This document discusses power aware routing protocols for wireless sensor networks. It begins by describing wireless sensor networks and how they are used to monitor environmental conditions. It then classifies routing protocols for sensor networks based on their functioning, node participation style, and network structure. Specific examples are provided for different types of routing protocols, including LEACH, TEEN, APTEEN, SPIN, Rumor Routing, and PEGASIS. Chain-based and clustering routing protocols are also summarized.

1. Power Aware Routing
Protocols
for
Wireless Sensor Networks
Darpan Dekivadiya
(09BCE008)

2. Wireless Sensor Networks
 A wireless sensor
network (WSN)
consists of spatially
distributed autonomous
sensors to monitor
physical or
environmental
conditions, such as
temperature, sound,
vibration, pressure,
motion or pollutants
and to cooperatively
pass their data through
the network to a main
location.

3. Classification Of Routing
Protocols
 Routing techniques are required for sending
data between sensor nodes and the base
stations for communication.
 Routing Protocols can be classified :
 Based on Mode of functioning and type of
target applications into Proactive, Reactive
and Hybrid.
 Based on Participation style of the nodes into
as Direct Communication, Flat and Clustering
Protocols .
 Depending on the Network Structure as
Hierarchical, Data Centric and Location

4. Proactive, Reactive and Hybrid
 In a Proactive Protocol the nodes switch on
their sensors and transmitters, sense the
environment and transmit the data to a BS
through the predefined route.
 The Low Energy Adaptive Clustering hierarchy
protocol (LEACH) utilizes this type of protocol.
 In Reactive Protocol if there are sudden
changes in the sensed attribute beyond some
pre-determined threshold value, the nodes
immediately react. This type of protocol is used
in time critical applications
 The Threshold sensitive Energy Efficient sensor
Network(TEEN) is an example of a reactive protocol.

5.  Hybrid Protocols Incorporate both Proactive
and Reactive concepts.
 They first compute all routes and then improve
the routes at the time of routing.
 Adaptive Periodic TEEN(APTEEN) is an example of
Hybrid Protocols.

6. Direct Communication, Flat and Clustering
Protocols
 In Direct Communication Protocols, any node can
send information to the BS directly.
 When this is applied in a very large network, the
energy of sensor nodes may be drained quickly.
 Its scalability is very small.
 SPIN is an example of this type of protocol.
 In the case of Flat Protocols, if any node needs to
transmit data, it first searches for a valid route to
the BS and then transmits the data.
 Nodes around the base station may drain their
energy quickly.
 Its scalability is average.
 Rumor Routing is an example of this type of protocol.

7.  According to the clustering protocol, the total
area is divided into numbers of clusters.
 Each and every cluster has a cluster head (CH)
and this cluster head directly communicates
with the BS.
 All nodes in a cluster send their data to their
corresponding Cluster Head.
 The Threshold sensitive Energy Efficient sensor
Network(TEEN) is an example of a clustering
protocol.

8. Data Centric, Hierarchical and
Location based
 Data centric protocols are query based and
they depend on the naming of the desired
data, thus it eliminates much redundant
transmissions.
 The BS sends queries to a certain area for
information and waits for reply from the
nodes of that particular region.
 Depending on the query, sensors collect a
particular data from the area of interest.
 This particular information is only required to
transmit to the BS and thus reducing the
number of transmissions
◦ SPIN was the first data centric protocol

9.  Hierarchical routing is used to perform energy
efficient routing.
 Higher energy nodes can be used to process and
send the information and low energy nodes are
used to perform the sensing in the area of interest
◦ examples: LEACH, TEEN, APTEEN
 Location based routing protocols need some
location information of the sensor nodes.
 Location information can be obtained from GPS
signals, received radio signal strength, etc.
 Using location information, an optimal path can be
formed without using flooding techniques.
◦ GEAR is an example of a location based routing
protocol.

10. Flooding
 Each node Which receives a packet
broadcasts it, if the maximum hop count of
the packet is not reached.
 This technique does not require complex
topology maintenance .
 The disadvantages of flooding are :
◦ Implosion
◦ Overlap
◦ Resource Blindness

11. Gossiping
 Gossiping is modified version of flooding.
 The nodes send packets to a randomly
selected neighbor to avoid Implosion.
 The disadvantages of Gossiping are:
◦ It does not guarantee that all the nodes of the
network will receive the message.
◦ It takes a long time for a message to propagate
throughout the network.

12. Rumor Routing
 It is an agent based path creation algorithm.
 Agents are basically packets which are circulated
in the network to establish shortest path to events.
 They can also perform path optimizations at nodes
they visit.
 When agent finds a node whose path to an event
is longer than its own, it updates the node’s
routing table.
 When query is generated at a sink, it is sent on a
random walk with the hope that it will find a path
leading to the required event.
 If query Does not find an event path , the sink
times out and uses flooding to propagate the

13. Working of Rumor
Routing

14. Sequential Assignment
Routing
 The SAR algorithm
creates multiple trees,
where the root of each
tree is a one-hop
neighbor of the sink.
 Each tree grows
toward from the sink
and avoids nodes with
low throughput or high
delay.
 At the end of
procedure, most
nodes belong to
multiple trees.

15. SPIN
 SPIN stands for Sensor Protocol for
Information via Negotiation.
 SPIN uses negotiation and resources
adaption to address the deficiencies of
flooding.
 Negotiation reduces overlap and
implosion.
 Meta-data is transmitted instead of row
data.
 SPIN has three types of messages :
ADV, REQ and DATA.
 The simple version of SPIN is shown in

16. SPIN
Sensor Protocol for Information via
Negotiation

17. Direct Diffusion
 Useful where the sensor nodes themselves
generate requests/queries for data sensed by
other nodes.
 Each sensor node names its data with one or
more attributes and other nodes express their
interest depending on these attributes.
 Data is propagated along the reverse path of the
interest propagation.
 Each path is associated with a gradient that is
formed at the time of interest propagation.
 The gradient corresponding to an interest is
derived from the interval/data-rate field specified
in the interest.
 This model uses data naming by attributes and
local data transformation to reflect the data
centric nature of sensor network operations.

18. Geographic Hash Table
 GHT is a system based on data centric
storage.
 GHT hashes keys into geographic co-
ordinates and stores a pair at the sensor
node nearest to the hash value.
 The calculated hash value is mapped onto
a unique node consistently, so that queries
for the data can be routed to the correct
node.
 Data is distributed among nodes such that it
is scalable and the storage load is
balanced.
 GHT is more effective in large network

19. Direct Transmission
 All sensor nodes transmit their data
directly to BS.
 This is extremely expensive in terms
of energy consumed, since the BS
may be very far away from some
nodes.
 Nodes must take turns while
transmitting to the BS to avoid
collision.
 The media access delay is also large

20. PEGASIS
 PEGASIS assumes that all sensor nodes
know the location of every other node.
 Any node has the required transmission
range to reach the BS in one-hop, when it is
select as a leader.
 The goals of PEGASIS are as follows :
Minimize the distance over which each node
transmits.
Minimize the broadcasting overhead.
Minimize the number of messages that need to
be sent to the BS.
Distribute the energy consumption equally across
all nodes.

21. PEGASIS
Power Efficient Gathering for Sensor Information
Systems

22.  A greedy algorithm is used to construct a
chain of sensor nodes, starting from the
node farthest from the BS.
 At each step, the nearest neighbor which
has not been visited is added to the chain.
 At every node, data fusion is carried out. so,
that only one message is passed on from
one node to next.
 The leader finally transmits one message to
BS.
 The delay involved in message reaching the BS
is O(N), where N is the total number of nodes in

23. Binary Scheme
 This is also a chain-based scheme like
PEGASIS.
 Classifies nodes into different levels.
 Nodes which receive messages at one
level rises to the next level.
 The number of nodes is halved from
one level to the next.

24. Binary Scheme
• In figure aggregated data reaches the BS in 4
steps,
which is O(log2 N),where N is the number of
nodes in the network.

25. Chain Based Three level
Scheme
 In this scheme chain is constructed as in
PEGASIS.
 The chain is divided into number of groups to
space out simultaneous transmission.
 One node out of each group aggregates data
from all group members and rises to the next
level.
 In the second level all nodes are divided into
two groups.
 Third level consist of a message exchange
between one node from each group of
second level.
 Finally the leader transmits a single message

26. Chain Based Three level Scheme

27. References
 Ad Hoc Wireless Networks
◦ C.Shiva Ram Murthy
◦ B.S.Manoj
 www.wikipedia.org/wiki/Wireless_sens
or_network
 www.mdpi.com/jouranal/sensor