A new type of air-ground communication application framework named FACT(framework for air-ground communication technology with weather-modification aircraft)is presented to track and command weather-modification aircr...A new type of air-ground communication application framework named FACT(framework for air-ground communication technology with weather-modification aircraft)is presented to track and command weather-modification aircraft to perform ideal cloud seeding.FACT provides a set of solutions from three perspectives,namely,onboard,onground and air-to-ground,with the core purpose of solving the problems of the rapid exchange of information,contract analysis and identifying potential seeding areas when flight plans and meteorological conditions change.On board,the observed data are processed centrally and transmitted downward through air-to-ground communication.The real-time application and sharing of aircraft detection data are strengthened on the ground,and potential areas of operation are automatically identified based on ground data.The communication between the air and the ground achieves a technical breakthrough by realizing double satellite links,adaptive data transmission and VPN channel encryption.Additionally,an application based on FACT is designed and implemented for the real-time command of weather-modified aircraft.This approach has become the key air-to-ground communication system support for more than 40 Chinese aircraft and the big data service support center of airborne data to ensure improved operation of weather-modification aircraft in China.展开更多
The research of three-dimensional integrated communication technology plays a key role in achieving the ubiquitous connectivity,ultra-high data rates,and emergency communications in the sixth generation(6G)networks.Ae...The research of three-dimensional integrated communication technology plays a key role in achieving the ubiquitous connectivity,ultra-high data rates,and emergency communications in the sixth generation(6G)networks.Aerial networking provides a prom⁃ising solution to flexible,scalable,low-cost and reliable coverage for wireless devices.The integration of aerial network and terrestrial network has been an inevitable paradigm in the 6G era.However,energy-efficient communications and networking among aerial net⁃work and terrestrial network face great challenges.This paper is dedicated to discussing green communications of the air-ground integrated heterogeneous network(AGIHN).We first provide a brief introduction to the characteristics of AGIHN in 6G networks.Further,we analyze the challenges of green AGIHN from the aspects of green terrestrial networks and green aerial networks.Finally,several solutions to and key technologies of the green AGIHN are discussed.展开更多
Similarly to other domains, maritime community requests for broadband services have been significantly increasing. Worldwide navigation footprint and the lack of practical alternatives to Satellite Communications (SAT...Similarly to other domains, maritime community requests for broadband services have been significantly increasing. Worldwide navigation footprint and the lack of practical alternatives to Satellite Communications (SATCOM) empower VHF band as the natural choice to support most of those demands. Nevertheless, the major challenge for an implementation of maritime broadband VHF services is unquestionably the spectrum availability and management. Eventually, the solution must include spectrum sharing, using a Cognitive Radio (CR) based approach, but unfortunately current regulatory framework and spectrum management regime are not appropriate for such concepts and emerging technologies. To overcome such constraints, it is necessary to address a whole field of regulatory and standardization issues in order to prepare an evolution towards a more flexible and dynamic approach to spectrum management and a transition that would ensure incumbents live operations and legacy systems. The required paradigm change encompasses a new policy definition, an enforcement mechanism implementation and a comprehensive transition plan. The presented analysis pretends to address the regulatory feasibility of a framework change, discusses its evolving process and points some challenges related with practical aspects associated to Quality of Service (QoS) enforcement metrics definition, centering the arguments in maritime VHF band.展开更多
According to the analysis of the very high frequency (VHF) self organized time division multiple access (S TDMA) aviation data link, a new dynamic slot assignment scheme is proposed in this paper, which adopts var...According to the analysis of the very high frequency (VHF) self organized time division multiple access (S TDMA) aviation data link, a new dynamic slot assignment scheme is proposed in this paper, which adopts variable data frame structure and can eliminate the effect of the idle slot on message delay. By using queue theory, the analysis models of the new scheme and previous scheme are presented, and the performance of message delay and that of system throughput are analyzed under two schemes. The simulation results show that the new scheme has a better performance than the previous one in the message delay and system throughput.展开更多
This paper proposes a novel flexible antenna design operating at very high frequency(VHF)band for on-body applications such as human body communication(HBC).The antenna consists of back-to-back E-shaped fractal and co...This paper proposes a novel flexible antenna design operating at very high frequency(VHF)band for on-body applications such as human body communication(HBC).The antenna consists of back-to-back E-shaped fractal and complimentary structures designed over a thin flex-ible substrate.The overall design working on the principle of fractal geometries and capacitive coupling is highly beneficial to achieve better antenna characteristics even at low frequencies around 35 MHz-45 MHz that are being used for HBC application.The proposed antenna obtained a large bandwidth of around 10.0 MHz in air and a bandwidth of around 8.0 MHz during on-body opera-tion.The antenna has been tested in three different scenarios viz.air,on-body single antenna and on-body communication using two antennas.The insertion loss is reduced to a minimum in all three scenarios,which is quite beneficial for better signal transmission.The size miniaturization with high flexibility in such low frequencies has also been achieved in the paper that makes the proposed design suitable for human body communication applications.展开更多
基金jointly funded by the National Key R&D Program of China(Grant Number 2018YFC1505702)the project of scientific research on weather modification in Northwest China,research for experimental design and application integration(RYSY201909).
文摘A new type of air-ground communication application framework named FACT(framework for air-ground communication technology with weather-modification aircraft)is presented to track and command weather-modification aircraft to perform ideal cloud seeding.FACT provides a set of solutions from three perspectives,namely,onboard,onground and air-to-ground,with the core purpose of solving the problems of the rapid exchange of information,contract analysis and identifying potential seeding areas when flight plans and meteorological conditions change.On board,the observed data are processed centrally and transmitted downward through air-to-ground communication.The real-time application and sharing of aircraft detection data are strengthened on the ground,and potential areas of operation are automatically identified based on ground data.The communication between the air and the ground achieves a technical breakthrough by realizing double satellite links,adaptive data transmission and VPN channel encryption.Additionally,an application based on FACT is designed and implemented for the real-time command of weather-modified aircraft.This approach has become the key air-to-ground communication system support for more than 40 Chinese aircraft and the big data service support center of airborne data to ensure improved operation of weather-modification aircraft in China.
基金This work was supported by National Natural Science Foundation of Chi⁃na under Grant Nos.61901051 and 61932005.
文摘The research of three-dimensional integrated communication technology plays a key role in achieving the ubiquitous connectivity,ultra-high data rates,and emergency communications in the sixth generation(6G)networks.Aerial networking provides a prom⁃ising solution to flexible,scalable,low-cost and reliable coverage for wireless devices.The integration of aerial network and terrestrial network has been an inevitable paradigm in the 6G era.However,energy-efficient communications and networking among aerial net⁃work and terrestrial network face great challenges.This paper is dedicated to discussing green communications of the air-ground integrated heterogeneous network(AGIHN).We first provide a brief introduction to the characteristics of AGIHN in 6G networks.Further,we analyze the challenges of green AGIHN from the aspects of green terrestrial networks and green aerial networks.Finally,several solutions to and key technologies of the green AGIHN are discussed.
文摘Similarly to other domains, maritime community requests for broadband services have been significantly increasing. Worldwide navigation footprint and the lack of practical alternatives to Satellite Communications (SATCOM) empower VHF band as the natural choice to support most of those demands. Nevertheless, the major challenge for an implementation of maritime broadband VHF services is unquestionably the spectrum availability and management. Eventually, the solution must include spectrum sharing, using a Cognitive Radio (CR) based approach, but unfortunately current regulatory framework and spectrum management regime are not appropriate for such concepts and emerging technologies. To overcome such constraints, it is necessary to address a whole field of regulatory and standardization issues in order to prepare an evolution towards a more flexible and dynamic approach to spectrum management and a transition that would ensure incumbents live operations and legacy systems. The required paradigm change encompasses a new policy definition, an enforcement mechanism implementation and a comprehensive transition plan. The presented analysis pretends to address the regulatory feasibility of a framework change, discusses its evolving process and points some challenges related with practical aspects associated to Quality of Service (QoS) enforcement metrics definition, centering the arguments in maritime VHF band.
基金Aeronautical Science F oundation of China !( N o.98E5 1116)
文摘According to the analysis of the very high frequency (VHF) self organized time division multiple access (S TDMA) aviation data link, a new dynamic slot assignment scheme is proposed in this paper, which adopts variable data frame structure and can eliminate the effect of the idle slot on message delay. By using queue theory, the analysis models of the new scheme and previous scheme are presented, and the performance of message delay and that of system throughput are analyzed under two schemes. The simulation results show that the new scheme has a better performance than the previous one in the message delay and system throughput.
基金National Key Research and Development Pro-gram of China(No.2018YFC2001002)Shenzhen Basic Re-search Project(Nos.JCYJ20180507182231907,PIFI 2020FYB0001)CAS Key Lab of Health Informatics.
文摘This paper proposes a novel flexible antenna design operating at very high frequency(VHF)band for on-body applications such as human body communication(HBC).The antenna consists of back-to-back E-shaped fractal and complimentary structures designed over a thin flex-ible substrate.The overall design working on the principle of fractal geometries and capacitive coupling is highly beneficial to achieve better antenna characteristics even at low frequencies around 35 MHz-45 MHz that are being used for HBC application.The proposed antenna obtained a large bandwidth of around 10.0 MHz in air and a bandwidth of around 8.0 MHz during on-body opera-tion.The antenna has been tested in three different scenarios viz.air,on-body single antenna and on-body communication using two antennas.The insertion loss is reduced to a minimum in all three scenarios,which is quite beneficial for better signal transmission.The size miniaturization with high flexibility in such low frequencies has also been achieved in the paper that makes the proposed design suitable for human body communication applications.