report contiki1

8/12/2019 Report Contiki1

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LIST OF FIGURES

FIG.NO FIGURES PAGE NO.

1 Structure of an IEEE 802.15.4 data frame 7

2 RPL Network Topology 7

3 SKY FROM MOTEIV 9

4 Network scenario 13

5

The power consumption of each node in the

network

14

6

The diagrammatic representation of sensornetwork

15

3.4 The number of hops in the network 17

3.5 Received packets per node in the network 17

3.6

The power consumption of each node in thenetwork

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3.7The power consumption of each node in thenetwork 19

3.8

The diagrammatic representation of averagepower consumption

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3.13

The diagrammatic representation of averagepower consumption

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3.14

The power consumption of each node in thenetwork

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3.15

The power consumption of each node in the

network

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3.16

The inter packet delay of each node in thenetwork

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3.17

The diagrammatic representation of average

power consumption

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LIST OF ABBREVIATIONS

MSDUMAC service data unit,PSDUPHY service data unit,PDUPHY protocol data unit.


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CHAPTER-I

INTRODUCTION

1.1 Introduction to IEEE 802.15.4Wireless sensor network differ from classical ad hoc networks inseveral ways, e.g., the number of nodes is larger and the spatial

distribution of the nodes is more dense, the nodes are normally static

(however, this is not always the case), the energy of the nodes is limited,

the amount of data transiting through the network is limited and in most

cases the data is converging to one single server node, collecting and

processing the data. All these factors have their influence on the choice

of the technology and routing protocol used in this type of ad hoc

networks.

The IEEE 802.15.4 is a recent standard, approved in 2003, describing

the physical (PHY) and medium access control (MAC) layers for low

rate wireless personal area networks (LR-PAN).IEEE 802.15.4 isexpected to be deployed on massive numbers of wireless devices, which

are usually inexpensive, long-life battery powered andlow computation

capabilities. As such, the standard is also ideal for WSN. At the physical

layer the standard provides for the use of 3 frequency bands. The most

popular one being the 2.4 GHz industrial, scientific and medical (ISM)

frequency band. In this frequency band, 16 channels are available, each

with a data throughput of 250 kbit/s on the physical layer. On the MAC

layer, the IEEE 802.15.4 standard supports different modes of operation:

beacon-enabled or beaconless network mode, with or without a PAN


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coordinator, in a star or in a peer-to-peer topology. Almost all

combinations of these 3 couples are possible.

FIG 1 Structure of an IEEE 802.15.4 data frame.

we only use the beaconless network mode, without a PAN coordinator ina peer-to-peer topology. This mode of operation allows multiple hops to

route messages from any device to any other device. These routing

functions can be added at the network layer, but are not part of the In a

beaconless network, the medium access is, just as in WIFI, based on un-

slotted carrier sense multiple access collision avoidance (CSMA-CA).

However, unlike the IEEE 802.11 standard, IEEE 802.15.4 omits the

request/clear to send (RTS/CTS) exchange; hence the hidden node

problem will be an issue. The omission of the RTS/CTS frames is

justified by the limited size of the MAC data packet unit, with is fixed to


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a maximum of 127 bytesin the standard. Each device (transmitter) is

identified by a unique 64 bit hardware address, called the extended

address, comparable with an Ethernet MAC address. The standard

however allows the allocation of a 16 bit short address, which

considerably reduces the addressing fields in the MAC frame.

1.2 TOPOLOGY FORMATIONLLNs do not typically have predefined topologies, for example

those imposed by point to point wires, so RPL has to discover links to

form a topology first.

Figure 2: RPL Network Topology

RPL creates a tree like topology with a root at the top and leaves at

the edges. In contrast to tree topology, RPL offers redundant links which

is a MUST requirement in LLN , so actually violating the actual treetopology. RPL uses "up" and "down" directions terminology regarding

the movement of traffic. The up is from the leaves to the root and down

from the root to the leaves.


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1.3 THE SENSOR NODEThe hardware platform that is used as building block for the WSN is the

Tmote Sky platform from Moteiv . The Tmote Sky platform is a wireless

sensor node based on a TI MSP430 microcontroller with an IEEE

802.15.4-compatible radio chip CC2420 from chipcon, with an onboard

antenna. The Tmote Sky platform offers a number of integrated

peripherals including a 12-bit ADC and DAC and a number of integrated

sensors like a temperature sensor, 2 light sensors and a humidity sensor.

FIG-3 TMOTE SKY FROM MOTEIV


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The microcontroller is programmed through the onboard universal serial

bus (USB) connector, which makes it easy to use; no additional

development kit for the microcontroller is needed. The USB can also be

used as a serial port to communicate with a host computer.

1.4 THE REAL TIME OS AND COMMUNICATION STACKContiki is used as real time operating system on the Tmote Sky sensor

nodes. Contiki is an open source multi-tasking operating system for

networked systems. It is designed for embedded systems with small

amounts of memory. A typical Contiki configuration is 2 kbytes of

RAM and 40 kbytes of ROM. Contiki consists of an event-driven kernel

on top of which application programs can be dynamically loaded and

unloaded at runtime. The main reason why Contiki was chosen as real

time operating system (RTOS) is that it is written in standard C, which

makes it easy to understand and to modify. As almost all applications on

military networks are IP based, we opted to use a TCP/IP stack on top ofthe IEEE 802.15.4 devices and not the usual ZigBee stack. Contiki

contains a small request for comments (RFC)- compliant TCP/IP stack

that makes it possible to communicate over an IP enabled network.

Contiki also contains a RFC-compliant ad hoc on-demand distance

vector(AODV) routing protocol. AODV is a reactive routing protocol

for ad hoc networks. In a reactive routing protocol,routes are only

created when desired by the source nodes.When a node requires a route

to a destination, it initiates a route discovery process within the network.

This process completes once a route is found or all possible route


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permutations are examined. The route is maintained only if there are

data packets periodically travelling from the source to the destination

along that path. This protocol is what is called source initiated.


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CHAPTER-II

IMPLEMENTATION IN CONTIKI

RPL ANALYSIS IN COOJA SIMULATION

1.Open cooja simulator and open the file2.Select the new simulation and give the name of simulation and

click ok.

3.Go to mote in the tool bar select add motes click create new typesimulation and select sky motes.

4.Browse for the file Contiki\examples\ipv6\rpl-udp. Add 25udp_sender nodes and 1 udp_sink nodes using the udp_sender.cand udp_sink.c programmes.

5.Change the interval between sending successive packets from 60seconds to 1 second.

6.Set the area as 0 to 30 in the add mote window and use randompositioning.

7.Click the start button and in the node output window to run thesimulation.

8.Open contiki collect plug-in and observe the power,Etx and delaymetrics.

9.Change the area to 0 to 75 and re-run the simulation.


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Figure 4 Network scenario


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CHAPTER-III

RESULT AND DISCUSSION

3.1 SIMULATION RESULT USING AREA 30

Figure 5 The power consumption of each node in the network

When we run the udp_sender.c and udp_Sink.c in cooja we get the

average power consumed of the network as 3.839 mW.

To exploit the data coming from the sensors, it is often inevitable to

have an idea of the (relative) position of the sensor nodes in the network.

Equipping the nodes with a GPS module could be a solution, although

this implicates an extra antenna on the node and a clear view of the sky,


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which is not always feasible. Furthermore, a GPS module will increase

the price of a node and will compromise the battery lifetime. Some other

well documented techniques for retrieving the position of the nodes in a

wireless network are based on radio hop count, RSSI, time difference of

arrival or angle of arrival. A relative simple technique is the one basedon the RSSI, also called radio positioning. In this technique the nodes

look at the power of the received signal from their neighbors and try to

estimate the distances to their neighbors for localization. In the IEEE

802.15.4 standard, the radio receivers are bound to measure the received

signal strength of arriving frames, hence the choice for using this

technique.

Figure 6 The diagrammatic representation of sensor network


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Figure 7 Instantaneous power in the network

Figure 8 Average power consumption per node in the

network


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Figure 9 Average radio duty cycle per node in the network


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3.2 SIMULATION RESULT USING AREA 75

Figure 10 The power consumption of each node in the network

When we run the udp_sender.c and udp_Sink.c in cooja we get the

average power consumed of the network as 3.847 mW.


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Figure11 The diagrammatic representation of sensor network

Figure 12 Instantaneous power in the network


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Figure 13 Average power consumption per node in the

network

Figure 14 Average radio duty cycle per node in the network


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From the results we can see that the average number of packet sent for

simulation area 30 is higher but the average power consumption is lower

in the simulation with area 75. The average number of packets lost is

higher with area 75 because some nodes might be outside the range ofthe sink and in those cases the packets are lost.

CONCLUSIONThus we have investigated the zigbee based wireless

sensor network for different sizes of area and then evaluated the network

performance in terms of Energy, Latency, Packet Delivery Ratio andaverage power consumption.

REFERENCE

1.Dunkels, Adam (May 2003), "Full TCP/IP for 8 BitArchitectures", Proceedings of the First ACM/Usenix International

Conference on Mobile Systems, Applications and Services

(MobiSys), San Francisco.

2.Durvy, Mathilde; Abeill, Julien; Wetterwald, Patrick; O'Flynn,Colin; Leverett, Blake; Gnoske, Eric; Vidales, Michael; Mulligan,

Geoff; Tsiftes, Nicolas; Finne, Niclas; Dunkels, Adam (November

2008), "Making sensor networks IPv6 ready", Proceedings of the

Sixth ACM Conference on Networked Embedded Sensor Systems

(SenSys) (poster session), Raleigh,NC,US:ACM.

3.Dunkels, Adam; sterlind, Fredrik; He, Zhitao (November 2007),"An adaptive communication architecture for wireless sensor

networks", Proceedings of the Fifth ACM Conference on

Networked Embedded Sensor Systems (SenSys), Sydney,AU.
http://en.wikipedia.org/wiki/North_Carolinahttp://en.wikipedia.org/wiki/United_States_of_Americahttp://en.wikipedia.org/wiki/Australiahttp://en.wikipedia.org/wiki/Australiahttp://en.wikipedia.org/wiki/United_States_of_Americahttp://en.wikipedia.org/wiki/North_Carolina


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4.Dunkels, Adam,The ContikiMAC Radio Duty CyclingProtocol (PDF).

5."Tiny OS & Cooja",Olaf land, Word press, 20101125 .6.Dunkels, Adam; Schmidt, Oliver; Voigt, Thiemo; Ali, Muneeb

(November 2006), "Protothreads: Simplifying event-driven

programming of memory-constrained embeddedsystems", Proceedings of the Fourth ACM Conference on

Embedded Networked Sensor Systems (SenSys), Boulder,CO,

USA.
http://dunkels.com/adam/dunkels11contikimac.pdfhttp://dunkels.com/adam/dunkels11contikimac.pdfhttp://en.wikipedia.org/wiki/PDFhttp://olafland.wordpress.com/2010/11/25/tinyos-and-cooja/http://en.wikipedia.org/wiki/Coloradohttp://en.wikipedia.org/wiki/Coloradohttp://olafland.wordpress.com/2010/11/25/tinyos-and-cooja/http://en.wikipedia.org/wiki/PDFhttp://dunkels.com/adam/dunkels11contikimac.pdfhttp://dunkels.com/adam/dunkels11contikimac.pdf

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