Cellular Standards

Overview

This lecture covers the evolution of cellular networks from early technologies like 2G and 3G through to LTE (4G) and 5G, explaining their features, standards, and functionalities.

Cellular Network Basics

• Cell phones operate on a cellular network, dividing geography into cells with antennas for continuous connectivity.
• Cellular networks began as circuit-switched and needed upgrades for data transmission.

2G Networks: GSM and CDMA

• 2G networks were dominated by two global standards: GSM (Global System for Mobile Communications) and CDMA (Code Division Multiple Access).
• GSM was used by 90% of the world and allowed SIM card portability between phones.
• GSM used multiplexing, giving each user a time slice on the network for simultaneous communication.
• CDMA assigned unique codes to each call, allowing multiple users on the same frequency by filtering with codes.
• In the US, AT&T and T-Mobile used GSM, while Verizon and Sprint used CDMA.
• CDMA limited handset choice and was less globally popular than GSM.

Advancements: 3G and LTE (4G)

• 3G networks (introduced in 1998) increased data speeds to several Mbps, enabling GPS, streaming, and more.
• LTE (Long-Term Evolution), a 4G standard, unified previous standards (GSM and CDMA) and achieved up to 150 Mbps (LTE-A up to 300 Mbps).
• LTE is based on GSM and EDGE (Enhanced Data rates for GSM Evolution).

5G Networks

• 5G (introduced in 2020) aims for speeds up to 10 Gbps, with current deployments offering 100–900 Mbps.
• 5G supports larger file transfers, more IoT (Internet of Things) devices, and enhanced cloud and app capabilities.

Network Management and Connectivity

• PRL (Preferred Roaming List) updates help devices find correct network towers and can be delivered via OTA (over the air) updates.
• Many phones can function as Wi-Fi hotspots, sharing cellular internet with other 802.11 devices.
• Providers may restrict or charge for Wi-Fi hotspot features, and data usage may apply.

Key Terms & Definitions

• Cellular Network — A network dividing regions into cells, each with its own antenna for coverage.
• GSM — Global System for Mobile Communications, a 2G cellular standard using SIM cards.
• CDMA — Code Division Multiple Access, a 2G cellular standard using unique codes per call.
• SIM Card — Subscriber Identity Module, storing user information for GSM networks.
• Multiplexing — Technique allowing multiple users to share one frequency by dividing it in time.
• LTE — Long-Term Evolution, a 4G data standard unifying previous networks.
• 5G — Fifth-generation cellular network with much higher data speeds.
• PRL — Preferred Roaming List, a database of network towers for device connectivity.
• OTA Update — Over-the-air update, used to update device software or PRL.
• Wi-Fi Hotspot — Turning a phone into an internet access point for other devices.
• IoT — Internet of Things, network of connected devices requiring internet access.

Action Items / Next Steps

• Check your device’s capabilities for Wi-Fi hotspot and confirm any related provider policies.
• Be aware of PRL and OTA update processes on your mobile device.