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Definition
A decentralized type of wireless network, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, It can turn the dream of networking at any place and at time into reality. We are almost there by the way .Ex- Bluetooth enabled mobile phones such as 3G, laptops, handheld digital devices, personal digital assistants, or wearable computers
Candidate solutions to improve Wireless Mesh Networks WMNs performance to mee...ijcseit
96% market share of existing Smart Grid network installations is wireless mesh networks [1]. The paper starts by justifying the selection of WMNs as opposed to any other communication technology based on quantifying the bandwidth/latency/QoS constraints of a number of Smart Grid applications. The main objective of this paper, however, is to discuss some optimization techniques that found in the literature and can be implemented to overcome some of the challenges currently being faced by WMNs deployment in Smart Grid’s NANs. Hybrid WMN (HWMN) is proposed as an optimization on the topology level to leverage WMNs convergence. Distributed Autonomous Data Routing DADR, multigate and diversity routing are optimizations on the protocol level to minimize the down time of WMNs. Cognitive Radio is investigated as an optimization on the physical level. The paper also explores the feasibility of using Wireless Software Defined Networks WSDN to improve the overall visibility and manageability of WMNs
Definition
A decentralized type of wireless network, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, It can turn the dream of networking at any place and at time into reality. We are almost there by the way .Ex- Bluetooth enabled mobile phones such as 3G, laptops, handheld digital devices, personal digital assistants, or wearable computers
Candidate solutions to improve Wireless Mesh Networks WMNs performance to mee...ijcseit
96% market share of existing Smart Grid network installations is wireless mesh networks [1]. The paper starts by justifying the selection of WMNs as opposed to any other communication technology based on quantifying the bandwidth/latency/QoS constraints of a number of Smart Grid applications. The main objective of this paper, however, is to discuss some optimization techniques that found in the literature and can be implemented to overcome some of the challenges currently being faced by WMNs deployment in Smart Grid’s NANs. Hybrid WMN (HWMN) is proposed as an optimization on the topology level to leverage WMNs convergence. Distributed Autonomous Data Routing DADR, multigate and diversity routing are optimizations on the protocol level to minimize the down time of WMNs. Cognitive Radio is investigated as an optimization on the physical level. The paper also explores the feasibility of using Wireless Software Defined Networks WSDN to improve the overall visibility and manageability of WMNs
CR technology is based on the fact that the licensed systems (also named primary systems PS) are not always using their spectrum bands; CR brings new radio types—cognitive radios—that should firstly, identify the existing spectrum holes, and secondly, utilize them according to an access
https://www.ijmst.com/
IJMST Volume 1 Issue 1, Manuscript 4
As the popularity of mobile devices and wireless networks significantly increased over the
past years. The wireless adhoc network has now become one of the most vibrant and active
fields of communication and networking research. These networks are a new generation of
networks offering unrestricted mobility without any underlying infrastructure. As their
principle application is in disastrous environments, security is critical. Various challenges are
faced in the adhoc environment, mostly due to the resource poorness of these networks. One
man confront in the design of these networks is their vulnerability to security attacks. The
solutions for conventional networks are usually not sufficient to provide efficient adhoc
operations. Just because of its wireless nature of communication and lack of any security
infrastructure raise several security problems and threats.
In this paper, we briefly review the threats an adhoc network faces and the security goals to
be achieved. Moreover, it also presents existing security schemes used in wireless adhoc
networks in order to handle security threats.
Analysis of Handoff techniques used for hybrid networks: cellular/WLAN IJORCS
Most real life networks are hybrid networks. A hybrid network combines the best features of two or more networks. In networking terminology, a hybrid network according to “Information Technology control and Audit” are reliable and versatile. They provide large numbers of connections and data transmission paths to users. These hybrid networks may be treated as network nodes for analysis purpose. The two radio access technologies (RATs) are considered with cellular/WLAN depending on whether it is voice/ data, video. For observing practical result, some setups are required in laboratory which includes interface from personal computer to mobile terminal and vice-versa. The network simulator (Ns-2) is used for analysis purpose. The results shows the parameters like energy good put, Bandwidth utilization, packet delivery ratio, energy good put and energy consumed are improved after using hybrid networks.
CR technology is based on the fact that the licensed systems (also named primary systems PS) are not always using their spectrum bands; CR brings new radio types—cognitive radios—that should firstly, identify the existing spectrum holes, and secondly, utilize them according to an access
https://www.ijmst.com/
IJMST Volume 1 Issue 1, Manuscript 4
As the popularity of mobile devices and wireless networks significantly increased over the
past years. The wireless adhoc network has now become one of the most vibrant and active
fields of communication and networking research. These networks are a new generation of
networks offering unrestricted mobility without any underlying infrastructure. As their
principle application is in disastrous environments, security is critical. Various challenges are
faced in the adhoc environment, mostly due to the resource poorness of these networks. One
man confront in the design of these networks is their vulnerability to security attacks. The
solutions for conventional networks are usually not sufficient to provide efficient adhoc
operations. Just because of its wireless nature of communication and lack of any security
infrastructure raise several security problems and threats.
In this paper, we briefly review the threats an adhoc network faces and the security goals to
be achieved. Moreover, it also presents existing security schemes used in wireless adhoc
networks in order to handle security threats.
Analysis of Handoff techniques used for hybrid networks: cellular/WLAN IJORCS
Most real life networks are hybrid networks. A hybrid network combines the best features of two or more networks. In networking terminology, a hybrid network according to “Information Technology control and Audit” are reliable and versatile. They provide large numbers of connections and data transmission paths to users. These hybrid networks may be treated as network nodes for analysis purpose. The two radio access technologies (RATs) are considered with cellular/WLAN depending on whether it is voice/ data, video. For observing practical result, some setups are required in laboratory which includes interface from personal computer to mobile terminal and vice-versa. The network simulator (Ns-2) is used for analysis purpose. The results shows the parameters like energy good put, Bandwidth utilization, packet delivery ratio, energy good put and energy consumed are improved after using hybrid networks.
Enhanced Quality of Service Based Routing Protocol Using Hybrid Ant Colony Op...Editor IJCATR
The main problem of QoS routing is to setup a multicast hierarchy that may meet particular QoS constraint. In order to reduce the constraints of the earlier work a new improved technique is proposed in this work. In the proposed technique the issue of multi-cast tree is eliminated using clustering based technique. First of all multi-radio and multichannel based clustering is deployed and these cluster head are responsible
for the multicasting. It will diminish the overall energy consumption of nodes and complexity of intelligent algorithms. The path will be evaluated based upon the ant colony optimization. Thus it has produced better results than other techniques.
Enhanced Quality of Service Based Routing Protocol Using Hybrid Ant Colony Op...Editor IJCATR
The main problem of QoS routing is to setup a multicast hierarchy that may meet particular QoS constraint. In order to reduce the constraints
of the earlier work a new improved technique is proposed in this work. In the proposed technique the issue of multi-cast tree is eliminated
using clustering based technique. First of all multi-radio and multichannel based clustering is deployed and these cluster head are responsible
for the multicasting. It will diminish the overall energy consumption of nodes and complexity of intelligent algorithms. The path will be
evaluated based upon the ant colony optimization. Thus it has produced better results than other techniques.
Enhanced Quality of Service Based Routing Protocol Using Hybrid Ant Colony Op...Editor IJCATR
The main problem of QoS routing is to setup a multicast hierarchy that may meet particular QoS constraint. In order to reduce the constraints
of the earlier work a new improved technique is proposed in this work. In the proposed technique the issue of multi-cast tree is eliminated
using clustering based technique. First of all multi-radio and multichannel based clustering is deployed and these cluster head are responsible
for the multicasting. It will diminish the overall energy consumption of nodes and complexity of intelligent algorithms. The path will be
evaluated based upon the ant colony optimization. Thus it has produced better results than other techniques.
Enhanced Quality of Service Based Routing Protocol Using Hybrid Ant Colony Op...Editor IJCATR
The main problem of QoS routing is to setup a multicast hierarchy that may meet particular QoS constraint. In order to reduce the constraints of the earlier work a new improved technique is proposed in this work. In the proposed technique the issue of multi-cast tree is eliminated using clustering based technique. First of all multi-radio and multichannel based clustering is deployed and these cluster head are responsible for the multicasting. It will diminish the overall energy consumption of nodes and complexity of intelligent algorithms. The path will be evaluated based upon the ant colony optimization. Thus it has produced better results than other techniques.
A wireless mesh network is a decentralized network where nodes communicate wirelessly, forming a web-like structure. It enables efficient data transmission and extends coverage by relaying signals through interconnected nodes.
A computer network links several computers. Office networks allow people to w...sherinjoyson
One of the first computer networks to use packet switching, ARPANET, was developed in the mid-1960s and is the direct predecessor of the modern Internet.
CA in Patna is a team of professional Chartered Accountant which are providing best services like Company Registration, Income Tax Return, Sales Tax Consultants, Bank Audit and other services specially in Patna.
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CA in Dwarka is a team of professional Chartered Accountant which are providing best services like Company Registration, Income Tax Return, Sales Tax Consultants, Bank Audit and other services specially in Dwarka and Delhi NCR.
Css Founder is Website Designing Company working with the mission of Website For Everyone Website Start From 999/-* More Packages are available. we are best company in website designing company in Delhi, as we are also working in Website Designing company in Mumbai.
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CA in Patna is a team of professional Chartered Accountant which are providing best services like Company Registration, Income Tax Return, Sales Tax Consultants, Bank Audit and other services specially in Patna.
CA in Dwarka is a team of professional Chartered Accountant which are providing best services like Company Registration, Income Tax Return, Sales Tax Consultants, Bank Audit and other services specially in Dwarka and Delhi NCR.
CA in Dwarka is a team of professional Chartered Accountant which are providing best services like Company Registration, Income Tax Return, Sales Tax Consultants, Bank Audit and other services specially in Dwarka and Delhi NCR.
CA in Dwarka is a team of professional Chartered Accountant which are providing best services like Company Registration, Income Tax Return, Sales Tax Consultants, Bank Audit and other services specially in Dwarka and Delhi NCR.
Css Founder is Website Designing Company working with the mission of Website For Everyone Website Start From 999/-* More Packages are available. we are best company in website designing company in Delhi, as we are also working in Website Designing company in Mumbai.
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June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
2. Chapter 5: Ad Hoc Wireless Networks
2
Introduction
Ad Hoc Wireless Networks
Ad Hoc Wireless Internet
School.edhole.com
3. Advent of Ad hoc Wireless Networks
The principle behind ad hoc networking is multi-hop relaying in
which messages are sent from the source to the destination by
relaying through the intermediate hops (nodes).
In multi-hop wireless networks, communication between two end
nodes is carried out through a number of intermediate nodes whose
function is to relay information from one point to another. A static
string topology is an example of such network:
3
0 1 2 3 4 5 6 7
In the last few years, efforts have been focused on multi-hop "ad
hoc" networks, in which relaying nodes are in general mobile, and
communication needs are primarily between nodes within the same
network.
School.edhole.com
4. Advent of Ad hoc Wireless Networks
An examples of such developments is the Bluetooth standard that
is one of the first commercial realizations of ad hoc wireless
networking developed by Bluetooth Special Interest Group (SIG):
• A piconet formed by a group of nodes establishes a single-hop (master node)
point-to-point wireless link.
• A scatternet formed by multiple piconets (master nodes) can establish a
multi-hop wireless network.
Though the IEEE 802.11 protocols have developed for the wireless
networks, they don’t function well in multi-hop networks.
Realizing the necessity of open standards in this emerging area of
computer communication, the mobile ad hoc networks (MANET)
standards are being developed by the Internet Working Tasking
Force (IETF) MANET working group.
4
School.edhole.com
5. Advent of Ad hoc Wireless Networks
Even though ad hoc wireless networks are expected to work in the
absence of any fixed infrastructure, recent advances in wireless
network architectures enable the mobile ad hoc nodes to function
in the presence of infrastructure
Multi-hop cellular networks (MCNs), self-organizing packet radio
ad hoc networks with overlay (SOPRANO), and mesh networks
are examples of such types of networks.
Mesh networks serve as access networks that employ multi-hop
wireless forwarding by non-mobile nodes to relay traffic to and
from the wired Internet. In such an environment, hybrid
technologies and/or hierarchical network organization can be used
for ad hoc and infrastructure wireless links.
5
School.edhole.com
6. Cellular and Ad Hoc Wireless Networks
The following figure represents different wireless networks.
6
• Infrastructure: cellular wireless networks
• Ad hoc: wireless sensor networks
• Hybrid: mesh networks
Cellular Wireless
Networks
Hybrid Wireless
Networks
Wireless Mesh
Networks
Wireless Sensor
Networks
School.edhole.com
7. Comparisons between Cellular and Ad Hoc
7
Wireless Networks (I)
Cellular Networks Ad Hoc Wireless Networks
Fixed infrastructure-based Infrastructureless
Guaranteed bandwidth (designed for
voice traffic)
Shared radio channel (more suitable for
best-effort data traffic)
Centralized routing Distributed routing
Circuit-switched (evolving toward
packet switching)
Packet-switched (evolving toward
emulation of circuit switching)
Seamless connectivity (low call drops
during handoffs)
Frequent path breaks due to mobility
High cost and time of deployment Quick and cost-effective deployment
Reuse of frequency spectrum through
Dynamic frequency reuse based on
geographical channel reuse
carrier sense mechanism
Easier to employ bandwidth reservation Bandwidth reservation requires complex
medium School.edhole.com access control protocols
8. Comparisons between Cellular and Ad Hoc
8
Wireless Networks (II)
Cellular Networks Ad Hoc Wireless Networks
Application domains include mainly
civilian and commercial sectors
Application domains include battlefields,
emergency search and rescue operations,
and collaborative computing
High cost of network maintenance
(backup power source, staffing, etc.)
Self-organization and maintenance
properties are built into the network
Mobile hosts are of relatively low
complexity
Mobile hosts require more intelligence
(should have a transceiver as well as
routing/switching capability)
Major goals of routing and call
admission are to maximize the call
acceptance ratio and minimize the call
drop ratio
Main aim of routing is to find paths with
minimum overhead and also quick
reconfiguration of broken paths
Widely deployed and currently in the
third generation of evolution
Several issues are to be addressed for
successful commercial deployment even
though widespread School.edhole.com use exists in defense
9. Applications of Ad hoc Wireless Networks
Military applications
9
• Ad hoc wireless networks is useful in establishing communication in a
battle field.
Collaborative and Distributed Computing
• A group of people in a conference can share data in ad hoc networks.
• Streaming of multimedia objects among the participating nodes.
Emergency Operations
• Ad hoc wireless networks are useful in emergency operations such as search
and rescue, and crowd control.
A Wireless Mesh Network is a mesh network that is built upon
wireless communications and allows for continuous connections
and reconfiguration around blocked paths by "hopping" from node
to node until a connection can be established.
School.edhole.com
10. 10
Wireless Mesh Networks
In a wireless mesh network, multiple nodes cooperate to relay a message to its
destination. The mesh topology enhances the overall reliability of the network,
which is particularly important when operating in harsh industrial environments. School.edhole.com
11. 11
Wireless Mesh Networks
The investment required in wireless mesh networks is much less
than in the cellular network counterparts.
Such networks are formed by placing wireless replaying
equipment spread across the area to be covered by the network.
The possible deployment scenarios include:
• Residential zones (where broadband Internet connectivity is required)
• Highways (where a communication facility for moving automobiles is
required)
• Business zones (where an alternate communication system to cellular
networks is required)
• Important civilian regions (where a high degree of service availability is
required)
• University campuses (where inexpensive campus-wide network coverage
can be provided)
School.edhole.com
12. 12
Wireless Mesh Networks
Wireless mesh networks should be capable of self-organization
and maintenance.
Advantages
• High data rate
• Quick and low cost of deployment
• Enhanced services
• High scalability
• Easy extendability
• High availability
• Low cost per bit
• High availability
• Low cost per bit
It operates at 2.4 GHz or 5 GHz
Data rates Sch oofo 2l .Medbphso tloe 6.c0 oMmbps can be supported.
13. 13
Wireless Sensor Networks
Wireless Sensor Networks are a special category of ad hoc
networks that are used to provide a wireless communication
infrastructure among the sensors deployed in a specific application
domain.
A sensor network is a collection of a large number of sensor nodes
that are deployed in a particular region.
Distinct properties of wireless sensor networks:
• Mobility of nodes are not needed in all cases in wireless sensor networks.
• The size of the network is much larger than that in a typical ad hoc wireless
network.
• The density of nodes in a sensor network varies with the domain of
application.
• The power constraints in sensor networks are much more stringent than those
in ad hoc wireless networks.
School.edhole.com
14. 14
Wireless Sensor Networks
Distinct properties of wireless sensor networks:
• The power source can be classified into three categories:
• Replenishable power resource
• Non- Replenishable power source
• Regenerative power source
• Data/information fusion aims at processing the sensed data at the
intermediate nodes and relaying the outcome to the monitor node.
• The communication traffic pattern varies with the domain of applications.
School.edhole.com
15. 15
Hybrid Wireless Networks
Hybrid Wireless Networks
• Multi-hop cellular networks (MCNs) allows the transmission through the
base stations or multi-hop of mobile nodes.
• Integrated cellular ad hoc relay (iCAR) is a system that combines
conventional cellular technology with Ad hoc Relay Station (ARS)
technology. In this system cellular stations will relay or reroute calls from
the congested cell to an adjacent one that is not congested.
Advantages
• Higher capacity than cellular networks
• Increased flexibility and reliability in routing
• Better coverage and connectivity
School.edhole.com
16. Issues in Ad hoc Wireless Networks
16
Medium access scheme
• Distributed operation is required.
• Synchronization is required in TDMA-based systems.
• Hidden terminals are nodes hidden from a sender.
• Exposed terminals are exposed nodes preventing a sender from sending.
• Throughput needs to be maximized.
• Access delay should be minimized.
• Fairness refers to provide an equal share to all competing nodes.
• Real-time traffic support is required for voice, video, and real-time data.
• Resource reservation is required for QoS.
• Ability to measure resource availability handles the resources.
• Capability for power control reduces the energy consumption.
• Adaptive rate control refers to the variation in the data bit rate.
• Use of directional antennas has advantages including increased spectrum
reuse, reduced interference, and reduced School.edhole.com power consumption.
17. Issues in Ad hoc Wireless Networks
17
Routing
• Mobility
• Bandwidth constraint
• Error-prone and shared channel: wireless channel (10-5 to 10-3), wired
channel (10-12 to 10-9)
• Location-dependent contention depends on the number of nodes.
• Other resource constraints such as computing power, battery power
• Minimum route acquisition delay
• Quick route reconfiguration
• Loop-free routing
• Distributed routing approach
• Minimum control overhead
• Scalability
• Provisioning of QoS
• Support for time-sensitive traffic: hard real-time and soft real-time traffic
• SecuSrictyh aondo plr.ievadchy ole.com
18. Issues in Ad hoc Wireless Networks
18
Provisioning of multiple links among the nodes in an ad hoc
network results in a mesh-shaped structure. The mesh-shaped
multicast routing structure work well in a high-mobility
environment.
The issues in multicast routing protocols are:
• Robustness: It must be able to recover and reconfigure quickly.
• Efficiency: It should make a minimum number of transmissions to deliver a
packet.
• Control overhead: It demands minimal control overhead.
• Quality of service: QoS support is essential.
• Efficient group management needs to be performed with minimal
exchange of control messages.
• Scalability: It should be able to scale for a large network.
• Security is important.
School.edhole.com
19. Issues in Ad hoc Wireless Networks
19
The objectives of the transport layer protocols include:
• Setting up and maintaining end-to-end connections
• Reliable end-to-end delivery of data packets
• Flow control
• Congestion control
Connectionless transport layer protocol (UDP), unaware of high
contention, increases the load in the network.
Pricing Schemes need to incorporate service compensation.
Quality of Service Provisioning
• QoS parameters based on different applications
• QoS-aware routing uses QoS parameters to find a path.
• QoS framework is a complete system that aims at providing the promised
services to each users.
School.edhole.com
20. Issues in Ad hoc Wireless Networks
20
Self-Organization is required in ad hoc wireless networks:
• Neighbor discovery
• Topology organization
• Topology reorganization
Security
• Denial of service
• Resource consumption
• Energy depletion: deplete the battery power of critical nodes
• Buffer overflow: flooding the routing table or consuming the data packet
buffer space
• Host impersonation: A compromised node can act as another node.
• Information disclosure: a compromised node can act as an informer.
• Interference: jam wireless communication by creating a wide-spectrum
noise.
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21. Issues in Ad hoc Wireless Networks
Addressing and Service Discovery is essential because of absence
of a centralized coordinator.
Energy Management
• Transmission power management: The radio frequency (RF) hardware
design should ensure minimum power consumption.
• Battery energy management is aimed at extending the battery life.
• Processor power management: The CPU can be put into different power
saving modes.
• Devices power management: Intelligent device management can reduce
power consumption of a mobile node.
Scalability is expected in ad hoc wireless networks.
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22. Issues in Ad hoc Wireless Networks
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Deployment considerations
• Low cost of deployment
• Incremental deployment
• Short deployment time
• Reconfigurability
• Scenario of deployment
• Military deployment
• Emergency operations deployment
• Commercial wide-area deployment
• Home network deployment
• Required longevity of network
• Area of coverage
• Service availability
• Operational integration with other infrastructure
• Choice of protocols at different layers should be taken School.edhole.com into consideration.
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Issues of Ad hoc Wireless Internet
Gateways
• Gateway nodes are the entry points to the wired Internet and generally
owned and operated by a service provider.
• Perform the following tasks: keeping track of the end users, band-width
fairness, address, and location discovery.
Address mobility
• Solutions such as Mobile IP can be used.
Routing
• Specific routing protocols for ad hoc networks are required.
Transport layer protocol
• Split approaches that use traditional wired TCP for the wired part and a
specialized transport layer protocol for the ad hoc wireless network part.
Load balancing
• Load balancing techniques are essential to distribute the load so as to avoid
the situation where the gateway nodes become School.edhole.com bottleneck nodes.
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Issues of Ad hoc Wireless Internet
Pricing/billing
• It is important to introduce pricing/billing strategies for the ad hoc wireless
internet.
Provisioning of security
• It is essential to include security mechanisms in the ad hoc wireless
Internet.
QoS support
• Voice over IP (VoIP) and multimedia applications require the QoS support.
Service, address, and location discovery
• Service discovery refers to the activity of discovering or identifying the
party which provides a particular service or resource.
• Address discovery refers to the services such as address resolution protocol
(ARP) or domain name service (DNS).
• Location discovery refers to different activities such as detecting the
location of a Schoo pl.aertdichuloarl meo.cbiolem node.