In order to save the energy and reduce the latency of the end-to-end transmission in mobile ad hoc networks an adaptive and distance-driven power control ADPC scheme is proposed by means of distance research in random...In order to save the energy and reduce the latency of the end-to-end transmission in mobile ad hoc networks an adaptive and distance-driven power control ADPC scheme is proposed by means of distance research in random geometrics. Through mathematical proof the optimal number of relay nodes and the optimal location of each node for data transmission can be obtained when a distance is given.In the ADPC first the source node computes the optimal number and the sites of the relay nodes between the source and the destination nodes.Then it searches feasible relay nodes around the optimal virtual relay-sites and selects one link with the minimal total transmission energy consumption for data transmission.Simulation results show that the ADPC can reduce both the energy dissipation and the end-to-end latency of the transmission.展开更多
For the Cooperative Adaptive Cruise Control （CACC） Algorithm, existing research studies mainly focus on how inter-vehicle communication can be used to develop CACC controller, the influence of the communication dela...For the Cooperative Adaptive Cruise Control （CACC） Algorithm, existing research studies mainly focus on how inter-vehicle communication can be used to develop CACC controller, the influence of the communication delays and lags of the actuators to the string stability. However, whether the string stability can be guaranteed when inter-vehicle communication is invalid partially has hardly been considered. This paper presents an improved CACC algorithm based on the sliding mode control theory and analyses the range of CACC controller parameters to maintain string stability. A dynamic model of vehicle spacing deviation in a platoon is then established, and the string stability conditions under improved CACC are analyzed. Unlike the traditional CACC algorithms, the proposed algorithm can ensure the functionality of the CACC system even if inter-vehicle communication is partially invalid. Finally, this paper establishes a platoon of five vehicles to simulate the improved CACC algorithm in MATLAB/Simulink, and the simulation results demonstrate that the improved CACC algorithm can maintain the string stability of a CACC platoon through adjusting the controller parameters and enlarging the spacing to prevent accidents. With guaranteed string stability, the proposed CACC algorithm can prevent oscillation of vehicle spacing and reduce chain collision accidents under real-world circumstances. This research proposes an improved CACC algorithm, which can guarantee the string stability when inter-vehicle communication is invalid.展开更多
In this paper, a relay selection strategy and distributed power control algorithm are proposed for the underlay spectrum sharing mode based cooperative cognitive ad hoc network with energy-limited users. The study aim...In this paper, a relay selection strategy and distributed power control algorithm are proposed for the underlay spectrum sharing mode based cooperative cognitive ad hoc network with energy-limited users. The study aims to minimize the total power consumption of cooperative cognitive ad hoc network while ensuring the quality of service(QoS) requirement of cognitive user and keeping the interference to primary user below interference tolerance. The power control problem is transformed into a convex optimization problem. Based on Lagrange dual decomposition theory, a gradient iterative algorithm is constructed to search for the optimal solution and complete distributed power optimization. Simulation results show that the algorithm converges fast and reduces transmit power of cognitive users effectively while guaranteeing the QoS requirement.展开更多
As a new sort of mobile ad hoc network(MANET), aeronautical ad hoc network(AANET) has fleet-moving airborne nodes(ANs) and suffers from frequent network partitioning due to the rapid-changing topology. In this work, t...As a new sort of mobile ad hoc network(MANET), aeronautical ad hoc network(AANET) has fleet-moving airborne nodes(ANs) and suffers from frequent network partitioning due to the rapid-changing topology. In this work, the additional relay nodes(RNs) is employed to repair the network and maintain connectivity in AANET. As ANs move, RNs need to move as well in order to re-establish the topology as quickly as possible. The network model and problem definition are firstly given, and then an online approach for RNs' movement control is presented to make ANs achieve certain connectivity requirement during run time. By defining the minimum cost feasible moving matrix(MCFM), a fast algorithm is proposed for RNs' movement control problem. Simulations demonstrate that the proposed algorithm outperforms other control approaches in the highly-dynamic environment and is of great potential to be applied in AANET.展开更多
In this paper, based on the inherent characteristic of the contention relation between flows in ad hoc networks, we introduce the notion of the link＇s interference set, extend the utility maximization problem represe...In this paper, based on the inherent characteristic of the contention relation between flows in ad hoc networks, we introduce the notion of the link＇s interference set, extend the utility maximization problem representing congestion control in wireline networks to ad hoc networks, apply the penalty function approach and the subgradient method to solve this problem, and propose the congestion control algorithm Penalty function-based Optical Congestion Control （POCC） which is implemented in NS2- simulator. Specifically, each link transmits periodically the information on its congestion state to its interference set; the set ; the sermon at each source adjusts the transmission rate based on the optimal tradeoffbetween the utility value and the congestion level which the interference set of the links that this session goes though suffers from. MATLAB-based simulation results showed that POCC can approach the globally optimal solution. The NS2-based simulation results showed that POCC outperforms default TCP and ATCP to achieve efficient and fair resource allocation in ad hoc networks.展开更多
A joint power control algorithm for ad hoc networks based on code division multiple access （CDMA） was studied. Firstly, the new algorithm was deduced in theory. Then, the system model was developed. In the proposed ...A joint power control algorithm for ad hoc networks based on code division multiple access （CDMA） was studied. Firstly, the new algorithm was deduced in theory. Then, the system model was developed. In the proposed algorithm, all transmitting nodes assigned in the same time slot adjust their transmitter power based on current information, which takes into account the adjustments of transmitter power of other transmitting nodes in next step and the prediction of inter-link interference power level at the receive node. Simulation results indicate that the proposed algorithm outperforms the conventional algorithms in terms of smaller standard deviation of receiver signal-to-interference-ratio, lower system interference and higher energy efficiency.展开更多
As device-to-device(D2D) communications usually reuses the resource of cellular networks, call admission control(CAC) and power control are crucial problems. However in most power control schemes, total data rates or ...As device-to-device(D2D) communications usually reuses the resource of cellular networks, call admission control(CAC) and power control are crucial problems. However in most power control schemes, total data rates or throughput are regarded as optimization criterion. In this paper, a combining call admission control(CAC) and power control scheme under guaranteeing QoS of every user equipment(UE) is proposed. First, a simple CAC scheme is introduced. Then based on the CAC scheme, a combining call admission control and power control scheme is proposed. Next, the performance of the proposed scheme is evaluated. Finally, maximum DUE pair number and average transmitting power is calculated. Simulation results show that D2 D communications with the proposed combining call admission control and power control scheme can effectively improve the maximum DUE pair number under the premise of meeting necessary QoS.展开更多
This paper presents a new topology to implement Class F power amplifier for eliminating the on-resistance (R_(ON))effect.The time-domain and frequency-domain voltage and current waveforms for Class F amplifier are ana...This paper presents a new topology to implement Class F power amplifier for eliminating the on-resistance (R_(ON))effect.The time-domain and frequency-domain voltage and current waveforms for Class F amplifier are ana- lyzed using Fourier series analysis method.Considering the on-resistance effect,the formulas of the efficiency,output power,dc power dissipation,and fundamental load impedance are given from ideal current and voltage waveforms.For experimental verification,we designed and implemented a Class F power amplifier,which operates at 850 MHz using MGaAs/GaAs Heterostructure FET(HFET)device,and analyzed the measurement results.Test results show that the maximum PAE of 67% can be achieved at 28 dBm output power level.展开更多
This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided in...This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided into common channel,broadcast channel and several data chan-nels. And dynamic power control mechanism is implemented to reduce near-far interference. Compared with IEEE 802.11 Distributed Coordination Function (DCF) protocol,the results show that the pro-posed mechanism improves the average throughput and limits the transmission delay efficiently.展开更多
Security in Ad Hoc network is an important issue under the opening circumstance of application service. Some protocols and models of security auditing have been proposed to ensure rationality of contracting strategy a...Security in Ad Hoc network is an important issue under the opening circumstance of application service. Some protocols and models of security auditing have been proposed to ensure rationality of contracting strategy and operating regulation and used to identify abnormal operation. Model of security auditing based on access control of devices will be advanced to register sign of devices and property of event of access control and to audit those actions. In the end, the model is analyzed and simulated.展开更多
IEEE 802.11 distributed coordination function(DCF)can alleviate the collision and hidden station problem,but it doesn't differentiate traffic categories(TC).Therefore,it can't provide sufficient quality of ser...IEEE 802.11 distributed coordination function(DCF)can alleviate the collision and hidden station problem,but it doesn't differentiate traffic categories(TC).Therefore,it can't provide sufficient quality of service(QoS)support for different TC.Recently,a new contention-based enhanced distributed channel access(EDCA)scheme is proposed which provides a probabilistic QoS support.In this paper,an improved EDCA scheme for service differentiation in ad hoc networks is proposed.In this scheme,signal channel resistance coefficient is used to adjust the contention window(CW).It proves that the scheme provides the traffic differentiation,high throughput and low delay through simulation.展开更多
The ad lamp-box controller is designed in consideration that ordinary urban ad lights usually remain lit through the night and a specially assigned staff needs to be on duty to control their switches.It can be automat...The ad lamp-box controller is designed in consideration that ordinary urban ad lights usually remain lit through the night and a specially assigned staff needs to be on duty to control their switches.It can be automatically controlled with a photo resistance testing the day and night as well as a CD4060 chip controlling the length of time interval between switching the ad lamp-boxes on and off.In this way,both energy and labor can be saved with the controller.It is matching with the target of"constructing a conservation-minded society"in our country and deserves to be promoted in market with its practical significance.展开更多
We consider the problem of fair rate control for wireless ad-hoc networks with time varying channel capacities. The interaction between links in wireless ad-hoc networks introduces additional constraints on the flow r...We consider the problem of fair rate control for wireless ad-hoc networks with time varying channel capacities. The interaction between links in wireless ad-hoc networks introduces additional constraints on the flow rate. A primal-dual algorithm that guarantees fair rate control is proved to be trajectory stable. Various fairness indexes are obtained by choosing the specified form of the utility functions, and the numerical results validate the effectiveness of the proposed algorithm.展开更多
Research on wide area ad hoc networks is of great significance due to its application prospect in long-range networks such as aeronautical and maritime networks,etc.The design of MAC protocols is one of the most impor...Research on wide area ad hoc networks is of great significance due to its application prospect in long-range networks such as aeronautical and maritime networks,etc.The design of MAC protocols is one of the most important parts impacting the whole network performance.In this paper,we propose a dis-tributed TDMA-based MAC protocol called Dynamic Self Organizing TDMA(DSO-TDMA)for wide area ad hoc networks.DSO-TDMA includes three main features:(1)In a distributed way,nodes in the network select transmitting slots according to the congestion situation of the local air interface.(2)In a selforganization way,nodes dynamically adjust the resource occupancy ratio according to the queue length of neighbouring nodes within two-hop range.(3)In a piggyback way,the control information is transmitted together with the payload to reduce the overhead.We design the whole mechanisms,implement them in NS-3 and evaluate the performance of DSO-TDMA compared with another dynamic TDMA MAC protocol,EHR-TDMA.Results show that the end-to-end throughput of DSO-TDMA is at most 51.4%higher than that of EHR-TDMA,and the average access delay of DSO-TDMA is at most 66.05%lower than that of EHR-TDMA.展开更多
基金The National Basic Research Program of China(973 Program)(No.2009CB320501)the National Natural Science Foundation of China(No.61370209,61272532)the Natural Science Foundation of Jiangsu Province(No.BK2010414,BK2011335)
文摘In order to save the energy and reduce the latency of the end-to-end transmission in mobile ad hoc networks an adaptive and distance-driven power control ADPC scheme is proposed by means of distance research in random geometrics. Through mathematical proof the optimal number of relay nodes and the optimal location of each node for data transmission can be obtained when a distance is given.In the ADPC first the source node computes the optimal number and the sites of the relay nodes between the source and the destination nodes.Then it searches feasible relay nodes around the optimal virtual relay-sites and selects one link with the minimal total transmission energy consumption for data transmission.Simulation results show that the ADPC can reduce both the energy dissipation and the end-to-end latency of the transmission.
基金Supported by National Natural Science Foundation of China(Grant No.61371076)
文摘For the Cooperative Adaptive Cruise Control （CACC） Algorithm, existing research studies mainly focus on how inter-vehicle communication can be used to develop CACC controller, the influence of the communication delays and lags of the actuators to the string stability. However, whether the string stability can be guaranteed when inter-vehicle communication is invalid partially has hardly been considered. This paper presents an improved CACC algorithm based on the sliding mode control theory and analyses the range of CACC controller parameters to maintain string stability. A dynamic model of vehicle spacing deviation in a platoon is then established, and the string stability conditions under improved CACC are analyzed. Unlike the traditional CACC algorithms, the proposed algorithm can ensure the functionality of the CACC system even if inter-vehicle communication is partially invalid. Finally, this paper establishes a platoon of five vehicles to simulate the improved CACC algorithm in MATLAB/Simulink, and the simulation results demonstrate that the improved CACC algorithm can maintain the string stability of a CACC platoon through adjusting the controller parameters and enlarging the spacing to prevent accidents. With guaranteed string stability, the proposed CACC algorithm can prevent oscillation of vehicle spacing and reduce chain collision accidents under real-world circumstances. This research proposes an improved CACC algorithm, which can guarantee the string stability when inter-vehicle communication is invalid.
基金supported by Natural Science Foundation ofChongqing(No.CSTC2009BA2064)Fundamental Research Fundsfor Central Universities(No.CDJZR12160004)PostgraduateScience and Technology Innovation Fund(No.CDJXS12161109)
文摘In this paper, a relay selection strategy and distributed power control algorithm are proposed for the underlay spectrum sharing mode based cooperative cognitive ad hoc network with energy-limited users. The study aims to minimize the total power consumption of cooperative cognitive ad hoc network while ensuring the quality of service(QoS) requirement of cognitive user and keeping the interference to primary user below interference tolerance. The power control problem is transformed into a convex optimization problem. Based on Lagrange dual decomposition theory, a gradient iterative algorithm is constructed to search for the optimal solution and complete distributed power optimization. Simulation results show that the algorithm converges fast and reduces transmit power of cognitive users effectively while guaranteeing the QoS requirement.
文摘As a new sort of mobile ad hoc network(MANET), aeronautical ad hoc network(AANET) has fleet-moving airborne nodes(ANs) and suffers from frequent network partitioning due to the rapid-changing topology. In this work, the additional relay nodes(RNs) is employed to repair the network and maintain connectivity in AANET. As ANs move, RNs need to move as well in order to re-establish the topology as quickly as possible. The network model and problem definition are firstly given, and then an online approach for RNs' movement control is presented to make ANs achieve certain connectivity requirement during run time. By defining the minimum cost feasible moving matrix(MCFM), a fast algorithm is proposed for RNs' movement control problem. Simulations demonstrate that the proposed algorithm outperforms other control approaches in the highly-dynamic environment and is of great potential to be applied in AANET.
文摘In this paper, based on the inherent characteristic of the contention relation between flows in ad hoc networks, we introduce the notion of the link＇s interference set, extend the utility maximization problem representing congestion control in wireline networks to ad hoc networks, apply the penalty function approach and the subgradient method to solve this problem, and propose the congestion control algorithm Penalty function-based Optical Congestion Control （POCC） which is implemented in NS2- simulator. Specifically, each link transmits periodically the information on its congestion state to its interference set; the set ; the sermon at each source adjusts the transmission rate based on the optimal tradeoffbetween the utility value and the congestion level which the interference set of the links that this session goes though suffers from. MATLAB-based simulation results showed that POCC can approach the globally optimal solution. The NS2-based simulation results showed that POCC outperforms default TCP and ATCP to achieve efficient and fair resource allocation in ad hoc networks.
文摘A joint power control algorithm for ad hoc networks based on code division multiple access （CDMA） was studied. Firstly, the new algorithm was deduced in theory. Then, the system model was developed. In the proposed algorithm, all transmitting nodes assigned in the same time slot adjust their transmitter power based on current information, which takes into account the adjustments of transmitter power of other transmitting nodes in next step and the prediction of inter-link interference power level at the receive node. Simulation results indicate that the proposed algorithm outperforms the conventional algorithms in terms of smaller standard deviation of receiver signal-to-interference-ratio, lower system interference and higher energy efficiency.
基金Supported by National Natural Science Foundation of China （60674036）, the Science and Technique Development Plan of Shandong Province of China （2004GG4204014）, the Program for New Century Excellent Talents in University of China （NCET-07-0513）, the Key Science and Technique Foundation of Ministry of Education of China （108079）, and the Excellent Young and Middle-Aged Scientist Award Grant of Shandong Province of China （2007BS01010）
基金supported in part by the Project of National Natural Science Foundation of China (61301110)Project of Shanghai Key Laboratory of Intelligent Information Processing, China [grant number IIPL-2014-005]+1 种基金the Project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Project of Jiangsu Overseas Research & Training Program for University Prominent Young & Middle-Aged Teachers and Presidents
文摘As device-to-device(D2D) communications usually reuses the resource of cellular networks, call admission control(CAC) and power control are crucial problems. However in most power control schemes, total data rates or throughput are regarded as optimization criterion. In this paper, a combining call admission control(CAC) and power control scheme under guaranteeing QoS of every user equipment(UE) is proposed. First, a simple CAC scheme is introduced. Then based on the CAC scheme, a combining call admission control and power control scheme is proposed. Next, the performance of the proposed scheme is evaluated. Finally, maximum DUE pair number and average transmitting power is calculated. Simulation results show that D2 D communications with the proposed combining call admission control and power control scheme can effectively improve the maximum DUE pair number under the premise of meeting necessary QoS.
文摘This paper presents a new topology to implement Class F power amplifier for eliminating the on-resistance (R_(ON))effect.The time-domain and frequency-domain voltage and current waveforms for Class F amplifier are ana- lyzed using Fourier series analysis method.Considering the on-resistance effect,the formulas of the efficiency,output power,dc power dissipation,and fundamental load impedance are given from ideal current and voltage waveforms.For experimental verification,we designed and implemented a Class F power amplifier,which operates at 850 MHz using MGaAs/GaAs Heterostructure FET(HFET)device,and analyzed the measurement results.Test results show that the maximum PAE of 67% can be achieved at 28 dBm output power level.
基金Supported by the Science Foundation of Shanghai Mu-nicipal Commission of Science and Technology under contract 045115012.
文摘This paper proposes a new multi-channel Medium Access Control (MAC) protocol named as Dual Reservation Code Division Multiple Access (CDMA) based MAC protocol with Power Control (DRCPC). The code channel is divided into common channel,broadcast channel and several data chan-nels. And dynamic power control mechanism is implemented to reduce near-far interference. Compared with IEEE 802.11 Distributed Coordination Function (DCF) protocol,the results show that the pro-posed mechanism improves the average throughput and limits the transmission delay efficiently.
文摘Security in Ad Hoc network is an important issue under the opening circumstance of application service. Some protocols and models of security auditing have been proposed to ensure rationality of contracting strategy and operating regulation and used to identify abnormal operation. Model of security auditing based on access control of devices will be advanced to register sign of devices and property of event of access control and to audit those actions. In the end, the model is analyzed and simulated.
文摘IEEE 802.11 distributed coordination function(DCF)can alleviate the collision and hidden station problem,but it doesn't differentiate traffic categories(TC).Therefore,it can't provide sufficient quality of service(QoS)support for different TC.Recently,a new contention-based enhanced distributed channel access(EDCA)scheme is proposed which provides a probabilistic QoS support.In this paper,an improved EDCA scheme for service differentiation in ad hoc networks is proposed.In this scheme,signal channel resistance coefficient is used to adjust the contention window(CW).It proves that the scheme provides the traffic differentiation,high throughput and low delay through simulation.
基金supported by the Doctor Subject Foundation of the Gansu Natural Science Foundation of China(1107RJ-ZA170)
文摘The ad lamp-box controller is designed in consideration that ordinary urban ad lights usually remain lit through the night and a specially assigned staff needs to be on duty to control their switches.It can be automatically controlled with a photo resistance testing the day and night as well as a CD4060 chip controlling the length of time interval between switching the ad lamp-boxes on and off.In this way,both energy and labor can be saved with the controller.It is matching with the target of"constructing a conservation-minded society"in our country and deserves to be promoted in market with its practical significance.
基金supported by the National Natural Science Foundation of China for Distinguished Young Scholars(No.60525303)the National Natural Science Foundation of China(No.60904048,60404022,60604012)the Natural Science Foundation of Hebei Province(No.F2005000390,F2006000270)
文摘We consider the problem of fair rate control for wireless ad-hoc networks with time varying channel capacities. The interaction between links in wireless ad-hoc networks introduces additional constraints on the flow rate. A primal-dual algorithm that guarantees fair rate control is proved to be trajectory stable. Various fairness indexes are obtained by choosing the specified form of the utility functions, and the numerical results validate the effectiveness of the proposed algorithm.
文摘Research on wide area ad hoc networks is of great significance due to its application prospect in long-range networks such as aeronautical and maritime networks,etc.The design of MAC protocols is one of the most important parts impacting the whole network performance.In this paper,we propose a dis-tributed TDMA-based MAC protocol called Dynamic Self Organizing TDMA(DSO-TDMA)for wide area ad hoc networks.DSO-TDMA includes three main features:(1)In a distributed way,nodes in the network select transmitting slots according to the congestion situation of the local air interface.(2)In a selforganization way,nodes dynamically adjust the resource occupancy ratio according to the queue length of neighbouring nodes within two-hop range.(3)In a piggyback way,the control information is transmitted together with the payload to reduce the overhead.We design the whole mechanisms,implement them in NS-3 and evaluate the performance of DSO-TDMA compared with another dynamic TDMA MAC protocol,EHR-TDMA.Results show that the end-to-end throughput of DSO-TDMA is at most 51.4%higher than that of EHR-TDMA,and the average access delay of DSO-TDMA is at most 66.05%lower than that of EHR-TDMA.
