regarding cognitive radio network

1. Virtual backbone formation and efficient data
delivery in cognitive radio network
16 September, 2015
Santosh Kumar
Roll no- 6140062
Department of Computer Engineering
National Institute of Technology,
Kurukshetra, Haryana, INDIA-136119

2. Outline
Introduction
Problem statement
Related work
Motivation
Proposed research area
References
2
NIT KKR, 9 Feb, 2015

3. Introduction
 Wireless ad hoc network [12] is a temporarily created network without
any fixed infrastructure or central control. Any two nodes in wireless
network can communicate with each other if they are in the
transmission range of each other and such nodes are called neighbors.
 A mobile Ad hoc Network (MANET) [1] is a collection of mobile
devices, which can make arbitrary movement. It is also known as self-
configured, infrastructure-less network of mobile nodes.
 The mobility or failure of a single node may adversely affect the
application continuity. In order to mitigate this problem, some ‘better’
nodes are assigned ‘more’ responsibility related to routing and
computing. These ‘better’ nodes are called backbone nodes.
3
NIT KKR, 9 Feb, 2015

4. Problem statement
 Nodes in mobile ad hoc network use wireless media to communicate.
Since mobile nodes are free to move in any direction, the network
structure is changed frequently and becomes an unpredictable
network topology over the time.It is a wired network.
 virtual backbone is used to handle the node mobility with fewer
messages and in less time as well as following challenges:
– Instability in network topology
– Routing overhead
– Bandwidth scarcity
NIT KKR, 9 Feb, 2015
4

5. Related work
5
NIT KKR, 9 Feb, 2015
 In [3], authors have focused on computing the CDS for the purpose of
virtual backbone formation. The proposed protocol to construct the
CDS is based on marking approach. It follows the following steps: (1)
All the nodes are initially unmarked. (2) A node is marked, only if at
least two of its neighbours are unconnected. (3) All marked nodes are
connected to form a CDS.
 In [11], Alzoubi et al. have proposed CDS for both wireless ad hoc
networks and mobile ad hoc networks. The concept of minimum
connected dominating set (MCDS) has been used for construction of
the virtual backbone.
 construction of MCDS is based on MIS, first MIS (maximal independent
set) is constructed, and then MIS nodes are connected using
intermediate nodes to form the CDS which leads to MCDS.

6. Motivation
 Rapid growth in wireless networks leading towards scarcity of
spectrum and connectivity problem among wireless devices. Static
allocation of spectrum has worked very well in past but now it is
leading to inefficient use of spectrum [8].
 Inefficient usage and limited availability of frequency bands necessitate
the new paradigm of network (cognitive radio network) that can use
available wireless spectrum opportunistically.
 Cognitive radio network (CRN) [7] consists of secondary users.
Secondary users are those, who can use the channels opportunistically
not occupied by the primary users. But as soon as primary users
appear, secondary users vacate the occupied channel without
disturbing the transmission of primary users
NIT KKR, 9 Feb, 2015
6

7. Contd..
 Virtual backbone construction in CRN is more challenging as compared
to other ad hoc networks.
 a virtual backbone protocol is desired to possess following features:
– Spectrum management
– Faster convergence
– Lower overhead
– Ability to handle network instability
 In [7], authors have proposed an algorithm to construct the virtual
backbone in cognitive radio network. In this approach nodes organized
themselves into cells, nodes organization into cells is based on
opportunistic use of spectrum. Nodes in the cells form clusters, each
cluster having a cluster head. Virtual backbone is formed over the
cluster heads, and used to carry out end to end data delivery.
NIT KKR, 9 Feb, 2015
7

8.  We will explore the following problems/challenges in cognitive radio
networks.
• Virtual backbone formation
• Efficient data delivery
• Spectrum management
NIT KKR, 9 Feb, 2015
8
Proposed research area

9. References
[1] N. Meghanathan. Graph theory algorithm for mobile ad hoc networks.
Informatica, vol. 36, 2012, pp. 185-200.
[2] M. Alzoubi, Peng-Jun Wan, and Ophir Frieder. Maximal Independent Set,
Weakly-Connected Dominating Set, and Induced Spanners in Wireless Ad
Hoc Networks. International Journal of Foundations of Computer Science,
Vol. 14, No. 2, 2003, pp. 287-303.
[3] Jie Wu, and Hailan Li. On Calculating connected Dominating Set for Efficient
Routing in Ad Hoc Wireless Networks. Proc. Third ACM Int’l Workshop
Discrete Algorithms and Methods for Mobile Computing and comm. (Dial M
1999), pp. 7-17, Aug. 1999.
[4] S. Basagni. Distributed Clustering for Ad Hoc Networks. Proc. 1999 Int’l
Symp. Parallel Architectures, Algorithms, and Networks (I-SPAN ’99), pp.
310-315, June 1999.
[5] S. Basagni. Localized Protocols for Ad Hoc Clustering and Backbone
Formation: A Performance Comparison. Published by IEEE transactions on
parallel and distributed systems, Vol 17, No 4, April 2006.
NIT KKR, 9 Feb, 2015 9

10. References (Cont.)
[6] S. Srivastava and R. K. Ghosh. Cluster Based Routing Using a K-Tree Core
Backbone for Mobile Ad Hoc Networks. Proc. the Sixth International
Workshop on Discrete Algorithms and Methods for Mobile Computing and
Communications (DIALM’02), Atlanta, Georgia, September 28, 2002.
[7] Ying Dai, Jie Wu and ChungSheng Xin. Virtual Backbone Construction for
Cognitive Radio Networks without common control channel. In Proc. of
IEEE Infocom, 2013.
[8] Shantanu Sharma and Awadhesh Kumar Singh. On Detecting Termination
in Cognitive Radio Networks. In PRDC, 2011 pp. 71-78.
[9] I. F. Akyildiz, W.-Y. Lee, M. C. Vuran, and S. Mohanty. Next
generation/dynamic spectrum access/cognitive radio wireless networks: A
survey. Computer Networks, 2006.
[10] B.-F. Wang. Finding a k-tree corre and a k-tree center of a tree network in
parallel. IEEE Transactions on Parallel and Distributed Systems, 9(2):186-
191, Feb 1998.
NIT KKR, 9 Feb, 2015 10

11. References (Cont.)
[11] K. M. Alzoubi, P.-J. Wan, O. Frieder. Message-Optimal Connected
Dominating Set Construction for Routing in Mobile Ad Hoc Networks.
Proc. ACM MobiHoc 2002, June 2002.
[12] Bo Han. Zone-based virtual backbone formation in wireless ad hoc
networks. Proc. Elsevier 2008.
[13] J. Wu and F. Dai. Virtual backbone construction in manets using
adjustable transmission ranges. IEEE Transaction on Mobile
Computing, 2006.
11