Mobile and Ad hoc Networks

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Mobile and Ad hoc Networks
Background of Ad hoc Wireless Networks
Wireless Communication Technology and Research
Ad hoc Routing and Mobile IP and Mobility
Wireless Sensor and Mesh Networks
Student Presentations
QoS in Ad Hoc
http//web.uettaxila.edu.pk/CMS/SP2012/teAWNms/
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Overview

• Introduction
• Ad-hoc Network definition
• Overview Ad-hoc networks
• Network architecture
• Applications of ad-hoc networks
• Ad-hoc networks characteristics and requirements
• Overview QoS
• What is QoS ?
• The need of QoS in MANETs
• Why QoS is hard in MANETs
• Current Solutions for Support in MANETs
• Flexible QoS Model for MANETs
• INSIGNIA-MANETs QoS Signaling
• SWAN for MANETs
• Conclusions
• QA

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Ad Hoc Network definition

• An ad-hoc network is a wireless LAN, in which
  some devices are part of the network only for the
  duration of a communication session or while in
  some close proximity to the rest of the network.
• A "mobile ad hoc network" (MANET) is an
  autonomous system of mobile routers (and
  associated hosts) connected by wireless links
  forming an arbitrary graph. Routers are free to
  move randomly and organize themselves
  arbitrarily network topology may change rapidly
  and unpredictably. May operate in a stand-alone
  fashion, or may be connected to the Internet.
• An ad hoc network can be regarded as a
  spontaneous network a network that
  automatically emerges when nodes gather together

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MANET Mobile Ad hoc NETworks
C
B
A
D

• - Mobility - Self configuring and healing -
  Rapid Deployment
• High capacity - Independent of public
  infrastructure - Relaying
• Internet compatible standards-based wireless
  systems

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Network Architecture

• Multi-layered network infrastructure

• Flat network infrastructure

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Applications of Ad Hoc Networks

• Personal communications
  
• Cell phones, laptops
• Cooperative environments
• Taxi cab network
• Meeting rooms
• Emergency operations
  
• Policing and fire fighting
• Military environments
• Battlefield
• Network of sensors or floats over water

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Ad Hoc Networks Characteristics and Requirements

• Autonomous and spontaneous nature of nodes
• Distributed Algorithms to support security,
  reliability and consistency of exchanged and
  stored information
• Time-varying network topology (no pre-existing
  infrastructure or central administration)
• Scalable routing and mobility management
  techniques to face network dynamics
• Fluctuating link capacity and network resources
• Enhanced functionalities to improve link layer
  performance, QoS network support and end-to-end
  efficiency
• Low-power devices
• Energy conserving techniques at all layers

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What is QoS ?

• Hard to agree on a common definition of QoS
• A QoS enabled network shall ensure
• That its applications and/or their users have
  their QoS parameters fulfilled, while at the same
  time ensuring an efficient resource usage
• That the most important traffic still has its QoS
  parameters fulfilled during network overload
• What are the most important QoS parameters
• Throughput, availability, delay, jitter and
  packet loss

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The need for QoS in MANETs

• Applications have special service requirements
• VoIP delay, jitter, minimum bandwidth
• Needs intelligent buffer handling and queueing
• High mobility of users and network nodes
• Routing traffic is important
• No retransmission of lost broadcast messages
• Routing contol messages must be prioritized
• For use in emergency and military operations
• User traffic prioritization is needed
• user, role, situation etc
• Wireless bandwidth and battery capacity are
  scarce resources
• Need efficient resource usage
• E.g. only route high priority traffic through
  terminals that are low on power
• Need QoS aware routing

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Why QoS is Hard in Mobile Ad Hoc Networks?
Video frame without QoS Support
Video frame with QoS Support
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Why QoS is Hard in Mobile Ad Hoc Networks?

• Dynamic network topology
• Flow stops receiving QoS provisions due to path
  disconnections
• New paths Must be established, causing data loss
  and delays
• Imprecise state information
• Link state changes continuously
• Flow states change over time
• No central control for coordination
• Error-prone shared medium
• Hidden terminal problem
• Limited resources availability
• Bandwidth, battery life, storage, processing
  capabilities
• Insecure medium

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Current Solutions for QoS support in Mobile Ad
Hoc Networks

• Because of the unique characteristics of the
  ad-hoc environment three models provide some good
  insight into the issues of QoS in MANETs
• These models provide a comprehensive solutions,
  namely
• FQMM
• INSIGNIA
• SWAN

• FQMM
• INSIGNIA
• SWAN

Flexibility!
Can be integrated with multiple routing
protocols
?
?
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Flexible QoS Model for MANETs (FQMM)

• First QoS Model proposed in 2000 for MANETs by
  Xiao et al
• Proposes a hybrid provisioning that combines
  the per-flow granularity on IntServ and per-class
  granularity of DiffServ
• Adopts DiffServ, but improves the per-class
  granularity to per-flow granularity for certain
  class of traffic
• Built over IntServ and DiffServ models, it can
  operate with extranet traffic
• Classification is made at the source node
• QoS provisioning is made on every node along the
  path
• FQMM Model provisions the traffic into two
  portions
• the highest priority is assigned per-flow
  granularity.
• the rest is assigned per-class granularity.
• Three types of nodes defined
• Ingress (transmit)
• Interior (forward)
• Egress (receive)

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Comparison
Best-Effort
Diffserv
Intserv
Service

• Connectivity
• No isolation
• No guarantees

• Per aggregation isolation
• Per aggregation guarantee

• Per flow isolation
• Per flow guarantee

Service Scope

• End-to-end

• Domain

• End-to-end

Complexity

• No set-up

• Long term setup

• Per flow setup

Scalability

• Highly scalable
• (nodes maintain only routing state)

• Scalable (edge routers maintains per aggregate
  state core routers per class state)

• Not scalable (each router maintains per flow
  state)

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INSIGNIA MANETs QoS Signaling

• First signalling protocol designed solely for
  MANETs by Ahn et al. 1998
• In-band signaling
• Base and enhanced QoS levels
• Per-flow management
• Resources management adapted as technology
• Intelligent packet scheduling
• Flow reservation, restoration and adaptation
• QoS reports periodically sent to source node
• Source node takes action to adapt flows to
  observed network condition
• Routing
• Any routing protocol can be used
• Route maintenance procedure will affect
• In-band signaling
• Establish, adapt, tear down reservations
• Control information embedded in data packets

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INSIGNIA OPTION Field

• Supports in-band signaling by adding a new option
  field in the IP header to carry the signaling
  control
• Reservation Mode (REQ/RES) indicates whether
  there is already a reservation for this packet.
• If no, the packet is forwarded to INSIGNIA
  Module which in coordination with a AC may
  either
• grant resources ? Service Type RT (real-time).
• deny resources? Service Type BE (best-effort).
• If yes, the packet will be forwarded with the
  allowed resources.
• Bandwidth Request (MAX/MIN) indicates the
  requested amount of bandwidth.

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INSIGNIA Bottleneck Node

• During the flow reservation process a node may be
  a bottleneck
• The service will degrade from RT/MAX -gt RT/MIN.

• If M2 is heavy-loaded it may also degrade the
  service level to BE/MIN where there is actually
  no QoS.

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SWAN - Stateless Wireless Ad Hoc Networks

• An alternative to INSIGNIA with improved
  scalabilities properties
• Is a stateless network scheme designed
  specifically for MANETs with no need to process
  complex signaling, or to keep per-flow
  information, to achieve scalability and
  robustness
• Promotes rate control system that can be used at
  each node to treat traffic either as real-time or
  best-effort
• Excessive real-time traffic is automatically
  demoted to best-effort
• While provides a model that deals with traffic on
  a per-class , it uses merely two level of
  service, best-effort and real-time traffic
• Both level of service can be mapped to DSCPs with
  known PHB (based on bandwidth requirement) to
  facilitate extranet QoS
• May decide to demote part of the real-time
  traffic to best-effort service due to lack of
  resources
• The transmission rate for the best-effort traffic
  is locally estimated and adjusted to accommodate
  the bandwidth required by Real Time traffic
• Supports source-based admission control and
  distributed congestion control for real-time
  traffic
• Uses Explicit Congestion Notification (ECN)

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Ad hoc QoS interconnectivity with fixed network

• Ad-Hoc network needs to cling to a host network
  in order to gain access to the internet
• Co-operation between ad hoc network and the host
  network can facilitate end-to-end QoS support
• Framework proposed by Morgan and Kunz defines a
  solution for interaction between ad hoc and host
  networks
• This framework is not affected by the specific
  QoS model implemented on either side
• Ad-Hoc network may decide to implement INSIGNIA,
  SWAN, or FQMM, while host network may decide to
  implement DiffServ or IntServ
• Ad-hoc networks rely on the host network
  resources and services in order to access to the
  outside world
• The host network provides support for the ad-hoc
  by providing access to specific domain services
  and agreements

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Conclusion

• In this lecture, we have discussed different
  existing QoS model for wireless ad-hoc networks
• INSIGNIA, SWAN and FQMM, each model provide the
  basics for a more comprehensive model
• Mobile nodes can connect to the Internet gateways
  of different types, providing different QoS
• Classified different approach with respect to
  different mobility scenarios
• In order to achieve an end-to-end QoS approach,
  QoS information in both fixed and ad-hoc networks
  should be involved
• This demands an interaction between these
  sections

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References

• 1 Towards End-to-End QoS in Ad-Hoc Networks
  Connected to Fixed Networks, David Remondo
  Catalonia Univ. of Technology (UPC)
• 2 An architectural framework for MANET QoS
  interaction with access domains, Yasser Morgan
  and Thomas Kunz, Carleton University
• 3A proposal for an ad-hoc network QoS gateway,
  Yasser Morgan and Thomas Kunz, Carleton
  University
• 4 A Glance at Quality of Services in Mobile
  Ad-Hoc Networks, Zeinalipour-Yazti Demetrios
  (csyiazti_at_cs.ucr.edu)
• 5 Quality of Service in Ad-Hoc Networks, Eric
  Chi, Antoins Dimakis el (smartnets_at_uclink.berkeley
  .edu)
• 6 QoS in Mobile Ad Hoc Networks, Prasant
  Mohapatra, Jian Li and Chao Gui, University of
  California
• 7 QoS-aware Routing Based on Bandwidth
  Estimation for Mobile Ad Hoc networks, Lei Chen
  and Wendi Heinzelman, University of
  Rochesterchenlei,wheinzel_at_ece.rochester.edu
• 8 Dynamic Quality of Service for Mobile Ad-Hoc
  Networks, M. Mirhakkak, N. Schult, D. Thomson,
  The MITRE Corporation
• 9 Network Architecture to Support QoS in Mobile
  Ad Hoc Networks, Lei Chen and Wendi Heizelman,
  University of Rochester

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Assignment 10

• Write note on the topics highlighted in Yellow.

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QA

• ?