For the previous generation service providers, the priority was to offer fast and reliable mobile data to consumers. Now 5G has increased the scope to offer a vast range of services with the fastest possible speeds and reduced latency.
5G has proved to be a coherent and flexible framework of numerous advancements supporting many applications. 5G uses an intelligent architecture consisting of fibre optic to transmit data signals without major ground disturbance, with RAN technology which can be installed using HDD (Horizontal Directional Drilling).
The 3rd Generation Partnership Project (3GPP) includes RAN, core transport networks, service capabilities, and other technologies, offering complete system specifications for 5G. These services are provided through a common structure to network functions. Some design considerations for 5G network architecture are reusability and modularity.
NFV and 5G
Network function virtualization (NFV) separates software from hardware by replacing different functions like load balancers, firewalls, and routers which eradicates the need to invest in many expensive hardware elements thereby providing an opportunity to generate revenue.
NFV enables the 5G infrastructure by virtualising appliances within the 5G network which includes the network slicing technology that makes many networks run simultaneously.
Horizontal Directional Drilling
Originating in the 1960s, HDD has now become the preferred method of installing utility lines, underground pipes, and cables via trenchless techniques. Before the invention of this drilling method, installing pipelines and cables required the cutting of trenches. And with the rise of 5G, HDD (Horizontal Directional Drilling) is here to stay.
The main ingredient that enables the full potential of 5G architecture is network slicing which adds another dimension to the NFV domain by enabling numerous networks to run side by side in a shared network infrastructure. This becomes vital to 5G architecture by creating end-to-end virtual networks that include both networking and storage functions.
In the Internet of Things (IoT) where the number of users may be extremely high, but the overall bandwidth demand is low, network slicing becomes very useful. The costs and resources management is dependent on the level of customisation. Also, network slicing enables advance trials for new 5G services and takes a quicker time-to-market.
5G Spectrum and Frequency
Many frequency ranges are now being dedicated to 5G new radio (NR). Since wavelengths range from 1-10 mm, the radio spectrum with frequencies between 30 GHz and 300 GHz is known as the millimetre wave. Frequencies between 24 GHz and 100 GHz are now being allocated to 5G in multiple regions worldwide.
Underutilised UHF frequencies between 300 MHz and 3 GHz are also being used for 5G. The assortment of frequencies employed can be made according to the unique applications considering the higher frequencies are characterised by higher bandwidth.
The millimetre wave frequencies are perfect for densely populated areas, but ineffective for longer distances. Each carrier has started to make their portions of the 5G spectrum within the high and low-frequency bands.
5G RAN Architecture
NFV extends to the RAN through the network breakdown which enables flexibility and makes new opportunities for competition. It also provides open interfaces to make deployment easier.
The O-RAN ALLIANCE objective is to allow multi-vendor deployment with off-the-shelf hardware for easier and faster inter-operability.
Network disaggregation allows components of the network to be virtualised, providing a means to scale and improve user experience as capacity grows. The benefits of virtualising components of the RAN provide a means to be more cost-effective from a hardware and software viewpoint especially for applications where the number of devices is in the millions.
Multi-Access Edge Computing (MEC) is one of the crucial components of 5G architecture. Depending on where it locates, it transports applications from centralised data centres to the network edge. This speeds up the content delivery between the user and host, thus eliminating the long network path.
MEC is not only used for 5G networks, but it certainly increases the efficiency of its architecture. Some of its characteristics include low latency, high bandwidth, and real-time access to RAN information, which is one of the key features of this architecture. The convergence of RAN and core networks opens up new pathways for network testing and validation.
For MEC deployment, it is ideal to have 5G networks that are based on 3GPP 5G specifications. These specifications are important to enable edge computing, and to allow MEC to route traffic in conjunction with 5G. The distribution of computing power that the MEC architecture provides is key for the deployment of 5G networks and facilitates the Internet of Things (IoT) devices.
eCPRI brings about many cost benefits with its advent, such as network disaggregation with the functional split. They are a cost-effective alternative to RF interfaces when testing large volumes of 5G carriers. The introduction of eCPRI interfaces reduces the number of interfaces needed for testing multiple 5G carriers, thus bringing down the cost. eCPRI can be used as a standardised interface for 5G used. It is much more effective than CPRI, which was developed for 4G but wasn’t standardised for all vendors.
Another technology is beamforming, which is the key to the success of 5G networks. Regular base stations carry out signal transmission in all directions without focusing on specific users or devices. By using multiple-input, multiple-output (MIMO) arrays with numerous small antennas in a single formation, signal processing algorithms trace out the most effective path of transmission to each user. Individual packets are sent in multiple directions and arranged to reach the end-user in a predetermined sequence.
Since 5G data transmission is carried out on the millimetre wave, it gives rise to free space propagation loss and diffraction loss, which is caused by smaller antenna sizes and higher frequencies, as well as lack of wall penetration.
Conversely, when the antenna size is smaller, it allows larger arrays to fill up the same physical space. These antennas reassign the beam direction several times in a single millisecond, it makes beam forming much easier. If a larger antenna density is maintained in the same physical space, MIMO can be used to achieve narrow beams, thus facilitating effective user tracking with high throughput.
These are all of the major components of 5G networking architectures that are used to ensure faster and more stable transmission. Of course, there are some challenges to how these architectures operate. For instance, it is necessary to take care of where a company locates its 5G network as HDD (Horizontal Directional Drilling) may cause a ground disturbance. These processes are also costly as trained workers are required and the equipment is a bit complicated to operate.
As time passes and research grows, we will continue to see the birth of newer architectures which may change the way data is transmitted to the end-user.