricultural burning), and lung function measurements (n = 5 pesticides, n = 6 agricultural burning). ![]() Similarly, most (11/12) of the agricultural burning studies also reported a positive association between exposure to agricultural burning and adverse respiratory health effects. A majority of the pesticide studies (18/25) reported a positive association between exposure to pesticides and adverse childhood respiratory health effects. In total we identified 25 studies that focused on pesticide exposures and children's respiratory health, and 12 studies that focused on exposure to agricultural burning and children's respiratory health. ![]() Studies were categorized based on main exposure of interest (i.e., pesticides or agricultural burning) and by respiratory health outcome assessment (i.e., self-reported asthma, acute respiratory symptoms, and lung function measurements). The initial search combining both exposure metrics (pesticides and agricultural burning) yielded zero publications and thus the queries were performed and presented separately. Two academic search databases (PubMed and Scopus) were queried for all available studies published in English before May 31st, 2021. We reviewed epidemiological studies to identify the respiratory health effects of children exposed to pesticides and agricultural burning through a systematic evaluation of peer-reviewed publications of children living in industrial agricultural areas. ![]() Exposure to pesticides and agricultural burning are likely to co-occur in agricultural communities, but these exposures have remained distinct bodies of research.
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