Transcript

MADAN MOHAN MALAVIYA ENGINEERING COLLEGE GORAKHPUR

SESSION – 2011-12 SEMINAR REPORT ON

UNDERWATER WIRELESS COMMUNICATION

SHUBHAM SRIVASTAVA ELECTRONICS & COMMUNICATION ENGG. B.TECH. 3RD YEAR ROLL NO. 0904231065

. Electromagnetic waves are not used as they propogate over short distances.INTRODUCTION Underwater wireless communication is the wireless communication in which acoustic signals (waves) carry digital information through an underwater channel. Over the past decades. underwater wireless communication has come into existence. To overcome such difficulties. heavy cables were used to establish a high speed communication between remote end and the surface.

• • • • . we require underwater wireless communication.NECESSITY OF UNDERWATER WIRELESS COMMUNICATION Wired underwater is not feasible in all situations as shown below-: Temporary experiments Breaking of wires Significant cost of deployment Experiment over long distances. To cope up with above situations.

FACTORS INFLUENCING ACOUSTIC COMMUNICATION • Path loss: Due to attenuation and geometric spreading. • Noise: Man-made noise and ambient noise(due to hydrodynamics) • Multi-path propogation • High propogation delay • Doppler frequency spread. .

optical. Transducers Signal modulation Hardware:  Software Defined Acoustic Modem (SDAM)  Reconfigurable hardware known to provide. high performance implementations for DSP applications . flexible. sampling strategies • Communication Interface: Amplifiers.HARDWARE PLATFORM INTERFACES • Sensor Interface: – Must develop common interface with different sensors (chemical. – Wide (constantly changing) variety of sensors.) and communication elements (transducer) . etc.

• Employ high performance error detection and correction coding scheme which reduces bit error rate to less than 107 Parts of an acoustic modem: • DSP Board • AFE(Analog Front End) Board • DC/DC Converter .ACOUSTIC MODEM • Employ advanced modulation scheme and channel equalization for improved signal to noise ratio.

This results in low power consumption. . the modem stays in sleep mode. Similarly when the data is to be transmitted . the modem receives data from its link in sleep mode and then switches to transmit mode and transmit the data. it periodically wakes up to receive possible data being transmitted by far end modem.DATA TRANSMISSION IN MODEM When no data is being transmitted.

ADVANCED MODEMS AVAILABLE .

performing collaborative tasks. • Equipment – Autonomous Underwater Vehicles (AUVs) – Underwater sensors (UW-ASN) .UNDERWATER ACOUSTIC SENSOR NETWORKS (UW-ASN) • Group of sensors and vehicles deployed underwater and networked via acoustic links.

UW-ASN COMMUNICATION ARCHITECTURE 2-D ARCHITECTURE .

3-D ARCHITECTURE .

• Pollution monitoring • Ocean currents monitoring • Equipment monitoring and control • Autonomous Underwater Vehicles (AUV) • Remotely operated vehicle(ROV) • Acoustic navigation technology for multiple AUVs.APPLICATIONS • Seismic monitoring. • Solar Powered AUVs .

corrosion. temperature and salinity. . • The available bandwidth is severely limited. • Highly affected by environmental and natural factors such as heterogeneities of the water column. multiple and random sea reflections and significant scattering by fish. • Underwater sensors are prone to failures because of fouling.LIMITATIONS • Battery power is limited and usually batteries can not be recharged easily. etc. bubble clouds and plankton. variations of sound velocity versus depth.

The main objective is to overcome the present limitations and implement advanced technology for oceanographic research and cope up with the environmental effects on the noise performance of acoustic systems to compete with the future challenges like effective transmission of audio and video signals etc. there is still an immense scope so more research as major part of the ocean bottom yet remains unexploded. .CONCLUSION Despite much development in this area of the underwater wireless communication.

gleonrcn.References • www.pps • www.php?name=Aquanode.ieee.edu/sigbed/archives/akyildiz.org/organizations/pubs/newslette rs/oes/html/spring06/underwater.link-quest.com/html/oceans2000.virginia.pdf/ • www.cs. pdf .org/pgmdownload_media.html • www.

THANK YOU .

QUERIES?? .