Module 3 Review Exam

Frequency Options

• Frequency bands are sections of the electromagnetic spectrum used by wireless devices for data transmission.
• Regulatory bodies assign specific bands for different wireless technologies in their regions.
• Frequency measures how many times an electromagnetic wave oscillates per second, measured in Hertz (Hz).
• Higher frequencies oscillate faster, while lower frequencies oscillate slower.
• 2.4 GHz oscillates 2.4 billion times per second; 5 GHz oscillates 5 billion times per second; 6 GHz oscillates 6 billion times per second.
• Wi-Fi data transmission uses radio waves, often following a sinusoidal pattern (sine wave).
• A cycle represents one complete oscillation, measured in Hertz (Hz).
• Frequency is critical for wireless communications, influencing attributes like data carrying capacity.
• Higher frequencies carry more data per second (data rate) than lower frequencies.

Wireless Performance Technologies

• Single Input Single Output (SISO) utilizes a single antenna for both transmission and reception, common in older devices.
• Multiple Input Multiple Output (MIMO) uses multiple antennas for simultaneous data transmission and reception.
• Single User MIMO (SU-MIMO) allows one device to send and receive up to 8 spatial streams to increase data rates.
• Multi-User MIMO (MU-MIMO) allows an access point to send data to multiple clients simultaneously.

Range and Obstacle Penetration

• Lower frequencies can travel further and penetrate obstacles better than higher frequencies.

Interference and Congestion

• Lower frequencies, especially the 2.4 GHz band, experience more congestion and interference due to competing devices.
• Higher frequencies generally experience less interference.

Band Steering

• Band steering is a network management feature which guides devices to connect to the most appropriate frequency band.
• Devices connect to the band with the best signal strength, lower network load, and supports the device.

Channels, Bandwidth, Overlap, and Regulatory Impacts

• Wi-Fi frequency bands are divided into channels, allowing multiple networks to operate in the same band without interference.
• Different regions have different channel allocations.
• Adjacent channel overlap can cause interference in 2.4 GHz networks.
• The 5GHz band supports numerous channels and typically has greater data capacity than the 2.4GHz band.

Wireless Security Settings

• Wireless communication needs confidentiality, integrity, authentication, and authorization.
• Wired Equivalent Privacy (WEP) was an initial attempt at wireless security but is now deprecated due to vulnerabilities.
• Wi-Fi Protected Access (WPA) was an improvement on WEP; WPA2 built on WPA and used AES encryption.
• Wi-Fi Protected Access 3 (WPA3) is the current standard, replacing WPA2 and improving security features like Simultaneous Authentication of Equals (SAE).

Service Set Identifier (SSID) and Basic Service Set Identifier (BSSID)

• The service set identifier (SSID) is a unique name identifying a wireless network.
• The basic service set identifier (BSSID) represents the MAC address of the access point (AP) within the network.

Network Types

• Infrastructure networks: A traditional Wi-Fi setup where devices connect to an access point.
• Ad hoc networks: Devices communicate with each other directly, without an access point.

Point-to-Point Networks

• Directly connects two devices, ideal for dedicated and high-bandwidth connections over a short distance.
• Often used for extending a network to remote locations, connecting to a cloud service provider or a similar use case.

Mesh Networks

• Decentralized wireless network architecture where nodes communicate directly with each other, forming a web-like structure.
• Enables dynamic routing and self-healing, useful for extended areas.

Antennas

• Antennas affect signal strength, range, and coverage patterns.
• Omnidirectional antennas provide broad coverage.
• Directional antennas concentrate the signal in a specific direction, for longer range or point-to-point connections.

Power Management

• "Perfect power" is rarely consistent. Stability is crucial for network device operation.
• Voltage fluctuations (surges, sags, brownouts, and blackouts) can damage equipment.
• Calculating total power load (wattage) is important for reliable power supply.
• Recommended using a power factor (0.7-0.8 or higher for safety) for sizing a UPS.

Environmental Factors

• Controlling humidity (40%-60% relative humidity) and temperature (64-80 degrees Fahrenheit) optimizes equipment performance and prevents ESD issues.
• Fire suppression systems, such as clean agents (water mist or pre-action sprinklers), are important for protecting valuable equipment.

Important Installation Implications

• Location of IDF and MDF (intermediate and main distribution frames) determines cable lengths and network access points.
• Proper network cabling follows standards, using structured cabling methods with components such as patch panels, keystone jacks, and connectors.
• Work Area outlines the connection point where end-user devices connect into the network. Horizontal and Backbone cables form the structured cabling.