Transcript Table-driven routing protocol

Wireless Networks Routing
Outlines
 Wireless networks architectures
 Routing protocols for wireless networks
 Mobile ad-hoc Networks (MANETs)
 Wireless Sensor Networks (WSNs)
 Vehicle ad-hoc networks (VANETs)
Wireless Communications
 Wireless networks use radio frequency channels as
their physical medium for communications.
 Each node in the network broadcast information
which can be received by all nodes within its direct
transmission range.
Wireless network architectures
 Infrastructure-based wireless networks
 Fixed base stations / access points are
used.
 Infrastructure-less wireless networks
(Ad-hoc networks)
 No fixed infrastructure support are
available.
 Hybrid wireless networking
architecture
Wireless network architectures (cont.)
 Infrastructure-based wireless networks
 Uses fixed base stations / access points which are responsible
for coordinating communication between the hosts.
 Single-hop communication
Wireless network architectures (cont.)
 Ad-hoc networks
 Consists of nodes which communicate with each other through
wireless medium without any fixed infrastructure.
 Multi-hop communications
Properties of ad-hoc networks
 No pre-build infrastructure
 All nodes are wireless capable
 Base stations are not necessary
 Ease of deployment
 Quickly deploy
Some emerging types of wireless networks
 MANETs (Mobile Ad-hoc Networks)
 WSNs (Wireless Sensor Networks)
 VANET (Vehicle Ad-hoc Networks)
 WMN (Wireless Mesh Networks)
…
Routing protocols for wireless networks –
MANETs
 A dynamically reconfigurable ad-hoc network.
 Main issues in the design and operation of MANETs.
 (1) MANETs are more unstable than wired-networks because
of the lack of a centralized entity.
Routing protocols for wireless networks –
MANETs (cont.)
(2) Mobility will cause network topology to change,
which results in a great change in connection between
two hosts.
(3) The connectivity between network nodes is not
guaranteed, so intermittent connectivity is common.
The main routing
problems for MANETs
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Node mobility 
Routing path broken
frequently
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Traditional ad-hoc routing protocols
Routing protocols for MANETs
 Flooding-type routing protocol (flooding)
 Table-driven routing protocol (proactive)
 On-demand routing protocol (reactive)
 Hybrid routing protocol
Flooding-type routing protocol
(Flooding)
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Flooding-type routing protocol
(Flooding)
 Advantage: They do not need to maintain network
topology, or is looking for data transmission path, so
they can quickly transfer information.
 Disadvantage: Node receives information after, must
repeat broadcast, making it fast consumes its battery
energy, and produces broadcast storm.
Routing protocols for MANETs (cont.)
 Table-driven routing protocol (proactive):
 They maintain the global topology information in the
form of tables at every node.
 These tables are updated frequently in order to
maintain consistent and accurate network state
information.
 For example, DSDV, WRP, and STAR.
Table-driven routing protocol—
Destination Sequenced Distance Vector routing (DSDV)
 The DSDV routing protocol is an enhanced version of
the distributed Bellman-Ford algorithm where each
node maintain a table that contain the shortest distance
and the first node on the shortest path to every other
node in the network.
Table-driven routing protocol – DSDV (cont.)
Example:
Routing table for Node 1
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Table-driven routing protocol – DSDV (cont.)
 Each node, upon receiving an update, quickly
disseminates it to its neighbors in order to propagate
the broken-link information to the whole network.
Thus a single link break leads to the propagation of
table update information to the whole network.
Table-driven routing protocol – DSDV (cont.)
Routing table for Node 1
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Table-driven routing protocol – DSDV (cont.)
 Advantage：
It can be applied to MANETs with few modifications.
The updates are propagated throughout the network in
order to maintain an up-to-date view of the network
topology at all the nodes.
Table-driven routing protocol – DSDV (cont.)
 Disadvantage：
 (1) The DSDV suffers from excessive control
overhead that is proportional to the number of
nodes in the network and therefore is not
scalable in MANETs, which have limited
bandwidth and whose topologies are highly
dynamic.
Table-driven routing protocol – DSDV (cont.)
 (2) In order to obtain information about a particular
destination node, a node has to wait for a table
update message initiated by the same destination
node. This delay could result in stale routing
information at nodes.
Routing protocols for MANETs (cont.)
 On-demand routing protocol (reactive):
 They execute the path-finding process and exchange
routing information only when a path is required by a
node to communicate with a destination.
 For example, AODV and DSR.
On-demand routing protocol –
Ah-hoc On-demand Distance-Vector Routing Protocol (AODV)
 AODV, a route is established only when it is required
by a source node for transmitting data packets.
 In AODV, the source node and intermediate nodes
store the next-hop information corresponding to each
flow for data packet transmission.
On-demand routing protocol – AODV (cont.)
 The major difference between AODV and other ondemand routing protocol is that it uses a destination
sequence number ( DestSeqNum) to determine an upto-date path to the destination.
 A node updates its path information only if the
DestSeqNum of the current packet received is greater
than the last DestSeqNum stored at the node.
On-demand routing protocol – AODV (cont.)
 AODV utilizes routing tables to store routing
information.
 The routing table stores:
destination
addr
next-hop
addr
destination
sequence
hop count
life time
The AODV routing procedure
1. If a node wants to send a packet to some destination. At
first, it checks its routing table to determine whether it has
a current route to the destination or not.
=>If yes, it forwards the packet to next hop node of
the route.
=>If no, it initiates a route discovery process.
The AODV routing procedure (cont.)
 The Route discovery process:
 It begins with the creation of a RouteRequest (RREQ) packet.
Broadcasting is done via flooding.
 Broadcast ID gets incremented each time a source node uses
RREQ.
 Broadcast ID and source IP address form a unique identifier for
the RREQ.
Type
Reserved Hop Count
Broadcast ID
RREQ packet format
Destination IP Address
Destination Sequence Number
Source IP Address
Source Sequence Number
Time Stamp
The AODV routing procedure (cont.)
2. Sender S broadcasts a RREQ to all its neighbors, each node
receiving RREQ forwards RREQ to its neighbors.
*Sequence numbers help to avoid the possibility of forwarding the same
packet more than once.
3. An intermediate node (not the destination) may also send a
RouteReply (RREP) packet provided that it knows a more
recent path than the one previously known to sender S.
Type
Reserved
Hop Count
Destination IP Address
RREP packet format
Destination Sequence Number
Source IP Address
Life Time
The AODV routing procedure (cont.)
 4. As an intermediate node receives the RREP packet,
it sets up a forward path entry to the destination in
its routing table.
 5. The source node can begin data transmission upon
receiving the first RREP.
Illustration of route establishment in AODV
 1. Node S needs a routing path to node D.
 2. Node S creates a RREQ packet
RREQ [D’s IP addr, seq#, S’s IP addr, seq#, hopcount]
 Node S broadcasts RREQ to its neighbors.
B
RREQ{D, D’seq, S, S’seq, 0}
S
A
D
C
Illustration of route establishment in AODV (cont.)
 2. Node A rebroadcasts RREQ to all its neighbors.
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RREQ{D, D’seq, S, S’seq, 1}
S
A
D
RREQ{D, D’seq, S, S’seq, 1}
C
Illustration of route establishment in AODV (cont.)
 3. Since, node C known a route to D.
 Node C creates a RREP packet and unicasts RREP to A.
 Set forward path in node C’s routing table.
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S
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RREP{D, D’seq, S, S’seq, 1}
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C’s Routing table
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Illustration of route establishment in AODV (cont.)
 3. Node A creates a RREP packet and unicasts RREP to S.
 4. Set forward path in node A’s routing table.
A’s Routing table
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RREP{D, D’seq, S, S’seq, 2}
C
C’s Routing table
dest
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hopcount
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Illustration of route establishment in AODV (cont.)
 4. Set forward path in node S’s routing table.
A’s Routing table
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hopcount
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Route maintenance in AODV (Path broken due to host mobility)
1. If intermediate nodes or the destination move.
The next hop links break.
Routing tables are updated for the link failures.
All active neighbors are informed by RouteError
(RRER) packet.
2. When a source node receives an RRER, it can
reinitiate the route discovery process.
3. It can be also dealt with by a local fix scheme.
Illustration of route maintenance in AODV
 Assume link between C and D breaks.
 Node C invalidates route to D in route table.
 Node C creates RRER packet and sends to its upstream
neighbors.
 Node A sends RRER to S.
 Node S rediscovers route if still needed.
B
RRER
S
A
RRER
C
D
On-demand routing protocol – AODV (cont.)
 Advantage:
 The routes are established on demand and the destination
sequence number can find the latest route to the
destination.
 Disadvantage:
 The intermediate nodes can lead to inconsistent routes if
the source sequence number is very old.
 The periodic beaconing leads to unnecessary bandwidth
consumption.
On-demand routing protocol –
Dynamic Source Routing Protocol (DSR)
 DSR designed to restrict the bandwidth consumed
by control packets in ad hoc wireless networks by
eliminating the periodic table-update messages
required in the table-driven approach.
Route Discovery
(broadcasting the RREQ packets)
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Destination
Route Discovery (cont.)
(propagating the RREP packets back to source)
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Hybrid routing protocol –
Zone Routing Protocol (ZRP)
 A hybrid routing protocol which effectively combines
the best features of both proactive and reactive routing
protocols.
 The key concept employed in ZRP is to use a
proactive routing scheme within a limited zone in the
γ-hop neighborhood of every node, and use a reactive
routing scheme for nodes beyond this zone.
Routing zone for node 8 in ZRP
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Routing Zone with Radius = 1
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Routing Zone with Radius = 2
Routing Zone for Node 8
Performing the Proactive Routing for node 8
(destination=node 16)
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Routing Zone for Node8
Routing Zone with Radius = 2
Hybrid routing protocol – ZRP (cont.)
 Advantage:
 By combining the best features of proactive and
reactive routing schemes, ZRP reduces the control
overhead.
 Disadvantage:
 But in the absence of a query control, ZRP tends to
produce higher control overhead than the previously
schemes.
Other routing issue for MANET –
The Intermittent connected routing problem
 In case of the nodes density of a MANET is sparse, it
will cause the intermittent connected routing problem,
and consequently the traditional routing protocols will
be no longer fit.
Intermittent connected routing problem
Epidemic routing protocol
 Epidemic is a simple routing protocol to resolve the
intermittent connected routing problem.
 The nodes adopt store-carry-forward communication
scheme.
 A node can carry the messages in its cache if no any direct
routing path to the destination is available.
 If a node moves into the node’s transmission range, they
will exchange the carried messages between them.
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(Epidemic routing)
S
PENUGASAN KELOMPOK
KELOMPOK 1 : MEMBUAT PAPER TENTANG MANET
KELOMPOK 2 : MEMBUAT PAPER TENTANG WSN
KELOMPOK 3 : MEMBUAT PAPER TENTANG RFID
KELOMPOK 4 : MEMBUAT PAPER TENTANG WIRELESS MESH NET
KELOMPOK 5 : MEMBUAT PAPER TENTANG CELLULAR SYSTEM
KELOMPOK 6 : MEMBUAT PAPER TENTANG MOBILE IP
KELOMPOK 7 : MEMBUAT PAPER TENTANG VANET
KELOMPOK 8 : MEMBUAT PAPER TENTANG PERVASIVE
COMPUTING
KELOMPOK 9 : MEMBUAT PAPER TENTANG MOBILE COMPUTING
BUAT KELOMPOK MAKSIMAL 5 ORANG……..
Routing protocols for wireless networks –
WSNs
 A sensor network is composed of a large number of
multifunctional and small sensor nodes.
 WSN allows random deployment in inaccessible
terrains or disaster relief operations.
 Sensor nodes are fitted with an onboard processor, it
consists of sensing, data processing, and
communicating components.
Introduction to WSNs -- Communication architecture
Sensor field
User
Sink
Internet or
satelite
Task manager node
Introduction to WSNs -- Communication architecture (cont.)
Satelite
Sink
Introduction to WSNs -- Communication architecture (cont.)
 The sensor nodes are usually scattered in a sensor
field.
 Sensor nodes can collect data and route data back to
sink.
 The sink may communicate with the task manager
node via Internet or Satellite.
Introduction to WSNs -- Applications
Military applications
Home
applications
Environmental
applications
Applications
Health applications
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Other commercial
applications
Introduction to WSNs –
The differences between WSNs and ad-hoc networks
 The number of sensor nodes in a sensor network
can be several orders of magnitude higher.
 Sensor nodes are densely deployed.
 Sensor nodes are prone to failures.
 Sensor nodes are limited in power, computational
capacities, and memory.
Introduction to WSNs –
The differences between WSNs and ad-hoc networks (cont.)
 Sensor nodes mainly use a broadcast communication
paradigm, whereas most ad hoc networks are based
on point-to-point communications.
 Sensor nodes may not have global identification (ID)
because of the large amount of overhead and large
number of sensors.
Introduction to WSNs – Sensor node
Introduction to WSNs – Sensor node (cont.)
Aqua node
Introduction to WSNs – Sensor node (cont.)
Aqua node
Introduction to WSNs – Sensor node (cont.)
Sensing Unit
Processing Unit
Transmission Unit
Processor
Sensor
ADC
Transceiver
Storage
Power Unit
Mobilizer
Location Finding System
Power Generator
Introduction to WSNs – Design factors
 Production costs
 The cost of each sensor node should be much less
than US $1 in order for the sensor network to be
feasible.
 Transmission media
 In a multi-hop sensor network, communicating
nodes are linked by radio, infrared or optical
media.
Introduction to WSNs – Design factors (cont.)
 Environment
 Sensor network usually work unattended in remote
geographic areas, such as large machinery, ocean,
biologically and chemically contaminated field.
 Hardware
 A sensor node is made up of four basic components:
sensing unit, processing unit, transceiver unit,
power unit, and also have additional applicationdependent components.
Introduction to WSNs – Network deployment
 Three phases of WSNs deployment
 Pre-deployment phase
 Sensor nodes can be either thrown in mass
or placed one by one in the sensor field.
 Post-deployment phase
 After deployment, topology changes are
due to change in sensor nodes’
 Position
 available energy
 malfunctioning
Introduction to WSNs – Network deployment (cont.)
 Re-deployment phase
 Additional sensor nodes can be re-deployed at
any time to replace the malfunctioning nodes
or due to changes in task dynamics.
 Addition of new nodes poses a need to re-
organize the network.
Introduction to WSNs – Routing challenges and design
issues
 Node deployment
 In manual deployment, the sensors are
manually placed and data is routed through
predetermined paths.
 Energy consumption without losing accuracy
 Sensor nodes can use up their limited energy
performing computations and transmitting
information.
Introduction to WSNs – Routing challenges and design
issues (cont.)
 Data reporting method
 Data reporting can be categorized as either time-
driven, event-driven, query-driven, or a hybrid.
 The time-driven method is suitable for
applications that require periodic data.
 Event-driven and query-driven methods, sensor
nodes react immediately to sudden and drastic
changes in the value of a sensed attribute
Introduction to WSNs – Routing challenges and design
issues (cont.)
 Coverage
 A given sensor’s view of the environment is
limited in both range and accuracy.
 Area coverage is an important design
parameter.
 Quality of service
 Bounded latency for data delivery is another
condition for time-constrained applications.
 As energy is depleted, the network may be
required to reduce the quality of results in
order to reduce energy dissipation.
Routing protocols for WSNs (cont.)
 Flat-based
 All nodes are typically assigned equal roles or
functionality.
 Hierarchical-based
 Nodes will play different roles in the network.
 Location-based
 Sensor node’s positions are exploited to route
data in the network.
Routing protocols for WSNs (cont.)
Flat-based routing
 Each node typically plays the same role and
sensor nodes collaborate to perform the sensing
task.
 This consideration has led to data-centric routing,
where the BS sends queries to certain regions and
waits for data from the sensors located in the
selected regions.
 Early work on data centric routing were shown to
save energy through data negotiation and
elimination of redundant data.
Flat-based routing example
SPIN (Sensor Protocols for Information via Negotiation)
ADV
REQ
DATA
A
1.
2.
3.
4.
DATA
REQ (ADV).
Data is ADV
described by meta-message
Send ADV to neighbors.
If neighbor do not have the data, sends REQ; otherwise, do nothing.
As the REQ received by sender, then it sends the data to the
neighbor.
Flat-based routing example
SPIN (cont.)
 Advantage
 Each node only needs to know its one-hop
neighbors.
 Disadvantage
 Data advertisement cannot guarantee the
delivery of data.
Routing protocols for WSNs (cont.)
Hierarchical-based routing
 Hierarchical routing is two-layer routing where one
layer is used to select cluster heads and the other for
routing.
 Higher-energy nodes can be used to process and send
the information, while low-energy nodes can be used
to perform the sensing in the proximity of the target.
 The creation of clusters and assigning special tasks to
cluster heads can greatly contribute to overall system
scalability, lifetime, and energy efficiency.
 Proactive clustering.
 Node transmits sensed data only if both of the following
conditions hold:
1. The sensed value is greater than a Hard Threshold.
2. The sensed value differs from last transmitted value
by more than a Soft Threshold.
Hierarchical-based routing example
TEEN (Threshold-Sensitive Energy Efficient Sensor Network Protocol)
S
Sink
Cluster
Node
1st cluster head
2nd cluster head
D
Hierarchical-based routing example
TEEN (cont.)
 Advantage
 Good for time-critical applications.
 Disadvantage
 Inappropriate for periodic monitoring,
e.g., habitat monitoring.
 Ambiguity between packet loss and
unimportant data.
Routing compare
Hierarchical-based routing
Flat-based routing
Reservation-based scheduling
Contention-based scheduling
Collisions avoided
Collision overhead present
Reduced duty cycle due to periodic
sleeping
Variable duty cycle by controlling
sleep time of nodes
Data aggregation by cluster head
Node on multi-hop path aggregates
incoming data from neighbors
Simple but non-optimal routing
Routing can be made optimal but
with an added complexity
Requires global and local
synchronization
Links formed on the fly without
synchronization
Overhead of cluster formation
throughout the network
Routes formed only in regions that
have data for transmission
Lower latency as multiple hops
network formed by cluster heads
always available
Latency in waking up intermediate
nodes and setting up the multipath
Routing protocols for WSNs (cont.)
Location-based routing
 The location of nodes may be available directly by
communicating with a satellite using GPS if nodes
are equipped with a small low-power GPS receiver.
 Relative coordinates of neighboring nodes can be
obtained by exchanging such information between
neighbors.
 To save energy, some location-based schemes
demand that nodes should go to sleep if there is no
activity.
Routing protocols for wireless networks –
VANETs
 Vehicular Ad hoc Network (VANET) is a special case of
MANET.
 The direct communication between vehicular using Ad
hoc network.
Introduction to VANETs
 Applications in a VANET fall into two categories
 comfort applications
 safety applications
 Comfort applications aim to improve the driving comfort
and the efficiency of the transportation system
 on-board Internet access
 high data rate content download
 driving through payment
Introduction to VANETs (cont.)
 Safety applications aim to provide driver’s information
about future critical situations
 inter-vehicle danger warning
 intersection collision avoidance
 work zone safety warning
Safety applications
Introduction to VANETs (cont.)
 VANETs provide the following three communications:
 Inter-Vehicle Communication (IVC)
 Roadside-to-Vehicle Communication (RVC)
 Hybrid-Vehicular Communication (HVC)
V2R
Emergency Event
V2V
RSU
Introduction to VANETs (cont.)
 Vehicles mobility is restricted to one-dimensional road
geometry.
 Factors affect the mobility of vehicles such as
 road configuration
 traffic laws
 safety limits
 physical limits
Introduction to VANETs (cont.)
 Vehicle mobility creates a highly dynamic topology.
 VANETs are potentially large-scale networks.
 Vehicles can provide more resources than other types of
mobile networks such as：
 large batteries
 antennas
 processing power
Introduction to VANETs (cont.)
 The connectivity of the network is affected by factors that
include
 transmitter power
 environmental conditions
 obstacles
 mobility
Introduction to VANETs (cont.)
 Factors such as the vast number of nodes that lack
inherent organization, as well as
 frequent topological changes
Routing for VANETs
 To enhance the safety of drivers
 To provide the comfortable driving environment
 The message for different purpose need to be sent to
vehicles through the inter-vehicle communications.
 Unicast routing
 Multicast and Geocast
 Broadcast
Routing for VANETs -- Unicast
 Unicast routing is a fundamental operation for vehicle to
construct a source-to-destination routing in a VANET
From Reference 1.
Routing for VANETs -- Unicast
 Routing objective:
Min-Delay
 The goal of min-delay routing protocols is to transmit
data packets to destination as soon as possible.
 Relative routing protocols：VADD、CAR、DIR
Unicast routing example for VANETs
Vehicle-Assisted Data Delivery (VADD)
 Carry-and-forward for data delivery from a moving
vehicle to a static destination.
 VADD is to select a forwarding path with the smallest
packet delivery delay.
Unicast routing example for VANETs
The VADD (cont.)
Disconnected due to sparse
Two Paths： (1) Ia => Ic => Id => Ib
(2) Ia => Ib
Delayacdb < Delayab
Unicast routing example for VANETs
The VADD (cont.)
1. Transmit through wireless channels as much as possible.
2. If the packet has to be carried through certain roads, the
road with higher speed should be chosen.
Unicast routing example for VANETs
The VADD (cont.)
3. Due to the unpredictable nature of vehicular ad-hoc
networks, so dynamic path selection should
continuously be executed throughout the packet
forwarding process.
−
The routing cannot expect the packet to be successfully
routed along the pre-computed optimal path
Unicast routing example for VANETs
Connectivity-Aware Routing (CAR)
 To overcome the limitation of the static destination.
 The CAR protocol establishes a routing path from source
to destination by setting the anchor points at intermediate
junctions.
Unicast routing example for VANETs
The CAR (cont.)
 CAR protocol sends the searching packets to find the
destination.
 Each forwarding vehicle records its ID, hop count, and
average number of neighbors in searching packets.
 Once the searching packets reach the destination, the
destination chooses a routing path with the minimum
delivery delay time and replies it to the source.
Unicast routing example for VANETs
The CAR (cont.)
 While destination sends the reply packet to the source, the
junctions passed through by the reply packet are set as the
anchor point.
 After the path set up, data packets are forwarded in a
greedy forwarding.
D
x
y
Greedy forwarding example:
x: the current message holder.
Assume y is the closest neighbor of x to D,
then x sends the message to y.
Unicast routing example for VANETs
An example for CAR (cont.)
 Vehicle VS tries to send data to vehicle VD, the anchor
points are set at I1,1, I2,1, I2,2, I3,2, I3,3, and I3,4.
 Data is forwarded according to order in the list of
anchor points.
Unicast routing example for VANETs
Diagonal-Intersection-based Routing (DIR)
 To improve the CAR protocol.
 DIR protocol constructs a series of diagonal intersections
between the source and destination vehicles.
 Auto-adjustability is achieved that one sub-path with low
data packet delay, between two neighboring diagonal
intersections, is dynamically selected to forward data
packets.
Unicast routing example for VANETs
The DIR (cont.)
 To reduce the data packet delay, the route is automatically
re-routed by the selected sub-path with lowest delay.
 DIR protocol constructs a series of diagonal intersections
between vehicles VS and VD.
Unicast routing example for VANETs
The comparisons between CAR and DIR
 DIR protocol may set the fewer number of anchors than
CAR protocol.
 DIR protocol can automatically adjust routing path for
keeping the lower packet delay, compared to CAR
protocol.
Routing for VANETs – Multicast and Geocast
 Multicast is defined by delivering multicast packets from
a single source vehicle to all multicast members by multihop communication.
 Geocast routing is to deliver a geocast packet to a specific
geographic region.
Geocast
Routing
Broadcast routing for VANETs
 Broadcast protocol is utilized for a source vehicle sends
broadcast message to all other vehicles in the network.
 Routing protocol type：Broadcast methods for V2V
communication
Advertisement Publicity Broadcast
Broadcast outing for VANETs (cont.)
 The purpose of emergency information is to announce an
urgent event by broadcasting for surrounding vehicles.
 emergency-vehicle-approach
 traffic accident information dissemination
Broadcast routing for VANETs (cont.)
 Emergency-vehicle-approach
 Emergency-vehicle-approach information is used to
announce the urgent event to those vehicles in front of the
current vehicle, so the emergency information is only
disseminated ahead.
 Traffic accident information dissemination
 Traffic accident information is used to announce the urgent
event to those vehicles behind the current vehicle, the
emergency information is only disseminated behind.
Broadcast routing for VANETs
(emergency message distribution)
1. Vehicle VA broadcasts the emergency message to the
restricted direction.
2. Vehicle VD does nothing.
Broadcast routing for VANETs -emergency message distribution (cont.)
3. Vehicle VB is located in the relay range, it re-broadcasts the
emergency information.
4. Vehicle VC is located in notification range but not in relay
range, VC just receives the emergency information and not
to re-broadcast.
References






I. F. Akyildiz, W. Su, Y. Sankarasubramaniam, and E. Cayirci, "Wireless
sensor network: a survey", Computer Networks, Vol. 38, pp. 393-422,
2002.
I. F. Akyildiz, W. Su, Y. Sankarasubramaniam, and E. Cayirci, "A survey
on sensor networks", IEEE Communications Magazine, Vol. 40, issue 8,
pp. 102-114, Aug. 2002.
J. N. Karaki, A. E. Kamal, "Routing techniques in wireless sensor
networks: a survey", IEEE Wireless Communications, pp. 6-28, Dec.
2004.
J. Zhao and G.Cao, “VADD: vehicle-assisted data delivery in vehicular
ad hoc networks,” IEEE Computer Communications, pp. 1-12, 2006.
V. Naumov and T. Gross, “Connectivity-aware routing (CAR) in
vehicular ad hoc Networks,” in Proceedings of IEEE International
Conference on Computer Communications, pp.1919-1927, 2007.
Y. W. Lin, Y. S. Chen and S. L. Lee, “Routing protocols in vehicular ad
hoc networks: a survey and future perspectives,” Journal of Information
Science and Engineering 26, pp.1-20, 2010.
References
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M. S. Bouassida and M. Shawky, “A cooperative congestion control approach
within VANETs : formal verification and performance evaluation,” EURASIP
Journal on Wireless Communications and Networking, Vol. 2010, 2010.
http://commonsense.epfl.ch/COMMONSense/description.htm
http://groups.csail.mit.edu/drl/wiki/index.php/AMOUR_(Autonomous_Modula
r_Optical_Underwater_Robot)
http://russnelson.com/wisan/Sensor-node-front.jpg
http://www.ece.ncsu.edu/wireless/Images/sensor.gif
http://blogs.iium.edu.my/jaiz/2008/12/22/what-is-vehicular-network/