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

To calculate the required transmit power (Tx Power) for a desired Effective Isotropic Radiated Power (EIRP), the following formula is used:

EIRP (dBm) = Tx Power (dBm) + Antenna Gain (dBi) - Cable Loss (dB)

Given:

Desired EIRP: 21 dBm

Antenna Gain: 5.85 dBd (which is approximately 8 dBi, since 0 dBd = 2.15 dBi)

Cable Loss: (25 feet / 100 feet) * 4 dB = 1 dB

Plugging into the formula:

21 dBm = Tx Power + 8 dBi - 1 dB

Tx Power = 21 dBm - 8 dBi + 1 dB = 14 dBm

Converting 14 dBm to milliwatts:

10^(14/10) ≈ 25.12 mW

However, since 14 dBm is approximately 25 mW, the closest answer is:

Answer:D

In Voice over WLAN (VoWLAN) deployments, it's crucial to differentiate between various types of voice-related traffic to ensure optimal Quality of Service (QoS).Real-Time Protocol (RTP) carries the actual voice payload, while control protocols like RTCP manage session control and quality feedback.Assigning distinct priority levels to these traffic types allows the network to prioritize voice payloads appropriately while still handling control traffic efficiently.

Comprehensive and Detailed Explanation:

The 2.4 GHz band has only three non-overlapping channels: 1, 6, and 11.Using other channels can lead to overlapping and interference.To prevent this, the automatic channel assignment settings should be configured to use only channels 1, 6, and 11, ensuring minimal overlap and optimal performance.

Comprehensive and Detailed Explanation:

The "Network Card Simul-ation" feature in site survey software allows the simul-ation of RF data as if it were received by a specific client device.This is particularly useful for assessing uplink performance and understanding how different client devices, with varying antenna gains and sensitivities, would perform in the surveyed environment.By simulating different client types, network designers can ensure that the WLAN design accommodates the performance requirements of all intended client devices.

This is a classic example of a WLAN designed for coverage but lacking capacity. Simply adding more APs without proper planning (option C) or increasing output power (option D) would likely lead to channel contention, co-channel interference, and degraded performance.

A proper redesign would include:

Evaluating user density

Planning for spatial reuse

Implementing low-power, high-density AP placement

Selecting appropriate channels and RF tuning

From CWDP-305:

“High-density environments such as auditoriums require WLANs designed for capacity, not just coverage. This includes AP placement optimization, channel planning, and potentially microcell designs to manage client load effectively.”

— Reference: CWDP-305 Official Study and Reference Guide, Chapter on Designing for Specific Applications

Comprehensive and Detailed Explanation:

Modulation is the technique of varying a carrier signal's properties—such as amplitude, frequency, or phase—to encode and transmit data. This process allows the transmission of information over various mediums, including radio frequencies used in wireless communications.

Option A:Describes spread spectrum techniques, not modulation.

Option B:Is a partial description but lacks the specificity of how the carrier is modified.

Option D:Is a vague statement that doesn't accurately define modulation.

Wi-Fi Multimedia (WMM) is a feature that enables Quality of Service (QoS) on 802.11 networks, allowing for the prioritization of different types of traffic such as voice, video, and data. If WMM is not enabled, the network cannot differentiate or prioritize traffic types, leading to potential performance issues, especially for latency-sensitive applications like VoIP or video conferencing. Therefore, without WMM, 802.11 QoS functionalities are unavailable, impacting the overall efficiency and user experience of the WLAN.

Comprehensive and Detailed Explanation:

The 5 GHz band offers more non-overlapping channels and is less susceptible to interference compared to the 2.4 GHz band. By moving corporate data clients and VoWiFi devices to the 5 GHz band, the network can achieve better performance and reduced interference, especially for latency-sensitive applications like voice over Wi-Fi.

An AP-on-a-Stick (APoS) survey is a method used to validate predictive WLAN designs by temporarily placing an access point at the planned installation location and measuring its performance in the actual environment. This approach helps in confirming the accuracy of the predictive model and ensures that the AP placement will meet the desired coverage and performance requirements.

In the 5 GHz band, all Wi-Fi traffic (802.11a/n/ac/ax) uses OFDM or OFDMA modulation. If multiple APs use overlapping or identical channels, this results in Co-Channel Interference (CCI). Legacy technologies like HR/DSSS and ERP operate in 2.4 GHz and do not contribute to CCI in 5 GHz.

From CWDP-305:

“CCI occurs when multiple devices share the same channel. In 5 GHz, all compliant Wi-Fi traffic uses OFDM-based PHYs, so other nearby OFDM networks are a primary source of CCI.”

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