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Wireless LAN Solution & Deployment Tjie Seng, Njauw. Fixed Communications. Mobile Communications. The Paradigm Shift. Fixed Work Area. Work where you want!. The Paradigm Shift. Tethered Network Connection. Wireless Network Connectivity Wireless LAN Products. The Paradigm Shift.
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Wireless LAN Solution & Deployment Tjie Seng, Njauw
Fixed Communications Mobile Communications The Paradigm Shift
Fixed Work Area Work where you want! The Paradigm Shift
Tethered Network Connection Wireless Network Connectivity Wireless LAN Products The Paradigm Shift
What is a Wireless LAN? • Radio Frequency Technologies • WLANs Product Categories • Standards Based Technology
Wireless LAN 802.11b Spread Spread Spectrum Spectrum Wireless Wireless LANs LANs Radio Frequency Technologies 10 Mbps 4 Mbps Wireless Data Infrared Infrared 2 Mbps Wireless Wireless Networks LANs LANs Data Rates 1 Mbps Broadband PCS Broadband PCS 56 Kbps Metricom Metricom Circuit & Packet Data Circuit & Packet Data 19.6 Kbps Cellular, CDPD, RAM, ARDIS Cellular, CDPD, RAM, ARDIS Satellite Satellite Narrow Band Narrow Band Narrowband PCS Narrowband PCS Wireless LANs Wireless LANs 9.6 Kbps Local Coverage Area Wide
2.4 – 2.4835 GHz 83.5 MHz (IEEE 802.11B) 902-928 MHz 26 MHz 5 GHz (IEEE 802.11A) HyperLAN HyperLAN2 Older Product Future Technology License Free ISM Band Short Wave Radio FM Broadcast Infrared wireless LAN AM Broadcast Television Audio Cellular (840MHz) NPCS (1.9GHz) Extremely Low Very Low Low Medium High Very High Ultra High Super High Infrared Visible Light Ultra- violet X-Rays Current Product
Binary phase shift keyed (BPSK) BPSK uses one phase to represent a binary 1 and another to represent a binary 0 for a total of two bits of binary data. This is utilized to transmit data at 1Mbps. Quadrature phase shift keying (QPSK). With QPSK, the carrier undergoes four changes in phase and can thus represent four binary bits of data. This is utilized to transmit data at 2 Mbps. Complementary code keying (CCK) CCK uses a complex set of functions known as complementary codes to send more data. One of the advantages of CCK over similar modulation techniques is that it suffers less from multipath distortion. This is utilized to transmit data at 5.5 and 11Mbps. Radio Modulation
2 Mbps DSSS 350 feet radius 5.5 Mbps DSSS 175 feet radius 11 Mbps DSSS 100 feet radius In Building WLANs Average 802.11b Access Point Range
Direct Sequence Modulation • Each data bit becomes a string of chips (chipping sequence) transmitted in parallel across a wide frequency range • Minimum chip rate per the FCC is 10 chips for 1 and 2MB (BPSK/QPSK) and 8 chips for 11Mb (CCK) data rates. If the data bit was: 1001 Chipping code is : 1=00110011011 0=11001100100 Transmitted data would be: 00110011011 11001100100 11001100100 00110011011 1 0 0 1
Channels- 802.11 DS 2472 2412 12 13 6 7 9 3 10 5 11 1 4 8 2 2400 • (11) 22 MHz wide stationary channels • x “chips per bit”, means each bit sent redundantly • 11 Mbps data rate • 3 non-overlapping channels • 3 Access Points can occupy same area
Scalability With Direct Sequence Blue= 11Mb Total Bandwidth=33MB!!! Green=11Mb Red=11Mb
35 30 25 20 DS-2Mb 15 Mbps Capacity DS-11Mb 10 5 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 Number of Access Points Scalability Wireless Capacity per Cell
200 Users on the Floor • Full Antenna Power – 30mW • Max 3 Access Points • 67 Users per AP of shared bandwidth 1 6 11 • 200 Users on the Floor • Reduce Power - 5mW • 18 Access Points • 11 Users per AP of shared bandwidth 1 11 6 1 11 6 6 1 11 6 1 11 11 6 1 11 6 1 In-Building Design Considerations
WLAN Product Categories In-Building WLANs Building-to-Building WLANS
Internet Ethernet Backbone In-Building WLANComponents
Internet Ethernet Backbone In-Building WLANComponents Overlapping “cells” Allow for Roaming
Internet Ethernet Backbone In-Building WLANComponents
Internet Ethernet Backbone In-Building WLANComponents
Source operating current from the Ethernet port, over the Cat 5 cable. Line power configuration is compliant with all of Cisco’s line power enabled devices such as switches and line power patch panels. Distances up to 100 meters AP Call Manager Server Switch Powered CAT5 VoIP Phone Inline Power
AP’s configured for load sharing use different RF channels in coverage area Policy can be based on number of users, bit error rate, or signal strength Load Balancing Channel 6 Channel 1
AP’s co-located for hot standby use SAME RF channel in coverage area Standby AP acts as probe for monitoring and management Hot Standby Channel X Active Standby Channel X
Encryption or WEP (*#&$(*#&$*( #(*&$*(#$ #)($__%# #$#% 40-Bit 128-Bit Security Considerations
Centralized User-Based Authentication RADIUS Semi-Public Network / Enterprise Edge EAP Over RADIUS EnterpriseIntranet AuthenticationServer EAP Over Wireless/LAN (EAPOW/EAPOL) Authenticator (e.g. Access Point, Catalyst Switch(?)) Supplicant Extended Enterprise (Branch Office, Home, etc.)
Signal Quality Signal Strength Manageability Site Survey • Diagnostic Utilities • Simple and Graphical • Minimizes Helpdesk Calls
Wireless Bridges • Decreases Implementation Costs • A Fraction the Cost of Trenching • High Speed Connections • Greater Bandwidth than T1 Lines • Eliminates Recurring Charges • No Monthly Leased Line Fees • Reduces Installation Delays • No Right of Way or Permits Required, Installation in an Afternoon • Makes Physical Barriers Irrelevant • Bypass Lakes, Rivers, Freeways, Railroads
Mast Mount High Gain Yagi Mast Solid Dish Patch Wall Mast Mount Type Directional Omni Omni Directional Directional Gain 8 dBi 5.2 dBi 12 dBi 13.5 dBi 21 dBi 60 H 55 V 360 H 75 V 360 H 7 V 30 H 25 V 12.4 H 12.4 V Beam Width Approximate Range at 2 Mbps 2.0 Miles 5000’ 4.6 Miles 6.5 Miles 25 Miles Approximate Range at 11 Mbps 3390’ 1580’ 1.4 Miles 2 Miles 11.5 Miles Cable Length 3’ 3’ 1’ 1.5’ 2’ Wireless AntennasBridges
Point-to-Point Configuration Building A Building B Optional Antenna Optional Antenna 0 to 25 miles (line of sight) Bridge Ethernet
Bridge-Bridge, Bridge-Client Bridge PCI Card MC Hub Bridge
Radio line of sight Earth bulge Fresnel Zone Antenna and cabling Data rate Outdoor Path Considerations
Channel #1 Channel #6 Channel #11 Bridge Application: Wireless Campus link
A very high-performance WLAN system Efficient MAC and high-quality radio 802.11 products perform better thanproprietary systems Client interoperability WEP standard privacy and authentication Standards-based migration path for system growth The IEEE 802.11 (July 1997) for 1 and 2Mb DSSS The IEEE802.11b (Sept 1999) for 11Mb DSSS IEEE 802.11 A Move Toward Standardization!
WECA certifies Interoperability between products. This provides assurance to customers of migration and integration options. Certified products can be found at http://www.wirelessethernet.org/ WI-FI Certification
Broadband solution for the mobile business professional that combines all of the following: Internet Mobile Office • Wired andwireless connectivity • Broadband speeds when on the move • Access to critical business applications • Secure, end-to-end VPN access • Nationwide and international coverage • Consolidated billing across service providers • Access to localized content
Bringing Mobile Offices to Mobile Professionals Enterprise Customers
Internet Wireless Mobile Business Professionals Public Spaces Enterprise Network Settlement System Server VPNConcentrator T1/T3 Firewall T1/T3 T1/T3 T1/T3 Airport / Public Spaces Hotels Router Service Subscriber Gateway Service Subscriber Gateway Switch Switch Wireless 802.11b Access Point Wireless 802.11b Access Point Wireless 802.11b Clients w/ VPN Client