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

Comprehensive and Detailed Explanation:

In a Point-to-Multipoint (PtMP) setup where one building serves as the central hub (root bridge) connecting to multiple other buildings arranged in a square, a100° sector antennais ideal. This type of antenna provides a wide coverage area, allowing it to effectively communicate with all the other buildings positioned around it. Sector antennas focus the RF energy in a specific direction, offering better performance and reduced interference compared to omni-directional antennas in such scenarios.

When designing a wireless bridge over a distance of 13 kilometers, it's crucial to account for the Earth's curvature, known as the "Earth bulge," which can obstruct the Fresnel Zone and degrade the signal.The Fresnel Zone is an elliptical area around the line of sight between two antennas, and any obstruction within this zone can cause signal diffraction and attenuation.

The CWDP-305 Official Study and Reference Guide highlights this consideration:

"For long-distance point-to-point links, the Earth’s curvature becomes a factor, and the Fresnel Zone must be clear of obstructions, including the Earth bulge, to maintain signal integrity."

Therefore, when planning such links, engineers must calculate the Fresnel Zone and ensure that the Earth bulge does not intrude into this zone, possibly requiring higher antenna placements or alternative solutions.

In a centralized data forwarding architecture, Access Points (APs) tunnel all client traffic to the WLAN controller.The controller then processes this traffic and forwards it to the appropriate destination.During this process, the controller maps the Differentiated Services Code Point (DSCP) values from the client's IP packets to the appropriate IEEE 802.1Q priority tag values.This mapping ensures that Quality of Service (QoS) is maintained across the wired network, allowing switches and routers to prioritize traffic based on these tags.Cisco

For long-range point-to-point bridge links, dish antennas are preferred due to their narrow beamwidth and high gain. An 11 dBi dish antenna focuses energy more efficiently in a single direction, which reduces the amount of Intentional Radiator (IR) power needed to meet link budget requirements.

From CWDP-305:

“Dish antennas provide high gain and a narrow beam, making them ideal for point-to-point bridge links over long distances. This minimizes interference and maximizes EIRP efficiency.”

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

In the 5 GHz band, certain channels like 144 are not universally supported across all devices, especially older 802.11n clients. If the AP is operating on channel 144, and the client's regulatory domain or hardware does not support this channel, the SSID will not be visible to the client.

The CWDP-305 Official Study and Reference Guide notes:

"Client devices may not support all channels in the 5 GHz band, depending on their regulatory domain and hardware capabilities. Channel 144, for example, is not supported by all 802.11n clients."

Centralized data forwarding means all wireless traffic is tunneled back to a central controller, which handles tasks such as filtering, firewalling, and policy enforcement.

From CWDP-305:

“Centralized data forwarding enables consistent policy enforcement and traffic filtering by handling all traffic at the controller rather than at individual APs.”

This approach provides better control and visibility, especially in environments with strict security and traffic management requirements.

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

The 1 dB compression point of an amplifier indicates the output power level at which the amplifier's gain drops by 1 dB from its linear gain, signaling the onset of non-linear behavior and potential distortion.

Given a 1 dB compression point of 32 dBm and a gain of 20 dB, the maximum linear input power can be calculated as:

32 dBm (compression point) − 20 dB (gain) = 12 dBm

To ensure operation within the linear region and avoid spectral regrowth, it's advisable to operate the amplifier below this threshold.An input power of 0 dBm provides a safe margin, ensuring signal integrity for a 24 Mbps 802.11g transmission.

Site survey adapters are often specialized devices with enhanced sensitivity and are calibrated for accurate measurements. In contrast, standard client devices may have varying hardware and driver configurations, leading to differences in RSSI readings. Therefore, it's common to observe discrepancies between survey results and actual client experiences. This emphasizes the importance of considering client device capabilities during WLAN design and validation.

When conducting a predictive site survey, it's essential to configure the simulated APs to reflect the expected real-world conditions.If dynamic Radio Resource Management (RRM) will be utilized, setting the AP transmit power to an estimated average level that matches the expected client devices, such as 25 mW, ensures that the predictive model accurately represents the operational environment.This approach helps in designing a WLAN that provides optimal coverage and performance.

Comprehensive and Detailed Explanation:

Ensuring high availability in RF design involves strategies that provide redundancy and resilience:

C. Deploy using 100 percent overlap:Overlapping coverage areas between APs ensure that if one AP fails, clients can seamlessly connect to another, maintaining network availability.

E. Use dual spectrums:Utilizing both 2.4 GHz and 5 GHz bands allows for flexibility and redundancy. If one band experiences interference or congestion, clients can switch to the other.

A. Powering APs to maximum powercan lead to increased interference and is not a recommended practice for high availability.

B. HSRP/VRRP protocolsare related to router redundancy and do not directly impact RF availability.

D. Deploying 802.3afrefers to Power over Ethernet standards and, while important for powering devices, does not directly contribute to RF high availability.