Mitsumi Electric Co DWLA001 manual Part IV

Mitsumi Electric Co., Ltd. Wavit11 User's Manual

When the automatic setting is selected, Wavit11

makes communication in the fastest possible rate, and

this depends on the equipment at the other end. If the

unication environment is degraded and making

communication in the present data rate becomes

impractical, the data rate will be lowered and the

10.4. Data Rate
There are 5 choices: 1Mbps, 2Mbps, 5.5Mbps, 11Mbps and the automatic
setting.

comm

wireless LAN communication will continue.

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where

wireless LAN under

fails

in receiving the radio wave, the roaming function will enable

her nearby Access

Point. If Wavit11 switches the Access Point successfully, it

the wireless LAN data without

interruption, and that it can access the network without any

Setting up of Roaming function will be possible only if the

10.5. Roaming
This is a way to set whether the Wavit11does a roaming or not.

What is Roaming?

This function can be activated in an environment
multiple Access Points exist. If the
communication with a certain Access Point moves and

Wavit11 to change the destination to the ot

can send and receive

interruption.

operational mode is as follows:

Infrastructure mode
AP mode

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s

Normally every

or not another wireless LAN has

not to

the already started

wireless LAN communication transmitting the data without

sensing the existence of another wireless LAN communication.

reless LAN that may disturb the other wireless

10.6. Hidden Node Compensation

Depended on the placement of multiple wireless LANs, there is a case that the
wireless LAN communication disturbance caused by other wireless LANs takes
place and the data rate may be fallen off. If the Hidden Node Compensation is
set to Enable, the Wavit11 seizes the wireless LAN communication line prior to
the actual data transmission, so it can mitigate the mutual disturbance of
wireless LAN communication and the degradation of data rate.

What is Hidden Node?

In the wireless LAN system, many wireless LAN
communicate each other on the same frequency.
wireless LAN senses whether
already started the wireless LAN communication so as
disturb the already started wireless LAN communication.

However, some wireless LANs disturb

Such a kind of wi
LAN communication is called Hidden Node.

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should be

10.7. Details

Click the “Details” button to enable the Wavit11 detailed setting.

Normally you do not need to change these items.
Check each item of this manual, when the setting
modified.

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improve when this

Hidden node

Check the performance by

you modify the value

threshold

10.8. RTS Threshold

In the case that the Hidden node compensation is set to Enable, setup of RTS

threshold will be possible .

The Wavit11 seizes the wireless LAN communication line prior to actual data
transmission if the data length is greater than RTS Threshold. When the Hidden
node compensation is set to Enable, the initial value is 0, therefore, the Wavit11
seizes the wireless LAN communication line prior to every length of actual data
transmission.

The wireless LAN performance will
RTS Threshold is enlarged, in the case that
disturbance is not so violent.
modifying the RTS threshold, when
from the initial value, because the optimal RTS
depends on the placement and application of wireless LAN.

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mes are sent without any data frame division in

10.9. Fragmentation Threshold

In the case that the transmitted data do not correctly reach the wireless LAN
on the partner side, the Wavit11 will retransmit the data predefined times . This
retransmission occurs frequently by a communication error under poor
communication condition and the performance of the wireless LAN network
sometimes deteriorates.

There is a way to mitigate the performance deterioration, that is the
retransmission of divided frame. Thus, the wireless LAN frame should be
divided into small pieces, and here is a way to set the size of divided frame.

All fra

default setting.

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try to

data many times to the wireless LAN at which the

he performance of the whole

degree

if you modify the

10.10. Short Retry Limit

In the case that the transmitted data do not correctly reach the wireless LAN
on the partner side, the Wavit11 will retransmit the data predefined times and the
number of retransmission times is set here. In Short Retry Limit, the number of
retransmission is set, for the data frame whose length is below RTS threshold.

If a big value is set needlessly, the Wavit11 may
retransmit
radio wave cannot get, so t
wireless LAN can be deteriorated. Closely examine the
of performance required by the application,
setting.

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