Cisco aironet 1522 Guide

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Cisco Aironet 1520, 1130, 1240 Series Wireless
Mesh Access Points, Design and Deployment
Guide, Release 6.0
Last revised: August 11, 2009
This document provides design and deployment guidelines for the deployment of secure enterprise,
campus, and metropolitan Wi-Fi networks within the Cisco wireless mesh networking solution, a
component of the Cisco Unified Wireless Network (CUWN).
Mesh networking employs Cisco 1520 Series outdoor mesh access points and Cisco 1130 and 1240
Series indoor mesh access points along with the Cisco wireless LAN controller, and Cisco Wireless
Control System (WCS) to provide scalable, central management, and mobility between indoor and
outdoor deployments. Control and Provisioning of Wireless Access Points (CAPWAP) protocol manages
the connection of mesh access points to the network.
End-to-end security within the mesh network is supported by employing Advanced Encryption Standard
(AES) encryption between the wireless mesh access points and Wi-Fi Protected Access 2 (WPA2)
clients. This document also outlines radio frequency (RF) components to consider when designing an
outdoor network.
The features for the following products are described:
•Cisco Aironet 1520 (1522, 1524) Series outdoor mesh access points.
•Cisco Aironet 1130 and 1240 Series indoor mesh access points.
•Mesh features in Cisco wireless LAN controller releases 4.1.190.5, 4.1.191.24M, 4.1.192.xxM,
4.2.176.51M, and 5.2.x. (Mesh features are not supported in controller releases 5.0.x and 5.1.x).
•Mesh features in Cisco WCS releases 4.1.90, 4.2, 5.0, 5.1, 5.2, and 6.0.

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Contents
Contents 2
Mesh Network Components 5
Mesh Access Points 5
Licensing for Indoor Mesh Access Points on a 5500 Series Controller 5
Access Point Roles 5
Network Access 6
Network Segmentation 7
Cisco 1130 and 1240 Indoor Mesh Access Points 7
Cisco 1520 Series Outdoor Mesh Access Points 7
Cisco Wireless LAN Controllers 26
Cisco WCS 26
Mesh Deployment Modes 27
Wireless Mesh Network 27
Wireless Backhaul 28
Architecture Overview 29
CAPWAP 29
CAPWAP Discovery on a Mesh Network 29
Dynamic MTU Detection 30
XML Configuration File 30
AWPP 31
Traffic Flow 31
Mesh Neighbors, Parents, and Children 33
Design Considerations 35
Wireless Mesh Constraints 35
Controller Planning 37
Site Preparation and Planning 38
Site Survey 38
Pre-Survey Checklist 39
Outdoor Site Survey 39
Determining Line of Sight 39
Weather 40
Fresnel Zone 40
Fresnel Zone Size in Wireless Mesh Deployments 41
Hidden Nodes Interference 42
Co-Channel Interference 43
Wireless Mesh Network Coverage Considerations 43
Cell Planning and Distance 43

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Wireless Propagation Characteristics 50
Wireless Mesh Mobility Groups 51
Increasing Mesh Availability 51
Indoor WLAN Network to Outdoor Mesh 53
Connecting the Cisco 1520 Series Mesh Access Point to Your Network 53
Upgrading to Release 6.0 54
Mesh and Mainstream Releases on the Controller 54
Software Upgrade Procedure 55
Adding Mesh Access Points to the Mesh Network 57
Adding MAC Addresses of Mesh Access Points to MAC Filter 58
Defining Mesh Access Point Role 60
Verifying Layer 3 Configuration 61
Configuring Multiple Controllers Using DHCP 43 and DHCP 60 62
Configuring External Authentication and Authorization Using a RADIUS Server 68
Configuring Global Mesh Parameters 71
Configuring Local Mesh Parameters 77
Configuring Advanced Features 97
Configuring Ethernet VLAN Tagging 98
Client Roaming 106
Configuring Voice Parameters in Indoor Mesh Networks 107
Voice Call Support in a Mesh Network 113
Enabling Mesh Multicast Containment for Video 118
IGMP Snooping 119
Checking the Health of the Network 120
Show Mesh Commands 120
Viewing Mesh Statistics for a Mesh Access Point 125
Using the GUI to View Mesh Statistics for a Mesh Access Point 125
Using the CLI to View Mesh Statistics for an Mesh Access Point 129
Viewing Neighbor Statistics for an Mesh Access Point 130
Using the GUI to View Neighbor Statistics for a Mesh Access Point 130
Using the CLI to View Neighbor Statistics for a Mesh Access Point 133
Troubleshooting 134
Installation and Connections 134
Debug Commands 135
Remote Debug Commands 136
AP Console Access 136
Mesh Access Point CLI Commands 137
Mesh Access Point Debug Commands 138
Mesh Access Point Roles 138

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Backhaul Algorithm 139
Passive Beaconing (Anti-Stranding) 139
DFS 141
Misconfiguration of BGN 145
Misconfiguration of the Mesh Access Point IP Address 146
Misconfiguration of DHCP 147
Identifying the Node Exclusion Algorithm 147
Throughput Analysis 149
Adding and Managing Mesh Access Points with Cisco WCS 151
Adding Campus Maps, Outdoor Areas, and Buildings with Cisco WCS 151
Adding Campus Maps 151
Adding Outdoor Areas 152
Adding a Building to a Campus Map 153
Adding Mesh Access Points to Maps with Cisco WCS 154
Monitoring Mesh Access Points Using Google Earth 155
Launching Google Earth in Cisco WCS 155
Viewing Google Earth Maps 156
Adding Indoor Mesh Access Points to Cisco WCS 159
Managing Mesh Access Points with Cisco WCS 160
Monitoring Mesh Networks Using Maps 160
Monitoring Mesh Health 167
Mesh Statistics for a Mesh Access Point 171
Viewing the Mesh Network Hierarchy 176
Using Mesh Filters to Modify Map Display of Maps and Mesh Links 177
Monitoring WGB 179
Viewing AP Last Reboot Reason 181

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Mesh Network Components
The Cisco wireless mesh network has four core components:
•Cisco Aironet 1520, 1240, and 1130 Series mesh access points
Note Cisco Aironet 1505 and 1510 mesh access points are not supported in this release.
•Cisco wireless LAN controller (hereafter referred to as controller)
•Cisco WCS
•Mesh software architecture
Mesh Access Points
Licensing for Indoor Mesh Access Points on a 5500 Series Controller
In order to use indoor mesh access points (1130, 1240) with a 5500 series controller, a wplus license
must be used on the controller. If an indoor mesh access point attempts to join a controller that is using
only a base license (and not the wplus license), the following message appears in the controller trap log:
“License Not Available for feature: IndoorMeshAP.” To view the controller trap log, choose Monitor
and click View All under “Most Recent Traps” on the controller GUI.
Refer to Chapter 4 of the Cisco Wireless LAN Controller Configuration Guide, Release 6.0 for
information on obtaining and installing licenses:
http://www.cisco.com/en/US/docs/wireless/controller/6.0/configuration/guide/Controller60CG.html
Note Outdoor mesh access points (1522, 1524PS, and 1524SB) do not require a wplus license.
Note Other controller platforms (such as the 2100 and 4400 series controllers) also require a license for use
with indoor mesh access points. Refer to the Cisco Enterprise Wireless Mesh Licensing and Ordering
Guide:
http://www.cisco.com/en/US/products/ps6087/products_data_sheets_list.html
Access Point Roles
Access points within a mesh network operate as either a root access point (RAP) or a mesh access point
(MAP).
Note All mesh access points are shipped configured as a MAP. You must reconfigure the mesh access point
for it to be a RAP. At least one RAP must exist in all mesh networks.
RAPs have wired connections to their controller, and MAPs have wireless connections to their controller.

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MAPs communicate among themselves and back to the RAP using wireless connections over the
802.11a radio backhaul. MAPs use the Cisco Adaptive Wireless Path Protocol (AWPP) to determine the
best path through the other mesh access points to the controller.
All the possible paths between the MAPs and RAPs form the wireless mesh network. Figure 1 shows the
relationship between RAPs and MAPs in a mesh network.
Figure 1 Simple Mesh Network Hierarchy
Network Access
Wireless mesh networks can simultaneously carry two different traffic types: wireless LAN client traffic
and MAP Ethernet port traffic.
Wireless LAN client traffic terminates on the controller, and the Ethernet traffic terminates on the
Ethernet ports of the mesh access points.
Access to the wireless LAN mesh for mesh access points is managed by:
•MAC authentication—Mesh access points are added to a referenceable database to ensure they are
allowed access to a given controller and mesh network. Refer to “Adding Mesh Access Points to the
Mesh Network” section on page 57.
148441
WCS
Network
RAP
MAP 1 MAP 2 MAP 3
MAP 4 MAP 6
MAP 5
MAP 7 MAP 8 MAP 9

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•External RADIUS Authentication—Mesh access points can be externally authorized using a
RADIUS server such as Cisco ACS (4.1 and later) that supports the client authentication type of
Extensible Authentication Protocol-FAST (EAP-FAST) with certificates. Refer to the “Using the
GUI to Enable External Authentication of Mesh Access Points” section on page 69.
Network Segmentation
Membership to the wireless LAN mesh network for mesh access points is controlled by bridge group
names (BGNs). Mesh access points can be placed in like bridge groups to manage membership or
provide network segmentation. Refer to “Using the GUI to Configure Antenna Gain” section on page 93.
Cisco 1130 and 1240 Indoor Mesh Access Points
Cisco 1130 and 1240 are indoor access points which are by default configured as local (non-mesh).
Specific configuration on the controller is required to convert these indoor access points to mesh access
points, and to assign a specific mesh role of RAP or MAP.
The Cisco 1130 and 1240 are equipped with two simultaneously operating radios: a 2.4-GHz radio used
for client access and a 5-GHz radio used for data backhaul.
The 5-GHz radio supports the following bands: 5.15 GHz, 5.25 GHz, and 5.47 GHz.
Note Mesh 1242 access points are exclusive Indoor Mesh access points. These access points do not provide
Outdoor Mesh support.
Cisco 1520 Series Outdoor Mesh Access Points
Cisco Aironet 1520 series outdoor mesh access points consist of the 1522 dual-radio mesh access point
and the 1524 multi-radio mesh access points. There are two models of the 1524: (1) the public safety
model, 1524PS, and (2) the serial backhaul model, 1524SB).
Note AP1524SB, introduced in release 6.0, is supported in the US, Canada, Singapore, and China.
Cisco 1520 Series mesh access points (hereafter referred to in general as AP1520s or specifically as
AP1522, AP1524PS (public safety), or AP1524SB (serial backhaul) are the core components of the
wireless mesh deployment. AP1520s are configured by both the controller (GUI, and CLI) and Cisco
WCS. Communication between outdoor mesh access points (MAPs and RAPs) is over the 802.11a radio
backhaul. Client traffic is generally transmitted over the 802.11b/g radio (but can be configured to accept
client traffic), and public safety traffic (AP1524PS only) is transmitted over the 4.9-GHz radio.
The mesh access point can also operate as a relay node for other access points not directly connected to
a wired network. Intelligent wireless routing is provided by AWPP. This Cisco protocol enables each
mesh access point to identify its neighbors and intelligently choose the optimal path to the wired network
by calculating the cost of each path in terms of signal strength and the number of hops required to get to
a controller.
AP1520s are manufactured in two different configurations: cable and non-cable.
•The cable configuration has three antenna connectors on the top of the unit, can be mounted to a
cable strand, and supports power-over-cable (POC).
•The non-cable configuration supports two antennas each on the top and bottom of the unit. It can be
mounted to a pole or building wall and supports several power options.

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AP1520s are available in a hazardous location hardware enclosure. When configured, the AP1520
complies with safety standards for Class I, Division 2, Zone 2 hazardous locations. Refer to the
“Hardware Enclosure for Hazardous Conditions (AIR–LAP1522HZ–X–K9)” section on page 25 for
more details.
Note Refer to the Cisco Aironet 1520 Series Lightweight Outdoor Access Point Ordering Guide for power,
mounting, antenna, and regulatory support by model:
http://www.cisco.com/en/US/prod/collateral/wireless/ps5679/ps8368/product_data_sheet0900aecd8066a157.html
Cisco 1522 Mesh Access Point (Part Nos. AIR–LAP1522AG–X–K9, AIR–LAP1522HZ–X–K9, AIR–LAP1522PC–X–K9)
The AP1522 mesh access point, includes two radios: a 2.4-GHz, and a 4.9 to 5.8-GHz radio. The
2.4-GHz (802.11b/g) radio is for client access and the 5-GHz (802.11a) radio is used as the backhaul.
•Uplinks support includes: Gigabit Ethernet (1000BaseT), and a small form-factor pluggable (SFP)
slot for fiber (100BaseBX) or cable modem interface.
•The 5-GHz radio is a 802.11a radio which covers the 4.9 to 5.8 GHz frequency band, and is used as
a backhaul. It can also be used for client access if the universal client access feature is enabled.
– For information on the universal access feature, refer to the “Viewing Global Mesh Parameter
Settings” section on page 123.
Note AP1522s with serial numbers prior to FTX1150XXXX do not support 5 and 10 MHz channels
on the 4.9-GHz radio; however, a 20-MHz channel is supported.
Note Those AP1522s with serial numbers after FTX1150XXXX support 5, 10 and 20 MHz channels.
Cisco 1524PS Mesh Access Point (Part No. AIR–LAP1524PS–X–K9)
The AP1524PS includes three radios: a 2.4-GHz, a 5.8-GHz, and a 4.9-GHz radio. The 2.4-GHz radio
is for client access (non-public safety traffic) and the 4.9-GHz radio is for public safety client access
traffic only. The 5.8-GHz radio can be used as the backhaul for both public safety and non-public safety
traffic.
The 4.9-GHz and 5.8-GHz radios are 802.11a sub-band radios which support a subset of specific 802.11a
channels and include a sub-band specific filter designed to lessen interference from other 11a sub-band
radios within the same mesh access point.
The 4.9-GHz sub-band radio on the AP1524 supports public safety channels within the 5-MHz (channels
1 to 10), 10-MHz (channels 11-19), and 20-MHz (channels 20-26) bandwidths.
•The following data rates are supported within the 5 MHz bandwidth: 1.5, 2.25, 3, 4.5, 6, 9, 12,
and13.5 Mb/s. Default rate is 6 Mb/s.
•The following data rates are supported within the 10 MHz bandwidth: 3, 4.5, 6, 9, 12, 18, 24, and
27 Mb/s. Default rate is 12 Mb/s.

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Cisco 1524SB Mesh Access Point (Part No. AIR–LAP1524SB–X–K9)
The AP1524SB is introduced in release 6.0 and can operate as a RAP or a MAP.
The AP1524SB includes three radios: one 2.4-GHz radio, and two 5.8-GHz radios.
The 2.4-GHz radio is for client access (non-public safety traffic). The two 5.8-GHz radios serves as
serial backhauls: one uplink and one downlink. The AP1524SB is suitable for linear deployments.
One of the 5.8-GHz radios can be used for universal access (client and backhaul traffic using an omni
antenna), and the other 5.8-GHz radio can be used for backhaul traffic only (directional antenna
required).
Each 5.8-GHz radio backhaul is configured with a different backhaul channel, so there is no need to use
the same shared wireless medium between the north-bound and south-bound traffic in a mesh tree-based
network.
On the RAP, the radio in slot 2 is used to extend the backhaul in the downlink direction; the radio in
slot 1 is used for client access.
On the MAP, the radio in slot 2 is used for the backhaul in the uplink direction; the radio in slot 1 is used
for the backhaul in the downlink direction as well as client access.
You only need to configure the RAP downlink (slot 2) channel. The MAPs automatically select their
channels from the channel subset. The available channels for the 5.8 GHz band are 149, 153, 157, 161,
and 165.
Figure 2 shows a channel selection example when the RAP downlink channel is 153.
Figure 2 Channel Selection Example
The antenna ports are labeled on the AP1524SB and are connected internally to the radios in each slot.
The AP1524SB has six ports with three radio slots (0, 1, 2) as described in Table 1.
RAP MAP1 MAP2 MAP3 MAP4
Slot 1
Slot 2
Channel 153 Channel 161 Channel 149 Channel 157
251625
Table 1 AP1524SB Antenna Ports
Antenna Port Radio Slot Description
1 1 5 GHz–Used for backhaul and universal access.
Universal access is configured only on slot 1.
Note Omni antenna required.
2 0 2 GHz–Used for client access.
3 0 2 GHz–Used for client access.
4 0 2 GHz–Used for client access.
5 --- Not connected.
6 2 5 GHz–Used for backhaul.
Note Directional antenna required.

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Note Depending on product model, the AP1524SB could have either 5.0-GHz radios or 5.8-GHz sub-band
radios installed in slot 1 and slot 2. Regardless of the radios installed, the AP1524SB running controller
software release 6.0 is restricted to the UNII-3 channels (149, 153, 157, 161, and 165) in slot 1 and slot 2.
Hardware
Figure 3 shows the AP1520 (all models) and its bottom connectors (radio side view).
Figure 4 shows the AP1520 (all models) and its top connectors (radio cover view).
Figure 3 Cisco 1520 Series Mesh Access Point (radio side view)
1Antenna port 4 7AC input connector
2Antenna port 5 8Fiber port
3Antenna port 6 9PoE out port
1
2
3
203822
4
5
8
9
11
76
10

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Figure 4 Cisco 1520 Series Mesh Access Point (radio cover view)
Note For details on antennas and their selection, refer to the “Antennas” section on page 19.
Note For details on power, refer to the “Multiple Power Options” section on page 12.
Ethernet Ports
Ethernet connections (10/100) support bridging between mesh access points. AP1520s supports four
Gigabit Ethernet interfaces.
4Fiber port (optional) 10 LEDs
5Cable POC port (optional) 11 PoE in port
6Aux/Console port
1Antenna port 3 4Ground screw holes
2Antenna port 2 5DC power connector
3Antenna port 1
1 2 3 4 5
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•Port 0 (g0) is a Power over Ethernet (PoE) input port–PoE (in)
•Port 1 (g1) is a PoE output port–PoE (out)
•Port 2 (g2) is a cable connection
•Port 3 (g3) is a fiber connection
You can query the status of these four interfaces in the controller CLI and Cisco WCS.
In the controller CLI, the show mesh env summary command is used to display the status of the ports.
•The Up or Down (Dn) status of the four ports is reported in the following format:
– port0(PoE-in):port1(PoE-out):port2(cable):port3(fiber)
•For example, rap1522.a380 in the display below shows a port status of UpDnDnDn. This indicates
that:
– PoE-in port 0 (g0) is Up, PoE-out port 1 (g1) is Down (Dn), Cable port 2 (g2) is Down (Dn) and
Fiber port 3 (g3) is Down (Dn).
(controller)> show mesh env summary
AP Name Temperature(C/F) Heater Ethernet Battery
-------- --------------- -------- ------- -------
rap1242.c9ef N/A N/A UP N/A
rap1522.a380 29/84 OFF UpDnDnDn N/A
rap1522.4da8 31/87 OFF UpDnDnDn N/A
Multiple Power Options
Power options include:
•90 to 480 VAC streetlight power
•12 V DC
•Cable power
•PoE using a separate power injection system
– For details on the power injection, its specifications, and installation refer to
http://www.cisco.com/en/US/docs/wireless/access_point/1520/power/guide/1520pwrinj.html
•Internal battery backup power
•802.3af-compliant PoE out to connect IP devices (such as a video cameras)
Battery Backup Module (Optional)
An optional battery backup module (part no. AIR-1520-BATT-6AH) is available for AP1520s.
The integrated battery can be used for temporary backup power during external power interruptions. The
battery run time for AP1520s is as follows:
•3-hour access point operation using two radios at 77oF (25oC) with PoE output port off
•2-hour access point operation using two radios at 77oF (25oC) with PoE output port on
The battery pack is not supported on the access point cable configuration.
Note For a complete listing of optional hardware components for AP1520s such as mounting brackets, power
injectors and power tap adapters refer to:
http://www.cisco.com/en/US/prod/collateral/wireless/ps5679/ps8368/product_data_sheet0900aecd8066a157.html

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Reset Button
The access point has a reset button located on the bottom of the unit (see Figure 5). The reset button is
recessed in a small hole that is sealed with a screw and a rubber gasket. The reset button is used to perform
these functions:
•Reset the access point—press the reset button for less than 10 seconds. LEDs turn off during the
reset and then reactivate when the reset is complete.
•Disable battery backup power—Press the reset button for more than 10 seconds. LEDs turn off, then on,
and then stay off.
– You can also disable the battery remotely by entering this command:
config mesh battery-state disable AP_name
•Switch off LEDS—Press the reset button for more than 10 seconds. LEDs turn off, then on, and then
stay off.
Figure 5 Reset Button Location
1Reset button location

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To reset the access point, follow these steps:
Step 1 Use a Phillips screwdriver to remove the reset button screw. Be careful not to loose the screw.
Step 2 Use a straighten paperclip, and push the reset button for less than 10 seconds. This causes the access point to
reboot (power cycle), all LEDs turn off for approximately 5 seconds and then the LEDs reactivate.
Step 3 Replace the reset button screw, and use a Phillips screwdriver to tighten to 22 to 24 in. lbs (2.49 to 2.71
Nm).
Monitoring LED Status
The four status LEDs on AP1520s are useful during the installation process to verify connectivity, radio
status, access point status, and software status. However, once the access point is up and running and no
further diagnosis is required, Cisco recommends turning off the LEDs to discourage vandalism.
If your access point is not working properly, look at the LEDs on the bottom of the unit. You can use them to
quickly assess the unit’s status.
Note LEDs are enabled or disabled using the following command: config ap led-state {enable | disable}
{cisco_ap_name | all}.
There are four LED status indicators on AP1520s. Figure 6 shows the location of the AP1520 LEDs.
Figure 6 Access Point LEDs on the Bottom of the Unit
The table below describes each LED and its status.

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Note The RF-1 and RF-2 LEDs monitor two radios simultaneously but do not identify the affected radio. For
example, if the RF-1 LED displays a steady red LED, one or both of the radios in slots 0 and 2 have
experienced a firmware failure. To identify the failing radio, you must use other means, such as the
access point CLI or controller GUI to investigate and isolate the failure.
Table 2 lists the access point LED signals.
1Status LED—access point and software status 3RF-1 LED—Status of the radio in slot 0
(2.4-GHz) and slot 2 (5.8-GHz for 1524SB
and 4.9-GHz for 1524PS)).
2Uplink LED—Ethernet, cable, or fiber status 4RF-2 LED—Status of the radio in slot 1
(5.8-GHz) and the radio in slot 3.1
1. Slot 3 is disabled in this release.
Table 2 Access Point LED Signals
LED Color1,2Meaning
Status Off Access is point is not powered on.
Green Access point is operational.
Blinking green Download or upgrade of Cisco IOS image file is in
progress.
Amber Mesh neighbor access point discovery is in progress.
Blinking amber Mesh authentication is in progress.
Blinking red/green/amber CAPWAP discovery is in progress.
Red Firmware failure. Contact your support organization
for assistance.
Uplink Off No physical connector is present. The uplink port is
not operational.
Green Uplink network is operational (cable, fiber optic, or
Ethernet).
RF-1
Slot 0
2.4-GHz radio
Off Radio is turned off.
Green Radio is operational.
Red Firmware failure. Contact your support organization
for assistance.
RF-1
Slot 2
4.9-GHz radio
Off Radio is turned off.
Green Radio is operational.
Red Firmware failure. Contact your support organization
for assistance.
RF-2
Slot 1
802.11 a radio
Off Radio is turned off.
Green Radio is operational.
Red Firmware failure. Contact your support organization
for assistance.

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Regulatory Domains
For information on the channels and maximum power levels of the AP1520 supported within the world's
regulatory domains refer to the Channels and Maximum Power Settings for Cisco Aironet Lightweight
Access Points manual at:
http://www.cisco.com/en/US/docs/wireless/access_point/channels/lwapp/reference/guide/1520_chp.html
Frequency Bands
The 2.4 GHz and 5 GHz frequency bands are supported on the AP1130, AP1240 and AP1520 radios.
Additionally, the 4.9 GHz public safety band is supported on the AP1524. (See Figure 7.)
Figure 7 Frequency Bands Supported By 802.11a Radios on AP1520s
The 5 GHz band is a conglomerate of three bands in the USA: 5.150 to 5.250 (UNII-1), 5.250 to 5.350
(UNII-2), 5.470 to 5.725 (UNII-2 Extended), and 5.725 to 5.850 (ISM). UNII-1 and the UNII-2 bands
are contiguous and are indeed treated by 802.11a as being a continuous swath of spectrum 200MHz
wide, more than twice the size of the 2.4GHz band.
The 4.9 GHz is a public safety channel within the 5-MHz (channels 1 to 10), 10-MHz (channels 11-19),
and 20-MHz (channels 20-26) bandwidths.
RF-2
Slot 3
Disabled in this release.
1. If all LEDs are off, the access point has no power.
2. When the access point power supply is initially turned on, all LEDs are amber.
Table 2 Access Point LED Signals (continued)
LED Color1,2Meaning

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Note Frequency depends on the regulatory domain in which the access point is installed. For additional
information, refer to the Channels and Power Levels document at:
http://www.cisco.com/en/US/docs/wireless/access_point/channels/lwapp/reference/guide/lw_chp2.html
Dynamic Frequency Selection
Previously, devices employing radar operated in frequency sub-bands without other competing services.
However, controlling regulatory bodies are attempting to open and share these bands with new services
like wireless mesh LANs (IEEE 802.11).
To protect existing radar services, the regulatory bodies require that devices wishing to share the newly
opened frequency sub-band behave in accordance with a protocol named Dynamic Frequency Selection
(DFS). DFS dictates that to be compliant, a radio devices must be capable of detecting the presence of
radar signals. When a radio detects a radar signal, it is required to stop transmitting to for at least 30
minutes to protect that service.The radio then selects a different channel to transmit on but only after
monitoring it. If no radar is detected on the projected channel for at least one minute then the new radio
service device may begin transmissions on that channel.
The process for a radio to detect and identify a radar signal is a complicated task that sometimes leads
to incorrect detects. Incorrect radar detections can occur due to a large number of factors, including due
to uncertainties of the RF environment and the ability of the access point to reliably detect actual
on-channel radar.
The 802.11h standard addresses DFS and Transmit Power Control (TPC) as it relates to the 5 GHz band.
DFS is to avoid interference with radar and TPC is used to avoid interference with satellite feeder links.
Note DFS is mandatory in the US for frequency bands 5250 to 5350, and 5470 to 5725. DFS and TPC are
mandatory for these same bands in Europe. (See Figure 8.)
Table 4 provides a summary of those regulatory domains that require DFS support.
Table 3 Frequency Band
Frequency Band Terms Description Model Support
UNII-11
1. UNII refers to the Unlicensed National Information Infrastructure.
Regulations for UNII devices operating in
the 5.15 to 5.25 GHz frequency band.
Indoor operation only,
1130, 1240
UNII-2 Regulations for UNII devices operating in
the 5.25 to 5.35 GHz frequency band.
DFS and TPC are mandatory in this band.
1130, 1240, 1522
UNII-2 Extended Regulations for UNII-2 devices operating
in the 5.470 to 5.725 frequency band.
1130, 1240, 1522
ISM2
2. ISM refers to Industrial Science and Mechanical.
Regulations for UNII devices operating in
the 5.725 to 5.850 GHz frequency band.
1130, 1240, 1522, 1524

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Figure 8 DFS and TPC Band Requirements
Table 4 Channels Requiring DFS by Regulatory Domain
Regulatory Domain/
Channel (Frequency Band) -A -E -C -P -S -K -T
52 (5260 MHz)
56 (5280 MHz) Y Y
60 (5300 MHz) Y Y
64 (5320 MHz) Y Y
100 (5500 MHz) Y Y Y Y
104 (5520 MHz) Y Y Y Y
108 (5540 MHz) Y Y Y Y
112 (5560 MHz) Y Y Y Y
116 (5580 MHz) Y Y Y Y
120 (5600 MHz) Y Y Y
124 (5620 MHz) Y Y Y
128 (5640 MHz) Y Y
132 (5660 MHz) Y Y Y
136 (5680 MHz) Y Y Y
140 (5700 MHz) Y Y Y

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Antennas
Overview
Antenna choice is a vital component of any wireless network deployment. Essentially, two broad types
of antenna exist: directional and omni-directional. Each type of antenna has a specific use and is most
beneficial in specific types of deployments. Because antennas distribute RF signal in large lobed
coverage areas determined by antenna design, successful coverage is heavily reliant on antenna choice.
An antenna gives a mesh access point three fundamental properties—gain, directivity, and polarization.
•Gain—A measure of the increase in power. Gain is the amount of increase in energy that an antenna
adds to an RF signal.
•Directivity—The shape of the transmission pattern. If the gain of the antenna goes up, the coverage
area decreases. The coverage area or radiation pattern is measured in degrees. These angles are
measured in degrees and are called beamwidths.
Note Beamwidth is defined as a measure of the ability of an antenna to focus radio signal energy
towards a particular direction in space. Beamwidth is usually expressed in degrees HB being
Horizontal Beamwidth usually the most important one with VB being the Vertical
Beamwidth (up and down) radiation pattern. When viewing an antenna plot or pattern, the
angle is usually measured at half-power (3 dB) points of the main lobe when referenced to
the peak effective radiated power of the main lobe.
Note An 8 dBi antenna transmits with a horizontal beamwidth of 360 degrees, causing the radio
waves to disperse power in all directions. Therefore, radio waves from an 8 dBi antenna do
not go nearly as far as those sent from a 17 dBi patch antenna (or a third-party dish) that has
a more narrow beamwidth (less than 360 degrees).
•Polarization—The orientation of the electric field of the electromagnetic wave through space.
Antennas can either be horizontally or vertically polarized, though other kinds of polarization are
available. Both antennas in a link must have the same polarization to avoid additional unwanted
signal loss. To improve performance, an antenna can sometimes be rotated to alter polarization and
thus reduce interference. A general rule of thumb is that vertical polarization is preferable for
sending RF waves down concrete canyons, and horizontal polarization is generally more preferable
for wide area distribution. Polarization can also be harnessed to optimize for RF bleed-over when
reducing RF energy to adjacent structures is important. Most omni-directional antennas ship with
vertical polarization as their default.
Antenna Options
A wide variety of antennas are available to provide flexibility when deploying the mesh access points
over various terrains. 5 GHz is used as a backhaul and 2.4 GHz is used for client access.
Table 5 lists the supported external 2.4- and 5-GHz antennas for AP1520s.
Table 5 External 2.4- and 5-GHz Antennas
Part Number Model Gain (dBi)
AIR-ANT2450V-N 2.4-GHz compact omnidirectional15
AIR-ANT2480V-N 2.4-GHz omnidirectional 8.0

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Refer to the Cisco Aironet Antenna and Accessories Reference Guide on Cisco antennas and accessories:
http://www.cisco.com/en/US/prod/collateral/wireless/ps7183/ps469/product_data_sheet09186a008008883b.html
Details on deployment and design, limitations and capabilities, and basic theories of antennas as well as
installation scenarios, regulatory information, and technical specifications are addressed.
Table 6 summarizes the horizontal and vertical beamwidth for Cisco antennas.
N-Connectors
All antennas are equipped with N connectors.
AP1522 has three separate N-connectors to attach two 2.4-GHz antennas, and one N-connector for a 5-
GHz antenna.
AP1524 has five N-connectors to attach three 2.4-GHz antennas and one N-connector for the 5.8-GHz
antenna, and one N-connector for the 4.9-GHz antenna.
Each radio has at least one TX/RX port. Each radio must have an antenna connected to at least one of its
available TX/RX ports.
Antenna locations for 5.8 GHz, 4.9 GHz, and 2.4 GHz are fixed and labeled.
Figure 9 shows antenna placement for a two-radio cable mesh access point.
Figure 10 shows antenna placement for a two-radio fiber mesh access point.
Figure 11 shows antenna placement for a three-radio fiber mesh access point.
AIR-ANT5180V-N 5-GHz compact omnidirectional28.0
4.9-GHz compact omnidirectional37.0
AIR-ANT58G10SSA-N 5-GHz sector 9.5
AIR-ANT5114P-N 4.9- to 5-GHz patch214.0
AIR-ANT5117S-N 4.9- to 5-GHz 90-degree sector217.0
1. The compact omnidirectional antennas mount directly on the access point.
2. The compact omnidirectional antennas mount directly on the access point.
3. Use of the 4.9-GHz band requires a license and may be used only by qualified Public Safety operators as defined in
section 90.20 of the FCC rules.
Table 5 External 2.4- and 5-GHz Antennas (continued)
Part Number Model Gain (dBi)
Table 6 Horizontal and Vertical Beamwidth for Cisco Antennas
Antenna
Horizontal Beamwidth
(degrees)
Vertical Beamwidth
(degrees)
AIR-ANT5180V-N 360 16
AIR-ANT58G10SSA-N 60 60
AIR-ANT5114P-N 25 29
AIR-ANT5117S-N 90 8