Download Comparison of Performance Metrics of DVR Protocol Using Node

Comparison of Performance Metrics of DVR Protocol Using
Node Remaining Energy and Aggregate Interface Queue
Length
Rajib Chowdhuri1 , Deb Barma M. K.2 , Sen S. K.3 and Sudipta Roy4
1,2 Department
of Computer Science & Engineering, NIT Agartala, India.
Guru Nanak Institute of Technology, Kolkata, India.
4 Dept. of IT, Assam University, Silchar.
e-mail: 1 [email protected]
3 SMIEEE,
Abstract. In this paper,an adaptive routing in Mobile Adhoc Networks(MANETs) is performed by modifying the AODV protocol.Routing is performed by calculating the load on
different routes using parameters like nodes remaining energy, aggregate interface queue
length and hop count. The weight of each route from source to destination is computed and
stored in a routing table. The path with the maximum load balanced routing metric value
is selected for transmitting data packets. The AODV protocol is modified in such a manner
that only the destination node will be able to respond to a route request. This will greatly
reduce transmission of control data packets in a network. Performance of modified AODV is
evaluated based on metrics like throughput, average end-to-end delay and normalized routing overhead.
Keywords: AODV, aggregate interface queue, average end-to-end delay, length, modified
AODV, remaining energy, throughput.
1. Introduction
Mobile Adhoc Network (MANET) is an infrastructure less network of mobile devices that changes
location and configure itself on the fly. The configuration of the communication network changes
rapidly and unpredictably over time due to mobility of nodes. The network is localized, where all
activities such as discovering the topology of a network and delivery of message are performed
by the nodes themselves, i.e., routing functionality is embedded into the mobile nodes [1–17].
Regardless of the set of applications ranging from small, static networks to large-scale, mobile,
highly dynamic networks, MANET require efficient distributed algorithm to determine network
organization, link scheduling and routing. In military environment, preservation of security, latency,
reliability, intentional jamming, and recovery from failure are of significant concerns, hence nodes
prefer to emit as little power as necessary and transmit as infrequently as possible, thereby decreasing the probability of detection. A lapse in any of these requirements may degrade the performance
K. R. Venugopal and L. M. Patnaik (Eds.) ICCN 2013, pp. 198–206.
© Elsevier Publications 2013.
Comparison of Performance Metrics of DVR Protocol
and dependability of the network [3]. The goal of our work is to implement a routing metric based
on load sensitivity of each route. Metrics such as throughput and average end-to-end delay are then
compared between the modified AODV protocol and the AODV routing protocol. We perform this
work using the Adhoc on demand Distance Vector (AODV) routing protocol, modified AODV and
ns-2.34 as the simulation tool.
2. Overview of Load Balancing Algorithm
2.1 Load balancing
Load balancing is a method to distribute the load across multiple paths, in order to maximize
throughput, packet delivery ratio, minimize average end-to-end delay, and avoid routing overhead.
Most of the existing routing protocols that do not have multi path from source to destination, balance
their load by just transferring the packets from the overloaded nodes to other idle nodes, which
results in routing overhead and also cause delay. In order to determine the quality of path before conveying load, the existing Adhoc protocols cant predict whether the nodes in that path are overloaded
or not during route discovery phase. Hence these protocols cant balance the load on different routes
[4]. The proactive protocols such as DSDV and reactive protocols such as DSR and AODV choose
a path with smallest number of hops from source to destination. But when there is congestion in
the network, this path may not prove to be the most significant route, because packet drop rate and
average end-to-end delay will increase and may cause routing overhead. The Load Balancing algorithm that are considering traffic load as the parameter to choose a route to destination, results in
more traffic or congestion. Route maintenance and Bandwidth reservation may be needed in order
to achieve good communication and to make the routing protocols more efficient even in presence
of node movement. Multipath routing can be a very good strategy for reducing congestion in the
network, and thereby increasing packet delivery ratio, reducing average end-to-end delay and routing overhead. In multipath routing, even if one path fails, data packets can still be routed through
another alternative route without the need to rediscover new paths. The major issues with these load
balancing algorithms are high remaining energy, etc.
2.2 Adhoc on-demand distance vector protocol
The Adhoc On-Demand Distance Vector (AODV) algorithm enables dynamic, self-starting, multihop routing between participating mobile nodes wishing to establish and maintain an adhoc network
[5]. AODV discover the route(s) to destination(s) only when it is needed. When a node requires
a route to destination, it initiates route discovery process within the network. After getting some
routes to the destination, the best among them is selected and used for forwarding the packets to the
destination. Once a route is discovered, it is maintained by route maintenance procedure until either
destination becomes inaccessible along every path from source or the route is no longer desired.
AODV avoids the “Counting-To-Infinity” problem by using sequence numbers for every route
and also ensures “Loop Freedom”.
In AODV, both the source node and the intermediate nodes store the next hop information of each
route for transmitting data packets to the destination. When there is no route available to a desired
destination, the source node floods Route Request packets in the network, for which it obtains multiple routes to the destination from a single route request. A node updates its path information only
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when it receives a packet with greater destination sequence number or a packet with same destination sequence number but with smaller number of hop counts. In AODV the nodes are purged that
are not in active communication. Whenever there is a link break, network topology changes and
AODV allows the mobile nodes to respond to link breakage in a timely manner by notifying the
nodes to invalidate the route using lost link. When there are more than one route to a destination,
the requesting node chooses a route with the greatest sequence number. AODV defines three types
of control messages for route maintenance:
(i) Route Requests (RREQs).
(ii) Route Replies (RREPs).
(iii) Route Errors (RRERs).
3. Modified AODV for Load Balancing
In the modified AODV routing protocol the load is uniformly distributed by using the information
available in the network. The idea is to select a routing path that consists of nodes with higher
remaining energy and hence longer life span in order to reduce routing overhead and also reduce
the average end-to-end delay by routing the packets over the path which is less utilized. The route
selecting parameters used in our modified AODV are defined as follows:
(i) Route Energy: The Route Energy is the sum of energy possessed by nodes falling on a route
from destination to source node. If route energy is high, then the probability of route failure due
to exhausted nodes will be less.
(ii) Aggregate Interface Queue Length: The sum of queue length possessed by intermediate nodes
from source node to current node.
The routing process involved in any routing protocol is mainly classified into three main divisions:
(i) Route Discovery.
(ii) Route Selection.
(iii) Route Maintenance.
The Route Discovery and Route Selection process are modified for implementing the load
balancing features in modified AODV routing protocol.
3.1 Route discovery
The route discovery procedure in modified AODV is similar to that of (AODV) routing protocol.
Whenever a node has some data packets to send to other nodes, it first detect whether there is any
route available to that destined node in its routing table. If no route is available, it initiates the route
discovery process by broadcasting Route Request packets to all the neighboring nodes [5]. Then the
intermediate node checks whether any reverse route from the requesting node is available or not.
If reverse route is unavailable, then the intermediate nodes update the reverse route in their routing table. Then the intermediate node verifies the destination IP address field in the Route Request
packets with its own IP and if the IP address matches, then that particular intermediate node is the
destination node for which a route is required by the source node to send data packets. The destination node then sends the Route Reply packets in the same reverse route through which the route
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Comparison of Performance Metrics of DVR Protocol
request packet had reached the destination node. If the IP address does not match, then the intermediate node simply forwards the Route Request packet towards the destination, i.e to the next
neighboring node. The destination node may receive many Route Request packets through different routes and responses to each of the Route Request packets by sending Route Reply packets
to each of the Route Request in the same route through which the corresponding Route Request
packets had arrived at the destination. Normally in AODV the RREP packet contains information
like HOP Count, Sequence number but in modified AODV to uniformly distribute the traffic load,
two more information are added in the RREP packet. They are Route Energy and Aggregate Interface Queue length. The destination node adds its remaining energy and interface queue length in
the Route Reply (RREP) packet and forwards the RREP to the intermediate node. When the intermediate node receives the RREP, it adds up their remaining energy and queue length and forwards
the RREP packet to the next neighboring node in the reverse path towards the source. Finally when
the RREP packet is received by the source node, it contains the sum of remaining energy and total
number of packets waiting in the queue of the intermediate node along the route through which the
corresponding RREP has reached the destination.
Algorithm 1 [Route discovery process] Source node Ns wants to find a path to destination
node Nd. Suppose that z is the number of mobile nodes and N is the set of mobile nodes, i.e.,
N = N1, N2, . . . , N z, where Ns, Ni, N d N, 1s, d, i, z and s, d. We assume that node Ni is an
intermediate node that receives the RREQ packet. The algorithm is described in Table 1.
3.2 Route selection
The source node after receiving all the RREP packets computes the weight value for each route.
Weight for a route i is calculated based on the following:
wi = C1 ∗ (R E i /Max R E) + C2 ∗ (H Ci /Max H C)
(1)
where |C1| + |C2| = 1.
Table 1. Algorithm: route discovery.
If (node Ni is the destination node Nd)
{
1. Destination node Nd adds its remaining energy (RE), hop count (HC) and aggregate interface queue
length (AIQL) to the RREP packet.
2. Destination node Nd forwards the RREP packet towards the source node along the path through
which the RREQ packet had arrived at the destination node.
3. Destination node responses to each of the RREQ by sending Route Reply for each RREQ packet
arriving at the destination node through different routes.
4. The intermediate node adds up its remaining energy and queue size with the route energy and aggregate interface queue length field in the RREP respectively and forwards the route reply towards the
source node Ns.
}
else
Node Ni forwards the RREQ packet to the neighboring node.
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Due to scarcely available battery-based energy, Route Energy is taken as a crucial factor in modified AODV protocol. If a route is used frequently, while other routes are idle or under loaded, it will
result in route failure due to exhausted nodes in that particular route. Since there are a large number
of nodes in a network, path with low hop count is preferred and hence the metric hop count has also
been considered. Our protocol combines effectively both the parameters with weighing factors C1
and C2. The values of these factors can be chosen as per the requirements, e.g. Energy being very
critical for MANETs should have more priority than constant factor C2. The weight of each route
W i is then computed with aggregate interface queue length to obtain load balanced routing metric
(LBRM) for modified AODV protocol as follows:
L B RM = ((α ∗ AI Q L) + ((1 − α) ∗ wi ))
(2)
where |α| = 1.
The aggregate interface queue length indicates how busy the route is. Its value shows the number
of packets waiting in the queue of the intermediate nodes in that particular route. Thus this parameter
helps in predicting the heavily loaded route in a network. This LBRM value is then updated in the
routing table of modified AODV and routing is performed by selecting the path with maximum
LBRM value among all feasible paths.
3.3 Route maintenance
In MANET, since the mobility of nodes are very high, link failure is a common phenomenon because
mobile nodes move out of their transmission range. Whenever link failure is depicted by any intermediate node, it immediately broadcasts a Route Error (RERR) packet to its neighbour node which
further transmit it and finally the RERR packet reaches the source node. As soon as the source node
receives the RERR, it immediately starts a new route discovery.
4. Methodology
The simulations of the AODV and modified AODV routing protocols are carried out using ns-2.34
network simulator. The simulation parameters are enlisted in Table 2.
5. Performance Metrics
We use the following performance metrics to evaluate the effect of each scheduling algorithm:
(i) Throughput – It is the average rate of successful message delivery over a communication
channel. The throughput is usually measured in bits per second (bit/s or bps).
(ii) Average end-to-end delay – It is the average time a data packet takes to travel from source to
destination in seconds. It is calculated by subtracting time at which first packet was transmitted
by source from time at which first data packet arrived to destination.
(iii) Normalized Routing Load – It is defined as the total number of routing packet transmitted per
data packet.
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Comparison of Performance Metrics of DVR Protocol
Table 2. Simulation parameters.
Number of Nodes
Variable (11 to 30)
X dimension of Topography
1000 m
Y dimension of Topography
1000 m
Simulation Time
200 sec
Packet Size
512 Bytes
Traffic Type
Constant Bit Rate
No. of CBR Links
10
CBR generate rate
4 packets/sec
MAC Type
IEEE 802.11
IFQ Type
QUEUE/DROPTAIL/PRIQUEUE
IFQ LEN
variable(10 to 50)
Ant Type
Antenna/OmniAntenna
Prop Type
Propagation/Two RayGround
Channel
Channel/WirelessChannel
Figure 1. Throughput of modified AODV and original AODV with CBR traffic.
5.1 Results and discussion
From Figure 1, it is clear that throughput of modified AODV increases with increase in the number
of packets in the interface queue compared to original AODV. The experiment was conducted with
11 nodes and the maximum speed was Vm = 5 m/s. The Interface Queue Length was varied from
10 to 50 packets. Throughput is measured in terms of Kbits/sec.
Figure 2, reveals that throughput incase of modified AODV increases with increase in the number
of nodes as compared to original AODV.
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Figure 2. Throughput of ModAODV and normal AODV vs no. of nodes.
Figure 3. Packet delivery ratio of modified AODV and original AODV.
Figure 3 shows that packet delivery ratio of modified AODV increases with increase in the number
of packets in the interface queue compared to original AODV. The number of nodes was increased
to 15 and maximum speed was Vm = 5 m/s.
Figure 4 exhibits that routing overhead of modified AODV even though is very high with lesser
number of packets in the interface queue, but then gradually decreases with increase in IFQLEN.
But routing overhead increases with increase in the number of packets incase of original AODV. The
number of nodes used was 15 and maximum speed was Vm = 5 m/s.
6. Conclusions
The Adhoc on demand Distance Vector (AODV) routing protocol is modified using NS2.34 as the
simulation tool. Modified AODV is evaluated using several experiments and simulations that measured the throughput, packet delivery ratio, and routing overhead. From the above results it is clear
that modified AODV out performs AODV in all the simulation scenarios. In modified AODV, routing path with the minimum weight value is selected among all the feasible paths. The three route
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Figure 4. Routing overhead of modified AODV and original AODV.
selection parameters used are route energy, aggregate interface queue length and hop count. The
routing overhead is low and throughput and packet delivery ratio are high in modified AODV when
compared to the original AODV.
References
[1] Chakrabarti, G. and Kulkarni, S.: Load Balancing and Resource Reservation in Mobile Adhoc networks.
Elsevier Adhoc Networks, accepted 14 April (2004).
[2] Perkins and Charles E.: Adhoc Networking. Addison Wesley, USA (2001).
[3] Johnson, David B., Maltz and Davis A.: The Dynamic Source Routing Protocol for Mobile Adhoc
Networks. Internet Draft, draft-ietf-manet-dsr-03.txt, October (1999).
[4] Hassanein, H. and Zhou, A.: Load-aware Destination-controlled Routing for MANETs. Elsevier
Computer Communications, 1551–1559, 26 (2003).
[5] Wang, N., Huang, Y. and Chen, J.: A Stable Weight-Based On-Demand Routing Protocol for Mobile
Adhoc Networks. Information Sciences 177, 5522–5537 (2007).
[6] Ahn, S., Lim, Y. and Choe, J.: A Load-Balancing Approach in Adhoc Networks. ICOIN 2003, LNCS,
2662, 672–681 (2003).
[7] Song, J-H., Wong, V. and Leung, V. C. M.: Load-Aware On-Demand Routing (LAOR) Protocol for
Mobile Adhoc Networks. The 57th IEEE Semiannual Vehicular Technology Conference, 3, 1753–1757
(2003).
[8] Song, Joo-Han, Wong, V. W. S. and Leung, V. C. M.: Efficient On-Demand Routing for Mobile Adhoc
Wireless Access Networks. IEEE GLOBECOM, 558–563 (2003).
[9] Hakoda, J., Uehara, H. and Yokoyama, M.: Performance Evaluation of Mobile Adhoc Routing Protocols Based on Link Expiration Time and Load of Node. IEICE Trans. Commun., J85B(12), 2108–2118
December (2002).
[10] Lee, Y. J. and Riley, G. F.: A Workload-Based Adaptive Load-Balancing Technique for Mobile Adhoc
Networks. IEEE Communication Society, WCNC, 2002–2007 (2005).
[11] Takahashi, S., Hakoda, J., Uehara, H. and Yokoyama, M.: A Load Balanced Routing Scheme for Mobile
Adhoc Networks. ISITA2004, Parma, Italy, October (2004).
[12] Wu, K. and Harms, J.: Load Sensitive Routing for Mobile Adhoc Networks. Proc. IEEE ICCCN’01,
Phoenix, AZ, 540–546, October (2001).
[13] Pham, P. P. and Perreau, S.: Increasing the Network Performance Using Multi-Path Routing Mechanism
with Load Balance, Ad Hoc Networks. 2(4), 433–459, October (2004).
205
Rajib Chowdhuri, et al.
[14] Jung, Jin-Woo, Choi, Dae In, Kwon, Keumyoun, Chong, Ilyoung, Lim, Kyungshik, Kahng and
Hyun-Kook: A Correlated Load Aware Routing Protocol in Mobile Ad Hoc Networks. ECUMN 2004,
LNCS, 3262, 227–236 (2004).
[15] Lee, S. J. and Gerla, M.: Dynamic Load Aware Routing in Adhoc Networks. Proc. ICC 2001, Helinski,
Finland, 3206–3210, June (2001).
[16] Cho, H. K., Kim, E. S. and Kang, D-W.: A Load-balancing Routing Considering Power Conservation in
Wireless Adhoc Networks. Proc. of the 16th International Workshop on Database and Expert Systems
Applications, DEXA05.
[17] Saigal, V., Nayak, A. K., Pradhan, S. K. and Mall, R.: Load Balanced Routing in Mobile Adhoc Networks.
Elsevier Computer Communications, 27, 295–305 (2004).
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