CWDP-305 Exam Dumps - CWNP CWDP Wi-Fi Design Questions and Answers

Channels 116-124 in the 5 GHz band fall under the Dynamic Frequency Selection (DFS) range. These channels are shared with radar systems, such as those used by airports. When radar activity is detected, Access Points (APs) operating on DFS channels must vacate the channel, leading to potential disruptions in service. In environments near airports, it's advisable to avoid using DFS channels to prevent such interruptions, ensuring a stable and reliable wireless experience for voice devices.

In wireless site surveys, especially when using predictive modeling tools,calibrationis a critical step to ensure that the simulated RF coverage accurately reflects the real-world environment.

Calibration involves measuring actual signal strengths at various locations within the environment and adjusting thesimul-ationparameters accordingly. This process accounts for real-world factors such as wall materials, furniture, and other obstructions that can affect signal propagation.

Failing to calibrate thesimul-ationcan lead to discrepancies between predicted and actual coverage, potentially resulting in poor network performance and user experience.

Each SSID broadcast by an AP adds additional management frame overhead, such as beacon frames. These beacon frames are transmitted periodically by the AP at the lowest mandatory data rate (e.g., 1 or 6 Mbps), which consumes airtime that would otherwise be used for client data.

According to CWDP-305:

“Each SSID increases beacon overhead. More SSIDs lead to greater airtime consumption by management traffic, which in turn decreases available throughput for actual client data traffic.”

Reducing the number of SSIDs is a best practice to minimize management overhead and optimize throughput in the wireless network.

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

A radome (a portmanteau of "radar" and "dome") is a structural, weatherproof enclosure that protects a radar or antenna system. Constructed from materials transparent to radio waves, such as fiberglass, radomes shield antennas from environmental elements like wind, rain, and debris without interfering with signal transmission. They are commonly used in outdoor wireless deployments to ensure the longevity and performance of antenna systems.

PMK caching(Pairwise Master Key caching) is a roaming technology where the access point (AP) stores the PMK derived during the initial authentication of a client station (STA).If the client roams away and then returns to the same AP, the stored PMK allows for a quicker re-association without the need for a full authentication process.

This mechanism enhances roaming efficiency by reducing latency during re-association, which is particularly beneficial for applications sensitive to delays, such as VoIP.

Comprehensive and Detailed Explanation:

While SSID hiding might seem like a security measure, it's not effective because certain management frames must include the SSID, making it discoverable. Specifically, theAssociation Requestframe always includes the SSID. This frame is sent by a client device when it attempts to associate with an access point (AP), and it must specify the SSID to identify the desired network. Therefore, even if the SSID is hidden in beacon frames, it can still be detected through association requests.

Beacon frames: Typically used by APs to advertise their presence; can be configured to omit the SSID.

Probe request/response frames: Used during active scanning; the SSID may or may not be included.

Authentication response frames: Do not necessarily include the SSID.

Antenna gain is a measure of how well an antenna directs or concentrates radio frequency energy in a particular direction. Higher gain antennas focus energy more narrowly, resulting in longer range and better signal strength in the targeted direction.

4λ Dipole:Typically offers modest gain and is omnidirectional, making it unsuitable for high-gain requirements.

Yagi:Provides moderate directional gain, generally up to around 20 dBi.

Horn:Offers directional gain, but usually not exceeding 20-25 dBi.

Dish:Parabolic dish antennas are designed for very high gain applications, often exceeding 30 dBi. They are ideal for point-to-point links over long distances.

Therefore, to achieve a gain of 35 dBi, a dish antenna is the appropriate choice.

In the 2.4 GHz band, 40 MHz channels are formed by bonding two adjacent 20 MHz channels. The primary channel is the one the client uses to initiate communication, and the secondary channel is either above (+1) or below (-1) the primary.

For channel 4 as primary with a +1 secondary offset:

Primary channel: 4 (2.427 GHz)

Secondary channel: 5 (2.432 GHz)

This configuration stays within the allowed channels 1-11.

The control plane in WLAN architectures is responsible for managing and optimizing various network functions to ensure efficient and reliable wireless communication. Key functions include:

Channel Reuse Plans:Determining optimal channel assignments to minimize interference and maximize spectrum efficiency.

Mobility Management:Facilitating seamless client roaming between access points without service interruption.

Transmit Power:Adjusting the power levels of access points to ensure adequate coverage while reducing interference.

Load Balancing:Distributing client connections across multiple access points to prevent overloading and maintain performance.

These functions are critical in both centralized and distributed WLAN architectures to maintain optimal network performance and user experience.

A client-to-AP link imbalance occurs when the AP's transmit power is significantly higher than that of the client device.This disparity can lead to situations where the client can receive signals from the AP but cannot transmit signals back effectively.This imbalance is particularly problematic in environments where clients have limited transmit capabilities, such as battery-powered devices.To mitigate this issue, it's recommended to adjust the AP's transmit power to match the capabilities of the client devices, ensuring balanced communication.