Hfr, Inc. · KRX:230240
Hfr — European Summit 2000 (Rome)
23 slides from Hfr's conference presentation, May 24, 2000
Slide 1: Case Study: Implementing A Fiber Optic Distribution Solution for In-Building Coverage
European Summit 2000 (Rome) CASE STUDY Implementing A Fiber Optic Distribution Solution To Provide Large Scale In-Building Coverage May 24, 2000 Cheong, Jong-Min (Ph.D) chjm@sktelecom.com; chjm@netsgo.com; chjm@hfrnet.com The spin-off company from SK Telecom 1
Slide 2: Contents
European Summit 2000 (Rome) Contents Introduction - Primary goals of CDMA system design - Service provider’s requirements for in-building coverage extension - Previous distributed antenna system Examining why a fiber-optic solution was chosen Benefits of converting a RF signal to an optical si
Slide 3: Major Cellular Phone Systems
European Summit 2000 (Rome) Major Cellular Phone Systems PCS-1900 PCS cdmaOne Parameters GSM TDMA EVRC Frequency Reuse K=7 K=7 K=1 (3-sector) Spectrum Allocation 15 MHz 15 MHz 15 MHz (including guard bands) Rx Rx Rx Carrier Bandwidth 200 kHz 30 kHz 1.25 MHz Number of Effective 4 24 11 Carriers per S
Slide 4: Primary Goal of CDMA System Design
European Summit 2000 (Rome) Primary Goal of CDMA System Design is to manage the three way trade-off so as to maximize the overall system performance without sacrificing system economics. Call Quality power control soft/softer handover Rake Receiver (multipath mitigation) Coverage Capacity spreading
Slide 5: What is the Cost-Effective Solution for Service Providers?
European Summit 2000 (Rome) What is the Cost-Effective Solution for Service Providers ? Busy No Service ? He …. llo ? Macro-cell BTS BTS BTS site No (DU) (DU) (RF) Service ? ? ? New BTS New BTS - Rural Blind Area Dense Urban Area (hilly or mountainous) (increasing traffic with blind areas) 5
Slide 6: Service Provider's Requirements for In-Building Coverage Extension (I)
European Summit 2000 (Rome) Service Provider’s Requirements for In-Building Coverage Extension (I) Soft/Softer handover - Between the in-building coverage and the surrounding macro cells Techno-Economics - Lower cost : system equipment and installation - Strategic coverage expansion plan is requ
Slide 7: Service Provider's Requirements for In-Building Coverage Extension (II)
European Summit 2000 (Rome) Service Provider’s Requirements for In-Building Coverage Extension (II) More stringent system performance is required - The indoor users more likely expect the indoor wireless services with quality comparable to that of wireline networks - Harsh environment in which fre
Slide 8: Basic CDMA Distributed Antenna System with Basestation Transceiver Subsystem
European Summit 2000 (Rome) Basic CDMA Distributed Antenna System with Basestation Transceiver Subsystem Patent of Qualcomm Inc. (1994) US Patent No. 5,280,472 8
Slide 9: Bottlenecks of the DAS w/ BTS (I)
European Summit 2000 (Rome) Bottlenecks of the DAS w/ BTS (I) Not Cost-Effective - One BTS per building requires high capital and recurring costs - SK Telecom uses 8 ~ 9 FAs for CDMA cellular services in Seoul Company A B C D E Year 1998 1999 1998 1999 1998 1999 1998 1999 1998 1999 Cell Sites 2,32
Slide 10: Bottlenecks of the DAS w/ BTS (II)
European Summit 2000 (Rome) Bottlenecks of the DAS w/ BTS (II) Hard to Design an In-Building Cell - High strength interference from the surrounding macro cell sites : Pilot pollution : Unnecessary handover : Not a 100 % available solution - HCS (hierarchical cell structure) is difficult to impleme
Slide 11: Bottlenecks of the DAS w/ BTS (III)
European Summit 2000 (Rome) Bottlenecks of the DAS w/ BTS (III) Limited Extension Length - High attenuation ratio of the coaxial cable limits the extension length : Trade-off between installation(radius) and feeding length(attenuation) : Neighbor building or underground shopping mall - Attenuation
Slide 12: Fiber-Optic DAS for In-Building Coverage
European Summit 2000 (Rome) Fiber-Optic DAS for In-Building Coverage Indoor coverage Macro-cell site MS BTS BTS BTS (DU) (DU) (RF) SMHM MS SRAU-A SHM < 5 km (Single core leased DF) SRAU-A SRAU-B SRAU-B < 2 km SRAU-B moving MS Subway Station CDMA Coverage Multi-band Coax SREAU Single core optical fib
Slide 13: Benefits of Fiber-Optic DAS
European Summit 2000 (Rome) Benefits of Fiber-Optic DAS Long Fiber Extension - Low cost FP laser diode : < 2 ~ 5 km (~ FA’s) - DFB laser diode : < 20 ~ 30 km (~ FA’s) Direct Transport of RF signal - No frequency conversion and no signal processing - Compact remote antenna unit Lighter Fiber-Op
Slide 14: WDM Multi-Drop FODAS
European Summit 2000 (Rome) WDM Multi-Drop FODAS CDMA TX RF Carrier Analog E/O E/O E/O E/O Existing BTS α L1 L2 L3 L4 (a) General fiber-optic repeater (Total Optical Fiber Length Leased = 4L1+3L2+2L3+L4) Analog E/O S S S L1 L2 L3 L4 (b) HFR’s WDM multi-drop repeater (MD-800) Ref. : http://www.hfrnet
Slide 15: Considerations to Make a Design Rule
European Summit 2000 (Rome) Considerations to Make a Design Rule Link Budget Analysis for Coverage Radius Estimation - Forward link (power bank) : Ec/Io, RX level - Reverse link (loading and noise figure) : mobile TX power - Link balance System Specifications and Requirements - Traffic (BHCA, Da
Slide 16: Estimating In-Building Pathloss?
European Summit 2000 (Rome) Estimating In-Building Pathloss ? Floor Averaged Model - S.Y.Seidel and T.S. Rappaport, IEEE Trans. Ant. & Prop., 1992 Ld ,n (dB ) = B + 10 ⋅ γ n ⋅ log10 (d ) + FAFn where B is a reference path loss, FAF is the cumulative floor attenuation, γ is the pathloss exponents,
Slide 17: Real Measurement is Important
European Summit 2000 (Rome) Real Measurement is Important Localized Model - K.S. Butterworth, et al., 1997 Ld ,n (dB ) = lookup _ table _ value - By not fitting a propagation model to the measured data no assumptions are made about the propagation mechanisms between transmitter and receiver 17
Slide 18: Forward Link Requirements
European Summit 2000 (Rome) Forward Link Requirements Frequency Stability : < 0.05 ppm - To facilitate initial acquisition of a mobile handset and to simplify handovers between cells Waveform Quality Factor : > 91.2 % - Representing the normalized cross correlation of the transmitted CDMA wavefo
Slide 19: Reverse Link Requirements
European Summit 2000 (Rome) Reverse Link Requirements Noise Figure : < 5 dB - To reduce mobile TX power of indoor handsets Signal Injection Ratio (I.R.) : < - 20 dB coupling - To reduce performance degradation of donor cell site Noise Funneling NFindoors (dB) = NFbasic + 10 ⋅ log10 (N )+ | I .
Slide 20: Effective Strategies to Overcome the High Installation/Maintenance Costs (I)
European Summit 2000 (Rome) Effective Strategies to Overcome the High Installation/ Maintenance Costs (I) Common Use of System and Fiber Cable - Cellular (800 MHz) and PCS (1.8 GHz) - Easy migration towards IMT-2000 IMT-2000 MSMD MS Mobile BTS 2000 Communication Network BTS Interface S Unit Optica
Slide 21: Effective Strategies to Overcome the High Installation/Maintenance Costs (II)
European Summit 2000 (Rome) Effective Strategies to Overcome the High Installation/ Maintenance Costs (II) Dynamic Resource Management - Dynamic resource allocation according to the traffic requirements IS-95B/C CBS SCP/STP MSC/BSC (BTS’ Group) (WIN) MD-800 sector switching PSTN MD-800 PABX Apartm
Slide 22: RF switching for dynamic allocation
European Summit 2000 (Rome) RF switching for dynamic allocation No Handover α α α β night γ β Cell splitting daytime More Capacity weekend κ κ α β Figure source : http://www.metawave.com γ β Ref. : J.M. Cheong et al., IEEE VTC’99 22
Slide 23: Conclusions
European Summit 2000 (Rome) Conclusions Coverage Achieved - For a large-scale building (above 1,000 m2 including any underground blind area or other neighbor building), WDM-based FODAS (fiber-optic distributed antenna system) is recommended to achieve a strategic in- building coverage. Quality o