Taxonomy and an Ad-hoc
Networks Overview
Wireless network taxonomy
single hop
infrastructure
(e.g., APs)
❒ What network type to select??
❒ Some characteristics of Ad-hoc networks
no
infrastructure
TDDD36: Ad-hoc networks
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
TDDD36: Ad-hoc networks
Classification of wireless
networks
Ad-hoc wireless networks
(multi-hop wireless networks)
Cellular networks
Wireless
mesh networks
Hybrid
Wireless
networks
Cellular
networks vs
ad-hoc
networks
Wireless sensor
networks
Infrastructure-dependent
(single-hop wireless networks)
TDDD36: Ad-hoc networks
TDDD36: Ad-hoc networks
Applications of ad-hoc
networks
Wireless mesh networks, example
❒ Military
❒ Collaborative and distributed computing
❒ Emergency operations
❒ Wireless mesh networks
❒ Wireless sensor networks
❒ Hybrid wireless networks
TDDD36: Ad-hoc networks
TDDD36: Ad-hoc networks
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Wireless mesh networks, example
Hybrid wireless networks, example
TDDD36: Ad-hoc networks
Issues in ad-hoc wireless networks
❒ Medium access
❒ Self-organization
scheme
❒ Routing
❒ Energy
❍
management
Multicasting
❒ Transport layer
protocol
❒ Pricing scheme
❒ Quality of service
provisioning
❒ Addressing and
service discovery
❒ Scalability
❒ Deployment
considerations
TDDD36: Ad-hoc networks
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
TDDD36: Ad-hoc networks
TDDD36: Ad-hoc networks
Issues in QoS provision for MANETs
QoS design choices
❒ Dynamically varying network topology
❒ Hard state vs soft state resource
reservation
❒ Imprecise state information
❒ Lack of central coordination
❒ Stateful vs stateless approach
❒ Error-prone shared radio channel
❒ Hard QoS vs soft QoS approach
❒ Hidden terminal problem
❒ Limited resources availability
❒ Insecure medium
TDDD36: Ad-hoc networks
TDDD36: Ad-hoc networks
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Classification of QoS approaches
Power Management (p214)
❒ Please see
textbook p. 214
TDDD36: Ad-hoc networks
TDDD36: Ad-hoc networks
Issues, self-organization
❒ Neighbour discovery
❍
Deployment considerations
❒ Scenario
beacons, snooping
❒ Longevity
❒ Topology organization
❍ the whole or part
❒ Area of coverage
❒ Topology reorganization
❍ exchange topological changes and then adapt
❍ network partitioning and merging
❒ Operational integration with other
❒ Service availability
infrastructure
❒ Choice of protocols: link layer vs transport
layer
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TDDD36: Ad-hoc networks
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