1.5 Compare and contrast transmission media and transceivers
Wireless Media
📘CompTIA Network+ (N10-009)
What is Cellular Communication?
Cellular communication is a type of wireless network technology that uses radio waves to provide mobile data and voice communication.
It allows users to connect to the internet or make calls without needing physical cables like Ethernet. Instead, communication happens between mobile devices (such as smartphones, laptops, or IoT devices) and cell towers managed by a cellular carrier (e.g., Verizon, AT&T, T-Mobile).
In networking, cellular technology is often used for:
- Remote connectivity where wired networks are unavailable.
- Backup Internet connections for businesses.
- Mobile workforce communication and IoT deployments.
🏗️ How Cellular Networks Work
Cellular networks divide geographic areas into smaller sections called cells.
Each cell has its own base station (cell tower) equipped with a transceiver that communicates with user devices.
When a device connects:
- It sends a radio signal to the nearest cell tower.
- The tower sends the data to the carrier’s core network.
- From there, the data travels to the public internet or another cellular device.
As a device moves, it automatically hands off the connection from one tower to another — this is called a handoff or handover.
🔢 Cellular Network Generations
Cellular technology has evolved through multiple generations (G) — each improving speed, capacity, and capability.
| Generation | Speed Range | Main Features | Common Use Cases |
|---|---|---|---|
| 1G | Up to 2.4 Kbps | Analog voice only | Basic voice calls |
| 2G (GSM, CDMA) | Up to 64 Kbps | Digital voice, basic SMS | Voice + text |
| 3G (UMTS, EV-DO) | Up to 2 Mbps | Mobile data, internet access | Web browsing, early smartphones |
| 4G (LTE) | 10–100 Mbps | High-speed data, all-IP network | HD streaming, VoIP |
| 5G | Up to 10 Gbps | Ultra-fast, low latency, IoT support | Smart cities, automation, VR/AR |
Network+ exam tip:
Remember that 4G LTE and 5G are the most relevant for modern enterprise and IT environments.
🧩 Key Components of a Cellular Network
- Mobile Device (User Equipment, UE)
- Examples: Smartphones, tablets, LTE routers, IoT sensors.
- Contains a SIM card for identification and authentication.
- Base Transceiver Station (BTS) or Cell Tower
- Handles wireless communication with devices within a cell.
- Uses antennas and transceivers.
- Base Station Controller (BSC)
- Manages multiple cell towers and controls frequency usage.
- Mobile Switching Center (MSC)
- Connects calls and manages data between towers and the core network.
- Core Network / Internet Gateway
- Routes data from the mobile network to the internet or enterprise networks.
🌐 Cellular Standards and Technologies
1. GSM (Global System for Mobile Communications)
- Used by most of the world.
- Supports SIM cards.
- Based on TDMA (Time Division Multiple Access).
2. CDMA (Code Division Multiple Access)
- Used mainly in North America (older networks).
- Devices don’t rely on SIM cards.
- Each device gets a unique code for data separation.
3. LTE (Long Term Evolution)
- 4G technology standard.
- All-IP based (uses TCP/IP protocols for everything).
- Supports high-speed data and voice over LTE (VoLTE).
4. 5G NR (New Radio)
- Latest generation.
- Extremely low latency (as low as 1 millisecond).
- Designed for IoT, self-driving systems, and high-density environments.
🏢 Cellular in Enterprise Networking
In IT and business environments, cellular networks are used for:
- Failover Internet connections (when the wired WAN goes down, LTE/5G backup kicks in).
- Remote sites or branch offices where fiber or cable internet isn’t available.
- Mobile workforce connectivity (laptops with built-in SIMs).
- IoT devices like smart sensors, ATMs, and security systems that need constant communication.
Network devices such as routers, firewalls, and gateways often include cellular transceivers or SIM card slots to provide 4G/5G WAN links.
🔌 Cellular Transceivers
A transceiver (transmitter + receiver) allows two-way communication between a device and a cellular tower.
In cellular networks, transceivers are found in:
- Cell towers (base transceivers) – handle communication for the entire cell.
- Mobile devices – send and receive data from the tower.
- Cellular routers or modems – provide network connectivity over LTE/5G.
Example (IT use):
A branch router with an LTE transceiver connects to the cellular network and provides backup internet to the LAN if the main fiber line fails.
📶 Frequency Bands
Cellular networks operate on licensed radio frequency bands.
Each country assigns specific bands for 3G, 4G, and 5G use.
- Lower frequencies (e.g., 700 MHz) → longer range, better wall penetration.
- Higher frequencies (e.g., 3.5 GHz, 28 GHz) → faster speeds but shorter range.
5G also introduces mmWave (millimeter wave) frequencies for ultra-high-speed short-range communication.
⚙️ Cellular Network Security
Since cellular is a shared wireless medium, security is essential:
- SIM authentication: Verifies user identity via IMSI and authentication keys.
- Encryption: Protects data between device and tower (e.g., AES in LTE).
- Carrier firewalls and VPNs: Used in enterprise to secure data over public cellular networks.
Exam Tip:
Enterprises often combine cellular + VPN for secure site-to-site or remote access.
⚖️ Advantages and Limitations
✅ Advantages:
- Wide coverage area.
- Easy to deploy (no cables required).
- Suitable for remote or mobile users.
- Scalable for IoT and temporary networks.
❌ Limitations:
- Data costs can be higher than wired.
- Speed may vary by location and network congestion.
- Limited bandwidth compared to fiber.
- Subject to signal interference and tower outages.
🧠 Exam Summary
| Concept | Key Points |
|---|---|
| Cellular network | Wireless communication using radio waves and towers. |
| Main use | Mobile and remote connectivity, WAN backup, IoT. |
| Common standards | GSM, CDMA, LTE (4G), 5G NR. |
| Generations | 1G to 5G – increasing speed and capability. |
| Security | SIM authentication, encryption, VPN for secure traffic. |
| Hardware | Cell towers, SIM-based devices, LTE/5G routers, modems. |
📝 Final Exam Tip
When preparing for the Network+ (N10-009) exam:
- Understand how cellular networks integrate with enterprise WANs.
- Know the difference between cellular and Wi-Fi (cellular uses carrier-managed infrastructure).
- Remember that 4G LTE and 5G are common WAN media types used for backup and remote connectivity.
