During routing information exchange, "Global State Routing" (GSR) is a static routing procedure in which nodes communicate link state vectors with their neighbors. Mobile hosts in the particular ad-hoc scenario must act as routers with no connected networked infrastructure in order to preserve connection information. Nodes in the network architecture keep global information and routing decisions are then optimized based on particular link-state paths locally. Conventional wired network routing techniques, on the other hand, are ineffective in the presence of lower SIR i.e., signal/interference ratio and high mobility, since to swiftly reflect upgrading topology they moreover disseminate the capacity or generate unnecessary transparency, which affects the networking performance.

1. Presentation
on
Simulation Evaluation Algorithm of
GSR in MANET
By
Sandeep Maurya (GE- 20161983)
Computer Science Dept. ( M-tech 1stYr )
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2. Table of Content
■ Introduction
– Background
– Motivation
– Organization
■ Routing Protocol for MANET
– Description about the LSR with algorithm
– Description about the GSR
■ Influences of GSR
– Used Cases of GSR (applications)
■ Conclusions and direction for work
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3. MANET Routing Protocols:
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Introduction

4. 1) Pro-active routing protocols: These are also known as table-driven
routing protocols. It has a limitation that is doesn’t work well for the
large networks as the entries in the routing table becomes too large
since they need to maintain the route information to all possible
nodes.
2) Reactive routing protocols: These are also known as on-demand
routing protocol. The route is discovered only when it is
required/needed.
3) Hybrid Routing protocol: It basically combines the advantages of
both, reactive and pro-active routing protocols. The whole network is
divided into different zones. If the source and destination mobile
nodes are present in the same zone, then proactive routing is used for
the transmission of the data packets between them. And if the source
and destination mobile nodes are present in different zones, then
reactive routing is used for the transmission of the data packets
between them.
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5. • Global State Routing (GSR) is based on Link State
(LS) routing.
• In the LS routing method, each node floods the link
state information directly into the whole network
(global flooding) once a link change between itself
and its neighbours is detected.
• A node gets to know the whole topology by obtaining
link information.
• LS routing works well in static topology networks.
• If links change quickly at high mobility, frequent
global flooding will lead to huge control overhead
(large amount of small packets).
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GSR

6. Background
■ Wireless communication is rapidly growing in our day to
day life because it is easy to deploy and is more flexible.
■ In particular, the wireless sensor network (WSN’s) is
one of the latest innovations in the field of wireless
communication.
■ The important part of this presentation is to investigate
efficient routing protocols which can successfully deliver
data packets in sensor network.
■ Wireless network protocols which are currently in place
have suffered from a number of issues such as drop
packets, address table overhead, topology
convergence, throughput, data packets delay, routing
overhead and so on.
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7. Motivation
■ Routing is an important research area in wireless
communication networks due to the emerging technologies
such as a wireless sensor network, network on chip and so
on.
■ The WSNs-based network is further evolving towards a
multimedia-based network which involves heavy traffic,
such as live video monitoring of a remote event and so on.
Therefore, the WSN is facing significant new challenges
such as drop packet, routing overhead, packet delay, and
so forth.
■ Number of routing algorithms were proposed but there is
an urgent need for a comparative study on these protocols
which will be used as a guide tool for researcher and
developer in the routing domain.
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8. Organization
 We call this scheme "global state routing" (GSR), where nodes
exchange vectors of link states among their neighbours
during routing information exchange.
 Based on the link state vectors, nodes maintain
a global knowledge of the network topology and optimize
their routing decisions locally.
 It is a pro-active/table driven routing protocol. It actually extends
the link state routing of the wired networks.
 In MANET there consist of a set of mobile nodes connected
wirelessly in a self-configured, self-healing network without
having a fixed infrastructure
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9. Routing Protocol for MANET
 Description about the LSR with algorithm
 Link state routing is a technique in which each router shares the
knowledge of its neighbour hood with every other router in the
internetwork.
 Some notations for algorithm: -
cost( i , z ) : Link cost from node i to node z. If i and z nodes are not
directly linked, then c(i , z) = ∞.
M(z): It defines the cost of the path from source code to destination z
that has the least cost currently.
P(z): It defines the previous node (neighbours of z) along with current
least cost path from source to z.
N: It is the total number of nodes available in the network.
w: It is the weight of the path from any source node to the destination
node.
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10. Algorithm for LSR
START
N = {i} [i is any root node]
for all nodes z
if
z adjoining to i then
M(z) = cost(i,z)
else
M(z) = infinity
LOOP
search w not available in N such that M(w)is minimum.
Add w to N
Update M(z) for every z adjacent to w and not in N: M(z)
= min((M(w) + cost(w,z)) , M(z))
Until all the nodes are in N
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11.  Description about the GSR (Solution of LSR )
■ GSR protocol uses and maintains three tables for
every node individually.
1) Distance Table : Contains the distance of a node from all
the nodes in network.
2) Topology Table : contains the information of Link state
data along with the sequence number which can be used
to determine when the information is updated last.
3) Next Hop Table :contain the information about the
immediate neighbours of a particular node.
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12. Influences
Advantages
• GSR greatly reduces the control overhead as it avoids flooding for
disconnects/reconnects and updates are time triggered than event
triggered.
• The routing accuracy of GSR is comparable to an ideal LS scheme
and thus superior to the traditional DBF.
• A bandwidth function can be used to realize QoS routing.
Disadvantages
• The main disadvantage is the large size of the routing message.
• As the entire topology table is broadcasted with each update, a
considerable amount of bandwidth is consumed.
• The latency of the link state change propagation depends on the
update period, meaning that it has to be carefully chosen. 12

13. Used Cases of GSR (applications)
 GSR can be applied anywhere where there is little or no
communication infrastructure or the existing infrastructure is
expensive or inconvenient to use.
 Military Battlefield: Military equipment now routinely
contains some sort of computer equipment.
 Commercial Sector: Ad hoc can be used in
emergency/rescue operations for disaster relief efforts, e.g.
in fire, flood, or earthquake.
 Personal Area Network (PAN): Short-range MANET can
simplify the intercommunication between various mobile
devices (such as a PDA, a laptop, and a cellular phone).
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14. Conclusions and Direction for work
■ To provide an efficient routing solution for wireless, mobile
networks.
■ The routing accuracy of GSR is comparable to an ideal LS
scheme and thus superior to the traditional DBF, although
it doesn’t require individual link state broadcasting which
may cause serious consumption of wireless bandwidth.
■ As a result, GSR is more desirable for a mobile
environment where mobility is high and bandwidth is
relatively low.
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15. ThankYou
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