Solving the controller placement problem (CPP) in an SDN architecture with multiple controllers has a significant impact on control overhead in the network, especially in multihop wireless networks (MWNs). The generated control overhead consists of controller-device and inter-controller communications to discover the network topology, exchange configurations, and set up and modify flow tables in the control plane. However, due to the high complexity of the proposed optimization model to the CPP, heuristic algorithms have been reported to find near-optimal solutions faster for large-scale wired networks. In this paper, the objective is to extend those existing heuristic algorithms to solve a proposed optimization model to the CPP in software-defined multihop wireless networking (SDMWN).Our results demonstrate that using ranking degrees assigned to the possible controller placements, including the average distance to other devices as a degree or the connectivity degree of each placement, the extended heuristic algorithms are able to achieve the optimal solution in small-scale networks in terms of the generated control overhead and the number of controllers selected in the network. As a result, using extended heuristic algorithms, the average number of hops among devices and their assigned controllers as well as among controllers will be reduced. Moreover, these algorithms are able tolower the control overhead in large-scale networks and select fewer controllers compared to an extended algorithm that solves the CPP in SDMWN based on a randomly selected controller placement approach.
{"title":"Using Heuristics to the Controller Placement Problem in Software-Defined Multihop Wireless Networking","authors":"Afsane Zahmatkesh, Chung-Horng Lung","doi":"10.4236/cn.2020.124010","DOIUrl":"https://doi.org/10.4236/cn.2020.124010","url":null,"abstract":"Solving the controller placement problem (CPP) in an SDN architecture with multiple \u0000controllers has a significant impact on control overhead in the network, \u0000especially in multihop wireless networks (MWNs). The generated control overhead \u0000consists of controller-device and inter-controller communications to discover \u0000the network topology, exchange configurations, and set up and modify flow \u0000tables in the control plane. However, due to the high complexity of the proposed \u0000optimization model to the CPP, heuristic algorithms have been reported to find \u0000near-optimal solutions faster for large-scale wired networks. In this paper, \u0000the objective is to extend those existing heuristic algorithms to solve a \u0000proposed optimization model to the CPP in software-defined multihop wireless networking (SDMWN).Our results demonstrate that \u0000using ranking degrees assigned to the possible controller placements, including \u0000the average distance to other devices as a degree or the connectivity degree of \u0000each placement, the extended heuristic algorithms are able to achieve the \u0000optimal solution in small-scale networks in terms of the generated control \u0000overhead and the number of controllers selected in the network. As a result, \u0000using extended heuristic algorithms, the average number of hops among devices \u0000and their assigned controllers as well as among controllers will be reduced. \u0000Moreover, these algorithms are able tolower the \u0000control overhead in large-scale networks and select fewer controllers compared \u0000to an extended algorithm that solves the CPP in SDMWN based on a randomly selected controller placement \u0000approach.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88296620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present an effective routing solution for the backbone of hierarchical MANETs. Our solution leverages the storage and retrieval mechanisms of a Distributed Hash Table (DHT) common to many (structured) P2P overlays. The DHT provides routing information in a decentralized fashion, while supporting different forms of node and network mobility. We split a flat network into clusters, each having a gateway who participates in a DHT overlay. These gateways interconnect the clusters in a backbone network. Two routing approaches for the backbone are explored: flooding and a new solution exploiting the storage and retrieval capabilities of a P2P overlay based on a DHT. We implement both approaches in a network simulator and thoroughly evaluate the performance of the proposed scheme using a range of static and mobile scenarios. We also compare our solution against flooding. The simulation results show that our solution, even in the presence of mobility, achieved well above 90% success rates and maintained very low and constant round trip times, unlike the flooding approach. In fact, the performance of the proposed inter-cluster routing solution, in many cases, is comparable to the performance of the intra-cluster routing case. The advantage of our proposed approach compared to flooding increases as the number of clusters increases, demonstrating the superior scalability of our proposed approach.
{"title":"A P2P Approach to Routing in Hierarchical MANETs","authors":"T. Kunz, Silas Echegini, B. Esfandiari","doi":"10.4236/cn.2020.123006","DOIUrl":"https://doi.org/10.4236/cn.2020.123006","url":null,"abstract":"We present an effective routing solution for the backbone of hierarchical \u0000MANETs. Our solution leverages the storage and retrieval mechanisms \u0000of a Distributed Hash Table (DHT) common to many (structured) P2P overlays. The DHT provides routing information in a \u0000decentralized fashion, while supporting different forms of node and \u0000network mobility. We split a flat network into clusters, each having a gateway \u0000who participates in a DHT overlay. These gateways \u0000interconnect the clusters in a backbone network. Two routing approaches \u0000for the backbone are explored: flooding \u0000and a new solution exploiting the storage and \u0000retrieval capabilities of a P2P overlay based on a DHT. We implement both approaches in a network \u0000simulator and thoroughly evaluate the \u0000performance of the proposed scheme using a range of static and mobile \u0000scenarios. We also compare our solution against flooding. The simulation results \u0000show that our solution, even in the presence of mobility, achieved well above 90% success rates and maintained very low and \u0000constant round trip times, unlike the flooding approach. In fact, the \u0000performance of the proposed inter-cluster \u0000routing solution, in many cases, is comparable to the performance of the intra-cluster routing case. The \u0000advantage of our proposed approach compared to flooding increases as the \u0000number of clusters increases, demonstrating the superior scalability of our \u0000proposed approach.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"19 1","pages":"99-121"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89682448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With ever-increasing applications of IoT, and due to the heterogeneous and bursty nature of these applications, scalability has become an important research issue in building cloud-based IoT/M2M systems. This research proposes a dynamic SDN-based network slicing mechanism to tackle the scalability problems caused by such heterogeneity and fluctuation of IoT application requirements. The proposed method can automatically create a network slice on-the-fly for each new type of IoT application and adjust the QoS characteristics of the slice dynamically according to the changing requirements of an IoT application. Validated with extensive experiments, the proposed mechanism demonstrates better platform scalability when compared to a static slicing system.
{"title":"Enhancing Cloud-Based IoT/M2M System Scalability by Dynamic Network Slicing","authors":"David de la Bastida, F. Lin","doi":"10.4236/cn.2020.123007","DOIUrl":"https://doi.org/10.4236/cn.2020.123007","url":null,"abstract":"With ever-increasing applications of IoT, and due to \u0000the heterogeneous and bursty nature of these applications, scalability has \u0000become an important research issue in building cloud-based IoT/M2M systems. \u0000This research proposes a dynamic SDN-based network slicing mechanism to tackle \u0000the scalability problems caused by such heterogeneity and fluctuation of IoT \u0000application requirements. The proposed method can automatically create a \u0000network slice on-the-fly for each new type of IoT application and adjust the \u0000QoS characteristics of the slice dynamically according to the changing \u0000requirements of an IoT application. \u0000Validated with extensive experiments, the proposed mechanism \u0000demonstrates better platform scalability when compared to a static slicing \u0000system.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"81 1","pages":"122-154"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82858382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In a cloud computing environment, users using the pay-as-you-go billing model can relinquish their services at any point in time and pay accordingly. From the perspective of the Cloud Service Providers (CSPs), this is not beneficial as they may lose the opportunity to earn from the relinquished resources. Therefore, this paper tackles the resource assignment problem while considering users relinquishment and its impact on the net profit of CSPs. As a solution, we first compare different ways to predict user behavior (i.e. how likely a user will leave the system before its scheduled end time) and deduce a better prediction technique based on linear regression. Then, based on the RACE (Relinquishment-Aware Cloud Economics) model proposed in [1], we develop a relinquishment-aware resource optimization model to estimate the amount of resources to assign on the basis of predicted user behavior. Simulations performed with CloudSim show that cloud service providers can gain more by estimating the amount of resources using better prediction techniques rather than blindly assigning resources to users. They also show that the proposed prediction-based resource assignment scheme typically generates more profit for a lower or similar utilization.
{"title":"Prediction-Based Resource Assignment Scheme to Maximize the Net Profit of Cloud Service Providers","authors":"Sarabjeet Singh, M. St-Hilaire","doi":"10.4236/cn.2020.122005","DOIUrl":"https://doi.org/10.4236/cn.2020.122005","url":null,"abstract":"In a cloud computing environment, users using the pay-as-you-go billing model can relinquish their services at any point in time and pay accordingly. From the perspective of the Cloud Service Providers (CSPs), this is not beneficial as they may lose the opportunity to earn from the relinquished resources. Therefore, this paper tackles the resource assignment problem while considering users relinquishment and its impact on the net profit of CSPs. As a solution, we first compare different ways to predict user behavior (i.e. how likely a user will leave the system before its scheduled end time) and deduce a better prediction technique based on linear regression. Then, based on the RACE (Relinquishment-Aware Cloud Economics) model proposed in [1], we develop a relinquishment-aware resource optimization model to estimate the amount of resources to assign on the basis of predicted user behavior. Simulations performed with CloudSim show that cloud service providers can gain more by estimating the amount of resources using better prediction techniques rather than blindly assigning resources to users. They also show that the proposed prediction-based resource assignment scheme typically generates more profit for a lower or similar utilization.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88072860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Performance evaluation is essential in maintaining the Quality of Service (QOS) of the Wideband Code Division Multiplexing Access (WCDMA). This work was motivated by the reception of the poor signals, increase call drop, failure rate which was a poor QoS Reception. The aim is to survey WCDMA services in Owerri environs and establish that there are degradation and the level of debasement in the network. The methodology involved an Empirical Analysis through Drive Test across Owerri City in Imo State. The work adopted the empirical approach and deduction of some Standard performance metrics like call drop rate, failure rate, call success rate, call completion rate, Handover success rate and handover Failure Rate, compare with expected KPI(key performance indicator) threshold. From the assessment, it was found that only one out Four Networks (“GLO”) met the target Call Drop Rate (CDR), Call Completion Success rate (CCSR), Call Setup Success Rate (CSSR) and Call Blocked Rate (CBR) and the Handover was better in “GLO” and 9 mobile than in the “MTN” and Airtel.
{"title":"Quality of Service (QoS) Evaluation in Wideband Code Division Multiplexing Access (WCDMA) Networks Using Empirical Analysis Methods","authors":"G. Chukwudebe, E. Ekwonwune, Florence O. Elei","doi":"10.4236/cn.2020.122004","DOIUrl":"https://doi.org/10.4236/cn.2020.122004","url":null,"abstract":"Performance evaluation is essential in maintaining the Quality of Service (QOS) of the Wideband Code Division Multiplexing Access (WCDMA). This work was motivated by the reception of the poor signals, increase call drop, failure rate which was a poor QoS Reception. The aim is to survey WCDMA services in Owerri environs and establish that there are degradation and the level of debasement in the network. The methodology involved an Empirical Analysis through Drive Test across Owerri City in Imo State. The work adopted the empirical approach and deduction of some Standard performance metrics like call drop rate, failure rate, call success rate, call completion rate, Handover success rate and handover Failure Rate, compare with expected KPI(key performance indicator) threshold. From the assessment, it was found that only one out Four Networks (“GLO”) met the target Call Drop Rate (CDR), Call Completion Success rate (CCSR), Call Setup Success Rate (CSSR) and Call Blocked Rate (CBR) and the Handover was better in “GLO” and 9 mobile than in the “MTN” and Airtel.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88861307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Ali, T. Wood-Harper, Abdullah Sultan Al-Qahtani, Abubakar Albakri
Although there have been remarkable technological developments in healthcare, the privacy and security of mobile health systems (mHealth) still raise many concerns with considerable consequences for patients using these technologies. For instance, potential security and privacy threats in wireless devices, such as Wi-Fi and Bluetooth connected to a patient hub at the application, middleware and sensory layers, may result in the disclosure of private and sensitive data. This paper explores the security and privacy of the patient hub, including patient applications and their connections to sensors and cloud technology. Addressing the privacy and security concerns of the patient hub called for a comprehensive risk assessment by using the OCTAVE risk assessment framework. Findings reveal that the highest risk concerned data exposure at the sensory layer. In spite of the countermeasures presented in this paper, most served as a means to identify risk early as opposed to mitigating them. The findings can serve to inform users of the potential vulnerabilities in the patient hub before they arise.
{"title":"Risk Assessment Framework of mHealth System Vulnerabilities: A Multilayer Analysis of the Patient Hub","authors":"M. Ali, T. Wood-Harper, Abdullah Sultan Al-Qahtani, Abubakar Albakri","doi":"10.4236/cn.2020.122003","DOIUrl":"https://doi.org/10.4236/cn.2020.122003","url":null,"abstract":"Although there have been remarkable technological developments in healthcare, the privacy and security of mobile health systems (mHealth) still raise many concerns with considerable consequences for patients using these technologies. For instance, potential security and privacy threats in wireless devices, such as Wi-Fi and Bluetooth connected to a patient hub at the application, middleware and sensory layers, may result in the disclosure of private and sensitive data. This paper explores the security and privacy of the patient hub, including patient applications and their connections to sensors and cloud technology. Addressing the privacy and security concerns of the patient hub called for a comprehensive risk assessment by using the OCTAVE risk assessment framework. Findings reveal that the highest risk concerned data exposure at the sensory layer. In spite of the countermeasures presented in this paper, most served as a means to identify risk early as opposed to mitigating them. The findings can serve to inform users of the potential vulnerabilities in the patient hub before they arise.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"206 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88738664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The world is moving at a high speed in the implementation and innovations of new systems and gadgets. 3G and 4G networks support currently wireless network communications. However, the networks are deemed to be slow and fail to receive signals or data transmission to various regions as a result of solving the problem. This paper will analyze the use of Software Defined Network (SDN) in a 5G (fifth generation) network that can be faster and reliable. Further, in Mobile IP, there exist triangulation problems between the sending and receiving nodes along with latency issues during handoff for the mobile nodes causing huge burden in the network. With Cloud Computing and ecosystem for Virtualization developed for the Core and Radio Networks SDN OpenFlow seems to be a seamless solution for determining signal flow between mobiles. There have been a lot of researches going on for deploying SDN OpenFlow with the 5G Cellular Network. The current paper performs benchmarks as a feasibility need for implementing SDN OpenFlow for 5G Cellular Network. The Handoff mechanism impacts the scalability required for a cellular network and simulation results can be further used to be deployed the 5G Network.
{"title":"Software Defined Network (SDN) and OpenFlow Protocol in 5G Network","authors":"Khaled Alghamdi, R. Braun","doi":"10.4236/cn.2020.121002","DOIUrl":"https://doi.org/10.4236/cn.2020.121002","url":null,"abstract":"The world is moving at a high speed in the implementation and innovations of new systems and gadgets. 3G and 4G networks support currently wireless network communications. However, the networks are deemed to be slow and fail to receive signals or data transmission to various regions as a result of solving the problem. This paper will analyze the use of Software Defined Network (SDN) in a 5G (fifth generation) network that can be faster and reliable. Further, in Mobile IP, there exist triangulation problems between the sending and receiving nodes along with latency issues during handoff for the mobile nodes causing huge burden in the network. With Cloud Computing and ecosystem for Virtualization developed for the Core and Radio Networks SDN OpenFlow seems to be a seamless solution for determining signal flow between mobiles. There have been a lot of researches going on for deploying SDN OpenFlow with the 5G Cellular Network. The current paper performs benchmarks as a feasibility need for implementing SDN OpenFlow for 5G Cellular Network. The Handoff mechanism impacts the scalability required for a cellular network and simulation results can be further used to be deployed the 5G Network.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"403 1","pages":"28-40"},"PeriodicalIF":0.0,"publicationDate":"2020-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78109821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lama Y. Hosni, Ahmed Y. Farid, Abdelrahman A. Elsaadany, M. Safwat
The fifth generation (5G) New Radio (NR) has been developed to provide significant improvements in scalability, flexibility, and efficiency in terms of power usage and spectrum as well. To meet the 5G vision, service and performance requirements, various candidate technologies have been proposed in 5G new radio; some are extensions of 4G and, some are developed explicitly for 5G. These candidate technologies include non-Orthogonal Multiple Access (NOMA), and Low Density Parity Check (LDPC) channel coding. In addition, deploying software defined radio (SDR) instead of traditional hardware modules. In this paper we build an open source SDR-based platform to realize the transceiver of the physical downlink shared channel (PDSCH) of 5G NR according to Third Generation Partnership Project (3GPP) standard. We provide a prototype for pairing between two 5G users using NOMA technique. In addition, a suitable design for LDPC channel coding is performed. The intermediate stage of segmentation, rate matching and interleaving are also carried out in order to realize a standard NR frame. Finally, experiments are carried out in both simulation and real time scenario on the designed 5G NR for the purpose of system performance evaluation, and to demonstrate its potential in meeting future 5G mobile network challenges.
{"title":"5G New Radio Prototype Implementation Based on SDR","authors":"Lama Y. Hosni, Ahmed Y. Farid, Abdelrahman A. Elsaadany, M. Safwat","doi":"10.4236/cn.2020.121001","DOIUrl":"https://doi.org/10.4236/cn.2020.121001","url":null,"abstract":"The fifth generation (5G) New Radio (NR) has been developed to provide significant improvements in scalability, flexibility, and efficiency in terms of power usage and spectrum as well. To meet the 5G vision, service and performance requirements, various candidate technologies have been proposed in 5G new radio; some are extensions of 4G and, some are developed explicitly for 5G. These candidate technologies include non-Orthogonal Multiple Access (NOMA), and Low Density Parity Check (LDPC) channel coding. In addition, deploying software defined radio (SDR) instead of traditional hardware modules. In this paper we build an open source SDR-based platform to realize the transceiver of the physical downlink shared channel (PDSCH) of 5G NR according to Third Generation Partnership Project (3GPP) standard. We provide a prototype for pairing between two 5G users using NOMA technique. In addition, a suitable design for LDPC channel coding is performed. The intermediate stage of segmentation, rate matching and interleaving are also carried out in order to realize a standard NR frame. Finally, experiments are carried out in both simulation and real time scenario on the designed 5G NR for the purpose of system performance evaluation, and to demonstrate its potential in meeting future 5G mobile network challenges.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"81 1","pages":"1-27"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85824727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ultraviolet (UV) photoresponses of Wurtzite GaN, ZnO, and 6H-SiC-based Optical Field Effect Transistor (OPFET) detectors are estimated with an in-depth analysis of the same considering the generalized model and the front-illuminated model for high resolution imaging and UV communication applications. The gate materials considered for the proposed study are gold (Au) and Indium-Tin-Oxide (ITO) for GaN, Au for SiC, and Au and silver dioxide (AgO2) for ZnO. The results indicate significant improvement in the Linear Dynamic Range (LDR) over the previously investigated GaN OPFET (buried-gate, front-illuminated and generalized) models with Au gate. The generalized model has superior dynamic range than the front-illuminated model. In terms of responsivity, all the models including buried-gate OPFET exhibit high and comparable photoresponses. Buried-gate devices on the whole, exhibit faster response than the surface gate models except in the AgO2-ZnO generalized OPFET model wherein the switching time is the lowest. The generalized model enables faster switching than the front-illuminated model. The switching times in all the cases are of the order of nanoseconds to picoseconds. The SiC generalized OPFET model shows the highest 3-dB bandwidths of 11.88 GHz, 36.2 GHz, and 364 GHz, and modest unity-gain cut-off frequencies of 4.62 GHz, 8.71 GHz, and 5.71 GHz at the optical power densities of 0.575 μW/cm2, 0.575 mW/cm2, and 0.575 W/cm2 respectively. These are in overall, the highest detection-cum-amplifi-cation bandwidths among all the investigated devices. The same device exhibits the highest LDR of 73.3 dB. The device performance is superior to most of the other existing detectors along with comparable LDR, thus, emerging as a high performance photodetector for imaging and communication applications. All the detectors show considerably high detectivities owing to the high responsivity values. The results have been analyzed by the photovoltaic and the photoconductive effects, and the series resistance effects and will aid in conducting further research. The results are in line with the experiments and the commercially available software simulations. The devices will greatly contribute towards single photon counting, high resolution imaging, and UV communication applications.
{"title":"Analysis of Wide-Bandgap Material OPFET UV Detectors for High Dynamic Range Imaging and Communication Applications","authors":"J. Gaitonde, R. Lohani","doi":"10.4236/cn.2019.114007","DOIUrl":"https://doi.org/10.4236/cn.2019.114007","url":null,"abstract":"The ultraviolet (UV) photoresponses of Wurtzite GaN, ZnO, and 6H-SiC-based Optical Field Effect Transistor (OPFET) detectors are estimated with an in-depth analysis of the same considering the generalized model and the front-illuminated model for high resolution imaging and UV communication applications. The gate materials considered for the proposed study are gold (Au) and Indium-Tin-Oxide (ITO) for GaN, Au for SiC, and Au and silver dioxide (AgO2) for ZnO. The results indicate significant improvement in the Linear Dynamic Range (LDR) over the previously investigated GaN OPFET (buried-gate, front-illuminated and generalized) models with Au gate. The generalized model has superior dynamic range than the front-illuminated model. In terms of responsivity, all the models including buried-gate OPFET exhibit high and comparable photoresponses. Buried-gate devices on the whole, exhibit faster response than the surface gate models except in the AgO2-ZnO generalized OPFET model wherein the switching time is the lowest. The generalized model enables faster switching than the front-illuminated model. The switching times in all the cases are of the order of nanoseconds to picoseconds. The SiC generalized OPFET model shows the highest 3-dB bandwidths of 11.88 GHz, 36.2 GHz, and 364 GHz, and modest unity-gain cut-off frequencies of 4.62 GHz, 8.71 GHz, and 5.71 GHz at the optical power densities of 0.575 μW/cm2, 0.575 mW/cm2, and 0.575 W/cm2 respectively. These are in overall, the highest detection-cum-amplifi-cation bandwidths among all the investigated devices. The same device exhibits the highest LDR of 73.3 dB. The device performance is superior to most of the other existing detectors along with comparable LDR, thus, emerging as a high performance photodetector for imaging and communication applications. All the detectors show considerably high detectivities owing to the high responsivity values. The results have been analyzed by the photovoltaic and the photoconductive effects, and the series resistance effects and will aid in conducting further research. The results are in line with the experiments and the commercially available software simulations. The devices will greatly contribute towards single photon counting, high resolution imaging, and UV communication applications.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74265024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper explores the exploitation of Mobile/Multi-access Edge Computing (MEC) for Vehicle-to-Everything (V2X) communications. Certain V2X applications that aim at improving road safety require reliable and low latency message delivery. As the number of connected vehicles increases, these requirements cannot be satisfied by technologies relying on the IEEE 802.11p standard. Therefore, the exploitation of the 4th generation Long Term Evolution (LTE) mobile networks has been considered. However, despite their widespread use, LTE systems are characterized by high end-to-end latency since the messages have to traverse the core network. MEC addresses this problem by offering computing, storage and network resources at the edge of the network closer to the end-users. This paper aims at investigating the benefits MEC may offer toward implementing V2X communications. In this framework, simulation scenarios were examined concerning various V2X use cases implemented employing either LTE or MEC. The simulation results indicate a clear superiority of MEC over LTE, especially in the case of delivering critical data.
{"title":"A Mobile Edge Computing Approach for Vehicle to Everything Communications","authors":"Plouton Grammatikos, P. Cottis","doi":"10.4236/cn.2019.113006","DOIUrl":"https://doi.org/10.4236/cn.2019.113006","url":null,"abstract":"This paper explores the exploitation of Mobile/Multi-access Edge Computing (MEC) for Vehicle-to-Everything (V2X) communications. Certain V2X applications that aim at improving road safety require reliable and low latency message delivery. As the number of connected vehicles increases, these requirements cannot be satisfied by technologies relying on the IEEE 802.11p standard. Therefore, the exploitation of the 4th generation Long Term Evolution (LTE) mobile networks has been considered. However, despite their widespread use, LTE systems are characterized by high end-to-end latency since the messages have to traverse the core network. MEC addresses this problem by offering computing, storage and network resources at the edge of the network closer to the end-users. This paper aims at investigating the benefits MEC may offer toward implementing V2X communications. In this framework, simulation scenarios were examined concerning various V2X use cases implemented employing either LTE or MEC. The simulation results indicate a clear superiority of MEC over LTE, especially in the case of delivering critical data.","PeriodicalId":91826,"journal":{"name":"... IEEE Conference on Communications and Network Security. IEEE Conference on Communications and Network Security","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89620915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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