The 5G Transport Network is the connectivity layer that links the 5G Radio Access Network (RAN) and the 5G Core Network (5GC). It carries both user data (payload) and control/signaling data, ensuring high bandwidth, ultra-low latency, and reliable communication between all components in a 5G system.
📡 Definition
The 5G Transport Network refers to the infrastructure and protocols that:
- Connect 5G cell sites (gNodeBs) to each other and to the core.
- Support massive data rates, low latency, and network slicing.
- Include fronthaul, midhaul, and backhaul segments.
🔀 3 Segments of the 5G Transport Network:
| Segment | Description | Example Technologies |
|---|---|---|
| Fronthaul | Connects RU (Radio Unit) to DU (Distributed Unit) | eCPRI, CPRI, RoE, fiber optics |
| Midhaul | Connects DU to CU (Centralized Unit) | Ethernet, IP/MPLS, Segment Routing |
| Backhaul | Connects CU to 5G Core (UPF/AMF) | IP/MPLS, Optical Transport (DWDM), Microwave |
🛠️ Key Technologies in 5G Transport:
- Fiber Optics: Preferred medium due to high speed and reliability.
- Time-Sensitive Networking (TSN): Ensures ultra-low latency for industrial use cases.
- Segment Routing (SRv6): Optimizes path control and network slicing.
- SDN (Software-Defined Networking): Centralized control of transport resources.
- Network Function Virtualization (NFV): Enables flexible service deployment.
⚡ Requirements of 5G Transport Network:
| Capability | Why It Matters in 5G |
|---|---|
| High Bandwidth | To support eMBB and high-capacity cells |
| Low Latency (<1 ms) | For URLLC (autonomous vehicles, robotics) |
| Reliability (5-nines) | For mission-critical services |
| Flexibility | To dynamically adjust to traffic and service needs |
| Network Slicing Support | Each slice may require different performance levels |
🧠 Role in 5G Network Architecture:
[RU] ⇄ Fronthaul ⇄ [DU] ⇄ Midhaul ⇄ [CU] ⇄ Backhaul ⇄ [5G Core]
- Enables centralized processing (vRAN, Open RAN).
- Plays a major role in latency reduction.
- Supports automation and orchestration through SDN.
🌐 Real-World Example:
Smart City Deployment:
- Fronthaul: Fiber links from street light pole small cells (RUs) to DUs.
- Midhaul: High-speed links from DUs in cabinet sites to centralized data centers.
- Backhaul: Optical or IP/MPLS networks connecting to the 5G core hosted in cloud data centers.
🧩 Why the 5G Transport Network Matters:
Without a robust transport layer:
- 5G’s promise of low latency and high throughput can’t be met.
- Network slicing and edge computing cannot be fully leveraged.
- URLLC applications would fail due to jitter and delay.
5G Transport Network
5G transport network, 5G fronthaul, 5G midhaul, 5G backhaul, 5G network architecture, 5G transport architecture, 5G RAN to core, 5G network slicing transport, fiber optic 5G, SDN in 5G, time-sensitive networking 5G, 5G transport latency, 5G transport capacity, 5G transport tutorial, 5G transport training, 5G DU to CU, 5G IP transport, SRv6 5G, 5G mobile backhaul, 5G transport for smart cities
