© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-1 © 2002, Cisco Systems, Inc. All rights reserved.

2 Antenna Concepts 6-2

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-3 Objectives Upon completion of this module, you will be able to perform the following tasks: Define how an antenna is used to propagate an RF signal. Define basic facts of EIRP. Define facts on FCC regulations for UNII-1 and UNII-2. Identify what an isotropic antenna is and why it is used as a reference for other antennas. Identify Cisco Aironet antennas, their coverage patterns, and the proper polarization of each antenna.

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-4 Definition of Terms dB- Decibel- Ratio of one value to another dBx where x = m = compared to 1 milliwatt (0 dBm=1 mW) i = compare to isotropic antenna d = compared to dipole antenna w = compared to 1 watt (0 dBw = 1 watt)

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-5 Cisco Aironet b Antennas FCC requires that ALL antennas sold by a spread spectrum vendor be certified with the radio they are to be sold with All Cisco Aironet b supplied cables, RF devices and antennas have reverse polarity TNC (RP-TNC) connectors Cisco Aironet supplied antennas meet all FCC rules Wide variety of b antennas for most applications

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-6 Cisco Aironet a Antennas FCC requires that all radios utilizing the UNII-1 Band (5.15 GHz – 5.25 GHz) must have non- removable or integrated antennas FCC allows radios utilizing the UNII-2 Band (5.25 GHz – 5.35 GHz) to have external or removable antennas The Cisco Aironet a radios utilize both UNII- 1 and UNII-2 bands, therefore cannot have external or removable antennas Cisco a antennas are integrated into the radio module

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-7 Antenna Concepts Directionality Omni (360º coverage) directional Directional (limited range of coverage) Gain Measured in dBi and dBd (0 dBd = 2.14 dBi) More gain means more coverage - in certain directions Polarization Antennas are used in the vertical polarization

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-8 Antenna Gain If the gain of an antenna goes up, the coverage area or angle goes down Coverage areas or radiation patterns are measured in degrees Angles are referred to as beamwidth Horizontal measurement Vertical measurement

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-9 Antenna Theory A theoretical isotropic antenna has a perfect 360º vertical and horizontal beamwidth This is a reference for ALL antennas

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-10 Antenna Theory- Dipole Energy lobes are pushed in from the top and bottom Higher gain Smaller vertical beamwidth Larger horizontal lobe Typical dipole pattern

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-11 High Gain Omni-Directionals More coverage area in a circular pattern Energy level directly above or below the antenna will become lower

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-12 Directional Antennas Lobes are pushed in a certain direction, causing the energy to be condensed in a particular area Very little energy is in the back side of a directional antenna Side View (Vertical Pattern) Top View (Horizontal Pattern)

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-13 FCC Part 15 Antenna Requirements b antenna Must use a unique, or proprietary connector Cisco Aironet products use RP-TNC connector Part 15 standards The installer is responsible for approved antennas not to exceed standards Exceeding may lead to interference problems Penalties could result in fines FCC standards apply to Part 15 users in the United States Different countries will have similar standards

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz EIRP Rules for FCC Governed Areas Point-to-Multipoint FCC allows increasing the gain of an antenna/cable system if the transmitter power is reduced below 30 dBm in a 1:1 ratio Reduce Transmit Power below maximum of 30 dBm by 1 dBm and increase antenna/cable system gain by 1dBi Point-to-Point Maximum of 36 dBm EIRP Installations – 30 dBm maximum transmitter power with 6 dBi in gain attributed to antenna and cable combination FCC allows exceeding the 36 dBm EIRP in Point-to- Point installations using the 3:1 rule Reduce Transmit Power below maximum of 30 dBm by 1 dBm and increase antenna/cable system gain by 3 dBi

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz EIRP Rules for FCC Governed Areas (cont.) Transmitter Power EIRP Cisco Maximum 6 dBi 36 dBm 100 mW 20 dBm FCC Maximum Maximum Gain Transmitter dBm 1 Watt Point-to-Multipoint 30 dBm 16 dBi 36 dBm Transmitter Power EIRP Cisco Maximum 6 dBi 36 dBm 100 mW 20 dBm FCC Maximum Maximum Gain Transmitter dBm 1 Watt Point-to-Point 30 dBm 36 dBi 56 dBm The above values reflect the 1:1 rule The above values reflect the 3:1 rule

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz EIRP Rules for ETSI Governed Countries Currently ETSI stipulates a maximum of 20 dBm EIRP on Point-to-Multipoint and Point- to-Point installations –17 dBm maximum transmitter power with 3 dBi in gain attributed to antenna and cable combination Professional installers are allowed to increase the gain of an antenna/cable system if the transmitter power is reduced below 17 dBm in a 1:1 ratio Reduce Transmit Power below maximum of 17 dBm by 1 dBm and increase antenna/cable system gain by 1 dBi

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz EIRP Rules for non-FCC Governed Bodies Transmitter Power EIRP Cisco Integrated Antennas 3 dBi 20 dBm Reduced TX Power 30 mW 5 dBi 15 dBm 50 mW 17 dBm 7 dBi 13 dBm 20 dBi 13 dBi 20 dBm Gov. Body Maximum Maximum Gain Transmitter dBm Reduced TX Power 50 mW 20 mW 5 mW 1 mW Point-to-Multipoint and Point-to-Point 17 dBm 7 dBm 0 dBm 2.2 dBi 19.2 dBm 20 dBm The above values reflect the 1:1 rule Governing bodies with 20 dBm ceiling on EIRP: ETSI, France/Singapore, Israel, Mexico

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module a and FCC 5 GHz Specifications FCC regulations for UNII-1 and UNII-2 UNII-1 –FCC max 50 mW –802.11a max 40 mW With max 6 dBi antenna gain –802.11a max of 40 mW complies with all countries except Singapore (20 mW) UNII-2 –FCC max 250 mW –802.11a max 200 mW

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-19 FCC Rules for a - Antennas FCC requires that all radios utilizing the UNII-1 Band (5.15 GHz – 5.25 GHz) must have non- removable or integrated antennas FCC allows radios utilizing the UNII-2 Band (5.25 GHz – 5.35 GHz) to have external or removable antennas FCC requires radios operating in both UNII-1 and UNII-2 bands must comply with antenna rules regulating UNII-1 band (including indoor use only) The Cisco Aironet a radios utilize both UNII-1 and UNII-2 bands, therefore cannot have external or removable antennas and must be used indoors only Cisco a antennas are integrated into the radio module

Cisco Aironet 2.4 GHz Antennas © 2002, Cisco Systems, Inc. All rights reserved. 20

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Omni-Directional Antennas 2 dBi Dipole "Standard Rubber Duck"

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Omni-Directional Antennas 5.2 dBi Ceiling Mount

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Omni-Directional Antennas 5.2 dBi Mast Mount Vertical

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Omni-Directional Antennas 5.2 dBi Pillar Mount Diversity

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Omni-Directional Antennas 12 dBi Omni-Directional (Outdoor only)

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Diversity Omni-Directional Antennas 2 dBi Diversity Omni-Directional Ceiling Mount

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Diversity Antennas 6.5 dBi Diversity Patch Wall Mount – 55 degree

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Directional Antennas (cont.) 6 dBi Patch Antenna – 65 degree

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Directional Antennas (cont.) 8.5 dBi Patch Antenna – 60 degree

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Directional Antennas (cont.) 13.5 dBi Yagi Antenna – 25 degree

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Directional Antennas (cont.) 21 dBi Parabolic Dish Antenna – 12 degree

Cisco Aironet a Antenna © 2002, Cisco Systems, Inc. All rights reserved. 32

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-33 Cisco Aironet Access Point: 5 GHz Upgrade b 5 GHz technology allows for the addition of an 11a network over your 11b network = b+a a

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Integrated Antenna Innovative 5 GHz Combo Antenna: Wall Mount: Fold antenna flat against access point housing for 6 dBi gain patch antenna Ceiling Mount: Fold antenna out at a 90° angle for 5 dBi gain omni antenna In 5 dBi omni position In 6 dBi patch position

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-35 Mounting/Antenna Arrangement 5 GHz 5 dBi Diversity Dipole 2.4 GHz Dipole Antenna 5 GHz 6 dBi Diversity Patch 2.4 GHz Antenna

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module GHz Radiation Pattern

Cisco Aironet 1100 Series Access Point © 2002, Cisco Systems, Inc. All rights reserved. 37

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-38 Mini-PCI Radio 2.2 dBi Omni-Directional Diversity Antennas Option 1: b Cisco Aironet 1100 Series Internal View

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-39 Cisco Aironet 1100 Series Antenna Details Cone of reduced coverage Sphere of influence Cone of reduced coverage

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-40 H-Plane Pattern E-Plane Pattern Top ViewSide View Floor Cisco Aironet 1100 Series Antenna Details (cont.)

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-41 Cisco Aironet 1100 Series Mounting Options Desktop mount: Stand allows cables to exit through rear of stand Stable for any flat horizontal surface Cube mount: Adjustable arm for variable cube wall sizes Wall mount: Padlock secures access point to mounting bracket and locks in all network and power cables

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-42 Cisco Aironet 1100 Series Mounting Options (cont.) Ceiling mount: Designed to attach to ceiling tile track Padlock locks access point to mounting bracket Metal arm locks in network and power cables to the access point

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-43 Summary Upon completion of this module, you will be able to perform the following tasks: Define how an antenna is used to propagate an RF signal. Define basic facts of EIRP. Define facts on FCC regulations for UNII-1 and UNII-2. Identify what an isotropic antenna is and why it is used as a reference for other antennas. Identify Cisco Aironet antennas, their coverage patterns, and the proper polarization of each antenna.

© 2002, Cisco Systems, Inc. All rights reserved. AWLF 3.0Module 6-44 Review Questions A 2.14 dBi antenna rating is the same as a 3.28 dBd antenna rating (True/False)? An antenna with more gain is always a better antenna? Why or why not? Ceiling mount antennas are always the best choice for an indoor installation? Why or why not? A higher gain antenna adds more output power to the access points output (True/False)? How is EIRP calculated? What can be done to correct the poor coverage directly under a high gain omni-directional antenna?