Nenad Milosevic, Bojan Dimitrijevic, Dejan Dušan Drajic, Zorica Nikolic, Milorad Tosic

DOI Number
First page
Last page


Since the future mobile networks will require significantly higher data throughput, and the Long-Term Evolution (LTE) licensed bands are already occupied, the frequency band extension and the data rate increase may be achieved by using some of the available unlicensed bands. The most appropriate unlicensed band for this purpose lies in 5 GHz frequency range. However, this unlicensed band is already occupied by WiFi networks and a special attention has to be paid to coordinate these two different networks in the shared spectrum usage. Therefore, this paper considers the shared access co-existence in 5 GHz unlicensed band between uncoordinated LTE and WiFi networks. More precisely, it considers the influence of the LTE downlink transmission on the performance of the WiFi networks. The experimental results show that the LTE significantly degrades the WiFi network performance, which means that some of the coordination algorithms have to be employed.


WiFi, LTE, co-existence, unlicensed band, shared access

Full Text:



Qualcomm, Extending the benefits of LTE Advanced to unlicensed spectrum, http://www.qualcomm.

com/media/documents/files/extending-the-benefits-of-lte-advanced-to-unlicensed-spectrum.pdf; 2014 [accessed 29.08.16].

A. Prijić, Lj. Vračar, D. Vučković, D. Danković, Z. Prijić, "Practical aspects of cellular M2M systems design", Facta Universitatis, Series: Electronics and Energetics, vol. 28, pp. 541-556, December 2015.

L. Polak, O. Kaller, L. Klozar, J. Sebesta, T. Kratochvil, “Mobile communication networks and digital television broadcasting systems in the same frequency bands: Advanced co-existence scenarios”, Radioengineering, vol. 23, pp. 375–386, April 2014.

3GPP. LTE in unlicensed spectrum,; 2014 [accessed 129.08.16].

3GPP. 3GPP Release 8,; 2014 [accessed 29.08.16].

3GPP. 3GPP Release 10,; 2014 [accessed 29.08.16].

R. Deka, S. Chakraborty, J. S. Roy, "Optimization of spectrum sensing in cognitive radio using genetic algorithm", Facta Universitatis, Series: Electronics and Energetics, vol. 25, pp. 235-243, December 2012.

J. Jeon, H. Niu, QC Li, A. Papathanassiou, G. Wu, “LTE in the unlicensed spectrum: Evaluating coexistence mechanisms”, In the Proceedings of the IEEE Globecom Work. GC Wkshps 2014, 2014, Austin, TX (USA), pp. 740–745.

A. Babaei, J. Andreoli-Fang, Y. Pang, B. Hamzeh, “On the Impact of LTE-U on Wi-Fi Performance”, Int J Wirel Inf Networks, vol. 22, pp. 336–344, December 2015.

S. Sagari, S. Baysting, D. Saha, I. Seskar, W. Trappe, Di. Raychaudhuri, “Coordinated dynamic spectrum management of LTE-U and Wi-Fi networks”, In the Proceedings of the IEEE Int. Symp. Dyn. Spectr. Access Networks, DySPAN 2015, Stockholm, Sweden, 2015, pp. 209–220.

LTE-U Forum,; [accessed 19.08.16].

3GPP, 3GPP Release 13,; 2015 [accessed 29.08.16].

3GPP, RP-151045: New Work Item on Licensed-Assisted Access to Unlicensed Spectrum,; 2015 [accessed 29.08.16].

R. Ratasuk, N. Mangalvedhe, A. Ghosh, “LTE in unlicensed spectrum using licensed-assisted access”, In Proceedings of the IEEE Globecom Work. GC Wkshps, Austin, TX, USA, 2014, pp. 746–751.

Li Y, Zheng J, Li Q, “Enhanced listen-before-talk scheme for frequency reuse of licensed-assisted access using LTE”, In Proceedings of the IEEE Int. Symp. Pers. Indoor Mob. Radio Commun. PIMRC, Hong Kong, China, 2015, pp. 1918–1923.

D. Raychaudhuri, X. Jing, I. Seskar, K. Le, JB Evans, “Cognitive radio technology: From distributed spectrum coordination to adaptive network collaboration”, Pervasive Mob Comput, vol. 4, pp. 278–302, June 2007.

K. Challapali, S. Mangold, Z. Zhong, “Spectrum agile radio: Detecting spectrum opportunities”, In the Proceedings of the Intern. Symp. Adv. Radio Technol, Boulder, CO, USA, 2004, po. 61–65.

X. Jing, SC. Mau, D. Raychaudhuri, R. Matyas. “Reactive cognitive radio algorithms for Co-existence between IEEE 802.11b and 802.16a networks”, In Proceedings of the GLOBECOM - IEEE Glob. Telecommun. Conf., St. Louis, MO, USA, vol. 5, 2005, pp. 2465–2469.

D. Raychaudhuri, X. Jing, “A spectrum etiquette protocol for efficient coordination of radio devices in unlicensed bands”, In Proceedings of the IEEE Int. Symp. Pers. Indoor Mob. Radio Commun. PIMRC, Beijing, China, vol. 1, 2003, pp. 172–176.

X. Jing, D. Raychaudhuri, “Spectrum Co-existence of IEEE 802.11b and 802.16a Networks Using Reactive and Proactive Etiquette Policies”, Mob Networks Appl, vol. 11, pp. 539–554, August 2006.

OpenAirInterface Software Alliance, OpenAirInterface,; 2015 [accessed 29.08.16].

NITlab, NITOS,; [accessed 29.08.16].

EURECOM, ExpressMIMO2,; [accessed 29.08.16].

Ettus, USRP X- and B- Series,; [accessed 29.08.16].

iPerf,; [accessed 29.08.16].


  • There are currently no refbacks.

ISSN: 0353-3670 (Print)

ISSN: 2217-5997 (Online)

COBISS.SR-ID 12826626