Understanding Mobile Network Architectures: From GSM to 5G

Posted on May 6, 2024 in Computers

LTE Network Architecture

The Long-Term Evolution (LTE) network architecture consists of three main components:

1. User Equipment (UE): Devices like smartphones or tablets that connect to the LTE network.
2. Evolved UMTS Terrestrial Radio Access Network (E-UTRAN): The radio access network with eNodeB base stations, providing the connection between the UE and the core network.
3. Evolved Packet Core (EPC): The core network handling signaling and data traffic, including nodes like the Mobility Management Entity (MME), Serving Gateway (SGW), and Packet Data Network Gateway (PGW).

The UE communicates with the eNodeB, which forwards data to the MME for mobility and security management. The MME then sends data to the SGW for routing to the appropriate PGW, connecting the LTE network to the internet or other data networks.

GSM Network Architecture

GSM architecture comprises three main subsystems:

1. Base Station Subsystem (BSS): Handles radio communication between the mobile station and the network, including the Base Transceiver Station (BTS) and Base Station Controller (BSC).
2. Network Switching Subsystem (NSS): Manages call routing, mobility management, and network services, including the Mobile Switching Center (MSC), Visitor Location Register (VLR), and Home Location Register (HLR).
3. Operation Support Subsystem (OSS): Provides operations and maintenance functions for the network, including the Operation and Maintenance Center (OMC).

GPRS Network Architecture

GPRS architecture builds upon the GSM network for packet data transmission. Key components include:

• Mobile Station (MS): User equipment with GPRS capability.
• Base Transceiver Station (BTS): Handles radio communication with the MS.
• Base Station Controller (BSC): Controls multiple BTSs and manages radio resources.
• Serving GPRS Support Node (SGSN): Manages mobility and data sessions for the MS within its coverage area.
• Gateway GPRS Support Node (GGSN): Connects the GPRS network to external data networks and performs routing, security, and charging functions.

The MS transmits data packets to the BTS, which are then routed through the BSC and SGSN to the GGSN for connection to external data networks.

MIMO Technology

2×2 MIMO (Multiple-Input Multiple-Output) improves data transmission speed and reliability by using multiple antennas at both the transmitter and receiver. It creates multiple spatial streams for data transmission, leading to faster downloads, uploads, and streaming experiences. MIMO is widely used in Wi-Fi routers, smartphones, and mobile base stations.

5G Network Architecture

5G network architecture involves various elements:

• 5G Terminal: Devices like phones that connect to the 5G network.
• gNB (Next-Gen NodeB): The base station for the 5G network.
• RAN (Radio Access Network): Connects devices to the core network, including gNBs and antennas.
• Core Network: Handles routing, security, and services.
• Internet: The global network of networks.
• Servers: Store data and applications.
• Control System/Policy Server: Manages the network.
• Streaming Server: Delivers streaming content.
• Data Server: Stores and retrieves data.
• Server for Real-Time Communication: Enables services like video chat.

TDD Frame Structure

For TDD (Time Division Duplex), the same carrier is used for both downlink and uplink transmission. The frame structure is divided into subframes, timeslots, and pilot signals for reference purposes. Different configurations are available to handle variable traffic conditions.