Chris Pearson, August 2023 –
At 5G Americas, one of the things we like to do is to uncover and explain the inner workings of a 5G network to a wide audience. If you’ve ever wondered how 5G works, we have an extensive library of white papers that help keep you up to speed on the latest developments and advances on wireless cellular network architecture and technology.
A lot has been said about core networks and radio access networks, but at the heart of 5G’s transformative journey lies the intricate web of transport networks, which are the unsung heroes that ensure seamless data transmission between the core network, radio access network (RAN), and our ever-growing array of devices. In our latest white paper, “Transport Networks for 5G,”we delve into the crucial role of transport networks in the 5G ecosystem, examining their current state, ongoing advancements, and their pivotal role in shaping the future of connectivity.
Overall, the ongoing evolution of 5G technology is driving remarkable advancements in transport networks. Several key areas of innovation are emerging to ensure the smooth flow of data and to accommodate the diverse requirements of the 5G landscape. Three key areas are coming into focus:
- Connectivity for Cloud-Based RAN Solutions: Cloud-based RAN solutions are gaining traction due to their flexibility and scalability. Transport networks are adapting to provide robust connectivity that can support the demands of these cloud-based architectures.
- Network Timing and Synchronization: In the world of 5G, precise timing and synchronization are paramount. Transport networks are grappling with the challenges of maintaining accurate frequency and phase synchronization to enable seamless operations across the network.
- End-to-End Network Slices: The concept of network slicing is a hallmark of 5G technology. It allows network operators to create virtual networks tailored to specific use cases. Transport networks play a crucial role in delivering these end-to-end network slices, catering to the diverse needs of industries ranging from healthcare to manufacturing.
Before we dive into the intricacies of 5G transport networks, it’s important to grasp the key components of the 5G ecosystem. 5G wireless cellular networks consist of a few primary elements: devices, spectrum, the core network responsible for managing and routing data; the radio access network (RAN) responsible for wireless communication with devices; and the transport networks, which serve as the backbone for data exchange between the core network and the RAN.
If you look at the image above, you’ll note that as data flows from devices to the RAN, the immediate next stop is the transport network. Because of this, transport network requirements are largely driven by advances in the 5G RAN. Currently, a multitude of advances are steering this evolution:
- Spectrum Allocation: New Radio (NR) spectrum in mid- and high bands, along with the introduction of Citizens Broadband Radio Service (CBRS) and wider channel sizes, are expanding the possibilities for high-speed data transmission.
- Radio Technologies: Higher order modulation, Advanced Antenna Systems/Beamforming, Massive MIMO, and enhanced Common Public Radio Interfaces (CPRI and eCPRI) are propelling data rates to unprecedented levels.
- RAN Coordination Services: Technologies like dual connectivity, dynamic spectrum sharing, carrier aggregation, and coordinated multipoint are optimizing network resources and enhancing user experiences.
- Device Ecosystem Improvements: Advancements in mmWave spectrum and sub-6GHz chipsets are enabling end-user devices to achieve remarkable speeds, exceeding 1 Gbps.
Of course, advances in transport networks themselves are also shaping the overall infrastructure of 5G. One area involves the evolution of 5G Standalone split architecture that offers deployment flexibility, enabling network components to be placed strategically to optimize performance. Depending on the local site conditions and network requirements, different elements of fronthaul, midhaul, or backhaul can be moved onto network cloud architecture.
Several other key advances are also currently being worked on in 5G transport networks. These include microwave and Ethernet use in areas where fiber connectivity is impractical or expensive, as microwave connections continue to play a pivotal role in providing reliable backhaul. Microwave technology has continuously evolved by leveraging and applying technologies like high-order modulation, adaptive modulation, dual band antennas, dual polarization and XPIC, higher order MIMO, and carrier aggregation. Another benefit of microwave radio systems is that its overall flexibility can be used for special events, public safety, disaster recovery, and connectivity for private networks.
In addition, Integrated Access and Backhaul (IAB) which we covered in a white paper “Innovations in 5G Backhaul Technologies“ preserves spectrum resources by allowing shared usage for both access and backhaul purposes. It is a great advance in technology that will help network operators provide backhaul services to a cell site when spectrum resources are scarce. Finally, advances in control and user plane separation (CUPS) architecture are reducing operational costs and enhancing user experiences by separating control and user plane functions, while virtualized RAN enhancements are promising reduced power consumption and capital expenditures, though challenges related to network timing and synchronization remain.
But even as the 5G landscape continues to evolve, certain areas demand attention to ensure the resilience and effectiveness of transport networks. Transport networks continue to evolve to be fortified to safeguard against cyber threats that have the potential to disrupt critical operations. Additionally, the impact of the metaverse and immersive applications will place immense pressure on transport networks. Mobile wireless networks must be prepared to handle the exponential increase in data demand brought about by these novel experiences.
Overall, the journey of 5G technology is intrinsically tied to the evolution of transport networks. As we continue to push the boundaries of connectivity, these networks will serve as the backbone upon which the future of communication is built. From enabling the metaverse to accommodating immersive applications, from optimizing spectrum utilization to ensuring security, the transport networks of 5G are poised to usher in an era of unprecedented connectivity that will reshape industries, societies, and the way we experience the world.