Course 145: Wireless RF Intro, 2G and 3G Design and Optimization

Transcription

1 Day One: Wireless Technologies, Basic Design Intro, Prerequisites, Signals and Hardware Street-View I. Survey of Wireless Technologies and Operators a. 2G: CDMA/1xRTT, GSM/GPRS/EDGE b. 3G: 1xEV-DO, UMTS/WCDMA/HSPA c. 4G: HSPA+(sorta), LTE, WiMAX II. The Heart of RF Design: Propagation a. Types of Propagation Models hands-on play in class b. Signal propagation/penetration: Wavelength is king c. Link Budget, Reliability design (50%?!), Fade Margin III. RF Design Methods to Obtain Desired Capacity a. Capacity vs. spectrum vs. signal-to-noise, interference b. Traffic Density, Cell Density, profiles and estimates Traffic Engineering Basics a. Units of measure, grade of service, blocking and trunking efficiency b. How do these relate to capacity of sectors, sites, and multiple carriers? c. Estimating offered traffic in wireless systems, identifying traffic sources d. How bad can it get? Some techniques for worst-case estimation e. How to predict and manage special situations traffic jams, sports events V. Practical workings of our RF hardware - Design and Troubleshooting a. Types of Wireless antennas: like choosing sprinkler heads for irrigation b. Transmission Lines: Loss, impedance, velocity, power what matters? c. Accessories: connectors, couplers, duplexers, filters, combiners, stubs d. Sheer Fright: Ohm s law in a thunderstorm e. Transmission line worries: Matching, reflected power, standing waves i. Units of measure, finding trouble, tools, pitfalls/problems missed ii. Passive Intermod Testing Is it needed? reliable? What s at stake? IX. General Air Interface Receiving Characteristics: C/I, S/N, Eb/No a. Thermal noise floor, Cochannel+Adjacent channel interference, images b. Detecting with PN scanners, Spectrum analyzers swept+dsp, hands-on Intermodulation: often-unseen spoiler, how avoid being a victim a. What is, where it s born, what frequencies, and how strong? Units/specs b. A fast hands-on demo: create some intermod right in class! c. Finding/solving Intermod: it s sneaky, truth serum techniques Sidebar: Are you comfortable working in decibels? a. What s the difference between db and dbm? b. What s a dbi? A dbd? Sidebar, Special tricks: DAS, Cell Enhancers/Boosters/Reradiators/Repeaters a. Bidirectional amplifiers, on-frequency repeaters: gain and link budgets b. Distributed Antenna Systems: Neutral Host, 1-Operator, hardware/design COURSE Scott Baxter & Associates 3/7/ of 5

2 Day Two: Intro to CDMA Signals, Channels, Call Processing, Problems I. Quick review of multiple access and how basic CDMA works and excels a. FDMA, TDMA, CDMA what actually carries a user s channel? II. CDMA: Intro and how it really works both forward and reverse a. Coding and Spreading Gain spread spectrum signals hopping and dsss b. Forward Link codes: Walsh codes for users, Short PN offsets for sectors c. Reverse Link codes: Long PN offsets for individual mobiles d. PN Planning, mobile PN offsets; search windows; nbr. lists, false handoffs III. CDMA Call Processing, Messaging a. CDMA Layer-3 Messagings: structure, format, reading/interpreting i. Idle Mode and Active Call messages: graphics to help remember ii. Handset structure: internal elements and their functions, limitations b. Call processing flow: see triggers, messaging, mobile & network actions i. System Acquisition: steps, PRL, idle carrier distribution, issues ii. Idle Mode Handoff: hysteresis, multicarrier nbrs, GSRM iii. Registration: probes, parameters, ACH/PCH capacity iv. Slotted Mode Paging: multicarrier, RF, system resource issues 1. QPCH, battery life, missed-page troubleshooting v. Receiving an Incoming Call: steps, parameters, troubleshooting vi. Outgoing Call: steps, parameters, troubleshooting vii. Ending a Call: normal and abnormal steps, timers, triggers viii. Feature Notification: Delivery, parameters, troubleshooting ix. Soft/Softer Handoff: mobile/network interaction, steps/parameters Easily Monitored CDMA Performance Indicators a. FER: What it is, how it is counted, what causes it, its significance b. Ec/Io What it is, how measured: loading, overlap, interference effects c. Mobile Receive Power (Io) what, how measured, range and side effects d. Mobile Transmit Power what and why do we care? Deeper significance e. Transmit Gain Adjust a special window into the BTS and mobile pain i. Normal range, normal and abnormal factors driving it up/down ii. Special factors: slew speed, feel of overall reverse pwr control f. Reverse Link Interference: sources, effects, conditions, solutions (skit) V. Signatures of Indicators under Normal and Abnormal RF Conditions a. Good Call b. Dropped Call in Poor Coverage: causes and solutions c. Forward Link Interference: sources, effects, conditions, solutions (skit) COURSE Scott Baxter & Associates 3/7/ of 5

3 Day Three: CDMA/1xRTT Performance Management/Optimization I. Search Windows: what, why they matter, and is your mobile an Ostrich? a. Units and settable values b. The relationship between window size and distance, and when it applies i. Mobile SRCH_WIN_A, _N, _R characteristics, consequences ii. Base Station Windows: ACQ Widths, auto linkages by some Mfrs II. PN Planning and Search Windows: How signals age with distance a. Popular PN assignment schemes and PN reuse plans b. PN trouble scenarios: Co-Active, Adjacent-Active, Adjacent-Neighbor c. PN Falsing -- Choosing a PN plan III. Practical Optimization: functional phases: cell turnup, additions, growth System Statistics to guide Optimization what are they good at finding? a. What is visible in System Stats? Where are they measured, how to tap in? b. Key Performance Indicator Statistics from the system c. How to analyze statistics: methods, management, analysis, alerting d. How do you track down the causes of bad statistics? e. In-class review of actual system examples V. Field Optimization Tools and Data what are they good at finding? a. Call-Processing Capture Tools: indications, configuration b. PN Scanners: Types, benefits, configuration, interpreting results c. Post-Processing Software: Functions and special insights offered d. Effective Drive Testing: Installation, Configuration, and personal survival e. A personal weapon Your Mobile!! Maintenance Mode Displays Multiple-Carrier and Intersystem Boundary Optimization Issues a. Multi-Carrier Configurations: Single, access-slaved, mixed mode b. Carrier transition management at system internal and external boundaries c. What s different when the boundary is inter-system? d. Traffic/Performance concerns make handoffs happen where you want e. When in doubt trace each step in the mobile s actions! 1xRTT Data and Data Performance Optmization a. Supplemental channel functions, assignment, parameters, resources b. Some additional Performance Indicators for Data Operation c. Mobile-Side Tools for 1x Performance Analysis: in-class exploration d. Data Flow Management: Sessions, Connections, MAC states A Quick Introduction to the Wireless Data Core Networks a. PDSN HA, FA; AAA; controller functions, tunnels, routing b. Optional: Refresher on TCP/IP basics COURSE Scott Baxter & Associates 3/7/ of 5

4 Day Four: 1xEV-DO Networks, Call Processing, Foundation for Optimization I. 1xEV-DO rev 0, A, and 1xEV-DV Technologies and Terminology a. 1xEV-DO Unique Features, differences from IS-95 and 1xRTT CDMA i. Rapid burst mgmt, adaptive modulation/coding, Hybrid ARQ II. 1xEV-DO Signal Structure and Call Processing a. Forward Channels - Pilot, MAC, DRC lock, RPC, control, traffic b. Reverse Channels -- Access, Traffic: ACK, MAC/DRC/SRC, RRI, Data c. 1xEV-DO Power Control d. 1xEV-DO Handoffs (Route Update), parameters, fwd/rev implications III. Access Terminal Architecture a. Network Elements in a typical implementation b. EV-DO Architectures of Lucent, Motorola, and Nortel 1xEV-DO Network Architecture a. The Core Network: PDSN HA and FA, RNC, BTS, AAA b. Simple IP and Mobile IP architectures and their capabilities c. User mobility across multiple networks d. BTS functions and Architecture e. EV-DO overlays on 1xRTT data networks V. IS-856 Standard Overview a. Reference Model and Protocol Stack Layers i. Physical, MAC, Security, Connection, Session, Stream, Applica n b. Default and Non-Default Protocols, Packet Encapsulation, Data transfer 1xEV-DO Layer-3 Messages a. Message format, vocabulary, priorities, default fields 1xEV-DO Call Processing a. System Acquisition i. Physical Layer activities ii. 1xEV-DO system selection and PRL guidance b. Registration, Connections, Sessions, Paging, Setup, Route Updates c. 1xEV-DO Route Update Operation i. Access Terminal Architecture, Pilot Sets, Search Windows d. Data Session Establishment and States e. 1xEV-DO / 1xRTT Interoperability i. Hybrid Mode features and triggers ii. Example Transitions Demonstrations from Captured Field Data a. Overhead messaging and state changes COURSE Scott Baxter & Associates 3/7/ of 5

5 Day Five (Half Day): 1xEV-DO Network Performance Evaluation and Optimization I. Introduction and Perspective: 1xEV-DO Operation and Performance II. Key 1xEV-DO Performance Indicators both RF and Data a. Is a problem in RF, AT-AP, AN-PDSN, IP-backbone, HA, or external IP? b. RF Methods for identifying problem sources c. Data-plane methods for identifying problem sources III. 1xEV-DO Performance Indicators a. System Indicators i. Aggregate data traffic levels by node, forward and reverse ii. Aggregate data traffic levels by user, forward and reverse iii. Sector/Carrier throughput, forward and reverse iv. Distribution of DRC levels of mobile requests, per sector b. Mobile Indicators i. Peak and Average throughput on test connections, fwd & rev. ii. Latency iii. Distribution of requested DRC levels iv. FER and BLER c. Performance Indicator Signatures of specific 1xEV-DO conditions i. RF limitations, uplink and downlink ii. Network congestion, RF and/or core iii. Excessive Latency and other session problems d. Class Examples: tests of local EV-DO network performance Survey of 1xEV-DO AN and AT Parameters requiring Optimization a. Functions, ranges, and consequences of inappropriate values V. Examples of Impairments and their effect on sessions and data flow a. Captured Field Data, in-class demonstration and analysis b. Review of classic issues and solutions c. How RF conditions affect obtainable throughput (in-class example) Optional: Examination of student-provided network data COURSE Scott Baxter & Associates 3/7/ of 5