Dual polarized directional communication reduces the problem of interference, exposed nodes and deafness in wireless networks. This presentation provides an insight to our research in this field.

1. Dual Polarized Directional
Antenna based Communication
Authors: Dr. Rinki Sharma, Dr. Govind R. Kadambi, Dr. Yuri Vershinin, Mr.
Mukundan K. N.
1

2. Overview of the Presentation
Outline
• Motivation of Research Topic
• Academic Gaps
• Research Questions and Answers
• Original Contributions
• Research outcome of thesis
• Recommendations for Future Work
2

3. Motivation of the Research
Enabling
Technology
•Mobile Ad-hoc Networks (MANETs) allow network
establishment during emergency and rescue operations during
natural disasters
•Popular due to ease of deployment without investing in
infrastructure
MANET
Challenges
•Limitation of throughput in communication over MANETs [1]
•Route breakages [2]
•Limited lifetime of participating nodes [3]
3

4. Motivation of the Research
Attributed to
•Limited bandwidth of wireless channel
•Interference and exposed nodes due to omnidirectional
communication [4]
•Deafness and directional exposed nodes due to directional
communication [5]
•Node mobility
•Hidden nodes Packet collision loss of information
•Limited battery power reduced node lifetime inactive
nodes 4

5. Motivation of the Research
•Define a method to overcome bandwidth limitation and
interference in wireless channel: Orthogonal polarisations of
antenna as separate channels for simultaneous
communication
•Overcome interference and exposed nodes: Through
directional communication
•Overcome deafness and directional exposed nodes: Dual
Polarised Directional Antenna based Medium Access Control
(DPDA-MAC) protocol and exchange of Link ID
information [6]
5
Arising Need
To

6. Motivation of the Research
•Achieve efficient routing of information in the presence of
node mobility: Dual Polarised Directional Antenna based
Multipath Routing Protocol (DPDA-MRP) [7]
•Define a method to handle collision of broadcast packet due
to hidden node problem: Transmission of Collision Detection
Pulse
•Provision for energy efficient communication among nodes:
Dynamic power control [8]
6
Arising Need
To

7. Research Topic
7

8. Academic Gaps and Significance
8
Gaps Identified Research Significance
Simultaneous data transfer over
orthogonal polarisations has not been
studied in MANETs
Enhanced throughput and bandwidth
utilization, reduced interference
Space reuse (directional antenna) leads
to deafness
Overcoming deafness to enhance network
throughput
Degradation of network throughput
over multihop communication
Throughput enhancement despite multihop
communication

9. Research Question 1
9
Question
What are the modifications needed in the existing Physical layer of conventional MANET protocol
stack to incorporate the concept of Dual Polarised Directional Antenna (DPDA) based communication
to mitigate the interference and realize better space reuse?
• Objective 3: To study the
effects of dual polarisation
on the efficiency of
simulated MANET system
by minimizing the
problem of interference
Solution Significance
• Simultaneous use of orthogonal polarisations of
antenna for data communication between nodes
• Capability of simultaneous directional
communication over orthogonal polarisations to
mitigate interference and achieve better space reuse

10. Research Question 2
10
Question
With the modified physical layer to support DPDA based concept of communication, will it be
possible to develop a DPDA-MAC protocol in MAC layer to mitigate the problems of exposed nodes,
directional exposed nodes and deafness?
Solution
• Objective 4: To study the
effects of dual polarisation
on the efficiency of
simulated MANET system
by avoiding the problem of
exposed nodes
• Objective 5: To study the
effects of the exchange of
link ID information on the
problem of deafness of a
node caused by the
directional antenna
Significance
• Dual Polarised Directional Antenna based Medium Access Control
(DPDA-MAC) protocol is developed to overcome problems of:
• Exposed nodes
• Directional exposed nodes
• Deafness
• Exchange of Link ID broadcast while carrying out dual polarized
directional communication
• Exchange of Link ID broadcasts facilitates maintenance of neighbour
tables for efficient operation of DPDA-MAC protocol

11. 11
Research Question 3
Question
Solution Significance
Is it possible to develop a method for efficient handling of collision of broadcast packets caused
due to hidden node problem, to develop a well populated neighbor table and routing table to
facilitate efficient routing of information from source to destination nodes?
Objective 5: To study the effects of
the exchange of link ID information
on the problem of deafness of a node
caused by the directional antenna
Objective 7: To arrive at an
appropriate protocol for robust and
efficient multipath routing system
• Hidden node problem leads to collision of packets
• Collisions of Link ID broadcasts and RREQ frames deter
efficient discovery of neighbour nodes and multiple
routes
• Collision Detection Pulse (CDP) based method to handle
collisions of Link ID broadcasts and RREQ frames

12. 12
Research Question 4
Question
Solution Significance
With the modified physical and MAC layers, can a DPDA based Multipath Routing Protocol (DPDA-MRP)
be developed in network layer to facilitate the discovery of multiple routes between the source and destination
nodes to route information in accordance with the DPDA based communication, to arrive at a cross layer
solution in MANETs?
Objective 7: To arrive at
an appropriate protocol for
robust and efficient
multipath routing system
• Dual Polarised Directional Antenna based Multipath Routing
Protocol (DPDA-MRP) for multihop communication in MANETs
• DPDA-MRP supports routing of information in accordance with
dual polarized directional communication at physical layer and
MAC layer, thus providing a cross layer solution

13. 13
Research Question 5
Question
Is it possible to develop a scheme to impart the feature of dynamic transmission power
control to the arrived cross-layer solution of MANET for energy efficient dual polarized
directional communication?
Solution Significance
Objective 6: To study the effects
of the exchange of Received
Signal Strength Indicator (RSSI)
information among nodes for
efficient use of system power
• Presented cross-layer solution allows the control of
transmission power based on stored RSSI and
location information

14. 14
Research Question 6
Question
Will it be possible for the arrived cross-layer solution to handle the conceptual
constraints of hidden node, exposed node, deafness, density of nodes and mobility of
nodes to result in reliable routing of information from source and destination nodes of
a realistic MANET scenario?
Solution Significance
All the Objectives • Performance of the proposed cross-layer solution is
studied for different values of density and mobility of
nodes since, density and mobility of nodes affect the
performance of realistic MANET scenarios

15. Interference Mitigation with Dual Polarized
Directional Communication
15
Single Polarized
Communication

16. 16
Interference Mitigation with Dual Polarized
Directional Communication
Dual Polarized
Communication

17. Performance over Single Hop Communication
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• Throughput comparison of DPDA-MAC and SPDA-MAC (Single Hop)
• At packet rate of 1 and 5 packets per second throughput of DPDA-MAC = SPDA-MAC
• At packet rate of 15 and 25 packets per second throughput of DPDA-MAC > SPDA-
MAC
• DPDA-MAC can handle high traffic loads of 25 packet per second by virtue of
availability of orthogonal polarisations for data communication

18. Performance over Multihop Communication
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◼ Throughput comparison of DPDA-MRP and SPDA-MRP (Multihop)
• Throughput of DPDA-MRP > SPDA-MRP for
• All rates of packet transmission
• All values of node density

19. Original Contributions
• Physical Layer
• Dual polarised directional communication in MANETs [9]
• MAC Layer
• Dual Polarized Directional Antenna based Medium Access Control (DPDA-MAC)
protocol for single hop communication [6]
• Exchange of Link ID broadcasts and use of dual polarisation to mitigate deafness
[10]
• Collision Detection Pulse (CDP) based method to overcome loss of broadcast
information due to collisions [11]
• Network Layer
• Dual Polarised Directional Antenna based Multipath Routing Protocol (DPDA-
MRP) for multihop communication [7]
• Cross Layer
• Integrated layered solution to support dual polarised directional communication in
MANETs [9, 12]
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20. Research Outcome of this Work
20
Sl.No Issue Before This Research After This Research
1 Data communication Limited to single
polarisation
Simultaneous use of orthogonal
polarisations made possible
2 Interference mitigation Directional communication
(space reuse)
Interference mitigation extended to
both space and polarisation reuse
3 Exposed nodes Exposed nodes mitigated
through space reuse, but
directional exposed nodes
prevailed
Space and polarisation reuse to
mitigate exposed node and directional
exposed node problem
4 Deafness Limited mitigation Wider mitigation
5 Hidden node Lack of collision detection
mechanism -> Unreliable
communication
Enhanced reliability of communication
6 Routing Directional routing with
single polarisation
Directional routing with dual
polarisation leading to better
throughput
7 Throughput Enhancement Space reuse
Per-hop:
Multihop:
Space and Polarisation reuse
Per-hop:
Multihop:

21. Recommendations for Future Work
Physical Layer:
• Simultaneous communication over multiple channels in orthogonal polarizations [13]
• Antenna design to enable dynamic switching between channels and polarizations
• Avoidance of deafness, hidden nodes and exposed nodes in dual polarization based
multichannel communication
• Routing of information in dual polarization based multichannel communication
MAC Layer:
• Solution to avoid delays in transmission of data packets in horizontal polarization caused
due to transmission of broadcasts only in vertical polarization in DPDA-MAC
Network Layer:
• Support for load sharing over multiple paths discovered by DPDA-MRP between source
and destination nodes
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22. References
[1] Gopinath, T., Kumar, A. R., & Sharma, R. (2013, April). Performance evaluation of TCP and UDP over
wireless ad-hoc networks with varying traffic loads. In 2013 International Conference on Communication
Systems and Network Technologies (pp. 281-285). IEEE.
[2] Thriveni, H. B., Kumar, G. M., & Sharma, R. (2013, April). Performance evaluation of routing protocols in
mobile ad-hoc networks with varying node density and node mobility. In 2013 International Conference on
Communication Systems and Network Technologies (pp. 252-256). IEEE.
[3] Chilukuri, S., Sharma, R., Borade, D. R., & Kadambi, G. R. (2012). Simulation studies on an energy
efficient multipath routing protocol using directional antennas for manets. International Journal of Wireless
& Mobile Networks, 4(4), 123.
[4] Adere, K., & Murthy, G. R. (2010, September). Solving the hidden and exposed terminal problems using
directional-antenna based MAC protocol for wireless sensor networks. In 2010 Seventh International
Conference on Wireless and Optical Communications Networks-(WOCN) (pp. 1-5). IEEE.
[5] Sharma, R., Kadambi, G., Vershinin, Y. A., & Mukundan, K. N. (2016). A survey of MAC layer protocols to
avoid deafness in wireless networks using directional antenna. In Mobile Computing and Wireless
Networks: Concepts, Methodologies, Tools, and Applications (pp. 1758-1797). IGI Global.
[6] Sharma, R., Kadambi, G. R., Vershinin, Y. A., & Mukundan, K. N. (2015, April). Dual Polarised Directional
Communication based Medium Access Control Protocol for Performance Enhancement of MANETs.
In 2015 Fifth International Conference on Communication Systems and Network Technologies (pp. 185-
189). IEEE.
22

23. References
[7] Sharma, R., Kadambi, G. R., Vershinin, Y. A., & Mukundan, K. N. (2015, April). Multipath Routing Protocol to Support
Dual Polarised Directional Communication for Performance Enhancement of MANETs. In 2015 Fifth International
Conference on Communication Systems and Network Technologies (pp. 258-262). IEEE.
[8] Sandhya, C. H., Borade, D. R., Sharma, R., & Kadambi, G. R. (2012). Multi-dimensional Performance Characterization of
Directional Antennas for Applications in Energy Efficient Ad-Hoc Network. In Advances in Computing and Information
Technology (pp. 575-585). Springer, Berlin, Heidelberg.
[9] Rinki, S. (2014). Simulation studies on effects of dual polarisation and directivity of antennas on the performance of
MANETs (Doctoral dissertation, Ph. D. thesis, Coventry University, UK).
[10] Sharma, R., Kadambi, G. R., Vershinin, Y. A., & Mukundan, K. N. (2015, April). Deafness Avoidance in MANETs through
Exchange of Link ID Broadcasts. In 2015 Fifth International Conference on Communication Systems and Network
Technologies (pp. 159-163). IEEE.
[11] Sharma, R., Kadambi, G. R., & Mukundan, K. N. (2013). Method for handling collisions of broadcast packets due to
hidden node problem. ACM SIGBED Review, 10(2), 6-10.
[12] Kadambi, Govind Rangaswamy, Rinki Sharma, and Shiva Kumar Ponnuraj. "Ad hoc network." U.S. Patent 9,408,242,
issued August 2, 2016.
[13] Sandhya, C. H., Borade, D. R., Sharma, R., & Kadambi, G. R. (2012). Multi-dimensional Performance Characterization of
Directional Antennas for Applications in Energy Efficient Ad-Hoc Network. In Advances in Computing and Information
Technology (pp. 575-585). Springer, Berlin, Heidelberg
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