Taxonomy and an Ad-hoc
Networks Overview
 What network type to select??
 Some characteristics of Ad-hoc networks
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Wireless network taxonomy
single hop
multiple hops
infrastructure
(e.g., APs)
no
infrastructure
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Wireless network taxonomy
single hop
infrastructure
(e.g., APs)
no
infrastructure
host connects to
base station (WiFi,
WiMAX, cellular)
which connects to
larger Internet
no base station, no
connection to larger
Internet (Bluetooth,
ad hoc nets)
multiple hops
host may have to
relay through several
wireless nodes to
connect to larger
Internet: mesh net
no base station, no
connection to larger
Internet. May have to
relay to reach other
a given wireless node
MANET, VANET
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Classification of wireless
networks
Ad-hoc wireless networks
(multi-hop wireless networks)
Cellular networks
Hybrid
Wireless
networks
Wireless
mesh networks
Wireless sensor
networks
Infrastructure-dependent
(single-hop wireless networks)
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Cellular
networks vs
ad-hoc
networks
5
Cellular
networks vs
ad-hoc
networks
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Applications of ad-hoc networks
 Military
 Collaborative and distributed computing
 Emergency operations
 Wireless mesh networks
 Wireless sensor networks
 Hybrid wireless networks
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Classification of wireless
networks
Ad-hoc wireless networks
(multi-hop wireless networks)
Cellular networks
Hybrid
Wireless
networks
Wireless
mesh networks
Wireless sensor
networks
Infrastructure-dependent
(single-hop wireless networks)
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Wireless mesh networks, example
9
Wireless mesh networks, example
10
Hybrid wireless networks, example
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Issues in ad-hoc wireless networks
 Medium access
scheme
 Routing

Multicasting
 Transport layer
protocol
 Pricing scheme
 Quality of service
provisioning
 Self-organization
 Energy
management
 Addressing and
service discovery
 Scalability
 Deployment
considerations
12
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Issues, QoS provisioning
 QoS parameters
 Bandwidth and delay?
Availability?
Trustworthy? Link life?
Minimum energy
consumption?
 QoS-aware routing
 Make use of network
throughput, packet
delivery ratio,
reliability, delay, jitter,
packet loss rate, bit
error rate, path loss
 QoS frameworks
 Users served persession or per-class
 Routing
 Signaling
 MAC
 Connection admission
control
 Scheduling schemes
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Issues in QoS provision for MANETs
 Dynamically varying network topology
 Imprecise state information
 Lack of central coordination
 Error-prone shared radio channel
 Hidden terminal problem
 Limited resources availability
 Insecure medium
16
QoS design choices
 Hard state vs soft state resource
reservation
 Stateful vs stateless approach
 Hard QoS vs soft QoS approach
17
Classification of QoS approaches
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Power Management (p214)
 Please see
textbook p. 214
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Issues, self-organization
 Neighbour discovery
 beacons, snooping
 Topology organization

the whole or part
 Topology reorganization
exchange topological changes and then adapt
 network partitioning and merging

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Deployment considerations
 Scenario
 Longevity
 Area of coverage
 Service availability
 Operational integration with other
infrastructure
 Choice of protocols: link layer vs transport
layer
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