Overview
This lecture explains cellular and wireless networking technologies, their evolution, and related mobile device features such as SIM cards, Bluetooth, and GPS.
Cellular Networks & Evolution
- Cellular networks divide land into "cells" covered by antennas transmitting on various frequencies.
- They support both voice and data communication; users can enable/disable features like cellular data and airplane mode.
- 3G (introduced in 1998) increased mobile data capacity, enabling GPS, video, and conferencing.
- 4G (LTE) is based on GSM technology and allows speeds up to 150 Mbps.
- LTE Advanced (LTEA) increases throughput to 300 Mbps.
- 5G (from 2020) supports up to 10 Gbps over high frequencies and 100–900 Mbps otherwise.
- 5G enables faster data transfer, supporting Internet of Things (IoT) devices and cloud processing.
Wi-Fi (802.11) Networks
- 802.11 wireless (Wi-Fi) provides high-speed connectivity at home/office but has limited range.
- Wi-Fi supports voice, video, and data; some phones can route calls over Wi-Fi if cellular signal is weak.
- Mobile phones can act as Wi-Fi hotspots, sharing their cellular connection with other devices.
- Hotspot use may require carrier approval and could involve extra charges.
SIM and eSIM Technology
- A SIM (Subscriber Identity Module) is a card storing user and network information (number, contacts, messages).
- Physical SIMs can be swapped between devices; eSIMs are embedded and managed by software.
- eSIMs make switching devices easier and can support multiple profiles/numbers on one phone.
Bluetooth Connectivity
- Bluetooth devices require a one-time "pairing" process for security and convenience.
- Pairing often uses a personal identification number (PIN), which may be fixed or dynamic.
- Devices must be discoverable during pairing, and instructions vary by device.
Location Services (GPS & Alternatives)
- GPS (Global Positioning System) uses at least four satellites to determine location and altitude.
- Some apps also use Wi-Fi networks or cellular tower triangulation for location if GPS is unavailable.
Key Terms & Definitions
- Cellular Network — Communication network divided into areas called cells, using antennas and frequencies for coverage.
- 3G/4G/5G — Generations of cellular technology, each increasing speed and functionality.
- GSM — Global System for Mobile Communications, a standard for 4G LTE.
- SIM/eSIM — Subscriber (or embedded) Identity Module, which stores network/user info.
- Bluetooth Pairing — One-time process to securely connect Bluetooth devices using a PIN.
- GPS — Global Positioning System, a satellite-based navigation system.
Action Items / Next Steps
- Check if your mobile carrier supports hotspot functionality and eSIM transfers.
- Review your device's documentation for Bluetooth pairing and discoverability instructions.