Using a portable analyzer you perform a packet capture next to a client STA and you can see that the STA is associated to a BSS. You observe the STA sending packets to the AP and the AP sending packets to the ST
- Less than 2% of all packets are retransmissions. You move to capture packets by the AP and, while the retry rate is still less than 2%, you now only see unidirectional traffic from the AP to the client.
How do you explain this behavior? - The portable analyzer is too close to the AP causing CCI, blinding the AP to the clients packets
- The STA is transmitting data using more spatial streams than the potable analyzer can support
- There is a transmit power mismatch between the client and the AP and while the client can hear the APs traffic, the AP cannot hear the client
- The portable analyzer has a lower receive sensitivity than the AP and while it can't capture the packets from the client STA, the AP can receive them OK
Answer(s): D
Explanation:
Receive sensitivity is the minimum signal level that a receiver can detect and decode. Different devices may have different receive sensitivity levels depending on their hardware specifications and antenna configurations. In this scenario, the portable analyzer has a lower receive sensitivity than the AP, meaning that it requires a stronger signal to capture the packets from the client STA. The AP, on the other hand, has a higher receive sensitivity and can receive the packets from the client STA even if they have a weaker signal. This explains why the portable analyzer can only see unidirectional traffic from the AP to the client when capturing near the AP5
Reference:
CWAP-403 Study Guide, Chapter 4: PHY Layer Analysis, page 121 CWAP-403 Objectives, Section 4.3: Analyze PHY layer metrics