space division multiple access (sdma) for

8/13/2019 Space Division Multiple Access (Sdma) For

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By

P.ARUN GOUD

08W81A0401


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INTRODUCTION: My paper proposes a robust and self-organizing

architecture for mobile ad hoc networks.

The proposed architecture, space division multiple

access(SDMA), relies on user position information and

provides user access to the communication channel based

on the spatial locations.

SDMA scheme is self-starting and self-maintaining,

guarantees delay bounded communication in real time .


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VEHICLE TO VEHICLE

COMMUNICATION: Exchange of information regarding vehicle dynamics and

road conditions among vehicles to promote driver and

passenger safety.

V2V communication not only enhances safety but also

vehicle automation.

V2V communication is likely to be through ad hoc

networks that do not rely on Infrastructure.


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WHY SDMA .? IN V2V COMMUNICATION: It is an innovative scheme for Medium Access Control

(MAC) with bounded delay for all users.

Also provides address resolution.

Makes efficient use of bandwidth by minimizing the MAC

and address resolution protocols.


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SPECIFIC CHARACTERISTICS OF

V2V COMM. NETWORKS: Medium Access Control (MAC):

It refers to the controlling user access to the

communication channel or sharing the bandwidth amongst

the users.

Communication Address Resolution:

It is the binding between a user personal ID and thelocation of its communication device in conventional

networks.


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ADDRESS RESOLUTION IN V2V

COMMUNICATION:


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EXISTING AD HOC NETWORKS: Bluetooth :

It is a wireless technology optimized for short range

communication with low power.

It is special appropriate for the cable replacement and

for use with portable devices in pervasive computing

applications.

It supports regular transmissions to keep slaves

synchronized to the channel.


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WIRELESS LOCAL AREA NETWORKS

(WLAN): It is an IEEE standard.

Provides both synchronous and asynchronous services that

can be implemented with or without infrastructure.

MAC protocol for ad hoc mode is Carrier Sense Multiple

Access with Collision Avoidance (CSMA/CA).


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BLUETOOTH AND WLAN SHORTCOMINGS FOR

V2V COMMUNICATION:

Both supports wireless ad hoc networks.

Mobility needs are to be consider with more care in

wireless technology and should be distinguished from

Portability .

V2V communication is likely to be multicast.


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SPACE DIVISION MULTIPLE ACCESS (SDMA):

It is an ad hoc network architecture that provides a fair

and delay bounded medium access to all the users based

on their position in space.

There exists one-to-one map between the space divisions

and band width divisions.


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FEATURES OF SDMA:

Medium Access Control (MAC).

Address Resolution.

Robust network Organization & Maintenance.

Band width Efficiency.

Positioning Accuracy and Error Margins.


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SDMA FOR AUTOMATED VEHICLES:

We use TDMA for the band width divisions.

The positioning system is the magnetic positioning system

which provides, desired positioning accuracy reliably.


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ASSUMPTIONS:

Relative clock accuracy of vehicles within

100nanoseconds.

Positioning accuracy is + 2mts or - 2mts.


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TECHNICAL SPECIFICATIONS:

Every vehicle broadcasts for every 20 millisecondsapproximately 100 bytes of data.

The longitudinal safety margin between two vehicles is10mts.

The communication range of vehicles is 150mts in eachdirections.

A time division with in a time period.


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ENHANCED SDMA FOR BANDWIDTH

EFFICIENCY:

It doesnt provide control over entire bandwidth.

Provides the opportunity for all the users to access the

bandwidth for the limited time interval and share there

address information & communication needs.

Allows a range in the quality of service for personal data

communication.


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POSITIONING ACCURACY:

Enhanced SDMA demands positioning accuracy that is

achievable and affordable by all the users.

Positioning accuracy depends on the number of space

divisions, bandwidth allocations and the number of users.


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BANDWIDTH EFFICIENCY:

Reduction in SDMA window that is necessary for network

organization and address resolution , effectively increases

amount of bandwidth utilized for data transmissions.

Data priorities announced to the users.


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CONCLUSION:

SDMA is an innovative scheme for Medium Access

Control in vehicle ad hoc networks.

All the advantages come without use of extra MAC and

address resolution protocols.


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Thank you


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QUERIES.??

space division multiple access (sdma) for

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