In this paper, virtual cell layout (VCL) based dynamic source routing (VB-DSR) technique is intro... more In this paper, virtual cell layout (VCL) based dynamic source routing (VB-DSR) technique is introduced for the mobile subsystem of the next generation tactical communications systems. VB-DSR uses dynamic source routing (DSR) protocol over VCL structure, which is a resource management and clustering technique for tactical communications. The application of the third generation personal communications services to the tactical communications is enabled through a hybrid, i.e., ad hoc and cellular, infrastructureless architecture by VCL. VB-DSR enhances the schemes for the ad hoc components of this architecture. The performance evaluation of the proposed technique shows that the VB-DSR is scalable for tactical communications.
2020 5th International Conference on Computer Science and Engineering (UBMK)
The amount of applications that require high bandwidth and low latency, such as video, audio, tel... more The amount of applications that require high bandwidth and low latency, such as video, audio, teleconferencing, is increasing more than ever. The use of such applications by the end user has also increased exponentially in the last 20 years and reached its peak in the 2020 pandemic period. In such applications, service providers had to reduce the quality of their services during the pandemic due to the inability to provide the desired bandwidth and delay. Therefore, to provide services in desired quality, especially for the time critical and interactive applications, it is very important to measure the delay precisely and accurately in order to determine the changes and anomalies occurring in delay and take precautions afterwards. This paper presents the methods and approaches developed for precise and accurate delay measurement and to determine actual state of the network more accurately.
2019 1st International Informatics and Software Engineering Conference (UBMYK), 2019
V2X communications is one key feature in the 5G standards that enables the vehicles get connected... more V2X communications is one key feature in the 5G standards that enables the vehicles get connected and access the cellular services anywhere anytime. It is essential to build a realistic simulation environment for large scale demonstration of the system under test including varying number of vehicles, application/network services, road network infrastructure and new solution approaches/methods proposed to enhance or make improvements on the system performance. This paper describes the simulation environment developed for this purpose and also evaluates the V2X communication and the services provided by the cellular network. The results provide insights on the system performance and the follow-up studies to improve the performance.
2021 24th Euromicro Conference on Digital System Design (DSD), 2021
Building on many discoveries and inventions, electronics started affecting people’s everyday live... more Building on many discoveries and inventions, electronics started affecting people’s everyday lives in a significant fashion following the invention of the first solid state transistor in late 1940s. The miniaturization paved way for the mass electronics production and later the digital revolution, the outcomes of which are visible to all members of the public today. After about a two-decade-long swing around 2000s from hardware towards software regarding what affects lives more, a point has now been reached where electronics is more important to all and its use is more ubiquitous and crucial than ever before. In most if not all of end user or industrial applications, the capability and quality of electronics hardware are the key determining factors.The European electronics components and systems (ECS) industry has traditionally had a high base line for electronics innovation. However, the industry is now compelled, partly due to competition and partly due customer demand, to manufacture even more reliable electronics products than before. Guaranteeing the reliability of electronics hardware entails the entire ECS value chain to undergo a paradigm shift to holistically address reliability as a key issue. The European ECS industry previously adopted overseas outsourcing considerably, however it is now taking steps to reshape itself into a more coherent value chain with the aim of having not only the electronics designs but also the electronics manufacturing made in Europe.H2020-ECSEL programme successfully funds highly competitive projects in the area of electronics components and systems. We present here a prologue to a similarly funded project entitled Intelligent Reliability 4.0 ("iRel40"), by providing a background to the topic of ECS, project objectives, and the methodologies and implementations we plan to undertake during the 36-month period of this ongoing project.
Sensor nodes in a Wireless Sensor Network (WSN) can be dispersed over a remote sensing area (e.g.... more Sensor nodes in a Wireless Sensor Network (WSN) can be dispersed over a remote sensing area (e.g., the regions that are hardly accessed by human beings). In such kinds of networks, datacollectionbecomesoneofthemajorissues. Getting connected to each sensor node and retrieving the information in time introduces new challenges. Mobile sink usage-especially Unmanned Aerial Vehicles (UAVs)-is the most convenient approach to covering the area and accessing each sensor node in such a large-scale WSN. However, the operation of the UAV depends on some parameters, such as endurance time, altitude, speed, radio type in use, and the path. In this paper, we explore various UAV mobility patterns that follow different paths to sweep the operation area in order to seek the best area coverage with the maximum number of covered nodes in the least amount of time needed by the mobile sink. We also introduce a new metric to formulate the tradeoff between maximizing the covered nodes and minimizing the o...
2016 IEEE 21st International Workshop on Computer Aided Modelling and Design of Communication Links and Networks (CAMAD), 2016
In Vehicular Ad Hoc Networks (VANETs), efficient use of the control channel affects both safety a... more In Vehicular Ad Hoc Networks (VANETs), efficient use of the control channel affects both safety applications that use the control channel and other applications that use the service channels. Its efficiency deteriorates due the collisions on accessing to the control channel or due to the merging collisions which happen when fast moving vehicles use the same allocated channels. In this paper, we propose an algorithm which predicts the possible merging collisions due to the overtaking of fast vehicles. It predicts the collisions within 2-hops neighborhood and recommends the vehicle to acquire a new time slot in the control channel. Through simulations, it is shown that proposed approach reduces the merging collisions.
2016 IEEE Symposium on Computers and Communication (ISCC), 2016
Understanding vehicle mobility is essential for devising successful protocols for vehicular commu... more Understanding vehicle mobility is essential for devising successful protocols for vehicular communications. Vehicles move at varying speeds on roads whose complexities range from plain highway lanes to urban boulevards with intersections/circles, traffic lights and various points of interest on them. This mobility pattern combined with vehicle density fluctuations depending on location and time makes understanding the vehicular mobility a challenging task and leads to vehicular communication solutions which are incomplete or low-performance. In this paper, we propose an alternative method for vehicular mobility analysis. We attempt to extract the spatio-temporal vehicular mobility characteristics of large, complex geographical areas by dividing them into cells and analyzing on these cells certain metrics that are of interest for vehicular communication. We first discuss the logic behind our approach. We then present definitions of the metrics used by the proposed analysis method. We conclude with a demonstration of the results achieved when the proposed method is applied in the analysis of a large scale mobility trace.
In recent year years, adaptive approaches are getting more interest in application areas. On the ... more In recent year years, adaptive approaches are getting more interest in application areas. On the other hand, canonical algorithms keep their importance as a first step solution approach and for comparison with adaptive approaches. In this paper, two problems, namely the One-Max Problem and the Generalized Rastrigin's Function, are solved using generational canonical algorithms with fixed mutation rate parameter and self-adaptive mutation rate parameter. For these problems, solution results of self-adaptive methods are compared with the results of deterministic methods. Observed results provide interesting results for these problems. KANONİK ALGORİTMALAR VE UYARLANABİLİR ALGORİTMALARIN BİLİNEN İKİ PROBLEM İÇİN DEĞERLENDİRİLMESİ Özetçe Son yıllarda uyarlanabilir yaklaşımlar uygulama alanlarında daha fazla ilgi görmektedir. Diğer taraftan, başvurulan ilk çözüm yöntemi olması ve uyarlanabilir algoritmaların karşılaştırılmasında kullanılması nedeniyle, kanonik algoritmalar hala önemlerini korumaktadırlar. Bu makalede, One-Max Problemi ve Genelleştirilmiş Rastrigin's Fonksiyonu, hem sabit Müjdat SOYTÜRK 27 mutasyon oranı hem de kendinden-uyarlamalı mutasyon oranı kullanılarak çözülmüştür. Kendinden uyarlamalı yöntem ile elde edilen sonuçlar, belirleyici yöntemden elde edilen sonuçlar ile karşılaştırılmıştır. Sonuçların, değerli katkısı olmuştur.
2015 IEEE International Conference on Communication, Networks and Satellite (COMNESTAT), 2015
EFFECTS OF UAV MOBILITY PATTERNS ON DATA COLLECTION IN WIRELESS SENSOR NETWORKS Sensor nodes in a... more EFFECTS OF UAV MOBILITY PATTERNS ON DATA COLLECTION IN WIRELESS SENSOR NETWORKS Sensor nodes in a Wireless Sensor Network (WSN) can be dispersed over a remote sensing area e.g. the regions that cannot be accessed by human beings (inaccessible regions). In such kind of networks, data collection becomes one of the major issues. Getting connected to each sensor node and retrieving the information in time introduces new challenges. Mobile sink usage, especially the Unmanned Aerial Vehicle (UAV), is the most convenient approach to cover the area and access each sensor node in such a large scale WSN. However, the operation of the UAV depends on some parameters such as endurance time, altitude, speed, radio type in use, and the path. In this paper, we
Bu makale, birinci yazar tarafından İTÜ Fen Bilimleri Enstitüsü, Bilgisayar Mühendisliği Programı... more Bu makale, birinci yazar tarafından İTÜ Fen Bilimleri Enstitüsü, Bilgisayar Mühendisliği Programında tamamlanmış olan "A Novel Communication Approach for Wireless Mobile Smart Objects" adlı doktora tezinden hazırlanmıştır. Makale metni 04.07.2007 tarihinde dergiye ulaşmış, 01.08.2007 tarihinde basım kararı alınmıştır. Makale ile ilgili tartışmalar 31.03.2009 tarihine kadar dergiye gönderilmelidir. Özet Tasarsız (ad hoc) ve duyarga (sensör) ağlar, altyapısız ağlar olduğu için altyapılı ağlarda bol miktarda bulunan enerji, işlemci, bellek, bandgenişliği gibi kaynaklar kısıtlıdır ve özenle tüketilmelidir. Ağ elemanlarının boyutlarının çok küçük olması, enerjiyi en kısıtlı kaynak yapmaktadır. Ancak, kaynak ile varış arasında veri akışının sağlanması için kullanılan yöntemler enerji tüketimini arttırmaktadır. Bu nedenle, literatürde enerji-etkin yönlendirme protokolleri sunulmuştur. Bu protokollerden, coğrafi yer bilgisine dayanarak yönlendirme yapan protokoller, diğerlerine göre daha yüksek başarıma ve performans değerlerine sahiptir. Bu çalışmada, Durumsuz Ağırlıklı Yönlendirme (DAY) isimli bir özgün kaynak-başlatmalı veri akış tekniği sunulmaktadır. Düğümler sadece kendi sanal coğrafi yer bilgilerini bilmekte, ağ topololoji bilgisine ihtiyaç duymamaktadır. Her düğüm kendi ağırlığını hesaplamaktadır. Başlangıçta bu değer varışa olan mesafedir. Düğümler kendilerine gelen paketlerin içindeki ağırlık bilgilerine bakarak paketi tekrar göndermeye veya düşürmeye karar vermektedir. Bu karşılaştırma işlemi durumsuz olma özelliğini sağlamaktadır. Ağırlık parametresi sadece yer bilgisini içerebildiği gibi düğümün kalan enerjisi gibi Servis Kalitesi parametre bilgisini de içerebilir. Servis Kalite bilgisi sistemin yaşamömrünü arttırmaya yöneliktir. Durumsuz olma özelliği ile de, yönlendirme tablosu tutulan algoritmalarda görülen iletişim yükü büyük oranda azalmaktadır. DAY, aynı zamanda, güvenirliği sağlayan ve gerçek-zamanlı veri için de gerekli olan çoklu-yollar veya örülü çoklu-yollar kullanır. Tekrar-gönderimlerde eşik değerlerinin kullanımı, sistemde esnek ve enerji etkin bir veri akışı sağlar. Aynı zamanda, DAY, MACkatmanından bağımsız çalışan ilk durumsuz coğrafi yönlendirme tekniğidir.
2015 International Wireless Communications and Mobile Computing Conference (IWCMC), 2015
Clustering algorithms improve network manageability through several topology partitioning techniq... more Clustering algorithms improve network manageability through several topology partitioning techniques. In some particular cases, such as vehicular ad hoc network (VANETs) communications, significant performance improvements can be introduced via clustered networking solutions whereas merging clusters for the sake of scalability may lead to degraded network stability. In this paper, we explore the impact of merging clusters, and furthermore based on these results, we propose a new clustering technique, namely Relatively Stable Clustering for Unbiased Environments (ReSCUE). The objective of ReSCUE is primarily guaranteeing cluster stability in an unbiased manner. ReSCUE keeps track of the spatio-temporal changes in VANET node characteristics, and uses these characteristics along with local information to prevent biased clustering which is based on common and general node characteristics. We evaluate the performance of ReSCUE through simulations and show that ReSCUE can form relatively more stable clusters while reducing the frequency of cluster merges, as well as that of the node status changes.
2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015
There is a number of ways to estimate the number of people in a particular area. From image proce... more There is a number of ways to estimate the number of people in a particular area. From image processing to movement pattern analysis, the sheer number of methods exist in the literature. An interesting one among these methods is the one estimating with the use of signal processing. Because it is much cheaper compared to the other methods in the literature, it is more commonly implemented. In this study, the number of people in a particular area is estimated by analyzing the WiFi signals captured from mobile devices.
International Journal of Distributed Sensor Networks, 2012
Resource limitations of sensor nodes in wireless sensor networks (WSN) bound the performance on i... more Resource limitations of sensor nodes in wireless sensor networks (WSN) bound the performance on its implementations. Main concern becomes utilizing these limited resources (CPU, memory, bandwidth, battery) as efficient as possible. Their efficiency is mostly affected by the applied routing algorithm, which carries gathered data to inclined/intended destinations. In this paper, a novel routing algorithm, stateless weight routing (SWR), is proposed. The SWR differs from other protocols in many ways. Major feature of the SWR is its simplicity. It is a completely stateless protocol without requiring any network or neighborhood information for routing. This feature decreases packet transmissions and energy consumption dramatically. For reliability, data flows to the sink node over multiple paths. Moreover, nodes have the ability of recovering from voids. Nodes process each packet independently and apply an adaptive approach according to the current conditions. These mechanisms are part o...
2006 IEEE Annual Wireless and Microwave Technology Conference, 2006
As the energy becomes the most valuable resource in the wireless sensor networks, to prolong the ... more As the energy becomes the most valuable resource in the wireless sensor networks, to prolong the lifetime of the network, energy-aware protocols are proposed which use the energy minimization techniques and multi-hop paths. However, multi-hop paths and complex calculations at nodes introduce delay and processing overhead. Providing energy-efficiency becomes a scalability problem. Scalability of a routing protocol for wireless sensor networks is mainly affected by the topological changes and by the number of sensor nodes in the network. In large scale networks with a large number of sensor nodes, multiple-sinks (gateways) should be used to provide scalability. In this paper, a novel stateless energy-efficient routing technique, Stateless Weight Routing with Multiple Sinks (MS-SWR), is introduced for wireless sensor networks. MS-SWR requires no local/global topological information. Property of being stateless avoids the communication overhead and reduces the calculations to minimum. In MS-SWR, reliability is provided by using multiple paths which also reduces the delay to minimum for the time-critical real-time traffic. The performance evaluation of the proposed technique shows that MS-SWR is scalable for large scale wireless sensor networks with multiple sinks.
In this paper, virtual cell layout (VCL) based dynamic source routing (VB-DSR) technique is intro... more In this paper, virtual cell layout (VCL) based dynamic source routing (VB-DSR) technique is introduced for the mobile subsystem of the next generation tactical communications systems. VB-DSR uses dynamic source routing (DSR) protocol over VCL structure, which is a resource management and clustering technique for tactical communications. The application of the third generation personal communications services to the tactical communications is enabled through a hybrid, i.e., ad hoc and cellular, infrastructureless architecture by VCL. VB-DSR enhances the schemes for the ad hoc components of this architecture. The performance evaluation of the proposed technique shows that the VB-DSR is scalable for tactical communications.
In this paper, virtual cell layout (VCL) based dynamic source routing (VB-DSR) technique is intro... more In this paper, virtual cell layout (VCL) based dynamic source routing (VB-DSR) technique is introduced for the mobile subsystem of the next generation tactical communications systems. VB-DSR uses dynamic source routing (DSR) protocol over VCL structure, which is a resource management and clustering technique for tactical communications. The application of the third generation personal communications services to the tactical communications is enabled through a hybrid, i.e., ad hoc and cellular, infrastructureless architecture by VCL. VB-DSR enhances the schemes for the ad hoc components of this architecture. The performance evaluation of the proposed technique shows that the VB-DSR is scalable for tactical communications.
2020 5th International Conference on Computer Science and Engineering (UBMK)
The amount of applications that require high bandwidth and low latency, such as video, audio, tel... more The amount of applications that require high bandwidth and low latency, such as video, audio, teleconferencing, is increasing more than ever. The use of such applications by the end user has also increased exponentially in the last 20 years and reached its peak in the 2020 pandemic period. In such applications, service providers had to reduce the quality of their services during the pandemic due to the inability to provide the desired bandwidth and delay. Therefore, to provide services in desired quality, especially for the time critical and interactive applications, it is very important to measure the delay precisely and accurately in order to determine the changes and anomalies occurring in delay and take precautions afterwards. This paper presents the methods and approaches developed for precise and accurate delay measurement and to determine actual state of the network more accurately.
2019 1st International Informatics and Software Engineering Conference (UBMYK), 2019
V2X communications is one key feature in the 5G standards that enables the vehicles get connected... more V2X communications is one key feature in the 5G standards that enables the vehicles get connected and access the cellular services anywhere anytime. It is essential to build a realistic simulation environment for large scale demonstration of the system under test including varying number of vehicles, application/network services, road network infrastructure and new solution approaches/methods proposed to enhance or make improvements on the system performance. This paper describes the simulation environment developed for this purpose and also evaluates the V2X communication and the services provided by the cellular network. The results provide insights on the system performance and the follow-up studies to improve the performance.
2021 24th Euromicro Conference on Digital System Design (DSD), 2021
Building on many discoveries and inventions, electronics started affecting people’s everyday live... more Building on many discoveries and inventions, electronics started affecting people’s everyday lives in a significant fashion following the invention of the first solid state transistor in late 1940s. The miniaturization paved way for the mass electronics production and later the digital revolution, the outcomes of which are visible to all members of the public today. After about a two-decade-long swing around 2000s from hardware towards software regarding what affects lives more, a point has now been reached where electronics is more important to all and its use is more ubiquitous and crucial than ever before. In most if not all of end user or industrial applications, the capability and quality of electronics hardware are the key determining factors.The European electronics components and systems (ECS) industry has traditionally had a high base line for electronics innovation. However, the industry is now compelled, partly due to competition and partly due customer demand, to manufacture even more reliable electronics products than before. Guaranteeing the reliability of electronics hardware entails the entire ECS value chain to undergo a paradigm shift to holistically address reliability as a key issue. The European ECS industry previously adopted overseas outsourcing considerably, however it is now taking steps to reshape itself into a more coherent value chain with the aim of having not only the electronics designs but also the electronics manufacturing made in Europe.H2020-ECSEL programme successfully funds highly competitive projects in the area of electronics components and systems. We present here a prologue to a similarly funded project entitled Intelligent Reliability 4.0 ("iRel40"), by providing a background to the topic of ECS, project objectives, and the methodologies and implementations we plan to undertake during the 36-month period of this ongoing project.
Sensor nodes in a Wireless Sensor Network (WSN) can be dispersed over a remote sensing area (e.g.... more Sensor nodes in a Wireless Sensor Network (WSN) can be dispersed over a remote sensing area (e.g., the regions that are hardly accessed by human beings). In such kinds of networks, datacollectionbecomesoneofthemajorissues. Getting connected to each sensor node and retrieving the information in time introduces new challenges. Mobile sink usage-especially Unmanned Aerial Vehicles (UAVs)-is the most convenient approach to covering the area and accessing each sensor node in such a large-scale WSN. However, the operation of the UAV depends on some parameters, such as endurance time, altitude, speed, radio type in use, and the path. In this paper, we explore various UAV mobility patterns that follow different paths to sweep the operation area in order to seek the best area coverage with the maximum number of covered nodes in the least amount of time needed by the mobile sink. We also introduce a new metric to formulate the tradeoff between maximizing the covered nodes and minimizing the o...
2016 IEEE 21st International Workshop on Computer Aided Modelling and Design of Communication Links and Networks (CAMAD), 2016
In Vehicular Ad Hoc Networks (VANETs), efficient use of the control channel affects both safety a... more In Vehicular Ad Hoc Networks (VANETs), efficient use of the control channel affects both safety applications that use the control channel and other applications that use the service channels. Its efficiency deteriorates due the collisions on accessing to the control channel or due to the merging collisions which happen when fast moving vehicles use the same allocated channels. In this paper, we propose an algorithm which predicts the possible merging collisions due to the overtaking of fast vehicles. It predicts the collisions within 2-hops neighborhood and recommends the vehicle to acquire a new time slot in the control channel. Through simulations, it is shown that proposed approach reduces the merging collisions.
2016 IEEE Symposium on Computers and Communication (ISCC), 2016
Understanding vehicle mobility is essential for devising successful protocols for vehicular commu... more Understanding vehicle mobility is essential for devising successful protocols for vehicular communications. Vehicles move at varying speeds on roads whose complexities range from plain highway lanes to urban boulevards with intersections/circles, traffic lights and various points of interest on them. This mobility pattern combined with vehicle density fluctuations depending on location and time makes understanding the vehicular mobility a challenging task and leads to vehicular communication solutions which are incomplete or low-performance. In this paper, we propose an alternative method for vehicular mobility analysis. We attempt to extract the spatio-temporal vehicular mobility characteristics of large, complex geographical areas by dividing them into cells and analyzing on these cells certain metrics that are of interest for vehicular communication. We first discuss the logic behind our approach. We then present definitions of the metrics used by the proposed analysis method. We conclude with a demonstration of the results achieved when the proposed method is applied in the analysis of a large scale mobility trace.
In recent year years, adaptive approaches are getting more interest in application areas. On the ... more In recent year years, adaptive approaches are getting more interest in application areas. On the other hand, canonical algorithms keep their importance as a first step solution approach and for comparison with adaptive approaches. In this paper, two problems, namely the One-Max Problem and the Generalized Rastrigin's Function, are solved using generational canonical algorithms with fixed mutation rate parameter and self-adaptive mutation rate parameter. For these problems, solution results of self-adaptive methods are compared with the results of deterministic methods. Observed results provide interesting results for these problems. KANONİK ALGORİTMALAR VE UYARLANABİLİR ALGORİTMALARIN BİLİNEN İKİ PROBLEM İÇİN DEĞERLENDİRİLMESİ Özetçe Son yıllarda uyarlanabilir yaklaşımlar uygulama alanlarında daha fazla ilgi görmektedir. Diğer taraftan, başvurulan ilk çözüm yöntemi olması ve uyarlanabilir algoritmaların karşılaştırılmasında kullanılması nedeniyle, kanonik algoritmalar hala önemlerini korumaktadırlar. Bu makalede, One-Max Problemi ve Genelleştirilmiş Rastrigin's Fonksiyonu, hem sabit Müjdat SOYTÜRK 27 mutasyon oranı hem de kendinden-uyarlamalı mutasyon oranı kullanılarak çözülmüştür. Kendinden uyarlamalı yöntem ile elde edilen sonuçlar, belirleyici yöntemden elde edilen sonuçlar ile karşılaştırılmıştır. Sonuçların, değerli katkısı olmuştur.
2015 IEEE International Conference on Communication, Networks and Satellite (COMNESTAT), 2015
EFFECTS OF UAV MOBILITY PATTERNS ON DATA COLLECTION IN WIRELESS SENSOR NETWORKS Sensor nodes in a... more EFFECTS OF UAV MOBILITY PATTERNS ON DATA COLLECTION IN WIRELESS SENSOR NETWORKS Sensor nodes in a Wireless Sensor Network (WSN) can be dispersed over a remote sensing area e.g. the regions that cannot be accessed by human beings (inaccessible regions). In such kind of networks, data collection becomes one of the major issues. Getting connected to each sensor node and retrieving the information in time introduces new challenges. Mobile sink usage, especially the Unmanned Aerial Vehicle (UAV), is the most convenient approach to cover the area and access each sensor node in such a large scale WSN. However, the operation of the UAV depends on some parameters such as endurance time, altitude, speed, radio type in use, and the path. In this paper, we
Bu makale, birinci yazar tarafından İTÜ Fen Bilimleri Enstitüsü, Bilgisayar Mühendisliği Programı... more Bu makale, birinci yazar tarafından İTÜ Fen Bilimleri Enstitüsü, Bilgisayar Mühendisliği Programında tamamlanmış olan "A Novel Communication Approach for Wireless Mobile Smart Objects" adlı doktora tezinden hazırlanmıştır. Makale metni 04.07.2007 tarihinde dergiye ulaşmış, 01.08.2007 tarihinde basım kararı alınmıştır. Makale ile ilgili tartışmalar 31.03.2009 tarihine kadar dergiye gönderilmelidir. Özet Tasarsız (ad hoc) ve duyarga (sensör) ağlar, altyapısız ağlar olduğu için altyapılı ağlarda bol miktarda bulunan enerji, işlemci, bellek, bandgenişliği gibi kaynaklar kısıtlıdır ve özenle tüketilmelidir. Ağ elemanlarının boyutlarının çok küçük olması, enerjiyi en kısıtlı kaynak yapmaktadır. Ancak, kaynak ile varış arasında veri akışının sağlanması için kullanılan yöntemler enerji tüketimini arttırmaktadır. Bu nedenle, literatürde enerji-etkin yönlendirme protokolleri sunulmuştur. Bu protokollerden, coğrafi yer bilgisine dayanarak yönlendirme yapan protokoller, diğerlerine göre daha yüksek başarıma ve performans değerlerine sahiptir. Bu çalışmada, Durumsuz Ağırlıklı Yönlendirme (DAY) isimli bir özgün kaynak-başlatmalı veri akış tekniği sunulmaktadır. Düğümler sadece kendi sanal coğrafi yer bilgilerini bilmekte, ağ topololoji bilgisine ihtiyaç duymamaktadır. Her düğüm kendi ağırlığını hesaplamaktadır. Başlangıçta bu değer varışa olan mesafedir. Düğümler kendilerine gelen paketlerin içindeki ağırlık bilgilerine bakarak paketi tekrar göndermeye veya düşürmeye karar vermektedir. Bu karşılaştırma işlemi durumsuz olma özelliğini sağlamaktadır. Ağırlık parametresi sadece yer bilgisini içerebildiği gibi düğümün kalan enerjisi gibi Servis Kalitesi parametre bilgisini de içerebilir. Servis Kalite bilgisi sistemin yaşamömrünü arttırmaya yöneliktir. Durumsuz olma özelliği ile de, yönlendirme tablosu tutulan algoritmalarda görülen iletişim yükü büyük oranda azalmaktadır. DAY, aynı zamanda, güvenirliği sağlayan ve gerçek-zamanlı veri için de gerekli olan çoklu-yollar veya örülü çoklu-yollar kullanır. Tekrar-gönderimlerde eşik değerlerinin kullanımı, sistemde esnek ve enerji etkin bir veri akışı sağlar. Aynı zamanda, DAY, MACkatmanından bağımsız çalışan ilk durumsuz coğrafi yönlendirme tekniğidir.
2015 International Wireless Communications and Mobile Computing Conference (IWCMC), 2015
Clustering algorithms improve network manageability through several topology partitioning techniq... more Clustering algorithms improve network manageability through several topology partitioning techniques. In some particular cases, such as vehicular ad hoc network (VANETs) communications, significant performance improvements can be introduced via clustered networking solutions whereas merging clusters for the sake of scalability may lead to degraded network stability. In this paper, we explore the impact of merging clusters, and furthermore based on these results, we propose a new clustering technique, namely Relatively Stable Clustering for Unbiased Environments (ReSCUE). The objective of ReSCUE is primarily guaranteeing cluster stability in an unbiased manner. ReSCUE keeps track of the spatio-temporal changes in VANET node characteristics, and uses these characteristics along with local information to prevent biased clustering which is based on common and general node characteristics. We evaluate the performance of ReSCUE through simulations and show that ReSCUE can form relatively more stable clusters while reducing the frequency of cluster merges, as well as that of the node status changes.
2015 23nd Signal Processing and Communications Applications Conference (SIU), 2015
There is a number of ways to estimate the number of people in a particular area. From image proce... more There is a number of ways to estimate the number of people in a particular area. From image processing to movement pattern analysis, the sheer number of methods exist in the literature. An interesting one among these methods is the one estimating with the use of signal processing. Because it is much cheaper compared to the other methods in the literature, it is more commonly implemented. In this study, the number of people in a particular area is estimated by analyzing the WiFi signals captured from mobile devices.
International Journal of Distributed Sensor Networks, 2012
Resource limitations of sensor nodes in wireless sensor networks (WSN) bound the performance on i... more Resource limitations of sensor nodes in wireless sensor networks (WSN) bound the performance on its implementations. Main concern becomes utilizing these limited resources (CPU, memory, bandwidth, battery) as efficient as possible. Their efficiency is mostly affected by the applied routing algorithm, which carries gathered data to inclined/intended destinations. In this paper, a novel routing algorithm, stateless weight routing (SWR), is proposed. The SWR differs from other protocols in many ways. Major feature of the SWR is its simplicity. It is a completely stateless protocol without requiring any network or neighborhood information for routing. This feature decreases packet transmissions and energy consumption dramatically. For reliability, data flows to the sink node over multiple paths. Moreover, nodes have the ability of recovering from voids. Nodes process each packet independently and apply an adaptive approach according to the current conditions. These mechanisms are part o...
2006 IEEE Annual Wireless and Microwave Technology Conference, 2006
As the energy becomes the most valuable resource in the wireless sensor networks, to prolong the ... more As the energy becomes the most valuable resource in the wireless sensor networks, to prolong the lifetime of the network, energy-aware protocols are proposed which use the energy minimization techniques and multi-hop paths. However, multi-hop paths and complex calculations at nodes introduce delay and processing overhead. Providing energy-efficiency becomes a scalability problem. Scalability of a routing protocol for wireless sensor networks is mainly affected by the topological changes and by the number of sensor nodes in the network. In large scale networks with a large number of sensor nodes, multiple-sinks (gateways) should be used to provide scalability. In this paper, a novel stateless energy-efficient routing technique, Stateless Weight Routing with Multiple Sinks (MS-SWR), is introduced for wireless sensor networks. MS-SWR requires no local/global topological information. Property of being stateless avoids the communication overhead and reduces the calculations to minimum. In MS-SWR, reliability is provided by using multiple paths which also reduces the delay to minimum for the time-critical real-time traffic. The performance evaluation of the proposed technique shows that MS-SWR is scalable for large scale wireless sensor networks with multiple sinks.
In this paper, virtual cell layout (VCL) based dynamic source routing (VB-DSR) technique is intro... more In this paper, virtual cell layout (VCL) based dynamic source routing (VB-DSR) technique is introduced for the mobile subsystem of the next generation tactical communications systems. VB-DSR uses dynamic source routing (DSR) protocol over VCL structure, which is a resource management and clustering technique for tactical communications. The application of the third generation personal communications services to the tactical communications is enabled through a hybrid, i.e., ad hoc and cellular, infrastructureless architecture by VCL. VB-DSR enhances the schemes for the ad hoc components of this architecture. The performance evaluation of the proposed technique shows that the VB-DSR is scalable for tactical communications.
Uploads
Papers by Mujdat Soyturk