Pass the CWNP CWDP Wi-Fi Design CWDP-305 Questions and answers with ValidTests

Comprehensive and Detailed Explanation:

An elevation chart provides a vertical radiation pattern of an antenna, which is essential for understanding how the antenna directs energy above and below the horizon. In bridge link deployments, especially over varying terrains or between buildings of different heights, the elevation pattern helps in aligning antennas to ensure optimal signal propagation and reception. Requesting elevation charts from antenna vendors allows for informed decisions on antenna placement and orientation, leading to more reliable and efficient wireless links.

iPerf is a widely used open-source network testing tool that measures bandwidth, latency, and packet loss over IP networks. It is frequently used in WLAN and LAN environments to evaluate end-to-end throughput performance.

From CWDP-305:

“iPerf is a commonly used tool for throughput validation in WLAN and LAN designs. It can be used with laptops or mobile devices to generate traffic and measure capacity in a controlled way.”

— Reference: CWDP-305 Official Study and Reference Guide, Chapter on Post-Design ValidationandTroubleshooting

To determine the minimum RSSI required for a VoWLAN deployment with a specified SNR, use the formula:

Minimum RSSI = Noise Floor + Required SNR

Given:

Required SNR = 25 dB

Noise Floor = -88 dBm

Calculation:

Minimum RSSI = -88 dBm + 25 dB = -63 dBm

Thus, the minimum RSSI needed is -63 dBm.

Explanation with Extract:

Per the *CWDP-305 Study Guide*, Voice over WLAN (VoWLAN) deployments require robust signal quality. The SNR is critical for voice performance, and the guide specifies:

"For VoWLAN, an SNR of 25 dB is typically required to ensure clear voice quality and minimal latency."

"The minimum RSSI is derived by adding the required SNR value to the measured noise floor."

This aligns with RF fundamentals where SNR is the difference between the received signal strength (RSSI) and the ambient noise floor. A higher SNR (e.g., 25 dB for voice) demands a stronger signal relative to noise. Here, a noise floor of -88 dBm plus 25 dB SNR results in -63 dBm RSSI (Option D).

Why other options fail:

A. -70 dBm: Results in 18 dB SNR (−70 − (−88) = 18 dB), insufficient for VoWLAN.

B. -67 dBm: Yields 21 dB SNR (−67 − (−88) = 21 dB), below the 25 dB requirement.

C. -65 dBm: Provides 23 dB SNR (−65 − (−88) = 23 dB), still inadequate.

Comprehensive and Detailed Explanation:

In the final meeting after successfully implementing a WLAN infrastructure, it is essential to have the acquirer and key stakeholders from the customer side present. The acquirer is typically the individual or group responsible for procuring the WLAN solution, while stakeholders include those who have an interest in the project's success, such as IT managers, network administrators, and department heads. Their presence ensures that the implementation aligns with the organization's requirements and expectations, and it provides an opportunity to address any concerns or questions before project closure.

Comprehensive and Detailed Explanation:

Hiding the Service Set Identifier (SSID) can serve specific purposes, such as:

Preventing guests from attempting to join the secured corporate network:By not broadcasting the corporate SSID, casual users are less likely to attempt connections, reducing unauthorized access attempts.

Minimizing help desk calls from users and guests attempting to join the wrong network:When only the guest network SSID is visible, it simplifies the connection process for visitors, leading to fewer support requests.

However, it's important to note that SSID hiding is not a robust security measure. Determined attackers can still detect hidden networks using various tools, as the SSID can be revealed in certain management frames like probe requests and association requests.

Comprehensive and Detailed Explanation:

Passive RFID tags lack an internal power source and rely on energy transmitted from an RFID reader to power up and communicate. In WLAN designs supporting RTLS, passive tags do not directly communicate with the WLAN infrastructure. Instead, they depend on tag readers to capture their information and relay it to the location server. This design consideration is crucial for accurate asset tracking and management.

Comprehensive and Detailed Explanation:

Including 5.5 and 11 Mbps as basic rates in a mixed 802.11b/g/n network necessitates the use of protection mechanisms, such as RTS/CTS or CTS-to-self, to prevent collisions between legacy 802.11b devices and newer 802.11g/n devices. These mechanisms introduce additional overhead, potentially reducing overall network throughput. Therefore, configuring 5.5 and 11 Mbps as basic rates will result in the constant use of protection mechanisms to maintain compatibility with 802.11b clients.

Comprehensive and Detailed Explanation:

In 802.11n, theHigh Throughput Long Training Field (HT-LTF)is utilized by the receiver to estimate the MIMO channel characteristics necessary for demodulating spatially multiplexed signals. The number of HT-LTF symbols corresponds to the number of spatial streams being transmitted. These fields are present in bothMixed ModeandGreenfield Modepreambles.

HT-LTF in Mixed Mode:The preamble includes legacy fields (L-STF, L-LTF, L-SIG) for backward compatibility, followed by HT-specific fields including HT-LTFs for MIMO channel estimation.

HT-LTF in Greenfield Mode:The preamble omits legacy fields and consists solely of HT-specific fields, including HT-LTFs, as there is no need for backward compatibility.

Comprehensive and Detailed Explanation:

Transitioning from a centralized to a distributed data forwarding model can introduce compatibility issues. Specifically:

C.Some APs designed for centralized architectures may lack the necessary hardware or firmware capabilities to support distributed forwarding features, such as local breakout or direct client-to-client communication, leading to potential limitations in functionality.

When designing a WLAN infrastructure, it's essential to calculate the Power over Ethernet (PoE) budget accurately to ensure all Access Points (APs) receive sufficient power. IEEE 802.3at, also known as PoE+, provides up to 30 watts of power per port. Therefore, for 6 APs:

6 APs × 30 W = 180 W

This calculation assumes that each AP requires the full 30 W provided by IEEE 802.3at and that there are no additional power losses or overheads. It's always a good practice to include a buffer in real-world scenarios to account for power losses in cables and potential future expansions.Quizlet