Book-Notes Section 13 Flashcards
📶 What are Bluetooth and Zigbee?
They are both wireless communication technologies used to connect devices without cables, but they are designed for different purposes.
🔵 Bluetooth – For short-range, high-speed connections
✅ Best for: Transferring files, audio, or connecting devices like headphones, keyboards, or phones
📏 Range: Short (usually up to 10 meters)
🚀 Speed: Faster (suitable for things like music or data transfer)
🔋 Power usage: Medium to high
👥 Connections: Usually 1-to-1 or a few devices
🧠 Example: Listening to music on wireless Bluetooth earbuds
🟣 Zigbee – For low-power, low-speed, long-range smart devices
✅ Best for: Home automation and IoT (Internet of Things), like smart lights, thermostats, or door sensors
📏 Range: Longer (10–100 meters, often with devices helping each other extend the range)
🚀 Speed: Slower (enough for tiny bits of data, like turning a light on/off)
🔋 Power usage: Very low (great for battery-powered sensors)
👥 Connections: Supports many devices (like a smart home network)
🧠 Example: A smart home hub controlling dozens of light switches and sensors
📡 What is an Ad Hoc Wireless Network?
An ad hoc network is a type of wireless network where devices connect directly to each other without needing a router or access point.
🧠 Simple Definition:
An ad hoc wireless network is when devices (like phones or laptops) talk directly to each other, like a peer-to-peer setup, instead of going through a central Wi-Fi router.
🧾 Example:
You’re with a friend and want to share files.
You set up a Wi-Fi direct or ad hoc connection between your laptops.
Now, your devices are connected without needing the internet or a Wi-Fi router.
🟦 Bluetooth – Can Be Ad Hoc
Yes, Bluetooth can be used as an ad hoc network, especially in peer-to-peer connections.
Example:
You pair your phone with your friend’s phone via Bluetooth to send a file — that’s ad hoc.
There’s no central device — just direct communication.
However:
In cases like using Bluetooth headphones or keyboards, it’s more like a simple paired connection, not a full network.
🟣 Zigbee – Usually Not Ad Hoc
Zigbee typically uses a coordinator (central device) to manage the network, so it’s usually not ad hoc.
Instead, Zigbee uses a mesh network, where devices forward messages to each other through the coordinator.
However:
In special setups where devices talk directly without a coordinator, it could behave like an ad hoc network, but that’s not the common use case.
📶 What does it mean that 5G needs greater antenna density?
It means that 5G networks need more antennas placed closer together than older networks like 4G or 3G.
🧠 Why?
Because 5G (especially the high-speed version, called mmWave) uses higher frequency signals. These signals:
📏 Don’t travel as far
🧱 Can’t pass through walls or buildings very well
🌳 Are easily blocked by trees, glass, or even rain
So to make sure the signal reaches your phone reliably and quickly, 5G networks need:
➡️ More antennas
➡️ Placed closer together (high density)
➡️ Often installed on light poles, rooftops, buildings, etc.
🔐 What are Bluetooth Security Modes?
Bluetooth security modes define when and how security (like authentication and encryption) is applied during a Bluetooth connection.
Different versions of Bluetooth (like Bluetooth Classic vs Bluetooth Low Energy) use different modes — but here’s a simple look at the main four modes, mostly for Bluetooth Classic:
🔹 Security Mode 1 – No Security
🔓 No authentication, no encryption
Devices connect freely with zero protection
❌ Not recommended today
🧠 Example: Very old Bluetooth devices or early prototypes
🔹 Security Mode 2 – Service-Level Security
🔐 Security is applied at the application/service level
Devices can connect without security, but specific services (like file sharing) may require pairing or encryption
Flexible but less secure, because the connection itself may be open
🔹 Security Mode 3 – Link-Level Security
🔒 Security is enforced before the Bluetooth connection is established
Requires authentication and encryption for every connection
Used by devices that need strong security, like industrial or medical devices
🔹 Security Mode 4 – Secure Simple Pairing (SSP)
🆕 Introduced in Bluetooth 2.1 and later
Supports Secure Simple Pairing with stronger encryption (AES-128)
Has different pairing methods based on the device’s capabilities:
Just Works
Passkey Entry
Numeric Comparison
Out-of-Band (like using NFC)
✅ Most modern Bluetooth devices (like smartphones, speakers, and headsets) use this mode
🏷️ What are RFID tags?
RFID tags are little devices used for tracking or identifying things wirelessly using radio signals.
They come in three types based on how they’re powered — and this affects their range, cost, and use.
🔋 1. Active RFID Tags
✅ Have their own battery
📡 Send signals on their own
🔁 Can talk to readers from far away
💲 More expensive, larger in size
📏 Range: Up to 100 meters or more
🧠 Used for: Vehicle tracking, toll systems, large asset tracking
🟡 2. Semi-Active (Semi-Passive) RFID Tags
✅ Have a battery, but…
❌ Don’t transmit on their own — wait for a reader to activate them
🔋 Battery helps power the chip (so it can respond better)
💲 Medium cost, smaller than active tags
📏 Range: Around 10 to 50 meters
🧠 Used for: Temperature sensors, warehouse tracking, shipping containers
⚪ 3. Passive RFID Tags
❌ No battery
💡 Get power from the RFID reader’s signal
🪶 Very small and cheap
📶 Need to be close to the reader
📏 Range: Very short — usually a few centimeters to a few meters
🧠 Used for: Contactless credit cards, key cards, library books, inventory tags
🏷️ First — What’s inside an RFID tag?
RFID tags have memory (like a tiny storage space) that holds data — like an ID number or product info.
Depending on the type of tag, that memory can be:
Locked (read-only)
Editable (write or rewrite)
📘 1. Read-Only Tags
✅ You can only read the data
❌ You cannot change or delete it
Data is programmed once (usually at the factory)
🧠 Example:
A tag with a serial number hardcoded into it
Used for tracking assets where the ID never changes
✍️ 2. Write-Only Tags
❌ You can only write data to it
✅ But you can’t read what you wrote (this is rare)
🧠 Example:
Used in secure environments where data must be hidden
Could be used for confidential logging (write-only box)
✅ Not common in everyday RFID use
🔄 3. Rewritable Tags (Read/Write Tags)
✅ You can read and update the data many times
🧹 You can erase and rewrite it as needed
Very useful for dynamic info (like changing temperatures, locations, or status)
🧠 Example:
A warehouse tag that updates a product’s location
A shipping tag that logs temperature over time
🚗💨 What is an RFID-based tolling system?
An RFID-based tolling system is a wireless way to collect tolls from vehicles as they pass through a toll road or bridge — without stopping.
Instead of paying cash or using a ticket, your car has an RFID tag, and toll sensors read it automatically when you drive by.
🧠 How does it work?
🚘 Your car has a small RFID tag (usually a sticker or device on your windshield).
🏗️ You drive through a toll lane or under a gantry.
📡 The system has RFID readers that scan your tag wirelessly.
💳 The system charges your account automatically.
No stopping. No barriers. Just drive through!
🏷️ What kind of tag is used?
Usually a passive RFID tag (no battery)
The toll reader sends a signal → powers the tag → reads its ID
✅ Benefits:
⏱️ Fast — no need to stop or slow down
🚫 Contactless — no cash, no touching
👮 Reduces traffic jams at toll booths
📈 Accurate and automated toll tracking
Passive RFID tags are typically short-range (a few centimeters to a few meters)…
So how do RFID-based tolling systems work if cars are moving fast and may be farther away?
✅ So to clarify:
Yes, passive tags are short-range in most everyday uses (like credit cards or access cards).
But in toll systems, they use UHF passive RFID, which gives much longer range, perfect for reading tags on fast-moving vehicles.
🎭 What is GPS spoofing?
GPS spoofing is when someone fakes GPS signals to trick a device into thinking it’s in the wrong location.
🧠 It’s like someone holding a fake map in front of your GPS, saying:
“You’re here!” …when you’re actually somewhere else.
🧪 How does it work?
A GPS spoofer sends out fake satellite signals.
Your device picks up the fake signals instead of the real ones.
It calculates a false location or wrong time.
This can make:
A drone fly off course ✈️
A ship think it’s in the wrong ocean 🚢
A phone think it’s in another country 📱
🧠 Simple analogy:
Imagine you’re blindfolded, and someone is guiding you using GPS directions.
If they fake the directions, you’ll walk into the wrong place — even though you’re trusting the GPS.
That’s GPS spoofing — the device is misled without knowing.
🎯 Why do people do GPS spoofing?
🚫 To confuse drones or self-driving vehicles
💰 To cheat location-based apps (like games, delivery, or mileage apps)
🕵️ To hide real locations of vehicles or people
⚠️ For military or cyberattacks
break down the four wireless connection models — point-to-point, point-to-multipoint, mesh, and broadcast — in simple terms,
🔹 1. Point-to-Point (P2P)
📡 One device talks directly to one other device.
Like a private conversation between two people
Very direct and secure
Often used for wireless bridges or linking two buildings
🧠 Example:
A wireless link between two offices across the street
📍 Key Features:
1 sender → 1 receiver
Fast and reliable
🔸 2. Point-to-Multipoint (P2MP)
📡 One device talks to many devices, but they don’t talk to each other.
Like a teacher talking to a classroom
Common in Wi-Fi networks (router to many clients)
One central node (base station or access point)
🧠 Example:
A Wi-Fi router connecting to multiple laptops and phones
📍 Key Features:
1 sender → multiple receivers
Only the center (the “point”) can talk to everyone
🔷 3. Mesh Network
📡 All devices talk to each other — no central point.
Like a group chat where everyone can pass messages
Great for resilience — if one device fails, others can route around it
Used in smart homes, IoT, military, and disaster networks
🧠 Example:
Zigbee smart bulbs, where each bulb passes the signal to the next
📍 Key Features:
Every device = a node
Self-healing, decentralized
🔊 4. Broadcast
📡 One device sends a signal to everyone within range — no specific receiver.
Like a radio station — whoever is listening can hear it
Used in TV, radio, emergency alerts, or certain Wi-Fi beacons
🧠 Example:
A Wi-Fi access point sending a “hello, I’m here!” beacon every few seconds
📍 Key Features:
One sender → all receivers in range
No two-way communication by default
is wireless controller the same as AP?
The short answer is: No, wireless controllers and APs (Access Points) are not the same, but they work together in a wireless network.
Let’s break it down simply 👇
📶 What is an Access Point (AP)?
An Access Point is the device that creates the Wi-Fi signal.
It allows wireless devices (phones, laptops, tablets) to connect to a network.
It connects to the wired network and “transmits” the wireless signal.
🧠 Think of an AP as the “Wi-Fi hotspot” that users connect to.
🧠 What is a Wireless Controller?
A Wireless Controller is a centralized system that manages multiple Access Points.
It tells APs:
How to handle security
Which channels to use
When to hand off clients between APs
Load balancing between busy APs
🧠 Think of the controller as the “brain” that manages all the APs in a large network.
🔗 How do they work together?
In small setups (like homes), you might just have an AP or Wi-Fi router — no controller needed.
In large networks (like schools, airports, or office buildings), a wireless controller manages dozens or hundreds of APs to keep the network running smoothly.
what’s the difference between Evil twin and Rogue AP?
🦹♂️ Evil Twin
✅ What it is:
An Evil Twin is a fake Wi-Fi network set up by an attacker to look like a real one — same name (SSID), same appearance.
🎯 Purpose:
To trick users into connecting so the attacker can:
Steal login info
Capture sensitive data
Launch man-in-the-middle attacks
🧠 Example:
You go to a coffee shop and see Wi-Fi called CoffeeFreeWiFi.
An attacker sets up another access point with the same name.
You accidentally connect to the Evil Twin, thinking it’s legit — now the attacker sees your traffic.
🧨 Rogue Access Point (Rogue AP)
✅ What it is:
A Rogue AP is any unauthorized access point connected to a secure network, either:
Malicious (planted by an attacker)
Accidental (someone plugs in their own Wi-Fi router at work)
🎯 Purpose:
Can be used to bypass network security
Or just be an unapproved device creating a backdoor into the network
🧠 Example:
An employee brings a personal Wi-Fi router and plugs it into the office network — now anyone can connect wirelessly without company monitoring. That’s a rogue AP.
🎯 In summary:
Evil Twin: Fake Wi-Fi that looks real — made to trick users
Rogue AP: Unauthorized device connected to your real network — can be accidental or malicious
📡 What are Management Frames in Wi-Fi?
Wi-Fi communication is made up of different types of frames (like messages).
One important type is called a management frame.
📋 Management Frames are used to:
📣 Announce a Wi-Fi network (beacons)
📶 Connect and disconnect devices (like association and disassociation)
🔁 Handle roaming between access points (handshakes)
🧠 These frames are essential for devices to discover and manage connections to Wi-Fi networks.
😬 What’s the problem with management frames?
In older Wi-Fi versions (WPA2 and below), management frames were not encrypted or protected.
That means attackers could:
Spoof them (pretend to be the access point)
Intercept or inject fake frames
Launch deauthentication attacks — force users off the network
Trick devices into connecting to a fake (evil twin) AP
🚨 This is why public Wi-Fi could be risky — attackers could mess with these frames easily.
🔐 How does WPA3 help?
✅ WPA3 introduces Protected Management Frames (PMF)
PMF encrypts and authenticates management frames
This means attackers can’t forge or tamper with them
Devices and APs verify that the frames are legit and came from the real network
🛡️ Benefits of PMF (in WPA3):
Threat Protection with PMF
Deauthentication attacks ❌ Blocked (fake disconnects won’t work)
Evil twin redirection ❌ Harder to fake legit signals
Frame injection/spoofing ❌ Invalid frames get rejected
🤝 Also used in WPA2 (optional), but in WPA3 it’s required
In WPA2, PMF was optional — not all devices supported it.
In WPA3, PMF is mandatory, making every connection more secure by default.
🔀 Blended WLAN (Blended Wi-Fi)
A blended WLAN is a wireless network setup that uses both standalone (fat) APs and controller-based (thin) APs together in the same environment.
It’s called “blended” because you’re mixing different types of Wi-Fi access point models or management styles.
🧠 What are the two types of APs?
Type Description
Autonomous (Fat) APs Manage everything themselves — security, DHCP, SSID broadcasting, etc. Like a mini-router.
Lightweight (Thin) APs Rely on a wireless controller to manage most functions. Just transmit the signal.
🎯 Why use a blended setup?
You might already have older fat APs installed but want to add newer controller-based APs.
You may have different security needs or coverage areas that work better with different AP types.
A phased upgrade — blending old and new until everything moves to controller-based.
✅ Benefits of a Blended WLAN:
Cost-effective: Reuse existing hardware while expanding or upgrading
Flexible: Choose the right AP type for each location
Scalable: Gradually move toward a centralized system
⚠️ Things to Watch For:
Managing both types can be complex without proper planning
Might require more effort to maintain consistent policies (like security and QoS)
Not ideal for very large or fast-moving environments unless well-integrated
📶 What is the Wi-Fi® trademark?
The Wi-Fi® trademark is the official brand name used to certify that a wireless device (like a router, phone, or laptop) meets certain technical standards for wireless communication — specifically, the IEEE 802.11 standards.
✅ “Wi-Fi” is not just a general word — it’s a registered trademark owned by:
The Wi-Fi Alliance
🧠 What is the Wi-Fi Alliance?
The Wi-Fi Alliance is a global non-profit organization that:
Develops Wi-Fi standards
Tests devices to ensure they meet interoperability, performance, and security requirements
Allows certified products to use the Wi-Fi® logo
📜 What does the Wi-Fi® trademark mean on a device?
If a device has the Wi-Fi® logo, it means:
It has been certified by the Wi-Fi Alliance
It works with other Wi-Fi-certified devices
It meets specific standards for speed, frequency, and security (like WPA3)
🧠 Example:
Your phone says “Wi-Fi 6 Certified” — this means it:
Uses 802.11ax (Wi-Fi 6)
Was tested by the Wi-Fi Alliance
Is allowed to display the Wi-Fi 6™ logo
🚫 Can anyone use the Wi-Fi name or logo?
No — it’s a protected trademark. Only devices that pass Wi-Fi Alliance certification tests can legally use the Wi-Fi® name or logo in their marketing or packaging.
🔐 First, what is Perfect Forward Secrecy?
Perfect Forward Secrecy means that even if someone steals your Wi-Fi password, they can’t go back and decrypt your past data.
It protects the privacy of your past sessions — like old messages, emails, or passwords — even if the network key is later compromised.
📶 How is it used in WPA3?
In WPA3, PFS is achieved using a better key exchange method called Simultaneous Authentication of Equals (SAE).
Here’s what happens:
When your device connects to the Wi-Fi, it uses SAE to agree on a unique encryption key with the router.
That key is used only for that session.
Even though both devices know the Wi-Fi password, they never send it directly, and the session key is never reused.
If someone captures your encrypted traffic today and steals the password tomorrow — they still can’t decrypt your past data.
❌ Why this matters (compared to WPA2):
In WPA2:
If someone recorded your encrypted data and later got your Wi-Fi password, they could go back and decrypt your old traffic 😬
In WPA3:
Thanks to Perfect Forward Secrecy, each session is protected independently ✅
🔐 What is OWE?
OWE stands for Opportunistic Wireless Encryption.
It’s a feature in WPA3 designed to make open Wi-Fi networks (like at airports, cafés, or hotels) much more secure — even when there’s no password.
🧠 Why is it needed?
In older open Wi-Fi networks (like WPA2 open networks):
There’s no encryption at all
Anyone nearby can see your traffic
Tools like Wireshark can snoop on what you’re doing
So, open Wi-Fi = 🔓 unsafe, even if it’s free.
✅ What OWE does (in simple terms):
OWE adds automatic encryption to open Wi-Fi networks, without needing a password.
Here’s what happens:
You connect to an open Wi-Fi with OWE enabled.
Your device and the access point perform a secure key exchange (kind of like a secret handshake).
They generate a unique encryption key — just for you.
Your traffic is now encrypted, even though you never entered a password!
❗ Important Notes:
OWE ≠ authentication — it still doesn’t verify who you are, but it does encrypt your data.
It’s mainly for privacy, not identity.
Your device must support WPA3/OWE to benefit from it.
🔐 What is PEAP?
PEAP stands for Protected Extensible Authentication Protocol.
It’s a secure way to authenticate users on a network — often used in enterprise Wi-Fi (like school, office, or corporate environments).
✅ Does PEAP require both client and server to have a certificate?
No — only the server needs a certificate.
Let’s break it down:
🛡️ How PEAP works (simplified flow):
📡 You try to connect to a secure Wi-Fi network using PEAP.
🖥️ The server sends its certificate to prove it’s trusted.
📲 Your device checks that certificate and builds a secure encrypted tunnel.
🔑 Inside the tunnel, you safely send your username and password to log in.
🧠 Bonus Tip:
PEAP is often used with EAP-MSCHAPv2 (for password-based logins).
If you wanted both server and client certificates, you’d use EAP-TLS instead.
difference between PEAP and EAP-TTLS
🔐 First, what do they have in common?
Both PEAP and EAP-TTLS:
Are EAP variants (used for secure authentication over Wi-Fi or VPN)
Create a secure tunnel using TLS (like HTTPS) 🔒
Only require a server certificate (not client certificate)
Protect the user’s login info (like username/password) from eavesdropping
✅ Summary:
Use PEAP if you’re in a Windows environment and just need username/password login over Wi-Fi.
Use EAP-TTLS if you want more flexibility or support for non-Windows systems or multiple back-end login systems.
📱💻 What is VDI (Virtual Desktop Infrastructure)?
VDI means users access a virtual desktop that runs on a central server, not directly on their mobile device.
It’s like streaming your desktop to your phone, tablet, or laptop — all the apps, files, and work happen on the server, not on the device.
🔐 So how does VDI make mobile device deployment more secure?
✅ 1. No sensitive data stored on the device
With VDI, your files, emails, and apps are stored on the server, not on the mobile device.
If the device is lost or stolen, there’s no data to steal.
📦 Think of it like accessing a bank vault remotely, instead of carrying money in your pocket.
✅ 2. Centralized security and control
IT teams manage everything in one place (the data center or cloud).
They can enforce:
🔒 Strong passwords
🔄 Regular updates
🚫 App restrictions
🧯 Quick lockouts or shutdowns if needed
👨💻 So even if you’re on a personal phone or tablet, IT can still control the workspace.
✅ 3. Reduced risk from malware or untrusted apps
Since apps run on the virtual desktop, they’re isolated from any potentially dangerous apps on the mobile device.
The mobile device becomes more of a viewer than a worker.
✅ 4. Easier compliance and auditing
All user activity happens on the virtual desktop, so it’s easier to:
Track logins and data access
Monitor behavior
Prove compliance with rules like HIPAA, GDPR, etc.
✅ 5. Access from anywhere, securely
Users can access their desktop from any mobile device — but the connection is encrypted and the data stays in the data center.
This supports BYOD (Bring Your Own Device) without sacrificing security.
🛡️ What is an RF-blocking bag?
An RF-blocking bag (also called a Faraday bag) is a special pouch or container made with metallic material that blocks radio signals from getting in or out.
RF = Radio Frequency
These bags block wireless communication like Wi-Fi, Bluetooth, GPS, and cellular signals.
🎁 What does it mean when apps “use wrappers”?
An application wrapper is like a security layer that’s added around an app to control how the app behaves — without changing the app’s actual code.
🧠 Think of it like this:
Imagine wrapping a regular water bottle in a tamper-proof cover that:
Keeps it from leaking
Tracks if it’s opened
Prevents it from being shared
The wrapper doesn’t change the water inside — it just adds extra controls around it.
✅ Why use wrappers?
Protect business data inside apps
Enforce security policies without rewriting the app
Let users use personal devices (BYOD) while still protecting company info
🧠 Example:
Let’s say a company uses an app like Microsoft Outlook for work email.
Without a wrapper:
The user could copy an email and paste it into WhatsApp or save files to personal storage 😬
With a wrapper:
The MDM enforces rules: no copy/paste to personal apps, no screenshots, auto-logout after inactivity — all without modifying Outlook itself ✅
✅ Summary:
In MDM, app wrappers add a security layer around apps to control what they can do — helping protect company data without needing to rebuild the app.
difference between MDM (Mobile Device Management) and UEM (Unified Endpoint Management)
📱 What is MDM?
MDM = Mobile Device Management
It focuses on managing mobile devices only, like:
Smartphones 📱
Tablets 📲
MDM lets companies:
Set security policies (like passcodes)
Wipe lost or stolen phones
Install or block apps
Control what users can or can’t do on their mobile devices
💻 What is UEM?
UEM = Unified Endpoint Management
It does everything MDM does, plus more.
UEM manages all types of endpoints, not just mobile.
This includes:
Mobile devices (phones, tablets)
Laptops & desktops (Windows, macOS)
IoT devices (smart sensors, wearables)
Printers, smart TVs, and more
🧠 UEM = MDM + Laptop/Desktop/IoT management
MDM is great if you only need to manage mobile devices.
UEM is better for managing everything in one place — phones, laptops, desktops, IoT, and more.
difference between SMS, MMS, and RCS
📩 1. SMS (Short Message Service)
🧾 Text-only messages
📏 Limited to 160 characters
📶 Works on any phone — even flip phones!
❌ No pictures, videos, or group chats
✅ Doesn’t need internet — uses your cellular network
🧠 Think of SMS as the “original” text message.
🖼️ 2. MMS (Multimedia Messaging Service)
🎨 Allows pictures, videos, audio, emojis, group messages
📶 Still uses cellular, not Wi-Fi
🧱 File size is usually limited (often <1MB)
Requires more data than SMS and may cost extra with some carriers
🧠 Think of MMS as “SMS with media.”
📱 3. RCS (Rich Communication Services)
💬 Next-gen texting — like iMessage or WhatsApp but built into your default messaging app (on Android)
✅ Supports typing indicators, read receipts, Wi-Fi/data messaging, large files, high-quality images, and group chats
🔒 Not all RCS is end-to-end encrypted (depends on the provider)
🧠 Requires RCS support from both phones and carriers
🧠 Think of RCS as texting upgraded to feel more like a messaging app.
