An Empirical Assessment of QuasiPermanently Vacant Channels in Mobile
Communication Bands for Cognitive Radio
Neeta Nathani*

G.C. Manna**

S.B.Mule**

Research Scholar, Department of Electronics Engineering, G.H. Raisoni College of Engineering, Nagpur, India.
**
Senior General Manager, Indian Telecommunication Service, BSNL, Jabalpur, India.
neeta_nathani@yahoo.com, gcmanna@gmail.com, mulesb1@gmail.com

Keywords: Cognitive Radio, Common control signalling, In-band signalling, Mobile communication, Radio link control.
Abstract: Basis of cognitive radio is to exploit unused frequency channels in licensed band. Recently standardisedIEEE 802.22 set of cognitive radio protocols envisages fixed and nomadic receivers at below 800 MHz bands. Radiolink design for this cognitive radio consider that the channels are available only dynamically to secondary users.
Scanning period is thus embedded in link layer control as overhead and reduces overall efficiency of cognitive radio
technology. For mobile receivers, availability of permanent channels for radio link control is essential for in-band
signalling. Existing mobile communication system uses CDMA 800, GSM 900, GSM 1800 and WCDMA 2000 MHz
bands for which approximately 1/8th of the band capacity is used for in-band signalling. Present work provides anassessment of vacant channels in mobile communications range which were permanently available at the time ofmeasurement. The study used conventional Radio frequency scanners available for different bands and dedicatedengineering handsets for tracking active frequencies. The tests were performed with assemblies carried in a vehicle andacross the length and breadth of each city. The allotment of frequencies by Frequency Regulatory Authority to local
mobile operators along with the frequency bands reserved for further distribution were also considered. The
experimentally collected data were analysed using RF analysis software and spread sheet database. An analysis of thecollected data lead to arrive at the conclusion that more than 1/8 th part of resources of each band are nearly
permanently vacant which is enough to design in-band common control signalling methods for cognitive radio. Also,with the help of collected data of eight cities, an empirical relationship has been established which can be taken as athumb rule for projection of channel occupancy from densely populated core areas of big cities to less populated
township areas when population is known.
Neeta Nathani was born in India in 1981. She received the B.E. and M.Tech. degrees from Rajiv Gandhi Proudyogiki
Vishwavidyalaya, India, in 2003,and 2009, respectively. She joined Sri Ram Institute of Technology, Jabalpur, India, in2003 and worked there for few years. Since 2008, she has been with Gyan Ganga Institute of Technology & Sciences,
Jabalpur, India where she is currently an Assistant Professor. Her main areas of research interest are WirelessCommunication, Quality of service of Cognitive Radio.

He is working as Senior General Manager (Head Quarters), Inspection Circle, BSNL, a wholly owned Company underDepartment of Telecommunications (DoT), Govt. of India. He has developed and conducted one week course on Quality ofService Monitoring at Information and Communication Technologies Authority, Mauritius as International Expert throughCommonwealth Telecom Organisation London during August 2010. He had also delivered a speech on WiMAX coverage
Evaluation at International Conference on Advanced Communications Technology 2011 at Seoul, Korea and chaired asession on Network Management. He had also delivered speech on ADSL at International Telecommunication Union
seminar in 2000 at Bangalore, India. He has carried out extensive research on coverage issues of GSM,CDMA, WCDMAand WiMAX radio access. Study of Wireless Traffic and QoS estimation of Cognitive Radio are his current areas ofresearch. In addition, he has written several articles on advanced telecommunications which has been published in nationaland international journals and symposiums.
Prof. Mule has completed his master degree in Electronics (Computer) from Government College of Engineering,Pune
and has six years of industrial experience. He has presented 25 papers international journals and conference.