UWCAH: Universal Weighted Clustering Algorithm for Heterogeneous nodes in MANET

International Journal of Emerging Technology and Advanced Engineering

355

UWCAH: Universal Weighted Clustering Algorithm for

Heterogeneous nodes in MANET

Rajwinder Kaur

_{, Parma Nand}

Abstract—Node clustering has become an efficient way to organize a MANET into a hierarchy with a view to improve the efficiency of routing and system performance. So many clustering algorithms have been proposed assuming homogeneous nodes. Some algorithms has worked for MANETS with heterogeneous nodes. But these algorithms work for two types of nodes[1].But nodes in MANETs can be heterogeneous in nature and in turn has different factors of

importance. In this paper, an algorithm named “Universal

Weighted Clustering Algorithm for Heterogeneous nodes in MANET” is proposed for adaptive clustering where different types of nodes are handled on the basis of different characteristics of nodes. In this work algorithm for Cluster formation and Cluster maintenance of such networks has been addressed.

Keywords—Ad hoc, MANET, Clustering .

I. INTRODUCTION

In today’s scenario multiprogramming and timesharing systems are becoming more popular for both user convenience and system efficiency.

Each process needs CPU time for the execution, To increase the degree of multiprogramming, memory competing for CPU time. CPU scheduler is a program which selects one process among processes waiting in ready queue for CPU time. The scheduler program invokes when a new process arrives in ready or some process completes execution.

There are different scheduling algorithms available (previous work) based on the type of application or type of system we are e.g. for a desktop system performance is more important that resource utilization, in multitasking systems, fare share is more important and in real time system, timely completion is more important .

For managing MANET, we organized the network in to different groups called clusters.Each cluster has its own leader called Cluster head (CH).Cluster head works as a

Certificate authority for own Cluster and manage all operations related to communication, like information about each cluster node, node mobility etc.

This paper is organized in sections. Section - I has introduced the work under Introduction. Section - II deals with background that includes related work. The proposed algorithm is discussed in Section - III under the heading Proposed work, conclusion of this paper is mentioned in section - IV. References are mentioned in last section.

II. BACKGROUND

MANET is divided into clusters with separate cluster head (CH) and all operations related to cluster management in cluster are controlled by CH. The cluster uses some cluster head election techniques [] for choosing the cluster head (CH) among all nodes.

In proposed work, clusters use the cluster head (CH), Cluster member (CM), warrant node and gateway node (CG).

A.

Weighted Clustering algorithm (WCA): WCA algorithm [2,3] proposed a weight based algorithm, which means that the cluster-head is elected according to its weight, which is computed by combining a set of system parameters like battery, mobility etc. WCA algorithm has not considered all types of MANETs due to rapid change of position of nodes in MANET. The weight factor considered is also fixed for each type of node. So, it is not applicable for heterogeneous nodes.

International Journal of Emerging Technology and Advanced Engineering

356

In SCA also, the weight factor are fixed for each factor for any type of nodes. So, it is not applicable for heterogeneous networks.

Weight based Adaptive Clustering for large scale Heterogeneous MANET (WACHM) algorithm: Homogeneous MANET suffers from poor scalability. So, WACHM proposed an algorithm for high scale heterogeneous networks. It considered two types of nodes Larger power but slower(type-0) and smallerpower but faster nodes(type-1). But there can be other differences in the nodes like size, characteristics, etc. which is not considered in this algorithm.

III. PROPOSED WORK:

Here we present a noval algorithm which will be applicable for MANET with homogeneous as well as hetrogeneous nodes.the proposed algorithm() is universal for both types of MANETs. It can handle as many number of different nodes with different characteristics.

The proposed mechanism works on weight based Clustering. Overall MANET is organized in Groups called Clusters. Each Cluster has its own leader called Cluster head (CH).Cluster head is responsible for managing every node which belongs to that cluster. Cluster head is selected in Cluster Head election procedure on the basis of different deciding parameters. There are different no of parameter for election of Cluster Head[2,3,6] discussed in following section.

A. Preliminaries

Cluster head plays an important role in Clustering, because there is no central administrative control of MANET so each cluster is managed and controlled by cluster head .Cluster Head maintains all the information about each node residing in the cluster like mobility of node, battery power , Trust value etc. In the proposed algorithm, following parameters are used to elect the cluster head of Cluster[2,5,6].

Trust value (WT): How much node is trusted to its

neighbor. we calculate the average trust value of all node reside in a cluster.

(1) Where Ti is the received trust value from node i.

The tracking based credence system The tracking based credence system [4,6] tracks the behavior of each node and records the number of times node misbehaved. The behavior of entity is tracked as:-

Rm +∆R

Rm+1= Rm/2i x ∆R Rm>0

Rm – 2j x ∆R Rm<0

It decreases the credence value to reach threshold faster for trusted node’s attack to detect non trusted node promptly.

Degree (WD): A network can be represented as a graph

G. So, degree of a node v is represented as

Dv= ∑ {edge (v,v') E(G)}

v' V, v ≠ v'

As Multi hop is a unique characteristic of MANET, the degree is calculated as number of neighborhood node of a particular node or the maximum no of node reside in any range of node is measured as degree of node.

WD = |N(v)|

where |N(v)| = ∑ { dist(v,v') < txrange }

v' V, v≠v'

Battery power (WB): Power plays an important role in

election of cluster head because cluster head have many responsibilities so it has to communicate for a long time.

Pv is calculated as the number of times a node is chosen as

cluster head. More the number of times it has served as a CH, lesser the battery is remaining. So the chances to get elected as a CH is more if Pv is less.

WB = (Pideal - Pv )

Where Pideal is ideal number of times it can serve as a CH.

International Journal of Emerging Technology and Advanced Engineering

357

Max Value (WM): WM is the maximum number of nodes

that can be handled by a cluster head. For load balancing, there is a threshold which a cluster head can handle ideally and is pre-defined for each type of node.

Stability (WS): It is also useful parameter to decide the

cluster head. Most stable node is elected as a cluster head of cluster. Mobility is calculated as follows.

T

Mv = 1/T

∑ √(

X

-X

)

+(Y

-Y

)

where (Xt , Yt) and (Xt-1 ,Yt-1) are co-ordinates of node v at

time t and t-1 respectively

Less the mobility more the Stability.

To calculate Stability, Mean Distance is calculated at two different time intervals say t and t-1.Less the difference more the stability.

STA = MDt – MDt-1

Lesser the value of STA more will be the chances of node

to be elected as CH.That is why WS is calculated as:-

WS = (-STA )

Weight Factor: Weight factor also plays a very

important role to decide the cluster head. We assign a weight factor value to each node in cluster in such a way that the summation of all weight factors will be unity.

Where Fi is the weight (importance) of ith factor. It

defines the degree of importance of each partial weight(WT,

WB, WD, WM, WS) when associated with it which was fixed

for homogeneous networks. In our algorithm, it varies for the nodes of heterogeneous nature because importance of each partial weight is different for each type of node.

For example for smaller devices, max no. of nodes it can handle is more important than a larger device.

Global weight (WG): This is the main parameter to

decide the cluster head (CH). Global weight is calcuted by using the all above disscussed parameters. Global weight is calculated by using following formula.

WG [i]= (WT[i]* FT[i])+

(WD[i]*FD[i])+(WB[i]*FB[i])+ (WM[i]*FM[i])+ (WS[i]*

FS[i])

Node with maximum global weight is assigned as a cluster head of a Cluster and others will be cluster members(CM).

Fig1.1: Homogeneous nodes in MANET

B. Cluster Creation in MANETs

Every node gets the certificate from the Certificate authority then a random number generator assigns a unique number to each node which serves as the node id. As we can see from fg1.1 there are four different types of nodes as described below:-

1. Red(Bigger but slower nodes):-

The nodes with bigger size means better battery power and a larger max_value. So the most important thing is its degree that is why in our example we have given maximum importance to degree factor. The weight factor decided for this particular example is as follows:-

Degree=.7, battery=.1, mobility=.05, max_value=.05, trust value=.1

International Journal of Emerging Technology and Advanced Engineering

358

The nodes which are unknown to the network. These nodes must be trusted or un-trusted ones. So, in spite of calculating trust value we give most of the importance to trust value.

Degree=.2, battery=.1, mobility=.05, max_value=.05, trust value=.6

3. Blue( Smaller nodes )

The nodes with smaller battery life.So, the only thing we should take care of is how many maximum number of nodes it can handle and maximum and given maximum importance.

Degree=.1, battery=.2, mobility=.05, max_value=.6, trust value=.05

4. Yellow(Normal nodes)

The nodes with average characteristics. So, average weight factors have been given as follows:-

Degree=.6, battery=.05, mobility=.05, max_value=.2, trust value=.1

After assigning node id, MANET divides itself into different groups on the basis of communication range called Clusters.First of all on the basis of range diameters degree is decided i.e. node is directly connected or not. This connectivity is shown in fig 1.2.

Fig 1.2 Range based clustering

The Module which is responsible for this is explained below and is known as cluster creation [5,6].

Cluster_Creation()

//Each node sends a Beacon Message to its

Neighbor to notify its presence ;

//Beacon message contains the state of node, each node builds neighbor list based on Beacon Message 2. Read Min_val, Max_val

3. while (recieve_beacon()) 4. Begin

5. N++; 6. End

7. For I= 0 to N 8. N_ID[i]=Random(); 9. if N>=Max_val 10. then

11. Cluster_split() 12. else if N<Min_val 13. then

14. Cluster_merge(); 15. else

16. Join_cluster();

17. End

C. Cluster Head Election criteria

Each cluster has one important node assigned as a Cluster Head(CH). Cluster head is elected on the basis of different parameters by using Cluster head election module. Review module is used to reassign a cluster head if the power of presently working cluster head is less than the defined threshold power.

After getting beacon messages, each node calculates the value for all parameters F[i] (Trust value, node degree, battery power, stability, Max value) of each node from which it received the beacon. After that assign a Weight Factor W[i](discussed earlier) to each parameter according to the type of node such that the sum of all weight factors of each node is unity. Node with highest global weight is elected as Cluster head. Global weight is calculated as follows:-

WG [i]= (WT[i]* FT[i])+ (WD[i]*FD[i])+(WB[i]*FB[i])+

(WM[i]*FM[i])+ (WS[i]* FS[i]); Where

i={1,2,3,…,N}

International Journal of Emerging Technology and Advanced Engineering

359

TABLEI

WEIGHT FACTORS FOR DIFFERENT NODES

Node type FD FB FS FM FT

RED 0.7 0.1 0.05 0.05 0.1

GREEN 0.2 0.1 0.05 0.05 0.6

BLUE 0.1 0.2 0.05 0.6 0.05

YELLOW 0.6 0.05 0.05 0.2 0.1

Cluster_Head_Election()

2. For I= 0 to N 3. Begin

4. define FT[i], FD[i], FB[i], FM[i], FS[i];

//Assign Weight factors for each node in such a way that the summation of all weight is unit

5. Read WT[i], WD[i], WB[i], WM[i], WS[i];

//Take all value from table which is created on the basis of Beacon Message by each node

//Calculate Global Weight WG

6. WG[i] = (WT[i] * FT[i]) + (WD[i] * FD[i]) +

(WB[i] * FB[i]) + (WM[i] * FM[i]) + (WS[i] *

FS[i]);

//Calculate Global Weight

WG

7. temp=Find_max(WG);

//Appoint the node having maximum global weight as Cluster Head

8. CH = Nodetemp

9. End

According to Cluster Head election method the values are calculated for all four tyoes nodes as follows:-

TABLEIII

WEIGHTS FOR NODE TYPE RED

RED

S.No. WD PV WB WS WM WT WG

1 2 1 4 -2 4 2 2.1

2 2 2 3 -3 3 4 2.1

3 1 3 2 -1 1 2 1.1

4 2 2 3 0 2 6 2.4

5 1 1 4 -2 2 2 1.3

TABLEIIIII

WEIGHTS FOR NODE TYPE GREEN

GREEN

S.No. WD PV WB WS WM WT WG

1 2 1 4 -1 2 2 2.05

2 2 2 3 -2 3 2 1.95

3 1 3 2 -1 3 4 2.9

4 2 4 1 -3 2 2 1.65

5 2 2 3 0 1 1 1.35

6 2 1 4 -1 4 2 2.15

7 0 3 2 -2 1 4 2.55

TABLEIV

WEIGHTS FOR NODE TYPE BLUE

BLUE

S.No. WD PV WB WS WM WT WG

1 2 1 4 -2 1 1 1.55

2 1 0 5 -3 2 2 2.25

3 2 0 5 -4 2 3 2.35

4 1 1 4 -2 1 1 1.45

TABLEV

WEIGHTS FOR NODE TYPE YELLOW

YELLOW

S.No. WD PV WB WS WM WT WG

1 2 4 1 -1 2 2 1.8

2 2 3 2 -2 3 4 2.2

3 1 2 3 -1 4 6 2.1

4 2 1 4 0 2 2 2

5 2 4 1 -2 3 2 1.95

6 1 3 2 -1 4 4 1.85

7 1 2 3 -2 2 6 1.65

After calculating Global weights for each nodes with the help of given formula for WG , Nodes with highest global

International Journal of Emerging Technology and Advanced Engineering

360

Review_Cluster_head()

1. Start //Check the battery power of Cluster Head

2. if( FB[CH]<Pthreshold)

3. then

4. broadcast(CH.low_battery_signal) 5. Cluster_head_election();

6. else //do

nothing 7. End

Fig 1.4: Formation of Clusters

D. Newly Arriving Node in MANET

Once a CH is elected and the cluster is created there is a possibility of some new arrivals by adding more nodes to the network or my moving nodes between clusters as it is a Mobile network. Now the only proceeding is to check whether the global weight of newly arrived node is greater than the weight of CH, if it is so then the new node will be elected as new CH otherwise the newly arriver node will follow conventional Join_cluster(); procedure.

Newly Arriving Node(k)

2. broadcast(k.beacon);

3. Calculate FT[k],FD[k],FB[k],FM[k],FS[k]

4. define WT[k],WD[k],WB[k],WM[k],WS[k]

5. Calculate WG[k]

6. if (WG[k]< WG[CH])

7. then 8. CH=nodek

//Appoint the new node as Cluster Head 9. else

10. Join_cluster 11. End

IV. CONCLUSION

In Mobile Ad hoc networks, as the number of nodes increases it is very difficult to manage the nodes following a flat structure. So, the nodes are organized in cluster. Each cluster is governed by a node called Cluster Head(CH) having most efficient capabilities among all nominees of Cluster head. This capability is judged by different defining parameters of nodes. These parameters were fixed for similar type of nodes .But in the proposed work, we can use the same Weight based clustering scheme for Heterogeneous networks also by keeping the importance of every weight factor variable depending upon the nature of node.

REFERENCES

[1] Yi Wang, Hairong Chen, Xinyu Y and Deyun Zhang ―WACHM: Weight Based Adaptive Clustering for Large Scale Heterogeneous MANET‖ 1-4244-0977-2/07/$25.00 © 2007 IEEE.

[2] Kadri†, A. M’hamed††, M. Feham ―Secured Clustering Algorithm for Mobile Ad Hoc Networks‖ National Institute of Telecommunications, Evry, France IJCSNS International Journal of Computer Science and Network Security, VOL.7 No.3, March 2007.

[3] M. Chatterjee, S. K. Das and D. Turgut. WCA: “A WeightedClustering Algorithm for Mobile Ad hoc Network‖s. Journal of Cluster Computing (Special Issue on Mobile Ad hocNetworks), Vol. 5, No. 2, April 2002, pp. 193-204.

[4] Parma Nand, S.C. Sharma and Rani Astya ―Tracking Based secure AODV Routing Protocol‖ V.V Das et al. (Eds.): BAIP 2010, CCIS 70, pp. 175-180,2010. Springer Verlag Berlin Heidelberg 2010

[5] P Kumar, A.K.Vatsa ― Novel Security Architecture and Mechanism for Identity based Information Retrieval System in MANET‖ International Journal of Mobile & Adhoc Network|Vol1|issue 3|Nov 2011.