2.3 - Wireless Devices and Technologies

Channels

Subdivisions of the frequency bands used for wireless communication, allowing multiple networks to operate simultaneously without interference. The availability and allowed types can vary by country, subject to regulatory impacts that dictate the specific options and power levels that can be used.

Channel Width

Refers to the frequency span of a wireless channel. Wider options (e.g., 40 MHz, 80 MHz) offer more bandwidth, which can increase data transmission speeds but may also increase the likelihood of interference in congested areas.

Non-Overlapping Channels

Do not interfere with each other and are crucial in environments with multiple wireless access points. For instance, in 2.4 GHz Wi-Fi, channels 1, 6, and 11 are commonly used in the US because they do not overlap.

Regulatory Impacts

Rules and regulations set by governmental or international bodies that govern the use of wireless frequencies and channels to prevent interference between different communication systems. These regulations affect the availability of certain frequencies and channels in different regions, impacting the design and deployment of wireless networks. Compliance ensures the wireless networks operate within the legal spectrum allocations and use approved power levels, minimizing interference with other devices and services.

802.11h

A standard that enhances 802.11a by adding support for dynamic frequency selection (DFS) and transmit power control (TPC) to comply with European regulations for 5 GHz WLANs. This helps in avoiding interference with radar and satellite communications, which also operate in the same frequency range.

2.4GHz

Widely used for wireless networking, offering a good balance between range and bandwidth. This band can penetrate walls and solid objects more effectively than higher frequencies, making it suitable for covering larger areas, but is more prone to interference from other devices like microwaves and Bluetooth due to its crowded spectrum.

5GHz

This band provides faster data rates at shorter distances compared to lower frequencies and is less likely to experience interference from other household devices. It supports more non-overlapping channels, reducing congestion and improving network performance, but has a shorter range and less effective penetration through walls and obstacles.

6GHz

This band marks a significant expansion in bandwidth for wireless networks, effectively doubling the spectrum available compared to the 5GHz band. This increase supports higher data rates, lower latency, and more simultaneous connections, making it ideal for high-demand applications and next-generation technologies like WiFi 6E.

Band Steering

A network management technology that automatically detects wireless devices capable of dual-band operations and moves them to the less congested 5 GHz or 6 GHz band. This process helps to balance the network load, maximize throughput, and improve overall wireless performance by minimizing interference found more commonly in the 2.4 GHz band. By optimizing the distribution of devices across available bands, efficiency and reliability of wireless networks is enhanced, especially in areas with high network density.

Service Set Identifier

The SSID is the name assigned to a wireless network. All devices attempting to connect to a particular wireless network must use this name to access it, serving as a basic form of network identification and security.

BSSID

A unique identifier that serves as the MAC address for a wireless access point (AP) and is used to differentiate one AP within a larger network or between multiple networks. It is essential in environments where multiple access points are deployed, helping client devices identify and connect to the specific physical device providing the network service.

Extended SSID

Also known as a Network Name, ESSID is used to identify a set of interconnected access points as a single network in larger WiFi deployments. It is shared among all APs in an Extended Service Set (ESS) to allow seamless connectivity for client devices as they move between APs. This facilitates the creation of large, scalable wireless networks, providing continuous connectivity across different physical locations within the covered area, enhancing user mobility and network efficiency.

Mesh Networks

Consist of nodes that connect directly and dynamically to as many other nodes as possible. This configuration creates multiple pathways for data to travel between points, enhancing reliability and redundancy. They are self-healing and scalable, making them ideal for large areas like smart cities and IoT applications.

Ad Hoc Networks

Decentralized and do not rely on a pre-existing infrastructure; P2P network. Nodes communicate directly without the use of a router or a network server, making them suitable for temporary setups in situations where quick deployment is necessary, such as emergency response or military operations.

Point-to-Point Networks

Establish a direct connection between two wireless devices. Commonly used for linking two locations in a WAN or providing a dedicated pathway for data transmission, ensuring consistent and reliable connectivity.

Infrastructure Networks

Rely on fixed routers or access points that manage traffic to and from wireless devices. This is the most common type of network setup for residential and commercial internet connections, providing stable and controlled connectivity, with the access points serving as the hub for all wireless communication.

Encryption

Crucial in wireless networking to secure data transmissions against unauthorized access and interception. It involves converting data into a coded format that can only be accessed and read by devices with the correct decryption key.

WPA2

A security protocol developed to secure wireless computer networks. It uses Advanced Encryption Standard (AES) encryption and provides substantial improvements in security over its predecessor by requiring stronger encryption methods and ensuring data integrity.

WPA3

The latest security protocol for wireless networks, introduced to address vulnerabilities found in WPA2 and provide enhanced security measures. It offers features like individualized data encryption, protection from brute-force attacks, and easier connection options for devices without a display.

Note the biggest difference between WPA2 and WPA3 is forward secrecy via Simultaneous Authentication of Equals; future cracked traffic won’t compromise past traffic

Guest Networks

Separate access networks provided by businesses or institutions to allow visitors limited internet access without exposing the main network. They help maintain network security by isolating visitor traffic from critical internal resources.

Captive Portals

Web pages that appear automatically when a user connects to a public or semi-public Wi-Fi network, requiring interaction before network access is granted. They are commonly used to manage access through authentication, terms of service agreements, or payment information.

Authentication

A critical security process in wireless networks, ensuring that only authorized devices can connect. It verifies the identities of devices attempting to connect, using various methods to prevent unauthorized access.

Pre-shared Key (PSK)

Involves a simple, shared key known to all users of the network, commonly used in home and small office environments. It offers ease of setup but lower security as the key is shared among users.

Enterprise Authentication

Uses a more secure approach by employing a RADIUS server to manage each user's authentication individually. This method is suited for larger organizations, providing stronger security through individual credentials and enhanced control over network access.

Directional Antenna

Antennas that focus the signal in a specific direction, offering longer range and improved signal strength in the targeted area. They are suitable for point-to-point connections or when the wireless signal needs to be directed over a long distance or to avoid interference.

Omnidirectional Antenna

Antennas that radiate and receive signals in all directions equally, making them ideal for covering a broad area from a central location. They are commonly used in home and office Wi-Fi setups where uniform coverage is needed.

Autonomous Access Point

Standalone units that handle all their operations and configurations independently, without the need for centralized control. Each unit is a self-contained router, performing all tasks including broadcasting SSIDs, serving as the DHCP server, and managing security protocols. Ideal for smaller networks or remote locations without centralized management.

Lightweight Access Point

Operate under the control of a centralized network controller, typically a wireless LAN controller (WLC). These units offload processing of real-time decision-making and user data broadcasting to the WLC, allowing for easier management and scalability. Suitable for larger networks where centralized control can provide significant advantages in performance and administration.

Autonomous AP vs Lightweight AP

The main difference is in their management architecture. Autonomous APs operate independently and are managed individually, while lightweight APs require a centralized wireless LAN controller for management and coordination. The choice between the two types of APs depends on factors such as the size of the deployment, management requirements, and scalability needs of the wireless network.