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Report No.: EM201300650-1                         Application No.: ZJ00032008                       Page 25 of 42 
 

 

Control frames facilitate in the exchange of data frames between stations. Some common 802.11 

control frames include: 

Acknowledgement (ACK) frame: After receiving a data frame, the receiving station will send an ACK 

frame to the sending station if no errors are found. If the sending station doesn't receive an ACK frame 

within a predetermined period of time, the sending station will resend the frame. 

Request to Send (RTS) frame: The RTS and CTS frames provide an optional collision reduction 

scheme for access points with hidden stations. A station sends a RTS frame to as the first step in a 

two-way handshake required before sending data frames. 

Clear to Send (CTS) frame: A station responds to an RTS frame with a CTS frame. It provides 

clearance for the requesting station to send a data frame. The CTS provides collision control 

management by including a time value for which all other stations are to hold off transmission while 

the requesting stations transmits. 

 

 

Report No.: EM201300650-1                         Application No.: ZJ00032008                       Page 26 of 42 
 

 

Frequency range 

Limit when operating 

Limit when in standby 

30 MHz to 1 GHz  

-36 dBm  

-57 dBm  

above 1 GHz to 12.75 GHz  

-30 dBm  

-47 dBm  

1.8 GHz to 1.9 GHz  

5.15 GHz to 5.3 GHz  

-47 dBm  

-47 dBm  

EUT operation status: 

Keep EUT on transmitting mode by the software provided by 
manufacturer. 
Pretest the EUT at different transmission rate and report show 
the worst case data. 

     

Test channel: 

802.11b/g 
Lowest channel: (2412MHz), Highest channel: (2472MHz) 

Test condition: 

Normal test conditions. 

Test equipment used: 

Refer to section 3.4 

Test procedure: 

1.  The EUT shall be performed at the highest power level at 

which the transmitter is intended to operate.and Interface 
cables, loads, and devices should be connected to at least 
one of each type of the interface ports of the EUT and, 
where practical, each cable shall be terminated in a device 
typical for its actual use. EUT shall be placed at the 1.5m 
support on the turntable. 

2.  The test antenna at a horizontal distance of 3 m .It shall be 

raised and lowered from 1m to 4m until a maximum signal 
level is detected by the measuring receiver. Then the 
turntable should be rotated through 360° in the horizontal 
plane, until the maximum signal level is detected by the 
measuring receiver. In both the vertical and the horizontal 
polarization. Record the reading level, antenna position, 
polarization and turntable position. 

3.  Remove the transmitter and replace it with a substitution 

antenna (the antenna should be half-wavelength for each 
frequency involved). The center of the substitution antenna 
should be approximately at the same location as the center 
of the transmitter. For frequencies of 80 MHz and above, the 
dipoles should have their arm lengths set for resonance at 

Report No.: EM201300650-1                         Application No.: ZJ00032008                       Page 27 of 42 
 

 

the frequency of test. Below 80 MHz, shortened arm lengths 
are recommended. For measurements above 1 000 MHz, a 
waveguide horn is recommended. The centre of this antenna 
should coincide with either the phase centre or volume 
centre. 

4.  Feed the substitution antenna at the transmitter end with a 

signal generator connected to the antenna by a cable. With 
the antennas at both ends vertically polarized, and with the 
signal generator tuned to a particular test frequency, raise 
and lower the test antenna to obtain a maximum reading at 
the spectrum analyzer. Adjust the level of the signal 
generator output until the previously recorded maximum 
reading for this set of conditions is obtained. This should be 
done carefully repeating the adjustment of the test antenna 
and generator output. 

5.  Repeat the step1~4 when the EUT is standby. 
6.  Where: E.I.R.P (dBm) = Pg (dBm) – cable loss (dB) + 

antenna gain (dBi). Pg is the generator output power into the 
substitution antenna 

Remark:    

Pre-scan all the rate, found that:  
11Mbps of rate is the worst case of 802.11b;  
54Mbps of rate is the worst case of 802.11g ; 

 

 

 

Report No.: EM201300650-1                         Application No.: ZJ00032008                       Page 28 of 42 
 

 

Below 1GHz 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Above 1GHz