volume | PIER Journals

Abstract

Underestimation of path loss when planning the deployment of 802.11n APs can lead to coverage gaps and user dissatisfaction. The use of Free Space Path Loss modelling can sometimes lead to underestimation of path loss in urban environments when the effect of small scale fading is not considered. A field experiment was conducted with the aim to investigate the applicability of the ITU-R P.1141-7 Recommendation in path loss estimation of 802.11n signals in an urban environment in Malaysia. The results showed that Section 4.3 of ITU-R P.1411-7 can estimate the path loss of 802.11n signals with very low error margins of between 0 dB and 5 dB for transmitter receiver distances of 50 m and more. At these distances, the average difference of path loss estimation between FSPL and measured path loss is approximately 18 dB. The study concludes that 802.11n APs may need to be placed at closer proximities than previously assumed if FSPL is used to model the path loss. This is to ensure that targeted traffic is actually offloaded; coverage gaps are reduced; user satisfaction is improved.

1. Adler, A. and M. Salhov, "A carrier-grade wireless lan network implementation [application notes]," IEEE Microwave Magazine, Vol. 9, No. 4, 108-119, 2008.
doi:10.1109/MMM.2008.924759

2. Halperin, D., et al. "Predictable 802.11 packet delivery from wireless channel measurements," ACM SIGCOMM Computer Communication Review, Vol. 41, No. 4, 159-170, 2011.
doi:10.1145/2043164.2018442

3. Paul, T. K. and T. Ogunfunmi, "Wireless LAN comes of age: Understanding the IEEE 802.11n amendment," IEEE Circuits and Systems Magazine,, Vol. 8, No. 1, 28-54, 2008.
doi:10.1109/MCAS.2008.915504

4. Sklar, B., "Rayleigh fading channels in mobile digital communication systems. A characterization," IEEE Communications Magazine, Vol. 35, No. 7, 90-100, 1997.
doi:10.1109/35.601747

5. Phillips, C., D. Sicker, and D. Grunwald, "A survey of wireless path loss prediction and coverage mapping methods," IEEE Communications Surveys & Tutorials, Vol. 15, No. 1, 255-270, 2013.
doi:10.1109/SURV.2012.022412.00172

6. Almorox-González, P. and J. I. Alonso, "Software tool for planning wireless local area networks (WLAN)," The European Conference on Wireless Technology, 387-390, IEEE, 2005.

7. Li, M. and D. Wang, "Indoor coverage performance comparison between IEEE 802.11g and IEEE 802.11ah of wireless nodes in M2M network," Internet of Vehicles-Technologies and Services, 211-217, Springer International Publishing, 2014.

8. Lopez-Perez, D. and M. Folke, "3 system-level simulation and evaluation models," Heterogeneous Cellular Networks: Theory, Simulation and Deployment, 2013.

9. International Telecommunications Union, Radiocommunications Bureau, "Recommendation ITUR P.1411-7: Propagation data and prediction methods for the planning of short-range outdoor radiocommunication systems and radio local area networks in the frequency range 300MHz to 100 GHz,", Sep. 2013.

10. Priya, T. S., S. P. N. Pillay, M. Saargunawathy, and D. Madhavan, "An investigation on the use of ITU-R P.1411-7 in 802.11n path loss modelling," Progress In Electromagnetics Research Letters, Vol. 50, 91-98, 2014.
doi:10.2528/PIERL14101601

11. Salo, L. V., H. M. El-Sallabi, and P. Vainikainen, "An additive model as a physical basis for shadow fading," IEEE Transactions on Vehicular Technology, Vol. 56, No. 1, 13-26, Jan. 2007.
doi:10.1109/TVT.2006.883797

12. International Telecommunications Union, Radiocommunications Bureau, "Recommendation ITUR P.1546-5 method for point-to-area predictions for terrestrial services in the frequency range 30 MHz to 3000 MHz,", Sep. 2013.

13. Nasreddine, H. and I. Jabri, "On the performance of IEEE 802.11 n protocol," Wireless and Mobile Networking Conference (WMNC), 2012 5th Joint IFIP, 2012.

14. Shittu, W. A., et al. "Prediction of received signal power and propagation path loss in open/rural environments using modified free-space loss and Hata models," RF and Microwave Conference, RFM, 2008.

Ms. Siva Priya Thiagarajah

Dr. Shamini Pillay Narayanasamy Pillay

Dr. Vasudhevan Pavindran

Dr. Sivasubramaniam Priyatini