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This study from June 2008 examines deployment scenarios and performance of WiMAX networks using different spectrum bands, focusing on the US 700 MHz band. It covers path loss, mobility support, coverage, capacity, and more, comparing deployments at 700 MHz and 2500 MHz. Detailed analysis includes building penetration loss, channel models, Doppler spreading impact on signal-to-interference-plus-noise ratio (SINR), and user throughput distribution. The results show that 700 MHz deployment offers greater coverage and capacity compared to 2500 MHz solutions in metropolitan areas.
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A Comparative Analysis of Spectrum Alternatives for WiMAX Networks with Deployment Scenarios Based on the U.S. 700 MHz Band June 2008 By MWG/AWG
Outline • Introduction • The “700 MHz Band” in the United States • Path Loss Comparison • High Mobility Support Based on Doppler Spread • Coverage and Capacity Simulations • Metropolitan Area Deployment Comparisons • Conclusion
Introduction • Mobile WiMAX Release 1.0 Profiles • 2300 MHz to 3800 MHz • 2500MHz and 3500MHz • Radio and TV broadcasting • 470 MHz to 862 MHz • Comparison of WiMAX Deployments at 700 MHz and 2500 MHz • Range, coverage, capacity , and performance
The “700 MHz Band” in the United States • “Lower” 700 MHz Band in the US
The “700 MHz Band” in the United States • “Upper” 700 MHz Band in the US
Path Loss Comparison • Channel Models • Building and Vehicular Penetration Loss • Other Parameter Differences • System Path Loss Model
Building and Vehicular Penetration Loss • Outdoor measurements were taken on both sides of the street and averaged • Indoor measurements were acquired in the rooms in an ‘X’ manner. • Attenuation for types of buildings, rooms and floors were measured and correlated
Building Penetration Loss in the 900 MHz Band • Buildings were grouped as follows: • High Integrated (HIn) : > 6 floors, sharing walls • High Isolated (HIs) : > 6 floors, non-sharing walls • Low Integrated (LIn) :< 6 floors, sharing walls • Low Isolated (LIs) :< 6 floors, non-sharing walls • Rooms were classified as follows: • Indoor Light (IL) : room with windows to outdoors • Indoor (I) : room without windows, one wall separation • Deep Indoor (DI): Multiple walls • Attenuation increased as you go deeper into the building (IL ~5dB, I~6dB, DI~9dB) • Attenuation penetration decrease for higher floors(~0.8 dB/floor)
Other Parameter Differences • Cable Losses • In 2500MHz band: cable losses from 2dB to 6dB • In 700MHz band: cable losses from 1dB to 3dB
High Mobility Support Based on Doppler Spread • PICI: inter-carrier interference power relative to received signal power • fd: Doppler frequency • Ts: symbol period
Coverage and Capacity Simulations • Compare coverage, interference, and channel capacity performance between 700 MHz and 2500 MHz WiMAX Systems • Simulation time is about 100 seconds, which contain 20,000 5 ms frames
90% of MSs have a DL data subcarrier CINR greater than -4dB in a 2500 MHz system 90%of MSs have a DL data subcarrier CINR greater than 0 dB in the 700 MHz system 700 MHz system achieve greater coverage Coverage Comparison Based on Data CDF Curves
DL MCS (Modulation and coding scheme) usage from QPSK ½ to 64QAM 3/4 Modulation & Coding Scheme Utilization Comparison
User Throughput Distribution 700 MHz system has both higher user throughput and better area coverage
Conclusion • Compared to WiMAX solution in the 2500 MHz frequency band, 700 MHz deployment provide a considerable rage benefit
Comment • Spectrum is limited, and low frequency spectrum is valuable • How to reuse the spectrum is an important issues
