Cisco Aironet 1850 Series Quick reference guide

Cisco Aironet Series 1850 Access Point Deployment Guide
Channel Rail Adapters –Cisco Part Number AIR-CHNL-ADAPTER 5
Physical Hardware and Mounting Options of an AP 7
Wall Mounting the AP 11
Above the Ceiling Tiles 12
Stadium / Harsh Environments 14
Ethernet Cable Recommendation 15
Antenna Cable Recommendation 16
Access Point Spacing Recommendations 17
Installations in IDF Closets (Telecommunications or Other Electrical Equipment) 18
Installations Inside and Around Elevators 19
Understanding AP 1850 Powering Options 20
PoE Negotiation 21
Approved antennas and Radiation Patterns 23
Antennas for Outdoor Deployments 25
General Considerations –WLAN Best Practice Guidelines 35
802.11ac Wave-2 primer and the AP 1850 37
Clients Supporting 3 and 4 Spatial Streams 37
Understanding Channel Plans and Bonded Channels 38
Understanding Channels and How They Relate to the Client 40

802.11ac and Legacy Client Recommendations 42
802.11ac Devices on the Market 45
Variables Impacting Performance 46
A Quick Look at a Few Non-Optimal Installations 49
New features 55
Auxiliary Ethernet Port 55
USB Port 57
Understanding Multi-User MIMO 58
Checking the Access Point LEDs 61
Access Point Status LEDs 61
Ethernet Port LEDs 62
Q & A 63
References 64
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Revised: January 25, 2017,
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ChannelRailAdapters–CiscoPartNumberAIR-CHNL-ADAPTER
When mounting APs to ceiling channel rails, an optional channel adapter AIR-CHNL-ADAPTER is used. The channel adapter comes
in a two-pack and is attached to the ceiling grid clip.
Figure 1: Example of Channel Rails
Figure 2: AIR-CHNL-ADAPTER (left) Slides Onto the Rails
Figure 3: AIR-CHNL-ADAPTER Mounted to Rail Clip (left) and Finished Installation (right)
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Revised: January 25, 2017,
Physical Hardware and Mounting Options of an AP
Figure 4: AP 1850 Model port view
Ports are easily accessible. Mode button is recessed and requires a tool such as a paperclip to engage.
Note the vent holes below the ports, avoid using chemicals or solvents around the AP as the ingress of such materials have the potential
to cause damage to the device.

AP 1850 has similar physical dimensions as other Cisco APs but with a few differences in physical appearance, most of which are
cosmetic changes to distinguish the different models. The mounting options and bracket configurations are identical and interchangeable
between Cisco 1140, 1600, 1700, 1850, 2600, 2700, and 3700 series APs.
Figure 5: Mechanical Dimensions AP 1850
Figure 6: Mechanical Dimensions AP 1850
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Different installation options are available depending upon the requirements of the customer. Brackets are available from Cisco as
well as third-party companies. During the ordering process, the customer may choose one of two brackets (but not both). Each bracket
is a zero-dollar ($0) option at the time of configuration. If the customer does not choose a bracket, the selection default is
AIR-AP-BRACKET-1, which is the most popular for ceiling installations. The other choice is a universal bracket that carries part
number AIR-AP-BRACKET-2.
Figure 7: Access Point Bracket Choices
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If the AP needs to be mounted directly to a ceiling on the grid work, then AIR-AP-BRACKET-1 is flush mounted and has the lowest
profile. However, if the AP is mounted to an electrical box, other wiring fixture, inside a NEMA enclosure, or wall mounted, then
AIR-AP-BRACKET-2 is a better choice. The extra space in the bracket allows for wiring, and the extra holes line up with many
popular electrical boxes. When mounting the bracket to the ceiling grid work, some ceiling tiles are recessed. For this reason, two
different styles of ceiling clips, such as recessed and flush rails are available
Figure 8: Different Clips are Available for Attaching to Ceiling Grid Work
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Revised: January 25, 2017,
Wall Mounting the AP
When the AP needs to be wall-mounted, the installer should understand that walls can be a physical obstacle to the wireless signal.
Therefore, maintaining 360 degree coverage may be compromised by the wall. If the wall is an outside wall and/or the goal is to send
the signal in an 180-degree pattern instead, a directional antenna, often referred to as a “patch”antenna, may be a better choice
assuming that the AP 1850e is used.
Avoid wall-mounting APs with internal antennas, such as the AP 1850i, unless you use the optional Oberon right-angle mount (Figure
9: Wall-Mounting APs Antennas Should be Vertical (Up/Down) or Use the Oberon Right-Angle Mounting Structure - Ideal for the
“I”series such as 1850i, 2700i, 3600i or 3700i Oberon P/N 1029-00), on page 11). The internal antenna model is designed to mount
to a ceiling to provide 360-degree coverage. If wall-mounted in a non-ceiling orientation, the signal may penetrate the floor above
and below causing unintended coverage. This results in additional and needless roaming access when a mobility client, for example
a user with Wi-Fi phone, walks by on an adjacent floor.
Instead, use the AP 1850e (with dipoles or patch antennas) or use an optional wall mount that puts the AP 1850i or AP 1850e into a
ceiling type orientation when mounted to a wall.
APs with internal antennas such as the AP 1850i that are wall mounted should use the Oberon mounting
bracket unless roaming is not an issue, for example, hotspot, kiosk, or small venue scenario.
Note
Figure 9: Wall-Mounting APs Antennas Should be Vertical (Up/Down) or Use the Oberon Right-Angle Mounting Structure - Ideal for the “ I ” series
such as 1850i, 2700i, 3600i or 3700i Oberon P/N 1029-00)
Oberon model 1029-00 is a right angle mount works with “i”and “e”models to put the AP in the right antenna orientation. If the unit
is an “e”model with dipoles that can be mounted (far right), then an Oberon wedge mount is not required.
See http://www.oberonwireless.com/WebDocs/Model1029-00_Spec_Sheet.pdf.

Revised: January 25, 2017,
Above the Ceiling Tiles
The AP 1850 series is rated for installation in the Plenum area (UL-2043). Many customers prefer to locate the AP in such a way that
nothing is visible on the ceiling. In some cases, this is preferred for aesthetic reasons, so customers may install the AP above a drop
ceiling. This may also be preferred in high theft areas such as classrooms or in areas where policy dictates that nothing can be visible
on the ceiling.
To meet this hard requirement, optional T-Bar hangar accessories such as Erico and Cooper, can be used (Figure 10: Example of
How to Hang an AP Above the Ceiling Tiles, on page 12). These accessories are manufactured by third-party companies. The Erico
Caddy 512a, the Cooper B-Line BA50a, or similar T-Bar Grid T-Bar hangars can be used.
For more information, see:
www.erico.com
www.cooperindustries.com
Figure 10: Example of How to Hang an AP Above the Ceiling Tiles
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Installing APs above the ceiling tiles must be done only when mounting below the ceiling is not an option.
The tiles must not be conductive; such installations will degrade advanced RF features such as voice and
location, so verify coverage and performance. Always, try to mount the AP as close to the inside middle
of the tile as possible, and avoid areas with obstructions
Note
Figure 11: Installing AP above ceiling tiles: Pick an area Clear of Obstructions and Avoid Ceiling Clutter
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Revised: January 25, 2017,
Stadium / Harsh Environments
Customers needing to install the APs in harsh environment such as sporting areas, stadiums, open garden areas, or warehouse freezers,
where it may be exposed to weather, may use a NEMA type enclosure.
Some APs may not be certified for outdoor deployments in a NEMA enclosure. This varies around the
world, for example some regulatory agencies permit AP outdoor NEMA enclosures if the AP is indoors
such as a freezer or garden area but may prohibit its usage outdoors. This seems to vary with regard to
weather radar compliance, UNII-1 compliance, and so on. Check with your Cisco account team or the
communications regulatory agency that has jurisdiction in your area.
Note
Figure 12: Example of NEMA 16x14x8 Enclosure with Pressure Vent on Bottom
Third-party sources for NEMA type enclosures include:
www.oberonwireless.com
www.sparcotech.com
www.terra-wave.com
When using a NEMA type enclosure, ensure that the cables exit out of the bottom of the enclosure so that rain and moisture do not
run down the cable into the enclosure. Also, the color of the enclosure may affect the heat rating; for example, a black enclosure gets
much hotter in the sun than a white one. You may also want to use a pressure vent to prevent moisture accumulation.
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Revised: January 25, 2017,
Ethernet Cable Recommendation
While the AP 1600, 1700, 1850, 2600, and 3600 work fine with CAT-5e cable, for newer cable installations, it is recommended that
the customers use CAT6a. Because, CAT6a is the cabling required by the 10GE standard.

Revised: January 25, 2017,
Antenna Cable Recommendation
Whenever practical/possible, ensure that the antenna cable runs as short as possible. Cisco offers low loss (LL) and ultra low loss
(ULL) cables, which have the same characteristics as Times Microwave LMR-400 and LMR-600.
Cisco cables carry the part number AIR-CAB (Aironet Cable) and its length parameter. For example, a 20 Ft length of LL cable with
RP-TNC connector is Cisco AIR-CAB-020LL-R. These heavy black cables are not Plenum rated and are primarily for outdoor use
or manufacturing areas.
Figure 13: When Drilling Holes for Cable, Allow for Size of Connector (Typically 5/8 Inch) Drill Bit
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Revised: January 25, 2017,
Access Point Spacing Recommendations
If you have an Wi-Fi device such as an AP and you are going to use another AP in the vicinity on a different channel, it is recommended
that you space each AP apart by approximately 6 ft (2 meters). Avoid clustering the APs or the antennas from different APs together,
because this could cause degradation in performance. This recommended distance is based on the assumption that both devices operate
in the unlicensed band and do not transmit RF energy more than 23 dB, that is, 200 mW. If higher power is used, space the APs
farther apart.
If you have other devices that transmit, especially if they operate in the same frequency ranges, for example, frequency hopping
legacy APs or other devices that operate close in frequency to those of the AP (think below or above the 2.4 and 5 GHz band), you
should consider moving or separating the devices as far as you can. After you have done this, check for interference by testing both
devices at the same time under heavy utilization (load) and then characterize each system independently to see how much, if any,
degradation exists.
To comply with FCC, EU, and EFTA RF exposure limits, antennas should be located at a minimum of
7.9 inches (20 cm) or more from the body of all persons. For more information, see the Declarations of
Conformity section in the Cisco Aironet 1850 Series Access Points Hardware Installation Guide.
Warning

Revised: January 25, 2017,
Installations in IDF Closets (Telecommunications or Other
Electrical Equipment)
When installing APs near electrical or telecommunications equipment, keep all wiring and metal away from the antennas and avoid
placing the antennas near electrical lines. Do not route wiring electrical or Ethernet in the near field (6-15 inches) from the antenna.
Try to refrain from installing the AP in the electrical closet, because the best place for the AP is as close to users as possible/practical.
If you have remote antenna cables from such a closet, you may be required to use Plenum rated cable (see local fire/safety regulations
for more on this).
Below are a few URLs for understanding interference:
http://www.cisco.com/en/US/prod/collateral/wireless/ps9391/ps9393/ps9394/prod_white_paper0900aecd807395a9_ns736_N
etworking_Solutions_White_Paper.html
http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps10981/white_paper_c11-609300.html
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Revised: January 25, 2017,
Installations Inside and Around Elevators
Elevator coverage can sometimes be accomplished by placing APs in the near field of an elevator, typically on each floor near the
elevator door. Because, elevators often have metal doors and the shafts are often concrete or contain other materials that degrade
Wi-Fi coverage. It is important to check the coverage inside the elevator. Though such coverage can be challenging, it is often do-able,
especially if the elevator is only a few floors.
High rise elevators are more challenging because roaming issues are problematic; the client is cycling through a large number of APs
quickly. Some companies that do in-elevator advertising put a patch antenna on the floor inside the shaft and a patch antenna on the
bottom of the elevator car, while other companies use leaky coaxial cable running on the side of the shaft.
When installing any Wi-Fi equipment inside the elevator cars or shafts, local regulations need to be followed. Because, many times
such installations are prohibited either for safety reasons or because the building owner or local fire department may prohibit the
same. Only elevator repair persons or contractors who have experience with this kind of work should be in those areas.

Revised: January 25, 2017,
Understanding AP 1850 Powering Options
Figure 14: Local 48 Volt DC Power Supply
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