Content Sharing over Smartphone-Based Delay-Tolerant NetworksIJERA Editor
With the growing number of smartphone end users, peer-to-peer ad hoc content giving is likely to occur often. Thus, new articles sharing mechanisms must be developed since traditional information delivery schemes will not be efficient with regard to content sharing due to the sporadic connectivity between smartphones on the market. To obtain data delivery such challenging environments, researchers include proposed the employment of store-carry-forward methodologies, in which a node stores a communication and holds it until a forwarding prospect arises through an encounter together with other nodes. Most past works in this field have dedicated to the conjecture of whether two nodes could encounter the other, without thinking about the place and also time from the encounter. In this particular paper, we propose to her discover-predict-deliver as a possible efficient articles sharing scheme for delay-tolerant touch screen phone networks. In this proposed scheme, contents are usually shared while using the mobility information of people. Specifically, our strategy employs the mobility understanding algorithm to spot places inside your own home and outdoor.
Delay Tolerant Networks(DTN) are a class of emerg- ing networks which experience intermittent connectivity and lack end-to-end paths due to absence of well-defined infrastructure. In this paper we explore the nuances of multicasting in DTNs. Multicasting enables efficient distribution of messages to a group of users, a paradigm that can be applicable in the context of DTNs. While multicasting in internet and ad-hoc networks has been studied extensively, realizing the same in DTNs is non- trivial given that many factors have to be considered. This paper, presents an implementation of multicast routing for various protocols in DTNs using ONE simulator. It also provides the analysis and performance results for the various protocols studies against the different movement models.
Content Sharing over Smartphone-Based Delay-Tolerant NetworksIJERA Editor
With the growing number of smartphone end users, peer-to-peer ad hoc content giving is likely to occur often. Thus, new articles sharing mechanisms must be developed since traditional information delivery schemes will not be efficient with regard to content sharing due to the sporadic connectivity between smartphones on the market. To obtain data delivery such challenging environments, researchers include proposed the employment of store-carry-forward methodologies, in which a node stores a communication and holds it until a forwarding prospect arises through an encounter together with other nodes. Most past works in this field have dedicated to the conjecture of whether two nodes could encounter the other, without thinking about the place and also time from the encounter. In this particular paper, we propose to her discover-predict-deliver as a possible efficient articles sharing scheme for delay-tolerant touch screen phone networks. In this proposed scheme, contents are usually shared while using the mobility information of people. Specifically, our strategy employs the mobility understanding algorithm to spot places inside your own home and outdoor.
Delay Tolerant Networks(DTN) are a class of emerg- ing networks which experience intermittent connectivity and lack end-to-end paths due to absence of well-defined infrastructure. In this paper we explore the nuances of multicasting in DTNs. Multicasting enables efficient distribution of messages to a group of users, a paradigm that can be applicable in the context of DTNs. While multicasting in internet and ad-hoc networks has been studied extensively, realizing the same in DTNs is non- trivial given that many factors have to be considered. This paper, presents an implementation of multicast routing for various protocols in DTNs using ONE simulator. It also provides the analysis and performance results for the various protocols studies against the different movement models.
Delay tolerant network routing protocol a comprehensive survey with hybrid...eSAT Journals
Abstract
Delay –disruption Tolerant networks are sparse wireless network which is recently being used by the existing /current network for the purpose to connect devices or the underdeveloped area of the world that works in challenging environment. In DTN there majority of time does not exist the total path from source to target which is leads to the difficulty of how to route the packet in such environment. A communications network which is accomplished of storing packets temporarily in intermediate nodes, until the time an end-to-end route is re-established or regenerated is known as a delay tolerant networks. Routing in such network is very difficult and for that different routing protocols are developed. In this Survey paper we discuss about various routing Strategy and at the end compared the different routing protocol with their various performance metrics.
Keywords: Delay tolerant networks (DTNs), Erasure coding, Replication, Routing.
Security Measure to Detect and Avoid Flooding Attacks using Multi-Agent Syste...IJECEIAES
Security is considered as one of the major challenge when it comes to infrastructure less and self dependent network without any centralized control. The vulnerability of Adhoc Network makes it susceptible to external attacks like flooding of hello messages or propagating fake routing messages etc. Such attacks generates a variety of problems like disturbing the network by flooding messages that results in waste of battery which is a vital resource to maintain the life span of the network. Most importantly cause agents to die when unable to reach destination due to fake routing messages causing a heavy loss on part of the nodes generating them to maintain the route knowledge. The paper proposes a novel technique to identify the flooding attack and measure to overcome them using Multi-Agent system
Throughput Maximization using Spatial Reusability in Multi Hop Wireless Networkijtsrd
Energy is a valuable resource in wireless networks. For many multi hop networking scenarios, nodes require power for performing their operation, so requiring capable power management to make certain connectivity across the network. Though when wireless networks are attached outside power source due to obstruction between lively links the network may demand excessive energy per unit time Power due to this the overall performance is reduced. Since network life time or network capacity is depend on the power efficiency, many efforts to study energy efficient networks in the wireless network community. In multi hop wireless networks well organized routing algorithms are significant for network performance. We dispute that by carefully considering spatial reusability of the wireless communication media, we can reduce the overhead in multi hop wireless networks. To support our argument, propose Broadcast Tree Construction BTC and compare them with existing routing and multi path routing protocols, respectively. Our estimate outcome shows that proposed protocols significantly improve the end to end throughput compared with existing protocols. We also introduce the sleep scheduling approach for energy consumption and hybrid cryptography for security of data that can be prevent the data leakage and jammer attacks. Twinkal P. Dudhagawali | Prof. L. K. Gautam | Prof. V. P. Vaidya ""Throughput Maximization using Spatial Reusability in Multi Hop Wireless Network"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23489.pdf
Paper URL: https://www.ijtsrd.com/engineering/information-technology/23489/throughput-maximization-using-spatial-reusability-in-multi-hop-wireless-network/twinkal-p-dudhagawali
This presentation covers some of the routing protocols for Delay Tolerant Networks (DTN) along with the overview of the Opportunistic Networking Environment which can be used for performance evaluation/comparison of/among these DTN protocols.
P.S. This presentation is for educational purpose only. It is not meant for any commercialization at all.
These days, the interests in challenged networks are increasing and many researches are performed to seek a reliable end-to-end connectivity under harsh environments, which have a long propagation delay, high error rates, low data rate, and intermittent connectivity. Delay Tolerant Network was introduced to provide challenged networks with reliable transmission and interoperability with an overlay network concept. In this paper, we present comprehensive overview of Delay Tolerant Network and introduce a study case about the implementation of this network. This paper is designed to encourage the exploration of this field by giving basic concept and also motivate to investigate this area by presenting a study case at the end section.
---
Please contact to lailiaidi@gmail.com for download request
COMMUNITY DETECTION USING INTER CONTACT TIME AND SOCIAL CHARACTERISTICS BASED...ijasuc
Delay Tolerant Networks (DTNs) where the node connectivity is opportunistic and end-to-end path between
any pair of source and destination is not guaranteed most of the time. Hence the messages are transferred
from source to destination via intermediate nodes on hop to hop basis using store-carry-forward paradigm.
Due to quick advancement in hand held devices such as smart phone and laptop with support of wireless
communication interface carried by human being, it is possible in coming days to use DTNs for message
dissemination without setting up infrastructure. The routing task becomes challenging in DTNs due to
intermittent network connectivity and the connection opportunity arises only when node comes in
transmission range of each other. The performance of the routing protocols depend on the selection of
appropriate relay node which can deliver the message to final destination in case of source and destination
do not meet at all. Many social characteristics are exhibited by the human being like friendship,
community, similarity and centrality which can be exploited by the routing protocol in order to take the
forwarding decisions. Literature shows that by using these characteristics, the performance of DTN routing
protocols have been improved in terms of delivery probability. The existing routing schemes used
community detection using aggregated contact duration and contact frequency which does not change over
the time period. We propose community detection through Inter Contact Time (ICT) between node pair
using power law distribution where the members of community are added and removed dynamically. We
also considered single copy of each message in entire network to reduce the network overhead. The
proposed routing protocol named Social Based Single Copy Routing (SBSCR) selects the suitable relay
node from the community members only based on the social metrics such as similarity and friendship
together. ICTs show power law nature in human mobility which is used to detect the community structure at
each node. A node maintains its own community and social metrics such as similarity and friendship with
other nodes. Whenever node has to select the relay node then it selects from its community with higher
value of social metric. The simulations are conducted using ONE simulator on the real traces of campus
and conference environments. SBSCR is compared with existing schemes and results show that it
outperforms in terms of delivery probability and delivery delay with comparable overhead ratio.
Opportunistic Networking: Extending Internet Communications Through Spontaneo...Waldir Moreira
The increasing number of personal devices with wireless communication capabilities makes it possible the creation of spontaneous networks in which devices communicate occasionally depending on contact opportunities. This intermittent communication may be due to mobility and power-limitations of devices, physical obstacles and distance, resulting in the possible nonexistence of end-to-end paths toward a destination. In summary, spontaneous networks are characterized by being highly dynamic, composed of mobile and static nodes that are able to take advantage of opportunistic time-varying contacts.
This tutorial aims to give an introduction to the challenges and research issues behind the development of
opportunistic networking solutions able to boost the deployment of spontaneous networks. Special attention will be
given to the fundamental building block: routing over opportunistic networks. Since the effciency of spontaneous
networks depends upon the way contacts occur between carriers of communication devices, special attention will
also be given to the analysis of method to detect social structures based on opportunistic contacts. To emphasize
the impact that opportunistic networking technology may have, this tutorial ends up with the description of major
aspects of future forwarding schemes: interest-based and information-centric forwardings.
This presentation was given as a tutorial in the IEEE 3rd Latin-American Conference on Communications (LATINCOM), on Oct 26th, 2011, in Belém/PA, Brazil.
http://www.ieee-latincom.ufpa.br/
PRoPHET uses its delivery predictability of node encounters and transitivity to forward bundles to its neighbor node. Regardless of their distance, it faces delivery dilemmas in a source node and drawbacks of low delivery ratio and high delay in case two or more neighbor nodes carry equal delivery predictability. To solve such consequences, we propose a Distance and Probabilistic Routing Protocol using History of Encounters and Transitivity (DPRoPHET) with the use of cross layer implementation for distance value retrieval. Our simulation results show that, by adding distance metric to the existing delivery predictability vector, DPRoPHET outperforms PRoPHET.
Comparative Analysis and Secure ALM P2P Overlay Multicasting of Various Multi...IJERD Editor
Multicasting is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from the source. The copies of the messages are automatically created in other network elements like routers but only when the topology of the network requires it. Multicast is implemented most commonly in IP multicast which is further could be employed in internet protocol applications of streaming media. In the IP multicast the implementation of the multicast concept occurs at the IP routing level where routers create optimal distribution paths for datagram sent to a multicast destination address. At the Data Link Layer, multicast describes one-to-many distribution such as Ethernet multicast addressing, Asynchronous Transfer Mode (ATM) point-to-multipoint virtual circuits (P2MP) multicast. In this paper we have compared various multicasting mechanisms. The comparison is done on the basis of various factors like complexity, overhead, maintenance, etc. The mechanisms that are part of the paper are a secure ALM P2P multicasting technique for large scale networks using face recognition, IP multicasting techniques and the overlay multicasting techniques. The comparison of these multicasting techniques will help us to design and Implement a Secure Application-Level Multicasting (SALM) P2P Overlay Multicasting for large Scale Network. The main objective of the paper is to discuss all the three above mentioned multicasting phenomenon’s and compare them on the basis of certain criterion so as carved out the best of all which can be further used for designing a secure multicasting technique which can take the best features of all combined together so as to get effective and efficient technique for multicasting the throughput of the network by effective and efficient delivery of the information to all the members of the group. The certain findings can be carved out of the comparison can help us to create a multicasting technique with less incurring of delays so that information can be delivered in limited time span and multicast path length so that efficient paths should be used so as to enhance performance in multicasting. Moreover in this paper we will study & investigate other issues that degrades the performance of Multicasting Techniques for large Scale Network and later we will come to know through the comparison that which technique performs well in these harsh environment and give effective results.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
Delay tolerant network routing protocol a comprehensive survey with hybrid...eSAT Journals
Abstract
Delay –disruption Tolerant networks are sparse wireless network which is recently being used by the existing /current network for the purpose to connect devices or the underdeveloped area of the world that works in challenging environment. In DTN there majority of time does not exist the total path from source to target which is leads to the difficulty of how to route the packet in such environment. A communications network which is accomplished of storing packets temporarily in intermediate nodes, until the time an end-to-end route is re-established or regenerated is known as a delay tolerant networks. Routing in such network is very difficult and for that different routing protocols are developed. In this Survey paper we discuss about various routing Strategy and at the end compared the different routing protocol with their various performance metrics.
Keywords: Delay tolerant networks (DTNs), Erasure coding, Replication, Routing.
Security Measure to Detect and Avoid Flooding Attacks using Multi-Agent Syste...IJECEIAES
Security is considered as one of the major challenge when it comes to infrastructure less and self dependent network without any centralized control. The vulnerability of Adhoc Network makes it susceptible to external attacks like flooding of hello messages or propagating fake routing messages etc. Such attacks generates a variety of problems like disturbing the network by flooding messages that results in waste of battery which is a vital resource to maintain the life span of the network. Most importantly cause agents to die when unable to reach destination due to fake routing messages causing a heavy loss on part of the nodes generating them to maintain the route knowledge. The paper proposes a novel technique to identify the flooding attack and measure to overcome them using Multi-Agent system
Throughput Maximization using Spatial Reusability in Multi Hop Wireless Networkijtsrd
Energy is a valuable resource in wireless networks. For many multi hop networking scenarios, nodes require power for performing their operation, so requiring capable power management to make certain connectivity across the network. Though when wireless networks are attached outside power source due to obstruction between lively links the network may demand excessive energy per unit time Power due to this the overall performance is reduced. Since network life time or network capacity is depend on the power efficiency, many efforts to study energy efficient networks in the wireless network community. In multi hop wireless networks well organized routing algorithms are significant for network performance. We dispute that by carefully considering spatial reusability of the wireless communication media, we can reduce the overhead in multi hop wireless networks. To support our argument, propose Broadcast Tree Construction BTC and compare them with existing routing and multi path routing protocols, respectively. Our estimate outcome shows that proposed protocols significantly improve the end to end throughput compared with existing protocols. We also introduce the sleep scheduling approach for energy consumption and hybrid cryptography for security of data that can be prevent the data leakage and jammer attacks. Twinkal P. Dudhagawali | Prof. L. K. Gautam | Prof. V. P. Vaidya ""Throughput Maximization using Spatial Reusability in Multi Hop Wireless Network"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23489.pdf
Paper URL: https://www.ijtsrd.com/engineering/information-technology/23489/throughput-maximization-using-spatial-reusability-in-multi-hop-wireless-network/twinkal-p-dudhagawali
This presentation covers some of the routing protocols for Delay Tolerant Networks (DTN) along with the overview of the Opportunistic Networking Environment which can be used for performance evaluation/comparison of/among these DTN protocols.
P.S. This presentation is for educational purpose only. It is not meant for any commercialization at all.
These days, the interests in challenged networks are increasing and many researches are performed to seek a reliable end-to-end connectivity under harsh environments, which have a long propagation delay, high error rates, low data rate, and intermittent connectivity. Delay Tolerant Network was introduced to provide challenged networks with reliable transmission and interoperability with an overlay network concept. In this paper, we present comprehensive overview of Delay Tolerant Network and introduce a study case about the implementation of this network. This paper is designed to encourage the exploration of this field by giving basic concept and also motivate to investigate this area by presenting a study case at the end section.
---
Please contact to lailiaidi@gmail.com for download request
COMMUNITY DETECTION USING INTER CONTACT TIME AND SOCIAL CHARACTERISTICS BASED...ijasuc
Delay Tolerant Networks (DTNs) where the node connectivity is opportunistic and end-to-end path between
any pair of source and destination is not guaranteed most of the time. Hence the messages are transferred
from source to destination via intermediate nodes on hop to hop basis using store-carry-forward paradigm.
Due to quick advancement in hand held devices such as smart phone and laptop with support of wireless
communication interface carried by human being, it is possible in coming days to use DTNs for message
dissemination without setting up infrastructure. The routing task becomes challenging in DTNs due to
intermittent network connectivity and the connection opportunity arises only when node comes in
transmission range of each other. The performance of the routing protocols depend on the selection of
appropriate relay node which can deliver the message to final destination in case of source and destination
do not meet at all. Many social characteristics are exhibited by the human being like friendship,
community, similarity and centrality which can be exploited by the routing protocol in order to take the
forwarding decisions. Literature shows that by using these characteristics, the performance of DTN routing
protocols have been improved in terms of delivery probability. The existing routing schemes used
community detection using aggregated contact duration and contact frequency which does not change over
the time period. We propose community detection through Inter Contact Time (ICT) between node pair
using power law distribution where the members of community are added and removed dynamically. We
also considered single copy of each message in entire network to reduce the network overhead. The
proposed routing protocol named Social Based Single Copy Routing (SBSCR) selects the suitable relay
node from the community members only based on the social metrics such as similarity and friendship
together. ICTs show power law nature in human mobility which is used to detect the community structure at
each node. A node maintains its own community and social metrics such as similarity and friendship with
other nodes. Whenever node has to select the relay node then it selects from its community with higher
value of social metric. The simulations are conducted using ONE simulator on the real traces of campus
and conference environments. SBSCR is compared with existing schemes and results show that it
outperforms in terms of delivery probability and delivery delay with comparable overhead ratio.
Opportunistic Networking: Extending Internet Communications Through Spontaneo...Waldir Moreira
The increasing number of personal devices with wireless communication capabilities makes it possible the creation of spontaneous networks in which devices communicate occasionally depending on contact opportunities. This intermittent communication may be due to mobility and power-limitations of devices, physical obstacles and distance, resulting in the possible nonexistence of end-to-end paths toward a destination. In summary, spontaneous networks are characterized by being highly dynamic, composed of mobile and static nodes that are able to take advantage of opportunistic time-varying contacts.
This tutorial aims to give an introduction to the challenges and research issues behind the development of
opportunistic networking solutions able to boost the deployment of spontaneous networks. Special attention will be
given to the fundamental building block: routing over opportunistic networks. Since the effciency of spontaneous
networks depends upon the way contacts occur between carriers of communication devices, special attention will
also be given to the analysis of method to detect social structures based on opportunistic contacts. To emphasize
the impact that opportunistic networking technology may have, this tutorial ends up with the description of major
aspects of future forwarding schemes: interest-based and information-centric forwardings.
This presentation was given as a tutorial in the IEEE 3rd Latin-American Conference on Communications (LATINCOM), on Oct 26th, 2011, in Belém/PA, Brazil.
http://www.ieee-latincom.ufpa.br/
PRoPHET uses its delivery predictability of node encounters and transitivity to forward bundles to its neighbor node. Regardless of their distance, it faces delivery dilemmas in a source node and drawbacks of low delivery ratio and high delay in case two or more neighbor nodes carry equal delivery predictability. To solve such consequences, we propose a Distance and Probabilistic Routing Protocol using History of Encounters and Transitivity (DPRoPHET) with the use of cross layer implementation for distance value retrieval. Our simulation results show that, by adding distance metric to the existing delivery predictability vector, DPRoPHET outperforms PRoPHET.
Comparative Analysis and Secure ALM P2P Overlay Multicasting of Various Multi...IJERD Editor
Multicasting is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from the source. The copies of the messages are automatically created in other network elements like routers but only when the topology of the network requires it. Multicast is implemented most commonly in IP multicast which is further could be employed in internet protocol applications of streaming media. In the IP multicast the implementation of the multicast concept occurs at the IP routing level where routers create optimal distribution paths for datagram sent to a multicast destination address. At the Data Link Layer, multicast describes one-to-many distribution such as Ethernet multicast addressing, Asynchronous Transfer Mode (ATM) point-to-multipoint virtual circuits (P2MP) multicast. In this paper we have compared various multicasting mechanisms. The comparison is done on the basis of various factors like complexity, overhead, maintenance, etc. The mechanisms that are part of the paper are a secure ALM P2P multicasting technique for large scale networks using face recognition, IP multicasting techniques and the overlay multicasting techniques. The comparison of these multicasting techniques will help us to design and Implement a Secure Application-Level Multicasting (SALM) P2P Overlay Multicasting for large Scale Network. The main objective of the paper is to discuss all the three above mentioned multicasting phenomenon’s and compare them on the basis of certain criterion so as carved out the best of all which can be further used for designing a secure multicasting technique which can take the best features of all combined together so as to get effective and efficient technique for multicasting the throughput of the network by effective and efficient delivery of the information to all the members of the group. The certain findings can be carved out of the comparison can help us to create a multicasting technique with less incurring of delays so that information can be delivered in limited time span and multicast path length so that efficient paths should be used so as to enhance performance in multicasting. Moreover in this paper we will study & investigate other issues that degrades the performance of Multicasting Techniques for large Scale Network and later we will come to know through the comparison that which technique performs well in these harsh environment and give effective results.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
An Efficient DTN Routing Algorithm for Automatic Crime Information Sharing fo...IJSRD
Delay Tolerant Network shows many issues that are exist in traditional network. Opportunistic network emerge as interesting evolution in MANET. Mobile nodes in the opportunistic network communicate with each other even in case of no route connection. In this paper a kiosk (or hub station) that is connected to villages to establish internet connection. Such kiosk is placed where traffic frequency is high. We will use high frequency sensor in vehicles. When passing through kiosk, high frequency sensor will establish connection to kiosk & kiosk will connect villages to internet. This system is very useful in crime information sharing services. As an example, if there are a person who is victim of any crime or in a trouble condition. He/she have mobile devices connect to internet. They send a trouble message which is passed to near kiosk and passed on to vehicles and forward their information to police station. This system is helpful in villages, where network communication is not proper.
A Comparison of Routing Protocol for WSNs: Redundancy Based Approach A Compar...ijeei-iaes
Wireless Sensor Networks (WSNs) with their dynamic applications gained a tremendous attention of researchers. Constant monitoring of critical situations attracted researchers to utilize WSNs at vast platforms. The main focus in WSNs is to enhance network localization as much as one could, for efficient and optimal utilization of resources. Different approaches based upon redundancy are proposed for optimum functionality. Localization is always related with redundancy of sensor nodes deployed at remote areas for constant and fault tolerant monitoring. In this work, we propose a comparison of classic flooding and the gossip protocol for homogenous networks which enhances stability and throughput quiet significantly.
DATA FORWARDING IN OPPORTUNISTIC NETWORK USING MOBILE TRACEScscpconf
Opportunistic networks are usually formed spontaneously by mobile devices equipped with
short range wireless communication interfaces. The idea is that an end-to-end connection may
never be present. Designing and implementing a routing protocol to support both service
discovery and delivery in such kinds of networks is a challenging problem on account of
frequent disconnections and topology changes. In these networks one of the most important
issues relies on the selection of the best intermediate node to forward the messages towards the
destination. This paper presents a mobile trace based routing protocol that uses the location
information of the nodes in the network. Using the trace information, next hop is selected to forward the packets to destination. Data forwarding is done via the selected nodes. The effectiveness is shown using simulation
Grid-Based Multipath with Congestion Avoidance Routing Protocolijtsrd
This Paper gives information about Grid base multipath wireless sensor network. We give a brief introduction about wireless sensor network, how sensor works in this network. How the Routing is done and if there is congestion detected in sensors networks and then how it can be solved. Routing protocols are also classified in several types like Proactive, Reactive, and Hybrid in also given here the details of that. Also here we describe various routing techniques like Traditional and Current techniques. In flooding based techniques, sensor broadcast the information and the destination sensor receives that information. In gossiping techniques, sensor sends information to neighbor sensor and so on. In this paper we also see that if any sensor id dies due to lack of power or any other problems then another path will be routed. Routing protocols are having 3 types Flat routing, Hierarchical routing and Location based routing. In Flat routing SPIN,DD, Rumor routing, etc protocols are used. In hierarchical routing LEACH, PEGASIS, TEEN protocols are used. Now a day LEACH and PEGASIS are widely used in cluster base Wireless Sensor Network. In leach protocol reduced the path using cluster head formulation in this method randomly any sensor make the cluster head n send messages in the network. In pegasis protocol use chaining concept and find the best path from base station to the destination station. PEGASIS and LEACH provide best routing techniques in wireless sensor network but they also have some disadvantages. We also differentiate flat and hierarchical routing techniques in which case which one gives best performances. Here we introduce the readers to Location based routing protocols GEAR and how it route the path is also briefly described here. Dr. Atul M Gosai | Lakshdeep M Raval"Grid-Based Multipath with Congestion Avoidance Routing Protocol" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-3 , April 2017, URL: http://www.ijtsrd.com/papers/ijtsrd72.pdf http://www.ijtsrd.com/computer-science/computer-network/72/grid-based-multipath-with-congestion-avoidance-routing-protocol/dr-atul-m-gosai
Survey on Routing in Opportunistic Networks
this paper basically overviews and disused those potential methods and Techniques to select next hop to forward the packets (message) to destination.
These slides cover the fundamentals of data communication & networking. It covers all data types which are used in communication of data over transmission medium. It is useful for engineering students & also for the candidates who want to master data communication & computer networking.
Hexagonal based Clustering for Reducing Rebroadcasts in Mobile Ad Hoc NetworksIJTET Journal
Abstract— In mobile ad hoc networks multihop routing is performed in order to communicate the packets from the source to destination. The nodes within these networks are dynamic due which frequent path change occurs which can cause frequent link breakages and induces route discoveries. These route discoveries can introduce overhead in terms of contention, collision and rebroadcasts which are non-negligible. Here, the paper discusses a hexagonal based clustering for reducing rebroadcasts thus maximizing the lifetime of the networks and providing coverage area thus reducing the end – end delays.
CompTIA exam study guide presentations by instructor Brian Ferrill, PACE-IT (Progressive, Accelerated Certifications for Employment in Information Technology)
"Funded by the Department of Labor, Employment and Training Administration, Grant #TC-23745-12-60-A-53"
Learn more about the PACE-IT Online program: www.edcc.edu/pace-it
To Get any Project for CSE, IT ECE, EEE Contact Me @ 09666155510, 09849539085 or mail us - ieeefinalsemprojects@gmail.com-Visit Our Website: www.finalyearprojects.org
To Get any Project for CSE, IT ECE, EEE Contact Me @ 09666155510, 09849539085 or mail us - ieeefinalsemprojects@gmail.com-Visit Our Website: www.finalyearprojects.org
Unit 1 Introduction to Non-Conventional Energy ResourcesDr Piyush Charan
This unit is part of the course EC228 Renewable Energy Engineering of program B.Tech. Electronics Engg. (Solar Photovoltaic Engineering). It gives an introduction to conventional and non-conventional energy resources.
Unit 5-Operational Amplifiers and Electronic Measurement DevicesDr Piyush Charan
Lecture Notes on Operational Amplifiers and Measuring Instruments. These notes cover unit 5 of the course Basic Electronics (EC101) taught at Integral University.
This presentation deals with the lecture notes of unit 4 of the course Basic Electronics EC101 which is a common course of B.Tech Curriculum having 4 credits.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
1. Lecture Notes on Introduction to
Wireless Standards
for
Pre-PhD Coursework Departmental Paper
on
Mobile Ad-Hoc and Sensor Networks(EC704)
by
Dr. Piyush Charan
Assistant Professor
Department of Electronics and Communication Engg.
Integral University, Lucknow
2. Contents
• Broadcasting and Multicasting
– Broadcast Storm,
– network flooding avoidance,
– multicast routing.
• TCP over mobile ad hoc networks
– IP address acquisition,
– effects of partitions on TCP,
– provisions for mobility and fairness.
20 March 2022 2
Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow
3. Contents contd…
• Wireless LAN (WiFi)
– IEEE 802.11 specifications,
• Medium Access Control Protocol issues;
– power control,
– spatial reusability, and
– Quality of Service (QoS)
• Bluetooth
– specifications,
– Piconet synchronization and master-slave switch,
– scatternet formations,
– interference issues,
– interoperability with WiFi.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 3
4. Casting
• Transmitting data (stream of packets) over the network is termed as casting.
• Unicast, multicast, and broadcast happen at layer-2 and layer-3.
• Remember layer-2 is the data-link layer where the switch device works using the
MAC addresses for communication, and layer-3 is the network layer where the
router device works using the IP addresses for communication.
• Here, “cast” refers to how many people or devices we send the data to. It can be
unicast, multicast, or broadcast. These 3 methods are the types of communication,
used to transmit packets over a network.
• Unicast means one-to-one, data send to only one device means sender sends data to
only one device. Multicast means one-to-many (or many-to-many), data sent to
multiple devices means sender sends data to many devices (not all devices like the
broadcast). Broadcast means one-to-all, data sent to all devices means sender sends
data to all devices.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 4
5. Types of Casting
Types of
Casting
Unicast Broadcast
Limited
Broadcast
Direct
Broadcast
Multicast
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 5
Figure 1.1: Types of Casting
6. Unicast
• Uni: means- ‘one’
• Cast: means- ‘to send’ or ‘to throw’
• So, unicast means a communication
technique in which there is
– one-to-one Communication
– has only one source and one destination
node.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 6
Figure 1.2: Unicast
7. Unicast Contd…
• Unicast is a one to one data transmission. In computer networking, Unicast is a term, that is used
when data is transmitted from one point to another point.
• It is a one-to-one communication; that is one sender and one receiver when one device transmits the
data to another device then it is called unicast transmission. Generally, we use one-to-one
communication on our daily basis like- sending a message, browsing a website, downloading a file
etc.
• Some Examples:
– Ex-1: A device having an IP address 20.1.3.0 in a network wants to transmit the data to the device with IP
address 30.10.5.0 in another network, then this transmission is called Unicast transmission.
– Ex-2: There are 4 computers connected to the switch device, so if pc1 wants to communicate with pc2, then
they can directly communicate with each other so this is unicast communication because it is one-to-one
communication.
– Ex-3: Browsing a website is also unicast communication, where the web server acts as a sender and our
computer acts as a receiver.
– Ex-4: Downloading a file from an FTP server is another example of unicast transmission, where the FTP
server acts as a sender and our computer acts as a receiver.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 7
8. Multicast
• Transmitting data from one
source host to a particular group
of hosts having interest in
receiving the data is called as
multicast.
• It is a one-to-many transmission.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 8
Figure 1.3: Multicast
9. Multicast contd…
• Multicast is a term, that is used when data is transmitted to multiple
devices. This type of multicast transmission is used, when data is sent to a
group. This type of transmission recline between the boundaries of unicast
(one-to-one) and broadcast (one-to-all).
• It can be one-to-many or many-to-many transmission means data send
efficiently from one source (or many sources) to many destinations
simultaneously, generally within a local network. So if we use the
multicast transmission in the local network, then a frame contains the
unique multicast MAC addresses of an application, protocol, or datastream.
• In multicast transmission, when a device sends one copy of data then it is
delivered to many devices (not delivered to all devices like in broadcast).
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 9
10. Broadcast
• A method of sending information over a
network. (specifically to all the nodes/motes
in a network)
– Data comes from one source and goes to all
other connected sources.
– This has the side effect of congesting a
medium or large network segment very
quickly.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 10
Figure 1.4: Broadcast
11. Broadcast contd…
• Broadcast is a term, that is used when data is transmitted to all the devices.
• It is a one-to-all transmission means there is one sender, but the information
is delivered to all the connected receivers.
• In broadcast transmission, when a device sends one copy of data, then that
data will be delivered to all the devices.
• This term “broadcast", mostly used in cable TV transmission.TV signals
are sent from one source (one point) to all the possible destinations (all
points).
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 11
12. Types of Broadcast
• We can classify broadcasting
techniques into two types:
– Limited Broadcasting:
• Information is sent to all the
nodes on the same network.
• When a sensor node transfers
data to all nodes on the same
network, it is referred to as
limited broadcasting.
– Direct Broadcasting:
• Information is directly sent to all
the nodes on another network.
• When a sensor node in one
network transfers data packet
stream to all the nodes on the
other network, it is referred to as
direct broadcasting.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 12
Figure 1.5: Types of Broadcast
13. Difference between Unicast, Multicast and
Broadcast
UNICAST MULTICAST BROADCAST
It has only one sender and one receiver
It has one or multiple senders and multiple
receivers.
It has one sender and multiple receivers.
Sends data from one device to single device
Data can be sent from one device to multiple
devices
Data sent from one device to all the other
devices in a network.
Works on Single Node Topology. Works on star, mesh, tree and hybrid topology. Works on star and bus topology
Two devices are connected to each other with a
single cable.
The switch is an example of a multicast device. Hub is an example of a broadcast device.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 13
14. Broadcast Storm in WSNs
• A Broadcast Storm is basically a situation when an abruptly
large number of data packets arrive in a very small amount of
time.
• Due to the broadcast storm, the network quality degrades
significantly.
– It leads to broadcast and multicast traffic accumulation in a Wireless Sensor
network.
– The broadcast storm problems in WSNs such as high probability of collisions
and redundancy of broadcasting.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 14
15. Flooding
• Flooding: Each node which receives a packet (queries/data) broadcasts it
until the packet reaches the destination node.
• Disadvantages:
– Implosion:
• Happens when duplicate messages sent to the same node.
• Occurs when a node receives copies of the same messages from many of its neighbors.
– Overlap:
• the same event may be sensed by more than one node due to overlapping regions of
coverage.
• This results in their neighbors receiving duplicate reports of the same event.
– Resource blindness: the flooding protocol does not consider the available
energy at the nodes and results in many redundant transmissions. Hence, it
reduces the network lifetime.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 15
16. Gossiping
• It is a modified version of flooding
• The nodes do not broadcast a packet, but send it to a randomly
selected neighbor.
• Avoid the problem of implosion
• It takes a long time for message to propagate throughout the
network.
• It does not guarantee that all nodes of network will receive the
message.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 16
17. Rumour Routing
• It is an agent based path creation algorithm.
• Agents are basically packets which are circulated in the network to
establish shortest path to events.
• They can also perform path optimizations at nodes they visit.
• When agent finds a node whose path to an event is longer than its
own, it updates the node’s routing table.
• When query is generated at a sink, it is sent on a random walk with
the hope that it will find a path leading to the required event.
• If query does not find an event path , the sink times out and uses
flooding as last resort to propagate the query.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 17
18. TCP over MANETs
• With the proliferation of mobile computing devices, the demand for
continuous network connectivity regardless of physical location has
spurred interest in the use of mobile ad hoc networks.
• Since Transmission Control Protocol (TCP) is the standard network
protocol for communication in the internet, any wireless network
with Internet service need to be compatible with TCP.
• TCP is tuned to perform well in traditional wired networks, where
packet losses occur mostly because of congestion.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 18
19. Issues of TCP in Ad-hoc N/w
• However, TCP connections in Ad-hoc mobile networks are
plagued by problems such as
– high bit error rates,
– frequent route changes,
– multi-path routing, and
– temporary network partitions.
• The throughput of TCP over such connection is not
satisfactory, because TCP misinterprets the packet loss or
delay as congestion and invokes congestion control and
avoidance algorithm.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 19
20. • TCP is reliable, end-to-end, connection-
oriented TL protocol that provides a byte
stream based service.
– Congestion control.
– Flow control.
– In-order delivery of packets.
– Reliable transportation of packets.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 20
21. Design Goals of A Transport Layer Protocol for
Ad Hoc Wireless Networks
❖ The protocol should maximize the throughput per connection.
❖ It should provide throughput fairness across contending flows.
❖ It should incur minimum connection set up and connection maintenance overheads.
❖ It should have mechanisms for congestion control and flow control in the network.
❖ It should be able to provide both reliable and unreliable connections as per the requirements of the
application layer.
❖ It should be able to adapt to the dynamics of the network such as rapid changes in topology.
❖ Bandwidth must be used efficiently.
❖ It should be aware of resource constraints such as battery power and buffer sizes and make efficient
use of them.
❖ It should make use of information from the lower layers for improving network throughput.
❖ It should have a well-defined cross-layer interaction framework.
❖ It should maintain End-to-End Semantics.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 21
22. Why Does TCP Not Perform Well in
Ad Hoc Wireless Networks?
• Transmission Control Protocol (TCP) is designed to operate in wired Networks. But when TCP
is deployed with wireless or ad hoc networks. Then it fails to establish continuous
transmissions due to various reasons:
• The major reasons behind throughput degradation that TCP faces when used in ad hoc wireless
net works are the following.:
1. Misinterpretation of packet loss: Traditional TCP was designed for wired networks where the packet
loss is mainly attributed to network congestion. Network congestion is detected by the sender's
packet RTO period. Once a packet loss is detected, the sender node assumes congestion in the network
and invokes a congestion control algorithm. Ad hoc wireless networks experience a much higher
packet loss due to factors such as high bit error rate (BER) in the wireless channel, increased collisions
due to the presence of hidden terminals, presence of interference, location-dependent contention, uni-
directional links, frequent path breaks due to mobility of nodes, and the inherent fading properties of
the wireless channel.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 22
23. Example WSN in Building
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 23
Figure 1.6: Cracks and Tilt Sensors as used in
Building Area Sensor Networks
24. 2. Frequent path breaks: Ad hoc wireless networks experience dynamic changes in network
topology because of the unrestricted mobility of the nodes in the network. The topology
changes lead to frequent changes in the connectivity of wireless links and hence the route to
a particular destination may need to be recomputed very often. The responsibility of finding
a route and reestablishing it once it gets broken is attached to the network layer. Once a path
is broken, the routing protocol initiates a route reestablishment process. This route
reestablishment process takes a significant amount of time to obtain a new route to the
destination. The route reestablishment time is a function of the number of nodes in the
network, transmission ranges of nodes, current topology of the network, bandwidth of the
channel, traffic load in the network, and the nature of the routing protocol. If the route
reestablishment time is greater than the retransmission timeout (RTO) period of
the TCP sender, then the TCP sender assumes congestion in the network, retransmits the
lost packets, and initiates the congestion control algorithm. These retransmissions can lead
to wastage of bandwidth and battery power. Eventually, when a new route is found,
the TCP throughput continues to be low for some time, as it has to build up the congestion
window since the traditional TCP undergoes a slow start.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 24
25. 3. Effect of path length: It is found that the TCP
throughput degrades rapidly with an increase in
path length in string (linear chain) topology ad
hoc wireless networks. This is shown in Figure
(a) alongside. The possibility of a path break
increases with path length. Given that the
probability of a link break is Pl, the probability
of a path break (Pb) for a path of length k can be
obtained as 𝑃𝑏 = 1 − 1 − 𝑃𝑙
𝑘
.
– Figure (b) alongside shows the variation
of Pb with path length for Pl = 0.1.
Hence as the path length increases, the
probability of a path break increases,
resulting in the degradation of the
throughput in the network.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 25
Figure 1.7:
Effect of Path
Length on
(a).Throughput
and (b). the
probability of
path breaks
26. 4. Misinterpretation of congestion window: TCP considers the congestion
window as a measure of the rate of transmission that is acceptable to the network
and the receiver.
– In ad hoc wireless networks, the congestion control mechanism is invoked
when the network gets partitioned or when a path break occurs.
• Hence, when there are frequent path breaks, the congestion window may not reflect
the maximum transmission rate acceptable to the network and the receiver.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 26
27. 5. Asymmetric link behavior: The radio channel used in ad hoc wireless networks
has different properties such as location-dependent contention, environmental
effects on propagation, and directional properties leading to asymmetric links.
– The directional links can result in delivery of a packet to a node, but failure in the delivery of the
acknowledgment back to the sender.
– It is possible for a bidirectional link to become uni-directional for a while.
– This can also lead to TCP invoking the congestion control algorithm and several retransmissions.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 27
28. 6. Uni-directional path: Traditional TCP relies on end-to-end ACK for ensuring
reliability. Since the ACK packet is very short compared to a data segment, ACKs
consume much less bandwidth in wired networks. In ad hoc wireless networks,
every TCP ACK packet requires RTS-CTS-Data-ACK exchange in case IEEE
802.11 is used as the underlying MAC protocol. This can lead to an additional
overhead of more than 70 bytes if there are no retransmissions. This can lead to
significant bandwidth consumption on the reverse path, which may or may not
contend with the forward path. If the reverse path contends with the forward path,
it can lead to the reduction in the throughput of the forward path. Some routing
protocols select the forward path to be also used as the reverse path, whereas
certain other routing protocols may use an entirely different or partially different
path for the ACKs.
– Path break on an entirely different reverse path can affect the performance of
the network as much as a path breaks in the forward path.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 28
29. 7. Multipath routing: There exists a set of QoS routing and best-
effort routing protocols that use multiple paths between a source-
destination pair. There are several advantages in using multipath
routing. Some of these advantages include the reduction in route
computing time, the high resilience to path breaks, high call
acceptance ratio, and better security. For TCP, these advantages
may add to throughput degradation. Multipath Routing can lead to
a significant amount of out-of-order packets, which in turn
generates a set of duplicate acknowledgments (DUPACKs) which
cause additional power consumption and invocation of congestion
control.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 29
30. 8. Network Partitioning and Remerging: The randomly moving nodes in an ad hoc wireless
network can lead to network partitions. As long as the TCP sender, the TCP receiver, and all the
intermediate nodes in the path between the TCP sender and the TCP receiver remain in the same
partition, the TCP connection will remain intact. It is likely that the sender and receiver of the TCP
session will remain in different partitions and, in certain cases, that only the intermediate nodes are
affected by the network partitioning.
– A network with two TCP sessions A and B is shown in Figure 1.8 (a) at time instant t1.
– Due to dynamic topological changes, the network gets partitioned into two as in Figure
1.8 (b) at time t2.
– Now the TCP session A’s sender and receiver belong to two different partitions and the
TCP session B experiences a path break.
– These partitions could merge back into a single network at time t3 (refer to Figure 1.8
(c)).
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 30
31. 20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 31
Figure 1.8: Effect of Partitioning and Merging of Networks
32. 9. The use of sliding-window-based transmission: TCP uses a sliding window for
flow control. The transmission of packets is decided by the size of the window,
and when the ACKs arrive from a destination, further packets are transmitted.
This avoids the use of individual fine-grained timers for transmission of each TCP
flow. Such a design is preferred in order to improve scalability of the protocol in
high-bandwidth networks such as the Internet where millions of TCP connections
may be established with some heavily loaded servers. The use of a sliding
window can also contribute to degraded performance in bandwidth-constrained ad
hoc wireless networks where the MAC layer protocol may not exhibit short-term
and long-term fairness. For example, the popular MAC protocols such as
CSMA/CA protocol show short term unfairness, where a node that has captured
the channel has a higher probability of capturing the channel again. This
unfairness can lead to a number of TCP ACK packets being delivered to the TCP
sender in succession, leading to a burstiness in traffic due to the subsequent
transmission of TCP segments.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 32
33. A comparison of TCP solutions for ad hoc wireless
networks
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 33
34. IEEE802.11 Wireless LAN, WiFi
• IEEE 802.11 standard, popularly known as WiFi (Wireless Fidelity), lays
down the architecture and specifications of wireless LANs (WLANs).
• WiFi or WLAN uses high-frequency radio waves instead of cables for
connecting the devices in LAN.
• Users connected by WLANs can move around within the area of network
coverage.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 34
35. IEEE 802.11 Architecture
• The components of an IEEE 802.11 architecture are as follows −
• Stations (STA) − Stations comprises of all devices and equipment that are
connected to the wireless LAN. A station can be of two types−
• Wireless Access Point (WAP) − WAPs or simply access points (AP) are
generally wireless routers that form the base stations or access.
• Client. Clients are workstations, computers, laptops, printers, smartphones, etc.
• Each station has a wireless network interface controller.
• Basic Service Set (BSS) − A basic service set is a group of stations
communicating at the physical layer level. BSS can be of two categories
depending upon the mode of operation−
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 35
36. IEEE 802.11 Architecture contd…
• Infrastructure BSS − Here, the devices
communicate with other devices through
access points.
• Independent BSS − Here, the devices
communicate in a peer-to-peer basis in
an ad hoc manner.
• Extended Service Set (ESS) − It is a set
of all connected BSS.
• Distribution System (DS) − It connects
access points in ESS.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 36
Figure 1.9: IEEE802.11 Architecture
37. Frame Format of IEEE 802.11
• The main fields of a frame of wireless LANs as laid down by IEEE 802.11
are −
• Frame Control − It is a 2 bytes starting field composed of 11 subfields. It
contains control information of the frame.
• Duration − It is a 2-byte field that specifies the time period for which the
frame and its acknowledgment occupy the channel.
• Address fields − There are three 6-byte address fields containing addresses of
source, immediate destination, and final endpoint respectively.
• Sequence − It a 2 bytes field that stores the frame numbers.
• Data − This is a variable-sized field that carries the data from the upper layers.
The maximum size of the data field is 2312 bytes.
• Check Sequence − It is a 4-byte field containing error detection information.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 37
38. Frame Format for IEEE802.11
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 38
Figure 1.10: IEEE802.11 Frame Format
39. Advantage/ Disadvantage of WLANs
• Advantages of WLANs
▪ They provide clutter free homes, offices and other networked places.
▪ The LANs are scalable in nature, i.e. devices may be added or removed from the network at a
greater ease than wired LANs.
▪ The system is portable within the network coverage and access to the network is not bounded
by the length of the cables.
▪ Installation and setup is much easier than wired counterparts.
▪ The equipment and setup costs are reduced.
• Disadvantages of WLANs
▪ Since radio waves are used for communications, the signals are noisier with more interference
from nearby systems.
▪ Greater care is needed for encrypting information. Also, they are more prone to errors. So, they
require greater bandwidth than the wired LANs.
▪ WLANs are slower than wired LANs.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 39
40. MAC ISSUES IN ADHOC
NETWORKS
Unit 1:
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 40
41. MAC Layer
• MAC stands for the Medium Access Control Layer.
• The MAC layer is the “Brain” of WiFi.
• The first version of 802.11 (the 802.11 legacy published in 1997).
• the MAC layer is responsible for incorporating a number of crucial features, such as
sharing of speech among users, the terms of network connection, error control or
security.
• The MAC layer also defines the network addresses: all devices have an identifier of
48 bits (6 bytes) known as the “MAC address”.
• The first three bytes identify the manufacturer of the network equipment. For
example, in hexadecimal notation, 00-00-0c corresponds to Cisco constructor, 00-
04-23 corresponds to Intel Corporation, etc.
• The following three bytes define an identifier one chosen by the manufacturer, for
example 8B-B5-0B. An address will look like for example: 00-04-23-8B-B5-0B.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 41
42. Responsibilities of MAC
Protocol in WSNs
➢Network overhead should be low.
➢Efficiently allocate the bandwidth.
➢Distributed MAC operation.
➢Power control mechanism should be present.
➢Maximum utilization of channel.
➢Hidden and Exposed problem should be removed.
➢Nodes should be sync with time.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 42
43. Functions of MAC Layer
• It provides an abstraction of the physical layer to the LLC and upper layers
of the OSI network.
• It is responsible for encapsulating frames so that they are suitable for
transmission via the physical medium.
• It resolves the addressing of source node as well as the destination node, or
groups of destination nodes.
• It performs multiple access resolutions when more than one data frame is to
be transmitted. It determines the channel access methods for transmission.
• It also performs collision resolution and initiating retransmission in case of
collisions.
• It generates the frame check sequences and thus contributes to protection
against transmission errors.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 43
44. Design issues of MAC Protocol
1. Bandwidth Efficiency –
– The shortage of data transfer capacity assets in these networks requires its proficient use.
– To evaluate this, we could state that bandwidth capacity is the proportion of the bandwidth used for data transmission to the
complete accessible bandwidth capacity.
2. Quality of Service Support –
– Quality of service support is difficult due to the mobility of the nodes. Once a node moves out of reach, the reservation in it is lost.
In these networks, QoS is extremely important because if it is being used in military environments, the service support needed time
to time.
3. Synchronization –
– Some instruments must be found so as to give synchronization among the nodes. Synchronization is significant for directing the
bandwidth reservation.
4. Hidden Terminal Problem –
– When there are two nodes, both are outside of each other’s range and try to communicate with same node within their range at the
same time, then there must be packet collision.
5. Exposed Terminal Problem –
– Uncovered nodes might be denied channel access pointlessly, which implies under usage of the bandwidth resources.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 44
45. Bluetooth
• Bluetooth is a Wireless Personal Area Network (WPAN) technology and is
used for exchanging data over smaller distances.
• This technology was invented by Ericson in 1994.
• It operates in the unlicensed, industrial, scientific and medical (ISM) band at
2.4 GHz to 2.485 GHz.
• Maximum devices that can be connected at the same time are 7.
• Bluetooth ranges upto 10 meters.
• It provides data rates upto 1 Mbps or 3 Mbps depending upon the version.
• The spreading technique which it uses is FHSS (Frequency hopping spread
spectrum) and supports 1600hops/sec.
• A Bluetooth network is called a piconet and a collection of interconnected
piconets is called scatternet.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 45
46. Bluetooth Architecture
• Bluetooth architecture defines two types of
networks:
1. Piconet
2. Scatternet
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 46
47. Piconet
• Piconet is a Bluetooth network that consists of one primary
(master) node and seven active secondary (slave) nodes.
• Thus, piconet can have up to eight active nodes (1 master
and 7 slaves) or stations within the distance of 10 meters.
• There can be only one primary or master station in each
piconet.
• The communication between the primary and the secondary
can be one-to-one or one-to-many.
• All communication is between master and a slave. Salve-
slave communication is not possible.
• In addition to seven active slave station, a piconet can have
up to 255 parked nodes. These parked nodes are secondary
or slave stations and cannot take part in communication
until it is moved from parked state to active state.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 47
48. Scatternet
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 48
• Scatternet is formed by combining various
piconets.
• A slave in one piconet can act as a master or
primary in other piconet.
• Such a station or node can receive messages
from the master in the first piconet and deliver
the message to its slaves in other piconet
where it is acting as master. This node is also
called bridge slave.
• Thus a station can be a member of two
piconets.
• A station cannot be a master in two piconets.
49. Bluetooth layers and Protocol
Stack
• Bluetooth standard has many protocols that are organized into
different layers.
• The layer structure of Bluetooth does not follow OS1 model,
TCP/IP model or any other known model.
• The different layers and Bluetooth protocol architecture.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 49
50. Bluetooth Protocol Stack
Radio
Baseband
Link Manager
Control
Host
Controller
Interface
Logical Link Control and Adaptation Protocol (L2CAP)
Audio
TCS BIN SDP
OBEX
vCal/vCard
IP
NW apps.
TCP/UDP
BNEP
RFCOMM (serial line interface)
AT modem
commands
telephony apps.
audio apps. mgmnt. apps.
AT: attention sequence
OBEX: object exchange
TCS BIN: telephony control
protocol specification – binary
BNEP: Bluetooth network
encapsulation protocol
SDP: service discovery
protocol
RFCOMM: radio frequency
comm.
PPP
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 50
51. Radio Layer
➢ The Bluetooth radio layer corresponds to the physical layer of OSI model.
➢ It deals with ratio transmission and modulation.
➢ The radio layer moves data from master to slave or vice versa.
➢ It is a low power system that uses 2.4 GHz ISM band in a range of 10
meters.
➢ This band is divided into 79 channels of 1MHz each. Bluetooth uses the
Frequency Hopping Spread Spectrum (FHSS) method in the physical layer
to avoid interference from other devices or networks.
➢ Bluetooth hops 1600 times per second, i.e. each device changes its
modulation frequency 1600 times per second.
➢ In order to change bits into a signal, it uses a version of FSK called GFSK
i.e. FSK with Gaussian bandwidth filtering.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 51
52. Baseband Layer
➢ Baseband layer is equivalent to the MAC sublayer in LANs.
➢ Bluetooth uses a form of TDMA called TDD-TDMA (time division duplex TDMA).
➢ Master and slave stations communicate with each other using time slots.
➢ The master in each piconet defines the time slot of 625 µsec.
➢ In TDD- TDMA, communication is half duplex in which receiver can send and receive
data but not at the same time.
➢ If the piconet has only no slave; the master uses even numbered slots (0, 2, 4, …) and the
slave uses odd-numbered slots (1, 3, 5, …. ). Both master and slave communicate in half
duplex mode. In slot 0, master sends & secondary receives; in slot 1, secondary sends
and primary receives.
➢ If piconet has more than one slave, the master uses even numbered slots. The slave sends
in the next odd-numbered slot if the packet in the previous slot was addressed to it.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 52
53. Baseband Layer-Types of Connections
• In Base-band layer, two types of links can be
created between a master and slave.
• These are:
1. Asynchronous Connection Less (ACL)
2. Synchronous Connection Oriented (SCO)
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 53
54. Asynchronous Connection Less
(ACL)
• It is used for packet switched data that is available at irregular intervals.
• ACL delivers traffic on a best effort basis. Frames can be lost & may have
to be re-transmitted.
• A slave can have only one ACL link to its master.
• Thus ACL link is used where correct delivery is preferred over fast
delivery.
• The ACL can achieve a maximum data rate of 721 kbps by using one, three
or more slots.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 54
55. Synchronous Connection Oriented
(SCO)
• SCO is used for real time data such as sound. It is used where fast delivery
is preferred over accurate delivery.
• In an SCO link, a physical link is created between the master and slave by
reserving specific slots at regular intervals.
• Damaged packet; are not re-transmitted over SCO links.
• A slave can have three SCO links with the master and can send data at 64
Kbps.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 55
56. Logical Link, Control Adaptation
Protocol Layer (L2CAP)
• The logical unit link control adaptation protocol is
equivalent to logical link control sub-layer of LAN.
• The ACL link uses L2CAP for data exchange but SCO
channel does not use it.
• The various function of L2CAP is:
1. Segmentation and reassembly
2. Multiplexing
3. Quality of Service (QoS)
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 56
57. Segmentation and Reassembly
• L2CAP receives the packets of up to 64 KB from upper layers
and divides them into frames for transmission.
• It adds extra information to define the location of frame in the
original packet.
• The L2CAP reassembles the frame into packets again at the
destination.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 57
58. Multiplexing
• L2CAP performs multiplexing at sender side and de-
multiplexing at receiver side.
• At the sender site, it accepts data from one of the upper layer
protocols frames them and deliver them to the Base-band
layer.
• At the receiver site, it accepts a frame from the base-band
layer, extracts the data, and delivers them to the appropriate
protocol1ayer.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 58
59. Quality of Service (QoS)
• L2CAP handles quality of service requirements, both when
links are established and during normal operation.
• It also enables the devices to negotiate the maximum payload
size during connection establishment.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 59
60. Bluetooth Frame Format
1. Access Code: It is 72 bit field that contains
synchronization bits. It identifies the master.
2. Header: This is 54-bit field. It contain 18 bit pattern
that is repeated for 3 time.
The header field contains following sub-fields:
i. Address: This 3 bit field can define up to seven slaves (1 to
7). If the address is zero, it is used for broadcast
communication from primary to all secondaries.
ii. Type: This 4 bit field identifies the type of data coming from
upper layers.
iii. F: This flow bit is used for flow control. When set to 1, it
means the device is unable to receive more frames.
iv. A: This bit is used for acknowledgement.
v. S: This bit contains a sequence number of the frame to detect
re-transmission. As stop and wait protocol is used, one bit is
sufficient.
vi. Checksum: This 8 bit field contains checksum to detect
errors in header.
3. Data: This field can be 0 to 2744 bits long. It contains
data or control information coming from upper layers
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 60
61. Suggested Readings
• https://www.nielit.gov.in/sites/default/files/6.pdf - Wireless
Data Acquisition system for estimating the water quality of
Dal Lake in Srinagar
• https://www.informit.com/articles/article.aspx?p=361984&seq
Num=5 – Chapter 9 of Book Ad-hoc Wireless Networks:
Architectures and Principles.
20 March 2022 Dr. Piyush Charan, Dept. of ECE, Integral University, Lucknow 61
62. Dr. Piyush Charan
Assistant Professor,
Department of ECE,
Integral University, Lucknow
Email: er.piyush.charan@gmail.com, piyush@iul.ac.in
20 March 2022
Dr. Piyush Charan, Dept. of ECE, Integral
University, Lucknow
62