Pub Date : 2018-01-01DOI: 10.1504/IJSSC.2018.098695
E. Rogova, A. Maraj, Blerat Ukaj
General aviation flights range from gliders and powered parachutes to corporate business jet flights. The majority of the world's air traffic falls into this category which covers a large range of activities, both commercial and non-commercial. As such, general aviation plays an important role in the economic development. This paper treats the importance of VFR flight planning while using a navigational database, navigation points, restricted zones, obstacles, positioning, air speed and routes based on global positioning system (GPS). It provides an overview of a spatial database for flight planning and registration of navigational coordinates. The paper continues with an analysis of the planning process and the impact of an e-system for flight planning and navigation safety during VFR flights in Kosovo airspace. The practical implementation of this paper will result in the development of a bespoke software application for planning electronic flights.
{"title":"Location-based applications, services and technologies in aid of flight planning and GPS-based navigation for visual flight rules in developing countries: with a case study","authors":"E. Rogova, A. Maraj, Blerat Ukaj","doi":"10.1504/IJSSC.2018.098695","DOIUrl":"https://doi.org/10.1504/IJSSC.2018.098695","url":null,"abstract":"General aviation flights range from gliders and powered parachutes to corporate business jet flights. The majority of the world's air traffic falls into this category which covers a large range of activities, both commercial and non-commercial. As such, general aviation plays an important role in the economic development. This paper treats the importance of VFR flight planning while using a navigational database, navigation points, restricted zones, obstacles, positioning, air speed and routes based on global positioning system (GPS). It provides an overview of a spatial database for flight planning and registration of navigational coordinates. The paper continues with an analysis of the planning process and the impact of an e-system for flight planning and navigation safety during VFR flights in Kosovo airspace. The practical implementation of this paper will result in the development of a bespoke software application for planning electronic flights.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"1 1","pages":"225-237"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75652402","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}
Pub Date : 2018-01-01DOI: 10.1504/IJSSC.2018.097291
Hiroyuki Suzuki, A. Koyama
Currently, various IoT applications are developed and used in various fields. Generally, the development model of IoT applications is still vertical type model. However, in vertical type model, when novel systems are developed, same functions of past developed system cannot be used. As the results, the application development period becomes long. In this paper, we propose a novel IoT application development method based on 'real object-oriented model' which is a horizontal type model. The proposed method can be applied in the application development without being conscious the middleware. In order to improve the development efficiency and reduce the development period, the proposed method automatically combines an application and a middleware, and transmits the combined code to devices, and automatically execute the code at the devices. We evaluated amounts of source codes and development time for each method, and showed the usefulness of the proposed method compared with two conventional methods.
{"title":"An implementation and evaluation of IoT application development method based on real object-oriented model","authors":"Hiroyuki Suzuki, A. Koyama","doi":"10.1504/IJSSC.2018.097291","DOIUrl":"https://doi.org/10.1504/IJSSC.2018.097291","url":null,"abstract":"Currently, various IoT applications are developed and used in various fields. Generally, the development model of IoT applications is still vertical type model. However, in vertical type model, when novel systems are developed, same functions of past developed system cannot be used. As the results, the application development period becomes long. In this paper, we propose a novel IoT application development method based on 'real object-oriented model' which is a horizontal type model. The proposed method can be applied in the application development without being conscious the middleware. In order to improve the development efficiency and reduce the development period, the proposed method automatically combines an application and a middleware, and transmits the combined code to devices, and automatically execute the code at the devices. We evaluated amounts of source codes and development time for each method, and showed the usefulness of the proposed method compared with two conventional methods.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"13 1","pages":"151-159"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78369398","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}
Pub Date : 2018-01-01DOI: 10.1504/IJSSC.2018.098691
Nitin Gupta, S. K. Dhurandher, I. Woungang, J. Rodrigues
In cognitive radio networks, handoff occurs when an unlicensed spectrum user has to switch to a new target channel from its current operating channel which a secondary user was using opportunistically. This situation raises whenever either the licensed primary user appears again or the channel's condition get worst. Substantial sensing time can be saved if a secondary user can make a proactive decision about selecting the future vacant target channel to resume the unfinished transmission before starting its transmission. This paper proposes a novel target channel sequence selection scheme for cognitive radio networks, which minimises the estimated service time of a secondary user by reducing the multiple handoffs. A non-iterative algorithm is implemented, which does not require the use of an exhaustive search technique as usual to determine the target channel sequence. Simulation results show that the proposed scheme outperforms both the random scheme and a considered benchmark scheme in terms of service time, cumulative handoff delay and throughput achieved by the secondary user.
{"title":"On the target channel sequence selection for multiple handoffs in cognitive radio-based wireless regional area networks","authors":"Nitin Gupta, S. K. Dhurandher, I. Woungang, J. Rodrigues","doi":"10.1504/IJSSC.2018.098691","DOIUrl":"https://doi.org/10.1504/IJSSC.2018.098691","url":null,"abstract":"In cognitive radio networks, handoff occurs when an unlicensed spectrum user has to switch to a new target channel from its current operating channel which a secondary user was using opportunistically. This situation raises whenever either the licensed primary user appears again or the channel's condition get worst. Substantial sensing time can be saved if a secondary user can make a proactive decision about selecting the future vacant target channel to resume the unfinished transmission before starting its transmission. This paper proposes a novel target channel sequence selection scheme for cognitive radio networks, which minimises the estimated service time of a secondary user by reducing the multiple handoffs. A non-iterative algorithm is implemented, which does not require the use of an exhaustive search technique as usual to determine the target channel sequence. Simulation results show that the proposed scheme outperforms both the random scheme and a considered benchmark scheme in terms of service time, cumulative handoff delay and throughput achieved by the secondary user.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"14 1","pages":"214-224"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73659280","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}
Pub Date : 2018-01-01DOI: 10.1504/IJSSC.2018.097293
Dhouha El Houssaini, Zinab Mohamed, Sabrine Khriji, K. Besbes, O. Kanoun
Localisation methods based on the received signal strength indicator (RSSI) are widely used in wireless sensor networks (WSNs). They offer an energy reduced and cost-effective solutions for wireless localisation. Due to radio irregularity, RSSI localisation is vulnerable to multipath, shadowing, interference and environmental effects, which reduces the accuracy of localisation results. In this paper, a new distance measurement correction algorithm is presented, which is based on feedback filter and hardware characteristic. It implements the feedback filter with consideration of historical values of RSSI. This enables to predict possible values of RSSI and thus nodes positions. Hardware characteristics, such as multiplication and summation capabilities are explored to improve the localisation accuracy. Real experiments were carried out on panStamp sensor nodes at two different temperatures. The new proposed RSSI technique shows a reduced localisation error compared to the simple RSSI method.
{"title":"Distance measurement correction based on feedback filter for RSSI localisation technique in WSNs","authors":"Dhouha El Houssaini, Zinab Mohamed, Sabrine Khriji, K. Besbes, O. Kanoun","doi":"10.1504/IJSSC.2018.097293","DOIUrl":"https://doi.org/10.1504/IJSSC.2018.097293","url":null,"abstract":"Localisation methods based on the received signal strength indicator (RSSI) are widely used in wireless sensor networks (WSNs). They offer an energy reduced and cost-effective solutions for wireless localisation. Due to radio irregularity, RSSI localisation is vulnerable to multipath, shadowing, interference and environmental effects, which reduces the accuracy of localisation results. In this paper, a new distance measurement correction algorithm is presented, which is based on feedback filter and hardware characteristic. It implements the feedback filter with consideration of historical values of RSSI. This enables to predict possible values of RSSI and thus nodes positions. Hardware characteristics, such as multiplication and summation capabilities are explored to improve the localisation accuracy. Real experiments were carried out on panStamp sensor nodes at two different temperatures. The new proposed RSSI technique shows a reduced localisation error compared to the simple RSSI method.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"139 1","pages":"160-168"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80011163","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}
Pub Date : 2018-01-01DOI: 10.1504/IJSSC.2018.097286
Kwenga Ismael Munene, N. Funabiki, M. Kuribayashi, R. Sudibyo, W. Kao
Currently, the IEEE 802.11n wireless local-area network (WLAN) has been deployed world-wide due to flexibility and low costs. A key challenge in the WLAN deployment is to provide high data-rate under strong interferences due to the limited frequency channels. In WLAN, the adjacent channels are partially overlapped with each other, called partially overlapping channels (POCs). Then, the optimal POC assignment to the access-points (APs) in WLAN using the mathematical model is important to improve the performance, particularly for usage of the channel bonding. In this paper, we propose the throughput estimation model extension for concurrent communications of two IEEE 802.11n links under interferences using POCs and the channel bonding, from extensive measurement results under a variety of conditions. Then, based on this model, we present the channel assignment extension in the active AP configuration algorithm for the elastic WLAN system, which dynamically optimises the topology depending on network conditions. For the evaluation, we verify the model accuracy through comparing estimated throughputs with measured ones under various conditions. On top of that, we confirm throughput improvements by adopting POCs from using merely orthogonal channels (OCs) in simulations and experiments in several topologies.
{"title":"A throughput estimation model under two-link concurrent communications with partially overlapping channels and its application to channel assignment in IEEE 802.11n WLAN","authors":"Kwenga Ismael Munene, N. Funabiki, M. Kuribayashi, R. Sudibyo, W. Kao","doi":"10.1504/IJSSC.2018.097286","DOIUrl":"https://doi.org/10.1504/IJSSC.2018.097286","url":null,"abstract":"Currently, the IEEE 802.11n wireless local-area network (WLAN) has been deployed world-wide due to flexibility and low costs. A key challenge in the WLAN deployment is to provide high data-rate under strong interferences due to the limited frequency channels. In WLAN, the adjacent channels are partially overlapped with each other, called partially overlapping channels (POCs). Then, the optimal POC assignment to the access-points (APs) in WLAN using the mathematical model is important to improve the performance, particularly for usage of the channel bonding. In this paper, we propose the throughput estimation model extension for concurrent communications of two IEEE 802.11n links under interferences using POCs and the channel bonding, from extensive measurement results under a variety of conditions. Then, based on this model, we present the channel assignment extension in the active AP configuration algorithm for the elastic WLAN system, which dynamically optimises the topology depending on network conditions. For the evaluation, we verify the model accuracy through comparing estimated throughputs with measured ones under various conditions. On top of that, we confirm throughput improvements by adopting POCs from using merely orthogonal channels (OCs) in simulations and experiments in several topologies.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"22 1","pages":"123-137"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90055510","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 focus on the automatic identification system (AIS), which is a probe data system. Some researchers propose using this system not only to support ship handling, such as through collision avoidance, but also in other ways, such as for navigation time analysis, accident tracing, or navigation management by administrators on land. Therefore, we focus on the importance of obtaining more marine ship position information, including that for a small ship using class B AIS, to enrich the intelligent transport system service for marine traffic. First, we develop a processing tool to create an operation management book from the recorded AIS data. We then study the implementation of these utility tools and evaluate their effectiveness.
{"title":"Design and evaluation of a utility tool for recorded class B AIS data in an unstable maritime environment","authors":"Misako Urakami, Hisaya Motogi, Tomohiro Sunada, Kenshiro Okamura, Takayuki Watanabe, N. Wakabayashi","doi":"10.1504/IJSSC.2018.098675","DOIUrl":"https://doi.org/10.1504/IJSSC.2018.098675","url":null,"abstract":"We focus on the automatic identification system (AIS), which is a probe data system. Some researchers propose using this system not only to support ship handling, such as through collision avoidance, but also in other ways, such as for navigation time analysis, accident tracing, or navigation management by administrators on land. Therefore, we focus on the importance of obtaining more marine ship position information, including that for a small ship using class B AIS, to enrich the intelligent transport system service for marine traffic. First, we develop a processing tool to create an operation management book from the recorded AIS data. We then study the implementation of these utility tools and evaluate their effectiveness.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"46 1","pages":"188-195"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77078315","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}
Pub Date : 2017-12-29DOI: 10.1504/IJSSC.2017.10010062
Khin Khin Zaw, N. Funabiki
To advance Java programming educations, we have developed the web-based Java programming learning assistant system (JPLAS) that provides the code writing problem. This problem asks a student to write a source code for a given assignment, where the correctness is verified by running the test code on JUnit. In this paper, we propose a design-aware test code approach for the code writing problem. The design-aware test code tests any important method in the model source code that has the advisable design for the assignment. Thus, by writing a code that can pass it, a student is expected to implement the code with the proper classes/methods in the model code. In evaluations of the proposal, all the students could complete highly qualitative codes for five graph algorithms using the design-aware test codes, where the code quality metrics were measured by metrics plugin for Eclipse.
{"title":"A design-aware test code approach for code writing problem in Java programming learning assistant system","authors":"Khin Khin Zaw, N. Funabiki","doi":"10.1504/IJSSC.2017.10010062","DOIUrl":"https://doi.org/10.1504/IJSSC.2017.10010062","url":null,"abstract":"To advance Java programming educations, we have developed the web-based Java programming learning assistant system (JPLAS) that provides the code writing problem. This problem asks a student to write a source code for a given assignment, where the correctness is verified by running the test code on JUnit. In this paper, we propose a design-aware test code approach for the code writing problem. The design-aware test code tests any important method in the model source code that has the advisable design for the assignment. Thus, by writing a code that can pass it, a student is expected to implement the code with the proper classes/methods in the model code. In evaluations of the proposal, all the students could complete highly qualitative codes for five graph algorithms using the design-aware test codes, where the code quality metrics were measured by metrics plugin for Eclipse.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"401 1","pages":"145-154"},"PeriodicalIF":0.0,"publicationDate":"2017-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74298504","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}
Pub Date : 2017-10-03DOI: 10.1504/IJSSC.2017.10008018
Mouna Ktari, M. Mosbah, A. Kacem
Leader election problem is among the important problems in distributed computing. The continued evolution of distributed systems keeps the distributed computing an open area of research. Distributed algorithms are hard to design and much harder to prove. To make designing distributed algorithm easier, we model this latter with a local computations model. Distributed algorithms are formally presented by rewriting rules. Beyond a formal presentation of these algorithms, local computations theory proposes not only a correctness proof by the use of invariants but also a termination proof by the use of the graph mathematical tool-box. Based on both, the local computations model and the mobile agent paradigms, we present in this paper a distributed algorithm that elects a leader and computes a spanning tree in a dynamic graph. Computations in dynamic graphs can be affected by a set of topological events: we address the appearance and the disappearance of places and communication channels. Our goal is to always maintain a tree by a single leader or a forest of sub-trees where each one has its own leader.
{"title":"Leader election and computation of a spanning tree in dynamic distributed networks using local computations and mobile agents","authors":"Mouna Ktari, M. Mosbah, A. Kacem","doi":"10.1504/IJSSC.2017.10008018","DOIUrl":"https://doi.org/10.1504/IJSSC.2017.10008018","url":null,"abstract":"Leader election problem is among the important problems in distributed computing. The continued evolution of distributed systems keeps the distributed computing an open area of research. Distributed algorithms are hard to design and much harder to prove. To make designing distributed algorithm easier, we model this latter with a local computations model. Distributed algorithms are formally presented by rewriting rules. Beyond a formal presentation of these algorithms, local computations theory proposes not only a correctness proof by the use of invariants but also a termination proof by the use of the graph mathematical tool-box. Based on both, the local computations model and the mobile agent paradigms, we present in this paper a distributed algorithm that elects a leader and computes a spanning tree in a dynamic graph. Computations in dynamic graphs can be affected by a set of topological events: we address the appearance and the disappearance of places and communication channels. Our goal is to always maintain a tree by a single leader or a forest of sub-trees where each one has its own leader.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"21 1","pages":"57-71"},"PeriodicalIF":0.0,"publicationDate":"2017-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84398469","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}
Pub Date : 2017-10-03DOI: 10.1504/IJSSC.2017.10008038
Riyadh Arridha, S. Sukaridhoto, D. Pramadihanto, N. Funabiki
Monitoring water conditions in real-time is a critical mission to preserve the water ecosystem in maritime and archipelagic countries, such as Indonesia that is relying on the wealth of water resources. To integrate the water monitoring system into the big data technology for real-time analysis, we have engaged in the ongoing project named smart environment monitoring and analytic in real-time system (SEMAR), which provides the IoT-big data platform for water monitoring. However, SEMAR does not have an analytical system yet. This paper proposes the analytical system for water quality classification using Pollution Index method, which is an extension of SEMAR. Besides, the communication protocol is updated from REST to MQTT. Furthermore, the real-time user interface is implemented for visualisation. The evaluations confirmed that the data analytic function adopting the linear SVM and decision tree algorithms achieves more than 90% for the estimation accuracy with 0.019075 for the MSE.
{"title":"Classification extension based on IoT-big data analytic for smart environment monitoring and analytic in real-time system","authors":"Riyadh Arridha, S. Sukaridhoto, D. Pramadihanto, N. Funabiki","doi":"10.1504/IJSSC.2017.10008038","DOIUrl":"https://doi.org/10.1504/IJSSC.2017.10008038","url":null,"abstract":"Monitoring water conditions in real-time is a critical mission to preserve the water ecosystem in maritime and archipelagic countries, such as Indonesia that is relying on the wealth of water resources. To integrate the water monitoring system into the big data technology for real-time analysis, we have engaged in the ongoing project named smart environment monitoring and analytic in real-time system (SEMAR), which provides the IoT-big data platform for water monitoring. However, SEMAR does not have an analytical system yet. This paper proposes the analytical system for water quality classification using Pollution Index method, which is an extension of SEMAR. Besides, the communication protocol is updated from REST to MQTT. Furthermore, the real-time user interface is implemented for visualisation. The evaluations confirmed that the data analytic function adopting the linear SVM and decision tree algorithms achieves more than 90% for the estimation accuracy with 0.019075 for the MSE.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"144 1","pages":"82-93"},"PeriodicalIF":0.0,"publicationDate":"2017-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77453230","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}
Pub Date : 2017-10-03DOI: 10.1504/IJSSC.2017.10008041
Visali Mushunuri, B. Panigrahi, H. Rath, Anantha Simha
In a moderate to high traffic scenario wireless fidelity (WiFi) performance degrades severely due to interference and back-off mechanism. Licensed assisted access (LAA) has been proposed by 3rd Generation Partnership Project (3GPP) to use long term evolution (LTE) in the un-licensed spectrum. As the centralised LAA has to co-exist with existing distributed wireless fidelity (WiFi), efficient listen before talk (LBT) technique is required to reduce interference and improve spectral efficiency of WiFi and LAA users. In this paper, we have proposed an LBT mechanism to share the medium in a fair manner and improves both WiFi-LAA combined system performances significantly. We have also analysed closed form solution for the LBT technique. We validated network performance of proposed LBT model using network simulator (NS-3) and Matlab. The results indicated that with proper choice of LAA channel occupancy and backoff counter, significant performance gains of WiFi-LAA can be achieved.
在中高流量场景下，由于干扰和后退机制，无线保真度(WiFi)性能严重下降。第三代合作伙伴计划(3GPP)提出了授权辅助接入(LAA)，以在未授权频谱中使用长期演进(LTE)。由于集中式LAA必须与现有的分布式无线保真度(WiFi)共存，因此需要高效的先听后讲(LBT)技术来减少干扰，提高WiFi和LAA用户的频谱效率。在本文中，我们提出了一种LBT机制，以公平的方式共享介质，显著提高了wi - fi - laa组合系统的性能。我们还分析了LBT技术的封闭形式解决方案。我们使用网络模拟器(NS-3)和Matlab验证了所提出的LBT模型的网络性能。结果表明，合理选择LAA信道占用率和退退计数器，可以显著提高WiFi-LAA的性能。
{"title":"Efficient listen before technique for LTE-WiFi co-existence in unlicensed bands","authors":"Visali Mushunuri, B. Panigrahi, H. Rath, Anantha Simha","doi":"10.1504/IJSSC.2017.10008041","DOIUrl":"https://doi.org/10.1504/IJSSC.2017.10008041","url":null,"abstract":"In a moderate to high traffic scenario wireless fidelity (WiFi) performance degrades severely due to interference and back-off mechanism. Licensed assisted access (LAA) has been proposed by 3rd Generation Partnership Project (3GPP) to use long term evolution (LTE) in the un-licensed spectrum. As the centralised LAA has to co-exist with existing distributed wireless fidelity (WiFi), efficient listen before talk (LBT) technique is required to reduce interference and improve spectral efficiency of WiFi and LAA users. In this paper, we have proposed an LBT mechanism to share the medium in a fair manner and improves both WiFi-LAA combined system performances significantly. We have also analysed closed form solution for the LBT technique. We validated network performance of proposed LBT model using network simulator (NS-3) and Matlab. The results indicated that with proper choice of LAA channel occupancy and backoff counter, significant performance gains of WiFi-LAA can be achieved.","PeriodicalId":43931,"journal":{"name":"International Journal of Space-Based and Situated Computing","volume":"1 1","pages":"108-118"},"PeriodicalIF":0.0,"publicationDate":"2017-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79867990","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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