Access Point Obstacle

Its on of those things really. It is very unlikely that a signal will be passed though it. You could change the wireless frequency used my your access point **If your AP allows it** Other manufacturers may have a more suitable solution if they have larger antena. You could try an external one....

James

Putu wrote:

Hi Putu,

You may wish to investigate the Cisco Aironet Antenna Reference Guide:

The density of the materials used in a building's construction determines the number of walls the RF signal can pass through and still maintain adequate coverage.

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Following are a few examples.

Actual effect on the RF must be tested at the site, and therefore a site survey is suggested.

Paper and vinyl walls have very little effect on signal penetration.

Solid walls and floors and precast concrete walls can limit signal penetration to one or two walls without degrading coverage.

This may vary widely based on any steel reinforcing within the concrete.

Concrete and concrete block walls may limit signal penetration to three or four walls.

Wood or drywall typically allow for adequate penetration through five or six walls.

A thick metal wall reflects signals, resulting in poor penetration.

Steel-reinforced concrete flooring will restrict coverage between floors to perhaps one or two floors.

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Recommendations for some common installation environments are outlined below:

Warehousing / Manufacturing

In most cases, these installations require a large coverage area.

Experience has shown that an omnidirectional antenna mounted at 20 to

25 feet typically provides the best overall coverage.

Of course, this also depends upon the height of the racking, material on the rack, and ability to locate the antenna at this height.

Mounting the antenna higher will sometimes actually reduce coverage, as the angle of radiation from the antenna is more outward than down.

The antenna should be placed in the center of the desired coverage cell and in an open area for best performance.

In cases where the radio unit will be located against a wall, a directional antenna such as a patch or yagi can be used for better penetration of the area.

The coverage angle of the antenna will affect the coverage area.

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Small Office / Small Retail

The standard dipole may provide adequate coverage in these areas depending on the location of the radio device.

However, in a back corner office a patch antenna may provide better coverage.

It can be mounted to the wall above most obstructions for best performance.

Coverage of this type antenna depends on the surrounding environment.

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Enterprise / Large Retail

In most cases, these installations require a large coverage area.

Experience has shown that omnidirectional antennas mounted just below the ceiling girders or just below the drop ceiling typically provide the best coverage ( this will vary with stocking, type of material, and building construction ).

The antenna should be placed in the center of the desired coverage cell and in an open area for best performance.

In cases where the radio unit will be located in a corner, or at one end of the building, a directional antenna such as a patch or yagi can be used for better penetration of the area.

Also, for areas that are long and narrow-such as long rows of racking-a directional antenna at one end may provide better coverage.

The radiation angle of the antennas will also affect the coverage area.

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Point-to-Point

When connecting two points together ( such as a wireless bridge ), the distance, obstructions, and antenna location must be considered.

If the antennas can be mounted indoors and the distance is very short ( several hundred feet ), the standard dipole or mast mount 5.2 dBi omnidirectional may be used.

An alternative is to use two patch antennas.

For very long distances ( 1/2 mi. or more ), directional high-gain antennas must be used.

These antennas should be installed as high as possible, and above obstructions such as trees, buildings, and so on; and if directional antennas are used, they must be aligned so that their main radiated power lobes are directed at each other.

Regarding a line-of-site configuration, distances of up to 25 miles at

2.4 GHz and 12 miles at 5 GHz can be reached using parabolic dish antennas, if a clear line-of-site is maintained.

With the use of directional antennas, fewer interference possibilities exist and there is less possibility of causing interference to anyone else.

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Point-to-Multipoint Bridge

In this case ( in which a single point is communicating to several remote points ), the use of an omnidirectional antenna at the main communication point must be considered.

The remote sites can use a directional antenna that is directed at the main point antenna.

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Hope this helps.

Brad Reese BradReese.Com - Cisco Jobs

Hendersonville Road, Suite 17 Asheville, North Carolina USA 28803 USA & Canada: 877-549-2680 International: 828-277-7272 Fax: 775-254-3558 AIM: R2MGrant BradReese.Com - Cisco Power Supply Headquarters