In order to solve the problems associated with Internet IP services management, a generic service model for n multi-providcr IP service management is proposed, which is based on a generalization of the bandwidth broke...In order to solve the problems associated with Internet IP services management, a generic service model for n multi-providcr IP service management is proposed, which is based on a generalization of the bandwidth broker idea introduced in the differentiated services （DiffServ） environment. This model consists of a hierarchy of service brokers, which makes it fit into providing end-to-end Internet services with QoS support. A simple and sealable mechanism is used to communicate with other cooperative domains to enable customers to dynamically setup services connections over multiple DiffServ domains. The simulation results show that the proposed model is real-time, which can deal with many flow requests in a short period of time, so that it is fit for the service management in a reasonably large network.展开更多
With the deployment of ultra-dense low earth orbit(LEO)satellite constellations,LEO satellite access network(LEO-SAN)is envisioned to achieve global Internet coverage.Meanwhile,the civil aviation communications have i...With the deployment of ultra-dense low earth orbit(LEO)satellite constellations,LEO satellite access network(LEO-SAN)is envisioned to achieve global Internet coverage.Meanwhile,the civil aviation communications have increased dramatically,especially for providing airborne Internet services.However,due to dynamic service demands and onboard LEO resources over time and space,it poses huge challenges in satellite-aircraft access and service management in ultra-dense LEO satellite networks(UDLSN).In this paper,we propose a deep reinforcement learning-based approach for ultra-dense LEO satellite-aircraft access and service management.Firstly,we develop an airborne Internet architecture based on UDLSN and design a management mechanism including medium earth orbit satellites to guarantee lightweight management.Secondly,considering latency-sensitive and latency-tolerant services,we formulate the problem of satellite-aircraft access and service management for civil aviation to ensure service continuity.Finally,we propose a proximal policy optimization-based access and service management algorithm to solve the formulated problem.Simulation results demonstrate the convergence and effectiveness of the proposed algorithm with satisfying the service continuity when applying to the UDLSN.展开更多
Technical features about CAN bus are described. One kind of scheme in Hotel Guest Room Service and Management System based on CAN bus is presented. The system's structure and main function are expounded. The work ...Technical features about CAN bus are described. One kind of scheme in Hotel Guest Room Service and Management System based on CAN bus is presented. The system's structure and main function are expounded. The work principle and design of the system's hardware and software are explained. The realization of the system's hardware and software is detailed from aspects of improving system's anti-jamming and fault self-examined capability, and the block diagram of each part's circuit is given. Finally, features of the system are summarized, and a comparison with the system based on RS485 was made to prove the advantages of the system. By practice, CAN bus in the system can transmit data steadily and reliably.展开更多
文摘In order to solve the problems associated with Internet IP services management, a generic service model for n multi-providcr IP service management is proposed, which is based on a generalization of the bandwidth broker idea introduced in the differentiated services （DiffServ） environment. This model consists of a hierarchy of service brokers, which makes it fit into providing end-to-end Internet services with QoS support. A simple and sealable mechanism is used to communicate with other cooperative domains to enable customers to dynamically setup services connections over multiple DiffServ domains. The simulation results show that the proposed model is real-time, which can deal with many flow requests in a short period of time, so that it is fit for the service management in a reasonably large network.
基金supported in part by the National Key R&D Program of China under Grant 2020YFB1806104in part by Innovation and Entrepreneurship of Jiangsu Province High-level Talent Program+1 种基金in part by Natural Sciences and Engineering Research Council of Canada (NSERC)the support from Huawei
文摘With the deployment of ultra-dense low earth orbit(LEO)satellite constellations,LEO satellite access network(LEO-SAN)is envisioned to achieve global Internet coverage.Meanwhile,the civil aviation communications have increased dramatically,especially for providing airborne Internet services.However,due to dynamic service demands and onboard LEO resources over time and space,it poses huge challenges in satellite-aircraft access and service management in ultra-dense LEO satellite networks(UDLSN).In this paper,we propose a deep reinforcement learning-based approach for ultra-dense LEO satellite-aircraft access and service management.Firstly,we develop an airborne Internet architecture based on UDLSN and design a management mechanism including medium earth orbit satellites to guarantee lightweight management.Secondly,considering latency-sensitive and latency-tolerant services,we formulate the problem of satellite-aircraft access and service management for civil aviation to ensure service continuity.Finally,we propose a proximal policy optimization-based access and service management algorithm to solve the formulated problem.Simulation results demonstrate the convergence and effectiveness of the proposed algorithm with satisfying the service continuity when applying to the UDLSN.
文摘Technical features about CAN bus are described. One kind of scheme in Hotel Guest Room Service and Management System based on CAN bus is presented. The system's structure and main function are expounded. The work principle and design of the system's hardware and software are explained. The realization of the system's hardware and software is detailed from aspects of improving system's anti-jamming and fault self-examined capability, and the block diagram of each part's circuit is given. Finally, features of the system are summarized, and a comparison with the system based on RS485 was made to prove the advantages of the system. By practice, CAN bus in the system can transmit data steadily and reliably.
