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MTSC Training Course Industrial Wireless Prepared by: Joe dela Cruz Date: 06-08-2010

Mar 26, 2015



  • Slide 1

MTSC Training Course Industrial Wireless Prepared by: Joe dela Cruz Date: 06-08-2010 Slide 2 Training Topics Slide 3 The Basics Wi-fi concepts, Cellular Concepts Antennas and Long Distance Knowledge AWK Series Killer Functions Turbo Roaming Dual RF Redundancy and Bridging VLAN & QoS OnCell Series Killer Functions OnCell Central Manager Routing function Slide 4 In This Section You Will Learn Whats new with AWK and OnCell products Whats important about antennas and long distance communications. Slide 5 Wi-Fi Basics Slide 6 What is a Wireless Network? A network of devices communicating over radio waves. A wireless network eliminates data cables. Slide 7 What is Wi-Fi? Three short-range, unlicensed radio technologies: IEEE 802.11a, 802.11b, and 802.11g StandardFrequency Max/Real Throughput Compatible with 802.11b Typical Range 802.11b2.4 GHz 11 Mbps/ 5 Mbps Yes Indoor: 100m Outdoor: 200m 802.11g2.4 GHz 54 Mbps/ 20 Mbps Yes Indoor: 100m Outdoor: 200m 802.11a5 GHz54 Mbps/ 20 Mbps NoIndoor: 50m Outdoor: 100m Slide 8 802.11b/g 802.11b speeds: 11, 5.5, 2, 1 Mbps 802.11g speeds: 54, 48, 36, 24, 28, 12, 9, 6 Mbps Actual throughput: ~50% of supported speeds (due to network overhead) Channels: 1~11 (US), 1~13 (EU), 1~14 (JP) Recommended channels of use: 1, 6, 11 (avoid frequency overlap) Regulations: FCC (US), ETSI (EU), ARIB (JP) Slide 9 802.11b/g Advantages/Disadvantages Advantages: Widely used Backwards compatibility Longer communication distance Disadvantages: More susceptible to interference (more devices communicating in 2.4 GHz band) Overlapping channels Slide 10 802.11a 802.11a speeds: 54, 48, 36, 24, 28, 12, 9, 6 Mbps Actual throughput: ~50% of supported speeds (network overhead) 5GHz Frequency bands (4 channels each): UNII-1, UNII-2, UNII-3 Ex: UNII-1 contains ch. 36, 40, 44, 48 (all non-overlap channels) Regulations: FCC (US), ETSI (EU), ARIB (JP) Slide 11 802.11a Advantages/Disadvantages Advantages: Less susceptible to interference (fewer devices communicating in 5 GHz band) All non-overlapping channels Regulators allow higher transmit power at higher frequencies Disadvantages: Shorter communication distance Not compatible with 802.11b/g Slide 12 Radio Signal Specs SpecsDefinitionMeasure UnitWhy Important? Frequency Range The range of radio frequency which the signal is transmitting MHz/GHz -Radio Signal frequency range has to match antennas frequency spec. -Difference frequency range may have different interferences Loss Loss of power in the radio signal dB/dBm -Loss weakens the signal strength -Use low loss cables Transmit (Tx) Power The power level of the signal being transmitted mW/dBm -Higher the power, further the distance -Power regulations in different countries Receive (Rx) Sensitivity The recognizable power level of the signal at the receiving end dBm-Higher sensitivity, further the distance -High gain antennas helps sensitivity Slide 13 AP/Client Concept Access Point (AP) A wireless hub Service wireless clients Provide filtering and security Client Mobile wireless device Wireless bridge for sub-networks Capable of roaming between APs Backbone LAN 1 Client LAN 2 Client AP Slide 14 AP/Client Specs and Settings Operation mode: Device plays role of AP or Client RF type: Select RF mode Channel: AP and Client will use the same channel SSID: AP and Client much have SAME SSID for association SSID broadcast: AP broadcast SSID for passive scanning client WDS: AP/Client connection if not enabled. Slide 15 WDS/Bridge Concept WDS (Wireless Distribution System) Bridging APs Wirelessly connect multiple BSS and LAN Fixed location communication Backbone LAN 1 AP Slide 16 Different WDS Configurations Slide 17 WDS Specs and Settings WDS: Device plays the role as bridge AP functionality: Device also plays the role as AP (allows client connection) WDS Settings: Enter MAC address of each bridge device in WDS link. Slide 18 What is throughput? Throughput is the actual data rate the device can transfer data. In WLAN devices, throughput is roughly half of theoretical data rate (when bandwidth is not shared) One should measure throughput to determine if actual data rate meets requirement. Slide 19 Confidential Jperf: WLAN throughput measurement tool. Throughput Measuring Tool Slide 20 Cellular Basics Slide 21 What is Cellular? A radio communication system that can send data over a wide area A wireless network that gives access to network subscribers through base stations Slide 22 Cellular Network Service Standards 1G NMT AMPS/TACS/ETACS 2G GSM CSD PHS GPRS / EDGE CDMA2000 3G W-CDMA UMTS (3GSM) TD-CDMA/UMTS-TDD TD-SCDMA HSPA HSDPA HSUPA HSPA+ HSOPA For Voice Only For Voice and Data Slide 23 2G/3G Telecom Technology 2G: CSD/SMS/GPRS/EDGE 3G: UMTS/HSDPA ServiceDownloadUploadCharge Rate CSD9.6 kbps By connection time SMS1120 bits/msg By number of message GPRS80 kbps20 kbps By amount of data traffic EDGE237 kbps59 kbps By amount of data traffic UMTS384 kbps64 kbps By amount of data traffic HSDPAUp to 7.3 mbps384 kbpsBy amount of data traffic Slide 24 What is CSD? CSD Like reserving a seat for dining: Exclusive Service, Needs Setup Peer-to-Peer Connection Low cost, charges are just like Voice Calls Stands for GSM Phase 2 Circuit Switched Data Slide 25 Modem Modem and CSD via PSTN COM1 Legacy DOS software Serial +886289191230 CNC machine Serial +886289191231 CNC machine Serial +88689191232 CNC machine Establish connection Transmit and receive data Establish connection Transmit and receive data CSD Features -Simulates a long serial cable -Dynamic destination Slide 26 CellularStation ElectricMeter ElectricMeter ElectricMeter OnCell G2150 CSD Application ElectricMeter 2. Transmit and receive data 1. Establish connection CellularStationCellularStation PBX / Administrator Slide 27 AT Command Dialing Modem A Modem B ATD+886289191230RING ATA CONNECT CONNECT abcd1234 abcd1234 +++ OK ATH OK NO CARRIER RINGRING Data Mode Dialing (Command Mode) Command Mode Slide 28 What is GPRS? GPRS Typically charged per megabyte of transferred data Stands for General Packet Radio Service When Will You Need GPRS? If you need ADSL-like modem behavior If you want to use the Internet Slide 29 2.5G GPRS (General Packet Radio service) Mobile Data Service available to GSM users GSM combined with GPRS is called 2.5 G Billed per kbyte/Mbyte/package (128 bytes) Packet Switched PPP, IP supported MMS (Multimedia Message Service) Push Mail High-speed Internet access for mobile phones High-speed Internet access for PCs Slide 30 What is APN? APN (Access Point Name) is the domain name for gateway to GPRS/internet network APN is different for different countries and cellular operators APN must be set correctly in order to properly register onto the 2G/3G networks Operator may assign private APN for specific users. Slide 31 What is SMS? SMS Short Message Service, for human-readable messages Low data volume: 140 bytes maximum 140 hexa characters or 160 ACSII characters or 70 uni-codes When will you need SMS? If you want to receive text messages If your application transfers messages infrequently Or you have a low volume of messages Slide 32 SMS to Whom? Ctrl+Z Press Ctrl+Z here Set 7-bits Ascii Send my message to Slide 33 Youve Got Mail!! Show Me!! Detailed Message & Info Slide 34 SMS Tunnel without AT Commands Serial-to-SMS SMS-to-Serial SMS Data Format Text Binary (8 bits) Unicode (UCS2) Slide 35 Antenna and Long Distance Knowledge Slide 36 Basic Antenna Concept Transmit -Power flow thru induces RF wave Receive -RF wave induces power -Receiver tuned to a specific frequency to pick up specific RF Slide 37 Antenna Selection (Omni Antenna) Longer Distance But narrow range due to the same power Slide 38 Antenna Selection (Semi-Directional Antenna) Yagi Antenna Patch Antenna Slide 39 Characteristics of the Antennas Omni-directional Dipole -360 degree coverage -Short distance applications -Service mobile clients Directional Panel / Patch -Less than 90 degrees of coverage -Long distance applications -Service fixed location clients/bridges. Slide 40 Basic Antenna Spec Example Technical information Frequency 2400 - 2500MHz Gain 12 dBi Polarization Vertical Beamwidth deg vertical & horizontal Horz.360Vert.7 VSWR 1.5 1 Impedance 50 Ohm Dimensions Length H1500 Weight 850 g Connector N-type / female Slide 41 Antenna Gain Comparison Higher gain means stronger (both) sent and received signals; watch for the regulation in your country Antenna TypeGain Range Omni Antenna2~12dBi Semi-Directive Antenna5~18dBi High Gain Antenna20~40dBi Slide 42 Beamwidth and plane field pattern HPBW Half Power Beamwidth ( 3dB ) The beam width is about 65 and the gain is about 9 dBi. (Patch panel example) Slide 43 Deployment Consideration Matching polarity on both sides Power Budget Enough Gain? Low loss? Free space loss is the distance achievable? Site Survey Use Network Stumbler Antenna height Antenna alignment (pointing direction) Jperf or Chariot is useful! Use GPS and compass for tuning angle Check RSSI, bit rate, noise level, throughput Slide 44 Confidential Antenna Polarity Polarity must match (vertical or horizontal) Slide 45 Power Budget WP II AP pigtail cable Lightning Protector RF Cable Antenna WP II Client pigtail cable Lightning Protector RF Cable Antenna + Transmit Power - LOSS Cable/connectors + Antenna Gain - LOSS Cable/connectors RSL ( receive signal level) > sensitivity + Fade Margin - Path Loss over link distance Slide 46 Free space Loss Loss of power in free air Free Space Loss (dB) = 36.56 + 20Log10(Frequency) + 20Log10(Distance in miles) Lower the frequency for less loss of free space Use 2.4 GHz for long distance! Slide 47 Antenna Height Antenna height helps to avoid obstacles Higher Antenna helps LOS (line of sight) and Fresnel Zone Slide 48 MOXA Wireless Distance Calculator