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A network administrator is designing the layout of a new wireless network. Which three areas of concern should be accounted for when building a wireless network? (Choose three.)

• mobility options
• security
• interference
• coverage area
• packet collision
• extensive cabling

When designing a wireless network, network administrators must consider several critical factors to ensure the network operates efficiently, securely, and meets the needs of the organization or environment it serves. Among the various factors to consider, security, interference, and coverage area stand out as three of the most crucial areas of concern. Each of these factors plays a significant role in the overall performance and reliability of the wireless network. Below, we will explore these three areas in detail, along with brief discussions on other related factors.

1. Security

Security is a paramount concern in wireless network design due to the inherent vulnerabilities associated with wireless communication. Unlike wired networks, where physical access to the network is required, wireless networks transmit data over the airwaves, making them susceptible to various security threats, including unauthorized access, eavesdropping, data interception, and man-in-the-middle attacks.

To mitigate these risks, network administrators must implement robust security measures, including:

• Encryption: Encrypting wireless communication using protocols such as WPA3 (Wi-Fi Protected Access 3) ensures that data transmitted over the network is not easily intercepted or deciphered by unauthorized individuals. WPA3 provides stronger security than its predecessors (WPA2, WPA) by offering improved encryption and authentication mechanisms.
• Authentication: Ensuring that only authorized users and devices can connect to the wireless network is crucial. Implementing authentication protocols like 802.1X, which uses a RADIUS server to verify credentials, can significantly enhance network security.
• Network Segmentation: Segmenting the wireless network into different virtual LANs (VLANs) based on user roles or device types can help contain potential security breaches. For example, guest users can be placed on a separate VLAN with limited access to critical network resources.
• Intrusion Detection and Prevention Systems (IDPS): Deploying IDPS can help detect and prevent unauthorized access attempts, as well as monitor network traffic for signs of suspicious activity.
• Regular Security Audits and Updates: Regularly auditing the wireless network’s security and keeping firmware and software up to date is essential in mitigating emerging threats.

2. Interference

Interference is another critical factor that can significantly impact the performance and reliability of a wireless network. Wireless networks operate on specific radio frequency (RF) bands, such as 2.4 GHz and 5 GHz, which are shared by various other devices and technologies. Interference occurs when these frequencies are congested or when other devices emit signals that disrupt wireless communication.

There are two main types of interference:

• Co-channel Interference: This occurs when multiple wireless access points (APs) operating on the same channel interfere with each other. To minimize co-channel interference, network administrators should carefully plan the placement and channel assignment of APs, ensuring that adjacent APs use non-overlapping channels.
• Adjacent-channel Interference: This occurs when APs operating on neighboring channels overlap in frequency, leading to signal degradation. Using proper channel spacing and avoiding the use of overlapping channels can help reduce adjacent-channel interference.

Other sources of interference include:

• Physical Obstacles: Walls, floors, and other physical barriers can weaken or block wireless signals, leading to reduced network performance. Using higher-frequency bands like 5 GHz, which are less susceptible to interference but have shorter range, may help in densely built environments.
• Electromagnetic Interference (EMI): Devices such as microwaves, cordless phones, Bluetooth devices, and even fluorescent lights can emit electromagnetic interference that disrupts wireless communication. Identifying and minimizing the presence of such devices in close proximity to the wireless network can help reduce interference.
• Environmental Factors: Weather conditions, such as heavy rain or humidity, can also affect wireless signal strength and quality. While these factors are harder to control, understanding their impact can help in designing a more resilient network.

3. Coverage Area

Coverage area refers to the geographical region within which a wireless network provides reliable connectivity. Properly planning the coverage area is essential to ensure that all intended users and devices can access the network with sufficient signal strength and quality.

Several considerations are important when planning the coverage area:

• Access Point Placement: The placement of wireless access points (APs) is crucial in determining the coverage area. APs should be strategically located to provide optimal coverage while minimizing dead zones (areas with little or no signal). In large or complex environments, using site surveys or heat maps can help identify the best locations for APs.
• Signal Propagation: Understanding how wireless signals propagate through the environment is essential. Factors such as building materials, room layout, and the presence of obstacles can affect signal strength and quality. For example, signals may be weaker in areas with thick walls or metal structures, requiring additional APs or the use of signal boosters to ensure adequate coverage.
• Frequency Band Selection: The choice of frequency band (e.g., 2.4 GHz vs. 5 GHz) also affects coverage. The 2.4 GHz band offers longer range but is more prone to interference, while the 5 GHz band provides faster speeds with less interference but has a shorter range. In some cases, a dual-band network may be implemented to balance coverage and performance.
• Capacity Planning: In high-density environments, such as offices or conference centers, it is important to consider the number of devices that will be connecting to the network. Ensuring that the network can handle the anticipated load without compromising performance is critical. This may involve using more APs, distributing clients across different bands, or implementing load-balancing techniques.

Brief Overview of Other Factors

While security, interference, and coverage area are among the top concerns, there are other factors that network administrators should also consider:

• Mobility Options: For networks that need to support mobile users or devices, ensuring seamless roaming between APs without dropping connections is important. This may require careful planning of AP overlap and the use of features like fast roaming.
• Packet Collision: While more of a concern in wired networks, packet collision can still occur in wireless networks, especially in environments with high traffic. Using proper network segmentation and collision avoidance protocols (e.g., CSMA/CA) can help reduce collisions.
• Extensive Cabling: Although wireless networks reduce the need for physical cabling, some cabling is still necessary, particularly for connecting APs to the wired backbone. Planning the cabling layout to minimize costs and complexity is an important consideration.

Conclusion

Designing a wireless network requires careful consideration of various factors to ensure optimal performance, security, and user satisfaction. Security, interference, and coverage area are three of the most critical areas of concern, but they are not the only ones. By addressing these concerns comprehensively and planning for the unique challenges of the deployment environment, network administrators can build a robust and reliable wireless network that meets the needs of its users.