1.4a - Cellular Networks: Professor Messer

Exam Objectives

Wireless/cellular data network (enable/disable):

• 2G/3G/4G/5G:

  • 2G: Cellular network that integrates 2 standards, GSM (Global System for Mobile Communications) and CMDA (Code Division Multiple Access) - both standards allow for excellent voice communication but poor data transfer

  • 3G: Introduced in 1998, and increased data transfer capabilities and speeds (typically several Mbps). Allowed GPS and on-demand video streaming.

  • 4G/LTE: LTE is a 4G standard that allows both GSM and CDMA providers to send data over the same network. Supports download rates up to 150 Mbps, and 300Mbps (for LTE Advanced).

  • 5G: Cellular networking standard released in 2020. Supports speeds up from 100-900 Mbps (slower speeds) to 10Gbps (high speeds). Significant IoT impact, as faster speeds mean fewer bandwidth constraints and larger data transfers.

• Hotspot: Using your phone as a wireless router - extends your cellular network (subject to your provider) and allows devices to connect to it using the 802.11 standard (connect via Wi-Fi).

• Global System for Mobile Communications (GSM) vs. code-division multiple access (CDMA)

  • GSM: Worldwide coverage - occupies 90% of the market. Uses a SIM (Subscriber Identity Module) card from phone to phone; uses multiplexing to allow multiple users to talk simultaneously over the same frequency.

  • CDMA: Everyone communicates simultaneously, but each call uses a different code - the codes are used to filter calls on the receiving device. Commonly used by Verizon in Sprint in the US.

• Preferred Roaming List (PRL) updates:

  • Available for CDMA networks - allows your phone to connect to the correct cell tower.

Introduction to Cellular Networks

• Everyday use of mobile phones relies on cellular networks.

• Cellular networks divide geographical areas into sections called cells, enhancing connectivity with antennas placed at cell boundaries.

Early Cellular Networks: 2G

• 2G Networks: Featured two global standards for communication.

  • GSM (Global System for Mobile Communications)

    • Dominated 90% of the global market.

    • Standard in the European Union.

    • Provided uniform coverage worldwide.

    • Common providers in the US: AT&T and T-Mobile.

    • Subscriber Identity Module (SIM) cards allowed users to switch phones while retaining their numbers.

    • Utilized multiplexing to enable multiple users to communicate simultaneously.

  • CDMA (Code Division Multiple Access)

    • Each call assigned a unique code, filtering communication effectively.

    • Commonly used by Verizon and Sprint in the US.

    • Less popular internationally.

Advancements with 3G

• 3G Technologies: Introduced in 1998 to enhance mobile data capabilities.

  • Allowed data transfer speeds of several megabits per second.

  • Enabled functionalities such as GPS, mobile television, streaming audio/video.

The Convergence of Standards: 4G LTE

• LTE (Long Term Evolution): A unified standard overcoming GSM and CDMA segregation.

  • Increases data throughput to 150 megabits per second.

  • Enhanced versions like LTE Advanced (LTE-A) can reach up to 300 megabits per second.

The Emergence of 5G

• 5G Networks: Introduced in 2020, significantly improving mobile data speeds.

  • Capable of reaching speeds up to 10 gigabits per second.

  • Speeds typically between 100 and 900 megabits per second during rollout.

  • Benefits multiple applications, especially for Internet of Things (IoT) devices, enabling larger file transfers and enhanced functionalities.

Mobile Device Updates and Features

• Regular updates, like PRL (Preferred Roaming List), enhance device-network interaction.

  • PRL updates enable devices to identify preferred towers for connectivity.

• Wi-Fi Hotspot Functionality: Enables cellular devices to act as personal data routers.

  • Uses cellular connection to provide internet access over 802.11 networks.

  • Check with the cellular provider for limitations and potential additional charges.