Indoor Propagation Models at 2.4 GHz for 802.11b Networks

1. Indoor Propagation Models at 2.4 GHz for 802.11b Networks Dinesh Tummala Department of Engineering Technology

2. Advisory Committee Dr. Albert B. Grubbs Dr. Robert Akl Dr. Robert G. Hayes Dr. Vijay Vaidyanathan

3. Outline • Introduction • Problem Statement • Background of the Problem • Review of Literature • Assumptions • Hypothesis • Methodology

4. Introduction • Wireless Communication • The first rush to wireless was for voice. Now, the attention is on data. • Wireless Local Area Networks (WLANs) provide network services where it is difficult or too expensive to deploy a fixed infrastructure. • WLANs operate mainly in a indoor environment.

5. Indoor use of wireless systems poses one of the biggest design challenges. It is difficult to predict the propagation of a RF wave in an indoor environment. To assist in deploying the above systems, characterization of the indoor radio propagation channel is essential. This study aims at developing an indoor propagation model from measurements taken using 802.11b compliant access point and client adapters. Problem Statement

6. Background of the Problem Line of Sight Propagation • Attenuation • Multipath • Fading • Free Space Loss • Noise • Atmospheric Absorption • Refraction

7. Background of the Problem Indoor RF Propagation and Wireless LAN Technology • Access Points • Wireless Client Adapter

8. Background of the Problem IEEE 802.11 Standard • 802.11a • 802.11b • 802.11g

9. Background of the Problem Frequency Range and Channel Allocation for 802.11b

10. Background of the Problem 802.11b Channel Overlap

11. Literature Review Existing models tend to focus on a particular characteristic like temporal fading or inter floor losses.

12. Assumptions • The scenarios considered provide a sufficient number of data acquisition values to develop an accurate model. • The access points considered for signal measurements possess the same antenna behavior in comparison to industry standards.

13. Hypotheses Null Hypotheses: Indoor radio propagation at 2.4 GHz is not dependent on the indoor environment. Alternative Hypotheses: Indoor radio propagation at 2.4 GHz is dependent on the indoor environment.

14. Methodology Hardware & Software Hardware • Access Points • Client Adapter Software • NetStumbler

15. Propagation Environment • The power received by a mobile receiver is influenced by the characteristics of the propagation environment. • The measurements are to be conducted at The College of Engineering, University of North Texas, Research Park.

16. NTRP 1st Floor

17. NTRP 2nd Floor

18. CSE Floor Plan

19. Measurement Scenarios Scenarios used will help in developing signal loss equations, by which a generalization for propagation in an indoor environment at 2.4 GHz can be obtained.

20. Measurement Scenarios • Open corridor • Closed Corridor • Class room • Staircase • Computer lab • Two Floor

21. Data Acquisition • Using NetStumbler measurements are taken for the above described scenarios. In each scenario the signal strength is measured for both (LinkSys and D-Link) access points at regular increments of distance. • At each interval sufficient signal measurements are taken.

22. Open Corridor Signal level vs Distance

23. Data Analysis • Signal strengths measured in each scenario at different distances are analyzed to get mean signal level values at each distance interval. • A loss equation is generated for each scenario using the obtained data values. • A GUI interface is developed to visualize the simulation.

24. Open Corridor D-Link vs LinkSys

25. Conclusion • Scenarios used will help in developing signal loss equations, by which a generalization for propagation in an indoor environment at 2.4 GHz can be obtained.

26. Thank You!! Questions?