Inflight broadband connectivity(commonly termed as inflight connectivity)can be considered one of the remaining milestones for ubiquitous Internet provision;therefore,several enabling technologies are being investigat...Inflight broadband connectivity(commonly termed as inflight connectivity)can be considered one of the remaining milestones for ubiquitous Internet provision;therefore,several enabling technologies are being investigated to provide high-capacity,reliable,and affordable Internet access.Multiple-input multiple-output(MIMO),based on the space-time processing(STP)concept,is one of the dominant technologies that consistently appear on the list of inflight connectivity(IFC)enablers.STP shows the potential to significantly increase user throughput,improve spectral/energy efficiencies,and increase the capacity as well as reliability of airborne networks through spatial multiplexing/diversity techniques.This article presents the preliminary outcomes of substantial research on STP techniques for enabling IFC,as the exploratory study on this topic is still in its early stages.We explore the theoretical principles behind different STP techniques and their implementation in airborne networks in direct air-to-ground(A2G)scenarios for the provision of a reliable and high-speed IFC.We also analyze the current technologies and techniques used for IFC and highlight their benefits and limitations.We present a comprehensive review that compares different STP techniques using metrics such as bit error rate(BER),spectral efficiency(SE),and capacity.Last,but not least,we discuss the substantial research challenges encountered and the prospective future research avenues that require special attention for enhancing the deployment of STP systems in forthcoming airborne networks,particularly for enabling IFC.Overall,this research study contributes to the body of knowledge by providing insights into the use of STP techniques in airborne networks for enabling IFC.It emphasizes the theoretical foundations,presents a literature review,discusses challenges and limitations,identifies potential areas for future research,and provides a performance analysis.展开更多
Syncope forms a major part of medical in-flight emergencies contributing one-infour in-flight medical events accounting to 70%of flight diversions.In such patients,it is important to elucidate the pathophysiology of s...Syncope forms a major part of medical in-flight emergencies contributing one-infour in-flight medical events accounting to 70%of flight diversions.In such patients,it is important to elucidate the pathophysiology of syncope prior to diversion.Postural hypotension is the most common etiology of in-flight syncopal events.However,individuals without any underlying autonomic dysfunction can still experience syncope from hypoxia also known as airline syncope.Initial steps in managing such patients include positioning followed by the airway,breathing and circulation of resuscitation.These interventions need to be in close coordination with ground control to determine decision for flight diversion.Interventions which have been tried for prevention include mental challenge and increased salt and fluid intake.The current paper enhances the understanding of airline syncope by summarizing the associated pathophysiologic mechanisms and the management medical personnel can initiate with limited resources.展开更多
文摘Inflight broadband connectivity(commonly termed as inflight connectivity)can be considered one of the remaining milestones for ubiquitous Internet provision;therefore,several enabling technologies are being investigated to provide high-capacity,reliable,and affordable Internet access.Multiple-input multiple-output(MIMO),based on the space-time processing(STP)concept,is one of the dominant technologies that consistently appear on the list of inflight connectivity(IFC)enablers.STP shows the potential to significantly increase user throughput,improve spectral/energy efficiencies,and increase the capacity as well as reliability of airborne networks through spatial multiplexing/diversity techniques.This article presents the preliminary outcomes of substantial research on STP techniques for enabling IFC,as the exploratory study on this topic is still in its early stages.We explore the theoretical principles behind different STP techniques and their implementation in airborne networks in direct air-to-ground(A2G)scenarios for the provision of a reliable and high-speed IFC.We also analyze the current technologies and techniques used for IFC and highlight their benefits and limitations.We present a comprehensive review that compares different STP techniques using metrics such as bit error rate(BER),spectral efficiency(SE),and capacity.Last,but not least,we discuss the substantial research challenges encountered and the prospective future research avenues that require special attention for enhancing the deployment of STP systems in forthcoming airborne networks,particularly for enabling IFC.Overall,this research study contributes to the body of knowledge by providing insights into the use of STP techniques in airborne networks for enabling IFC.It emphasizes the theoretical foundations,presents a literature review,discusses challenges and limitations,identifies potential areas for future research,and provides a performance analysis.
文摘Syncope forms a major part of medical in-flight emergencies contributing one-infour in-flight medical events accounting to 70%of flight diversions.In such patients,it is important to elucidate the pathophysiology of syncope prior to diversion.Postural hypotension is the most common etiology of in-flight syncopal events.However,individuals without any underlying autonomic dysfunction can still experience syncope from hypoxia also known as airline syncope.Initial steps in managing such patients include positioning followed by the airway,breathing and circulation of resuscitation.These interventions need to be in close coordination with ground control to determine decision for flight diversion.Interventions which have been tried for prevention include mental challenge and increased salt and fluid intake.The current paper enhances the understanding of airline syncope by summarizing the associated pathophysiologic mechanisms and the management medical personnel can initiate with limited resources.
