A Comparative Analysis of Spectrum Alternatives for WiMAX Networks with Deployment Scenarios Based on the U.S. 700 MHz Ban

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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

Possible BS Configurations for US 700 MHz Band Plan

Path Loss Comparison

• Channel Models

• Building and Vehicular Penetration Loss

• Other Parameter Differences

• System Path Loss Model

Parameters for Path Loss Comparison

Suburban Outdoor Path Loss Comparison

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

System Path Loss Model

High Mobility Support Based on Doppler Spread

• PICI: inter-carrier interference power relative to received signal power

• fd: Doppler frequency

• Ts: symbol period

• : depend on the particular Doppler spectrum value

Doppler Spreading Impact on SINR

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

Average Interference Margin

Coverage Comparison Based on Data CDF Curves

• 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

Modulation & Coding Scheme Utilization Comparison

• DL MCS (Modulation and coding scheme) usage from QPSK ½ to 64QAM 3/4

User Throughput Distribution700 MHz system has both higher user throughput

and better area coverage

Metropolitan Area Deployment Comparisons

Metropolitan Area Deployment Comparisons

Other Mobile WiMAX™ Usage Models

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