Wireless LAN Calculator (Q207)

7/27/2019 Wireless LAN Calculator (Q207)

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Wireless LAN CalculatorBefore we start using the Wireless LAN Calculator, it is useful to understand how is works.

It is important to gather the environmental information before doing the physical setup.

Imformation include :

1. Suitable locations for mounting the devices

2. Background noise. If there is too many devices using 2.4GHz band in the region, you can consider 5GHz.

Calculate Fade MarginFade margin is the difference, in dB, between the magnitude of the received signal at the receiver input and the minimum level of signal determ

operation.Higher the fade margin, the more reliable the link will be.The exact amount of fade margin required depends on the desired reliabil

of thumb is 20 to 30 dB.Fade margin is often referred to as "thermal" or "system operating margin".

where

Received Signal = Tx Power - Tx Cable Loss + Tx Antenna Gain - Free Space Path Loss + Rx Antenna Gain - Rx Cable Loss

Received Threshold = Receiver SensitivityTo use this calculator, you need to input the required distance and select transmitter & receiver access points, optional cables & anten

Calculate Distance

From the Fade Margin equation, Free Space Path Loss can be computed with the following equation.

Free Space Path Loss = Tx Power - Tx Cable Loss + Tx Antenna Gain + Rx Antenna Gain - Rx Cable Loss - Rx Sensitivity - Fade Margin

Free Space Path Loss can also be computed with the following equation.

Free Space Path Loss = 32.44 + 20 log10 FrequencyMHz + 20 log10 Distancekm

With the above two Free Space Path Loss equations, we can find out the Distance in km.

To use this calculator, you need to input the fade margin and select transmitter & receiver access points, optional cables & antennas.

Calculate Fresnel Zone Radius

The Fresnel Zone is the area around the visual line-of-sight that radio waves spread out into after they leave the antenna. You want a clear line

strength, especially for 2.4 GHz wireless systems. This is because 2.4 GHz waves are absorbed by water, like the water found in trees. The ru

Fresnel Zone must be clear of obstacles. Typically, 20% Fresnel Zone blockage introduces little signal loss to the link. Beyond 40% blockage

significant.

To use this calculator, you need to input the fade margin and select transmitter & receiver access points, optional cables & antennas.

Find Suitable Antenna

To find a suitable antenna, it can be done by calculating the antenna gain from the two Free Space Path Loss equations.

To find out both Transmitter and Receiver Antenna Gain (assuming that they have the same value)

To find out Transmitter Antenna Gain (assuming you have Receiver Antenna Gain information)

To use this calculator, you need to input the distance & fade margin and select transmitter & receiver access point, optional cables & r

Fade Margin = Received Signal - Receiver Threshold

Distancekm = 10(Free Space Path Loss - 32.44 - 20 log10 FrequencyMHz) / 20

Fresnel Zone Radiuskm = 17.32 x Squareroot ( Distancekm / (4 x FrequencyGHz) )

Tx or Rx Antenna Gain = (Fade Margin - Tx Power + Tx Cable Loss + Rx Cable Loss + Rx Sens32.44 + 20 log10 FrequencyMHz + 20 Log10 Distancekm) / 2

Tx Antenna Gain = Fade Margin - Tx Power + Tx Cable Loss + Rx Cable Loss + Rx Sensitivity

32.44 + 20 log10 FrequencyMHz + 20 Log10 Distancekm - Rx Antenna Gain

Access Point Access Point

Transmitter (Tx) Receiver (Rx)

Tx PowerRx Sensitivity

Tx Cable Loss Rx Cable Los

Tx Antenna Gain

Rx Antenna Gain

CableCable

AntennaAntenna


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Calculate Fade Margin

0.1 kmDistance 100 meters Input the distance in meters

Unit No. 1 (Transmitter)

Select a Wireless Bridge/Access Point This access point supports 802.11g only.

0

Select a Cable 0 dB Loss

2 0

Select a Transmitter Antenna 2 dBi Gain

This antenna supports 802.11g only.

Unit No. 2 (Receiver)

Select a Wireless Bridge/Access Point This access point supports 802.11g only.0


2 0

Select a Receiver Antenna 2 dBi Gain


IEEE 802.11b/g

Data Transfer Rate

54Mbps 5.9558 dB

48Mbps 10.9558 dB

36Mbps 15.9558 dB

24Mbps 19.9558 dB

18Mbps 22.9558 dB

12Mbps 24.9558 dB

9Mbps 25.9558 dB

6Mbps 26.9558 dB

IEEE 802.11a

Data Transfer Rate

54Mbps N.A.

48Mbps N.A.

36Mbps N.A.

24Mbps N.A.

18Mbps N.A.

12Mbps N.A.

9Mbps N.A.6Mbps N.A.

Remarks : The transmitter access point & antenna and receiver access point & antenna do not support 802.11a.

Fade margin is the difference, in dB, between the magnitude of the received signal at the receiver input and the minimum

level of signal determined for reliable operation.Higher the fade margin, the more reliable the link will be.The exact

amount of fade margin required depends on the desired reliability of the link, but a good rule-of-thumb is 20 to 30 dB.

Fade margin is often referred to as "thermal" or "system operating margin".

Fade Margin

Fade Margin

DI Product Marketing Release 1.0 (08 Jun 2007)


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Calculate Distance Fresnel

Fade Margin 28 dB Fade Margin - Typical good reliable link is 20-30 dB



0


2 0 2

Select a Transmitter Antenna 2 dBi Gain




0


2 0 2

Select a Receiver Antenna 2 dBi Gain


IEEE 802.11b/g

Data Transfer Rate

54Mbps 0.0079 km 7.90 meters 0.50 meters 0.30 meters








IEEE 802.11a

Data Transfer Rate

54Mbps N.A. N.A. N.A. N.A.








Remarks : The transmitter access point & antenna and receiver access point & antenna do not support 802.11a.

The Fresnel Zone is the area around the visual line-of-sight that radio waves spread out into after they leave the antenna. You want

a clear line of sight to maintain signal strength, especially for 2.4 GHz wireless systems. This is because 2.4 GHz waves are

absorbed by water, like the water found in trees. The rule of thumb is that 60% of the Fresnel Zone must be clear of obstacles.

Typically, 20% Fresnel Zone blockage introduces little signal loss to the link. Beyond 40% blockage, the signal loss will

become significant.

Distance (km) Distance (m) Fresnel Zone Radius (m) 60% Fresnel Zone Ra

Distance (km) Distance (m) Fresnel Zone Radius (m) 60% Fresnel Zone Ra


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F

Input Distance 100 meters 0.1 km

Input Fade Margin 28 dB Typical good reliable link is 20-30dB



0


0 0 0

Select a Transmitter Antenna I want to find a suitable Transmitter Antenna



0


0 0 0

Select a Receiver Antenna I want to find a suitable Receiver Antenna

IEEE 802.11b/g

Data Transfer

Rate

Transmitter

Antenna Gain

Reciever

Antenna Gain

54Mbps 14 dBi 14 dBi

48Mbps 11 dBi 11 dBi

36Mbps 9 dBi 9 dBi

24Mbps 7 dBi 7 dBi

18Mbps 5 dBi 5 dBi

12Mbps 4 dBi 4 dBi

9Mbps 4 dBi 4 dBi

6Mbps 3 dBi 3 dBi

IEEE 802.11a

Data Transfer

Rate

Transmitter

Antenna Gain

Reciever

Antenna Gain

54Mbps N.A. N.A.

48Mbps N.A. N.A.

36Mbps N.A. N.A.

24Mb N A N A

ANT24-0400; ANT24-0401; ANT24-0500; ANT24-0501; ANT24-0501C; ANT24-0600; ANT24

0700; ANT24-0700C; ANT24-0800; ANT24-0801; ANT24-1200; ANT24-1201; ANT24-1400;

ANT24-1500; ANT24-1800; ANT24-1801; ANT24-2100; ANT70-0800; ANT70-0801; ANT70-

1000; ANT70-1800; DWL-R60AT

Supported Antennas

See Remarks.

See Remarks.

ANT24-0500; ANT24-0501; ANT24-0501C; ANT24-0600; ANT24-0700; ANT24-0700C; ANT

0800; ANT24-0801; ANT24-1200; ANT24-1201; ANT24-1400; ANT24-1500; ANT24-1800;

ANT24-1801; ANT24-2100; ANT70-0800; ANT70-0801; ANT70-1000; ANT70-1800; DWL-

R60AT

Supported Antennas

See Remarks.

S R k

ANT24-0400; ANT24-0500; ANT24-0501; ANT24-0501C; ANT24-0600; ANT24-0700; ANT24

0700C; ANT24-0800; ANT24-0801; ANT24-1200; ANT24-1201; ANT24-1400; ANT24-1500;

ANT24-1800; ANT24-1801; ANT24-2100; ANT70-0800; ANT70-0801; ANT70-1000; ANT70-1800; DWL-R60AT

ANT24-0400; ANT24-0500; ANT24-0501; ANT24-0501C; ANT24-0600; ANT24-0700; ANT24

0700C; ANT24-0800; ANT24-0801; ANT24-1200; ANT24-1201; ANT24-1400; ANT24-1500;


1800; DWL-R60AT

ANT24-1400; ANT24-1500; ANT24-1800; ANT24-1801; ANT24-2100; ANT70-1800


2100; ANT70-1800


2100; ANT70-1800

ANT24-0700; ANT24-0700C; ANT24-0800; ANT24-0801; ANT24-1200; ANT24-1201; ANT24

1400; ANT24-1500; ANT24-1800; ANT24-1801; ANT24-2100; ANT70-0800; ANT70-0801;

ANT70-1000; ANT70-1800


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Release Date Description

1.0 8-Jun-07 First Release

DI Product Marketing Release 1.0 (07 Jun 2007)

Wireless LAN Calculator (Q207)

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