Getnet Router GR-534W User Manual

							 
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The parameters’ description of Repeater Mode, please refer to the Bridge Mode. 
  HT Physical Mode 
 
The parameters of HT Physical Mode are described as follows: 
Field Description 
Operation Mode  You may select Mixed Mode or Green Field. The 
default operation mode is Mixed Mode. 
Channel  You may select 20 or 20/40. The default channel  
						

							 
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Field Description 
BandWidth bandwidth is 20/40. 
Guard Interval  You may select Long or Auto. The default guard 
interval is Auto. 
MCS  You may select the MCS value from 0 to 32. The 
default MCS is Auto. 
Reverse Direction 
Grant(RDG) You may select Disable or Enable. The default 
RDG setting is Enable. 
Extension 
Channel Select a proper channel in the drop down list. 
When the channel bandwidth is set to be 20/40 
MHz, the extension channel will provide a channel 
that is adjacent to the primary channel but not 
overlaps. The wireless network will acquire diploid 
bandwidth by this extension channel, that is, 20MHz 
bandwidth. 
Note: 
IEEE 802.11n can bind two adjacent 20 MHz 
bandwidths together to form a 40MHz bandwidth. 
Actually, the 40MHz bandwidth can act as two 20 
MHz bandwidths. One is the primary bandwidth, the 
other is the secondary bandwidth. When data is 
being transmitted, it can act as 40MHz bandwidth, 
and it can also acts as 20 MHz bandwidth 
independently. In this way, the data rate is doubled.
Aggregation 
MSDU 
(A-MSDU)  Enable or disable A-MSDU. 
MSDU is the aggregation of multiple MSDUs by 
using certain method and the multiple MSDUs forms 
a greater load. MSDU can be considered as 
Ethernet message. Usually, when AP or wireless 
client receives MSDUs from protocol stack, the 
MSDUs will be marked with the Ethernet message 
header (also called A-MSDU Subframes). Before 
sending them out, the A-MSDU Subframes need to 
be transformed into the message format of 802.11 
one by one. 
A-MSDU aggregates multiple A-MSDU Subframes  
						

							 
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Field Description 
and encapsulates them to be an 802.11 message. In 
this way, PLCP Preamble, PLCP Header, and 
802.11 MAC overhead that are needed to send an 
802.11 message decrease. At the same time, the 
acknowledge frames also decrease, and the 
efficiency for sending message is improved. 
Auto Block ACK  Enable or disable Auto Block ACK. 
In order to insure the security of the data 
transmission, 802.11n protocol requires that if the 
client receives a unicast frame, it should 
immediately send back a ACK frame. After the 
receiver of A-MPDU receives A-MPDU, it needs to 
process every MPDU. In that case, it sends out ACK 
frames to every MPDU. Block Acknowledgement is 
used to reduce the number of the ACK frames by 
using a ACK frame. 
Decline BA 
Request Enable or disable Decline BA Request. 
 
5.4.2   Advanced Settings 
Click Wireless > Advanced to display the Advanced Wireless Settings page.  
						

							 
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On this page, you may configure advanced wireless parameters, such as beacon 
interval, data beacon rate, and Tx power. 
 
Note: 
The advanced wireless setting is only for advanced user. For the common user, do 
not change any setting on this page. 
 
  Advanced Wireless  
						

							 
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The parameters of Advanced Wireless are described as follows: 
Field Description 
BG Protection 
Mode Yo u  m a y  s e l e c t  On, Off, or Auto. The default BG 
protection mode is Auto. 
Beacon Interval  By default, wireless beacon signal sends data to 
station every other 100 ms. The range is 20~999. 
Data Beacon Rate 
(DTIM)  The default DTIM is 1ms. The range is 1~255. 
Fragment 
Threshold  The default fragment threshold is 2346. The range is 
256~2346. 
RTS Threshold  The default RTS threshold is 2347.The range is 
1~2347. 
TX Power  Set the Tx power. 100% indicates full power. 
Short Preamble  Enable or disable short preamble. The default 
setting is Disable. 
Preamble defines the length of CRC correction 
block for wireless devices. Short preamble adopts 
56-bit synchronization field. The network whose  
						

							 
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Field Description 
network traffic is dense should use shorter 
preambles. 
Short Preamble is mainly applied to the efficiency 
improvement of real- time applications, such as 
streaming video, and Voice-Over-IP telephony. 
Short Slot Enable or disable short slot. 
Tx Burst  Tx Burst can be used to improve the efficiency of 
data transmission. It can make system transmit 
more data during a period of time. 
Pkt_Aggregate Pkt_Aggregate can aggregate multiple data packets 
together for improving the transmission efficiency. 
Country Code Select a proper country code in the drop down list. 
 
  Wi-Fi Multimedia 
 
 
The parameters of WMM are described as follows: 
Field Description 
Wi-Fi Capable  Enable or disable WMM. After enabling WMM, AP 
can process different types of wireless data 
according to their priority levels. 
APSD Capable  Enable or disable APSD. After enabling APSD, it 
can decrease the consumption of the power supply 
device. 
DLS Capable  Enable or disable DLS. 
WMM Parameters  Click the WMM Configuration button to display the 
configuration page of WMM parameters. 
  
						

							 
62    Multicast-to-Unicast Converter 
 
 
Enable or disable Multicast-to-Unicast. After enabling this function, the transmission 
quality of wireless multicast stream can be improved. 
 
  About WMM 
- WMM Access Categories 
At present, WMM defines traffic into 4 access categories. 
 
 
AC_VO: Voice (highest priority) 
AC_VI: Video (high priority) 
AC_BE: Best effort (medium priority) 
AC_BK: Background (low priority) 
802.11 uses DCF (Distributed Coordination Function) scheme of the CSMA/CA 
(Carrier Sense Multiple Access / Collision Avoidance) protocol to reduce the chances 
of packets collision while one more devices access the wireless media at the same 
time. A client wishing to transmit has to first listen to the channel for a predetermined 
amount of time so as to check for any activity on the channel. If the channel is sensed 
idle then the client is permitted to transmit. If the channel is sensed as busy the 
station has to defer its transmission. The random interval provides a fair transmission  
						

							 
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chance for all the devices. 
When each priority queue waits for sending packets, it has to wait a fixed time AIFSN 
and a random time CW. They define time values by multiple time slots. For 802.11b, 
its time slot is 20ms. The time slot of 802.11a and 802.11g is 9 ms. CW insures the 
random delay time of DCF, so that the packets collision among the devices with the 
same access category can be avoided. If collision occurs, CW is doubled until it 
exceeds its maximum value. After every successful transmission, CW returns to the 
minimum value. 
The priority queue that succeeds in the competition of sending packets will acquire 
Txop time to send packets. If the txop value is 0, it is limited to be a MSDC (MAC 
Service Data Unit).
 
- Set WMM Parameters 
Click the WMM Configuration button on the Advanced Wireless Settings page, the 
following page appears. 
 
On this page, you can configure the WMM parameters of access point and station. 
 
Note: 
GR-534W provides standard WMM settings. If you want to modify the parameters 
above, please refer to the WMM settings of your WMM products. 
  
						

							 
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The parameters on this page are described as follows: 
Field Description 
Aifsn  Aifsn (Arbitrary Inter-Frame Space Number). This 
parameter influences the delay time of WMM access 
category. If you use voice or video service, you’d 
better set this parameter to be smaller in the fields of 
AC_VI and AC_VO. If it is E-mail or Web service, 
you should set a bigger value in the fields of AC_BE 
and AC_BK. 
Cwmin  Cwmin (Mini. Contention Window) also influences 
the delay time of WMM access category. The 
difference between AC_VI and AC_VO should be 
smaller, but the difference between AC_BE and 
AC_BK should be bigger. 
Cwmax Cwmax (Max.Contention Window) 
Txop  Txop (Opportunity to Transmit) may optimize the 
WMM access. Compared to the WMM access that 
needs a higher priority, such as AC_VI and AC_VO, 
this value should be bigger. 
ACM  ACM (Admission Control Mandatory) parameter 
only reacts on AC_VI and AC_VO. If you set this 
value to be 0, it indicates that AP is in the charge of 
the access commands. If this value is 1, it means 
the client is in the charge of the access commands.
Ackpolicy  When WMM packets are transmitting, AP will 
receive an echo request. If you set this value is 0, it 
means AP does not send back an echo request, 
which will bring positive effect for WMM. If this value 
is 1, AP generates the response to the request. 
- DLS (Direct Link Setup) 
GR-534W provides DLS function. Suppose that there are two WMM devices. Enter 
the MAC address of a WMM device in the DLS setting of the other device, and then 
connect the two WMM devices to the GR-534W. In this way, these two WMM devices 
can transmit message directly. 
If you want to configure WMM DLS, do as follows:
 
Step1 Prepare two wireless network cards (A and B) and one GR-534W.  
						

							 
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Step2 Enable the DLS function on the Advanced Wireless Settings page. 
 
 
Step3 Enable the DLS function of wireless network cards. Enter the MAC address 
of wireless card A on the WMM page of the wireless network card B, and 
then click the Apply button. 
 
 
Step4 If DLS succeeds, you can view the MAC address of wireless card A on the 
WMM page of wireless card B, and vice versa.