Benefits and Risks of Wireless Networks

Benefits of Wireless Networks

• Wireless networks allow devices to connect without wires, increasing freedom of movement.
• Mobile phones can use Wi-Fi to save on data costs.
• Wi-Fi networks offer high bandwidth, suitable for internet connectivity.
• Any Wi-Fi-enabled device can connect if it complies with the Wi-Fi standard and has permission.
• Setting up a Wi-Fi network at home is relatively simple, even for those without technical expertise.
• Wireless networks are comparatively cost-effective due to the reduced need for cabling.
• Employees can utilize their own devices (BYOD) at work.

Risks of Wireless Networks

• Hackers can access data transmitted over a wireless network if encryption is not implemented.
• Hackers need not gain physical access to the network, merely a wireless connection.

Disadvantages of Wireless Networks

• Wireless bandwidth typically falls short of wired bandwidth, but this is usually not a concern if the internet bandwidth is limiting.
• Obstacles can interrupt wireless signals, leading to data packet loss and reduced bandwidth.
• The range of wireless connections is limited, requiring additional access points for larger areas.
• Interference from electrical signals and microwaves can disrupt signals, resulting in data packet loss and reduced bandwidth.
• Bandwidth is shared among all devices connected to the network.

Bluetooth

• A wireless communication protocol designed for short-range (approximately 10 meters) communication.
• It does not require a direct line of sight, making it practical for portable devices within a personal area network (PAN).

Typical Bluetooth Applications

• Utilizing a mobile phone in a vehicle via Bluetooth.
• Employing a Bluetooth speaker to play music.
• Tethering a mobile phone’s internet connection to create a mobile hotspot.
• Viewing text messages on an Apple Watch connected through Bluetooth.

Advantages of Bluetooth

• Widely available on numerous portable devices.
• No radio frequency license is required.
• No line of sight is necessary.
• Passkeys can be used to prevent unauthorized devices from connecting.
• Lower power consumption compared to Wi-Fi.

Limitations of Bluetooth

• Current data transfer speeds are slow.
• The maximum range is limited to approximately 10 meters.
• Only one device can connect to another device at a time. For instance, a Bluetooth headset cannot be used concurrently with a Bluetooth speaker when both are linked to the same mobile phone.

Zigbee

• A personal area network (PAN) protocol based on low energy, low data rates, and short-range communication.
• It is commonly employed for smart home devices and falls under the Internet of Things (IoT) umbrella.
• Devices can be added to a Zigbee network in an ad-hoc manner.

Smart Home Devices

• Common devices that may use Zigbee include:
  • House alarms.
  • Light bulbs.
  • Light switches.
  • Smart plugs.
  • Central heating systems.
  • Electronic blinds.
• Many smart home devices are battery-powered, and Zigbee’s long battery life can extend up to several years.

Zigbee vs. Other Wireless Methods

• Zigbee has a greater range than Bluetooth and forms its own mesh network, allowing smart devices to act as repeaters.
• Zigbee's maximum bandwidth is 250 kbps, significantly lower than Wi-Fi, but sufficient for most smart devices.
• Zigbee does not rely on cloud servers and can connect directly to a controller.

Zigbee Standards

• While Zigbee is a protocol, there is no standardized implementation.
• Different manufacturers use it in varying ways, requiring separate controllers for each.
• Some manufacturers are compatible with common controllers such as Amazon Echo Show, Samsung Smart Things, and Apple Home Kit.
• The Project Connected Home Over IP (CHIP) is an alliance of
  manufacturers aiming to standardize communication between smart devices.

Example of Standards Problem

• Devices from the "Red" manufacturer can only communicate with a "Red" controller and other "Red" devices.
• Devices from the "Red" manufacturer cannot communicate with "Blue" or "Pink" devices or controllers.
• This results in three separate mesh networks.
• CHIP's goal is to establish a unified mesh network encompassing devices from all manufacturers.

Combining Wired and Wireless Networks

• Most networks are a blend of wired and wireless components.
• Examples include copper cables, fiber optics, Wi-Fi, Bluetooth, and Zigbee.
• Controllers, such as Wi-Fi access points, Zigbee controllers, RFID scanners, and NFC-enabled devices, are connected to the network.

Network Speed Expressions

• Network speeds are measured in bits per second (bps).
• Common multiples used include:
  • Kilobits per second (Kbps): 1,000 bits per second.
  • Megabits per second (Mbps): 1,000,000 bits per second.
  • Gigabits per second (Gbps): 1,000,000,000 bits per second.
• One byte is equal to 8 bits.
• Network speeds are traditionally measured in bits, not bytes. For instance, 16 Mbps is equivalent to 2 MB per second.

Base-10 vs. Base-2

• Network speeds employ base-10 units:
  • 1 Kbps = 1,000 bits per second (103) or (10001).
  • 1 Mbps = 1,000,000 bits per second (106) or (10002).
  • 1 Gbps = 1,000,000,000 bits per second (109) or (10003).
• File sizes use base-2 units:
  • 1 KiB (kibibyte) = 1,024 bytes (210).
  • 1 MiB (mebibyte) = 1,024 x 1,024 bytes (220).
  • 1 GiB (gibibyte) = 1,024 x 1,024 x 1,024 bytes (230).

File Size in Bits

• 1 byte (B) = 8 bits.
• 1 KiB (kibibyte) = 1,024 bytes (210) = 1,024 x 8 bits.
• 1 MiB (mebibyte) = 1,024 x 1,024 bytes (220) = 1,024 x1,024 x 8 bits.
• 1 GiB (gibibyte) = 1,024 x 1,024 x 1,024 bytes (230) = 1,024 x 1,024 x 1,024 x 8 bits.

Expression for Time Taken

• Time taken to transfer a file (seconds) = File size in bits / Network speed in bits per second.

Time Taken Expression - Example

• File size = 15 MiB.
• File size in bytes = 15 x 1,024 x 1,024.
• File size in bits = 15 x 1,024 x 1,024 x 8.
• Network speed = 1 Gbps.
• Network speed = 1 x 1,000 x 1,000 x 1,000 bps.

Expression for Number of Bytes Per Second

• Number of bytes per second = Network speed in bits per second /

• Number of MB (megabytes) per second = Network speed in bits per second / 8 / 1,024 / 1,024.

Bytes Per Second Expression - Example

• Network speed = 2 Mbps.
• Network speed = 2 x 1,000 x 1,000 bps.
• Number of KiB (kibibytes) transferred per second = Network speed in bits per second / 8 / 1,024.

Expression for Number of Files Per Second

• Number of files/packets per second = Network speed in bits per second / File size in bits.
• Number of files/packets per second = Network speed in bits per second / (File size in bytes x 8).

Files Per Second Expression – Example

• Network speed = 18 Mbps.
• Network speed = 18 x 1,000 x 1,000 bps.
• File size = 250 KiB.
• 250 KiB = 250 x 1,024 bytes.
• 250 KiB in bits = 250 x 1,024 x 8.