Abstract— Wireless sensor network is the collection of nodes. It is used in the field of networking which provides the data anytime, anywhere. Wireless sensor network plays a very important role in various fields like location finding, location monitoring, etc. Since large number of sensor nodes are deployed in a wireless sensor network which has the capability of providing the location information and transmitting the information, there is a possibility of congestion in the data packets. Congestion occurs due to packet overflow, packet collision and hence increase the delay. Congestion thus results in packet loss which decrease the network performance and throughput. Hence a congestion control mechanism is necessary. Receiver assisted congestion control(RACC) mechanism is used for reducing the congestion and delay and monitor the traffic. It consists of sender and receiver functions for reducing the delay and control the congestion. We will also consider an aggregate location monitoring where wireless sensor nodes capable of detecting the number of objects within their sensing areas. This system is evaluated through the simulation experiments. NS2 network simulator version 2 is used for the implementation of efficient location management and delay avoidance.
Keywords:
Location management, congestion control, RACC, delay, receiver.
I. INTRODUCTION
Wireless sensor network has gained very much popularity in recent years. Wireless sensor network are used in various fields which performs various monitoring tasks such as search, rescue and other target tracking tasks A wireless sensor networks consists of various sensor nodes that monitors the physical and environmental conditions.
Manuscript received May, 2011.
Ms. Prachi K. Gonnade, Computer Science and Engineering, G.H.Raisoni College of Engineering Affiliated to Rashtrasanth Tukdoji Maharaj Nagpur University. Nagpur, India,
Mr. Bhushan N. Mahajan, Computer Science and Engineering, G.H.Raisoni College of Engineering Affiliated to Rashtrasanth Tukdoji Maharaj Nagpur University., Nagpur, India.
Wireless sensor networks are also used in variety of application areas which includes healthcare application, health monitoring, location monitoring etc. Wireless sensor
networks consists of largenumber of sensors which collects
the information. Each sensor node comprises of sensing, processing and location finding system. These wireless sensor nodes collects and transmits the information.
Wireless ad-hoc networking techniques are required in sensor network applications. Even if large number of algorithms and protocols are proposed for wireless ad-hoc networks, they are not well suited for the unique features and requirements of wireless sensor networks. In order to illustrate this point, there are some differences between wireless sensor networks and ad-hoc networks:
-Wireless sensor nodes are densely deployed. -Wireless sensor nodes are more prone to failures.
-The number of wireless sensor nodes in a wireless sensor network is several order of magnitude higher than the nodes in an ad-hoc wireless network.
-Wireless sensor nodes uses a broadcast communication while ad-hoc networks are based on point-to-point communications.
-Wireless sensor nodes not have global identification because of the large amount of overheads and very large number of wireless sensors[3].
Wireless sensor nodes consists of two types of sensor nodes:-source nodes and sink nodes. Source nodes collects the information about the sensors that are deployed in that particular sensing area while sink node is in charge of connection between the sensor nodes and the internet. Wireless sensor nodes are of very small size. Wireless sensor nodes communicates in short distances. These tiny wireless sensor nodes consists of sensing, data processing and communicating components.
Wireless sensors are deployed in the following two ways:
-Several sensors can be positioned far from the actual phenomenon.
-Several sensors perform only sensing can be deployed. A wireless sensor network is composed of a large number of sensor nodes are densely deployed in a particular sensing area either inside the phenomenon or very close to it. The position of wireless sensor nodes need not be pre-determined. Another important feature of wireless sensor network is the co-operative effort of wireless sensor nodes. Instead of sending the raw data to the wireless sensor nodes, wireless sensor nodes use their processing abilities to
Managing the Location Information by Using RACC
Approach in Wireless Sensor Network
compute simple computations and transmit only the required and processed data.
Location information is intended only for legitimate users since a wireless sensor network is deployed in order to monitor certain events and pointing their locations. One can monitor the traffic and deduce the appropriate location of monitored objects in certain situations. Wireless communication has a major challenge of information running on the network
In this paper, we will implement the location information , and the receiver assisted congestion control mechanism. The experimental results will be given by the simulation results.
The most important issue in wireless sensor network in network congestion. Congestion detection is the method when a packet is been transferred from one node to another predicament events can happen[5]. Data traffic increases and load becomes heavy when an event has been detected. Various sources for congestion are buffer overflow, packet collision. Network congestion causes packet loss which in turn reduces throughput and increases delay. Congestion in wireless sensor networks should be controlled in terms of throughput and packet loss ratio along with the packet delay. A wireless sensor network consists of hundreds or thousands of sensor nodes scattered in an sensing area. Congestion follows tow important steps:- Congestion detection and congestion control. Congestion detection plays a very important and vital role in congestion control in wireless sensor networks.
In this paper, we try to solve the problem of congestion to avoid delay using the congestion control technique. This technique is called as Receiver Assisted Congestion Control technique (RACC). By using RACC technique which has both sender and receiver functions, we can improve the throughput and decrease the delay. In this paper, we also try to find out the locations of the nodes within the sensing area along with the avoidance of delay using the Receiver Assisted Congestion Control technique.
II. Review of Literature:
A very important issue in a wireless sensor network is the congestion control. Large number of sensor nodes are deployed in a wireless sensor network which provides the location information and transmitting the information, there is a possibility of congestion in the data packets. Congestion occurs due to packet overflow, packet collision and hence increase the delay. Congestion thus results in packet loss which decrease the network performance and throughput. Hence a congestion control mechanism is necessary.
-Preserving Source Location Privacy in
Monitoring-Based Wireless Sensor Networks:
In this paper, a wireless sensor network monitors certain events and pinpoint their locations, the location information is intended only for legitimate users. However, anyone can monitor the traffic and deduce the approximate location of monitored objects in certain situations[2].
-A Privacy-preserving location monitoring system for wireless sensor networks:
In this paper, monitoring the personal locations with a potentially non trusted server has a privacy threats to the monitored individuals. Two algorithms, resource aware algorithms and quality aware algorithms aims to enable the system to provide high quality location monitoring services for system users while preserving location privacy.
Both these algorithms, resource aware and quality aware algorithms rely on well established k-anonymity privacy concept, that is, a person is indistinguishable among k persons, to enable trusted wireless sensor nodes to provide aggregate location information of monitored persons for the system. Resource aware algorithm aims to minimize communication and computation cost. Quality aware algorithms aims to minimize the accuracy of aggregate locations by minimizing their monitored areas[1].
-Analysis of Latency of stateless opportunistic forwarding in intermittently connected networks:
In this paper, stateless opportunistic forwarding is a distributed scheme for packet delivery, data gathering and information querying in the network by which packets are forwarded to the next available neighbors until they reach their intended destinations or expire. Data delivery in sensor networks, ad-hoc networks and delay tolerant networks are
the well-known applications besides searching in
peer-to-peer networks. Challenge for stateless opportunistic forwarding is the difficulty to predict end-to-end latency.
-Receiver assisted congestion control to achieve high throughput in lossy wireless network:
The sender performs loss-based control, while the receiver is performing delay-based control. The receiver measures the network bandwidth based on the packet interarrival interval and uses it to compute a congestion window size deemed appropriate for the sender[4].
Summary of Literature Survey:
In the existing location system, in an
identity-sensor location monitoring system, each and every node report their exact position and location information of each monitored object to the server, anyone can identify each and every object’s exact location. And in the counting-sensor location monitoring system in a wireless sensor network, each and every node reports the number of objects which are within its sensing area to the server. Anyone can map the monitored areas of the sensor nodes to the system layout. Proposed scheme proposes a location monitoring system for wireless sensor networks to provide monitoring services. This scheme uses a receiver assisted congestion control technique which reduces the network congestion and reduce the delays and monitors the location information.
III. Proposed Scheme
A. Objectives of the Study:
The objective of this study is :
-Enable the system to provide high quality location monitoring services for system users.
-Monitoring the location of the nodes.
-Avoid congestion i.e. delay while locating and monitoring the nodes.
-Sensor nodes should report the exact location information of the monitored node to the cluster head for the location monitoring system. This is a major security breach. In order to tackle such a privacy breach , the concept of aggregation of location information is an very effective approach.
-Increasing the throughput.
B. Location monitoring Module:
Sensor nodes: Each sensor node in the system architecture is responsible for determining the number of objects in its sensing area.
Cluster head: Cluster head is responsible for collecting the aggregate locations reported from the sensor nodes to estimate the distribution of the monitored objects and answering range queries based on estimated object distribution.
System users: System users can issue the range queries to the system either through the cluster head or the sensor nodes. Spatial histogram approach is used by the cluster head to answer the queries[1].
C.Node discovery and database updation:
Figure consists of 3 phases: Node discovery phase, Request for database phase and Database updation phase.
In Node discovery phase, the node discovers all the nodes that are within its communication range. Each node discovers the nodes in its communication range and performs communication and computation functions.
In Request for database phase, consists of request and reply messages .It takes place in bottom to top manner. It maintains the log.
In database and updation phase, database is updated in top to bottom manner. Each and every database is updated.
D. Congestion Control:
In a wireless sensor network, sensor nodes are responsible for generating large amount of data. Thus congestion occurs in a wireless sensor network because of the generation of large amount of data. If the large number of packets drops which consists of sensed location, throughput gets lowered and delay occurs in the network. To avoid this congestion in a wireless sensor network there are two solutions:- traffic control or resource control. Traffic control which reduce the traffic volume and resource control which increase the available resource. There are various congestion control techniques for increasing the throughput and reducing the delay in the network. End-end congestion control, network
assisted congestion control and receiver assisted congestion control. In this paper, we use receiver assisted congestion control technique for reducing the congestion in the network. Its main objective is to limit the delays and a buffer overflow that is caused by network congestion and provides tradeoffs between efficient and fair resource allocation.
Two types of congestion could occurs in Wireless Sensor Networks: they are- node-level congestion and link-level congestion. The node-level congestion that is common in conventional networks. It is caused by buffer overflow in the node and can result in packet loss, and increased queuing delay. Link-level congestion increases packet service time, and decreases both link utilization and overall throughput at the sensor nodes.
E. Receiver Assisted Congestion Control(RACC) Technique:
AIMD Additive Increase Multiplicative Decrease is the congestion control algorithm which increases additively the rate of the senders until the particular system reaches the congestion. Upon congestion, all the senders decreases their rate multiplicatively using a decrease ratio.
In Receiver Assisted Congestion Control technique, -The receiver performs the flow control function and also the receiver participates in the congestion control. The receiver first measures the bandwidth, and then it computes an congestion window size. Congestion window size is based on the measured bandwidth and the round trip time. In order to perform these functions, receiver maintains two timers: one timer for measuring the round trip time and other timer for recording the packet inter-arrival time.
-The sender uses this information obtained from the receiver in order to adjust the congestion window. The receiver adjusts the rate the sender adapt in order to make the best use of measured bandwidth based on packet inter-arrival time. The round trip time at the receiver considers the arrival of the next packet and also detects the packet drop if timeout occurs. Since the receiver detects the packet drop earlier than the sender. It then sends the acknowledge to inform the sender reducing the waiting time of sender to retransmit a loss packet[4].
F. Receiver Assisted Congestion Control Algorithm:
1) 1) N1 send packet say 50 to N2 at the rate rate=60.
N2 receive the packet 50 from N1 at the rate=60.
2) 2) N2 send ack to N1.
N1 receive the ack from N2.
3) N1 start its timer.
It has internal=0.001 Maxcount=60 S-counter=1
Send in timer S-counter ++;
4) N2 receive all the 60 packets
R-counter ++; Node
Discovery
Request for Database
5) After 60, N1should stop.
6) After 60, N2 sends ack to N1.
7) N1 receive from N2.
8) N1 will reset all the variables.
9) N1 will again start from step 1.
IV.SIMULATION RESULT
In the figure, nodes are created. The nodes are numbered accordingly. All the nodes broadcasts the message and sends the request message to all the other nodes which are in the broadcast range of node which had send the request.
In fig(a), the nodes which have received the request message from the node which have sent the request replies with the reply message by sending the packets to that node.
Fig(a)
In the following fig(b) and the fig(c) nodes broadcasts the message to all the nodes which are in the communication range.
Fig(b)
All the nodes which broadcasts the message performs the location management and controls the congestion thus reducing the delay and increasing the throughput.
Fig (c)
Fig (d)
In the figure (d), is the graph for Throughput. The graph shows the x and y co-ordinates as time and throughput. N1 N2
Ack Reset
By using the RACC technique, the throughput which was minimum is increased to maximum value.
Fig (e)
In the figure (e), is the graph for delay. The graph shows the x and y co-ordinates as time and delay. Using this RACC technique, the delay is reduced to minimum. Because of this, there is the smooth flow of traffic in the network. Congestion is controlled due to which delay is reduced.
V.SOFTWARE REQUIREMENT
In this project NS-2.34 has been installed in Fedora 7 using VMware Workstation.
Fedora 7 coded as Moonshine, is an RPM-based, general
purpose collection of software, including an operating system based on the Linux kernel, developed by the community supported Fedora Project and sponsored by Red Hat.
VMware Workstation 7.1, is a virtual machine software suite for x86 and x86-64 computers from VMware, a division of EMC Corporation which allows users to set up multiple x86 and x86-64 virtual computers and to use one or more of these virtual machines simultaneously with the hosting operating system.
Ns-2 (Network Simulator Version 2)---Ns-2(Network Simulator Version 2) is a discrete event simulator targeted at networking research. Ns provides substantial support for simulation of TCP, routing, and multicast protocols over
wired and wireless (local and satellite) networks. ns or the network simulator (also popularly called NS-2, in
reference to its current generation) is a discrete event network simulator. NS is popularly used in the simulation of routing and multicast protocols, among others, and is heavily used in ad-hoc networking research. ns supports an array of popular network protocols, offering simulation results for wired and wireless networks alike. It can be also used as limited-functionality network emulator. It is popular in academia for its extensibility (due to its open source model) and plentiful online documentation. ns is licensed for use under version 2 of the GNU General Public License. NS2 is a discrete event network simulator. It is aimed at network research, and supports simulation of various facets of networking, including TCP, multicast, and routing protocols.
NS2 is used as a backend for the simulated world. It will be used to track the wireless topology as agents communicate and gather and calculate metrics. It will also be used to support the various wireless/interference algorithms built into the simulator.
VI. CONCLUSION
Receiver Assisted Congestion Control technique is used for location monitoring and management. Location monitoring systems are used by wireless sensor networks in order to detect the current node activities and providing the monitoring services. Receiver assisted congestion control scheme is a congestion control technique which is necessary to monitor and regulate the traffic levels at an acceptable value. For detecting and controlling congestion, receiver assisted congestion control mechanism is used i.e. avoids delay. In sender and receiver combined congestion control mechanism the receiver estimates a congestion window deemed to be appropriate from the measured bandwidth and RTT, and then advertises the window size to the sender.
Wireless sensor networks for location monitoring discovers the nodes and the activities of the nodes and updates the database. It avoids the delay for smooth flow of the traffic in the network.
Experimental results are evaluated through simulation and graphical results.
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Ms. Prachi K. Gonnade received the B.E. degree in Computer Science and Engineering from G. H. Raisoni College of Engineering, Rashtrasant Tukdoji Maharaj Nagpur University in 2009 and persuing M.E. degree in Wireless Communication and Computing from G.H.Raisoni College of Engineering ,Nagpur university. Her research work includes wireless communication, wireless sensor network.
