Cellullar Technology and Radio Access Network (RAN)

- Overview

A radio access network (RAN) is a part of a cellular network that connects devices to the core network. RANs have been used since 1979 in Tokyo and 1983 in the US. 

RANs use radio frequency to connect devices, such as smartphones, computers, or machines, to the core network. Devices send information to the RAN's transceivers via radio waves, and then the transceivers send information to the core network, which connects to the internet.

5G connectivity requires RAN virtualization (vRANs) because 5G needs more automation, visibility, and adaptability than traditional hardware-based RANs can provide. Ericsson Cloud RAN (C-RAN) is a cloud-native software solution that handles compute functionality in the RAN.  

- Virtual RAN (vRAN)

A virtual RAN (vRAN) uses software-based network functions instead of hardware-based network functions. The process of network functions virtualization (NFV) is what virtualizes the RAN. A vRAN can adapt to changes in the network faster because administrators can remotely update it with a software patch. 

A virtual radio access network (vRAN) is a type of RAN with its networking functions separated from the hardware it runs on. The control and data planes of the vRAN are also separated as part of the virtualization. 

- Cloud RAN (C-RAN)

Cloud RAN (C-RAN) is a type of vRAN (virtualized radio access network) that uses cloud-native technologies. vRAN virtualizes the RAN infrastructure using on-premises hardware, while C-RAN uses cloud technology to deploy the RAN infrastructure in public, private, or hybrid cloud environments.

vRAN components may not always be cloud native. When the virtualized functions (vDU and vCU) are implemented in a true cloud-native fashion, the vRAN implementation is called C-RAN. 

C-RAN re-architects the vRAN functions by breaking up the code components into micro-services. This provides greater agility, flexibility, scalability, and sometimes higher resiliency.

C-RAN has the advantage of being able to implement LTE-Advanced features such as Coordinated MultiPoint (CoMP) with very low latency between multiple radio heads. 

However, the economic benefit of improvements such as CoMP can be negated by the higher backhaul costs for some operators.

- 5G: More Capacity for More Devices

Existing cellular technologies are rapidly reaching their performance limits. This is not only because of the growth in data traffic and the number of connected endpoints, but also because we are on the verge of a new era in which everyone and everything will be connected, with more demanding and diverse requirements than can be met by the current networks.

Global mobile network operators (MNOs) struggle to meet growing customer demand for 5G and mobile data as key use cases. MNOs can add capacity to their wireless networks in three main ways: buying more spectrum; making spectrum utilization more efficient by optimizing spectrum efficiency; and making the network denser by adding more cell sites while reusing available spectrum.

- Radio Access Network (RAN)

RAN (Radio Access Network) is a network infrastructure typically used in mobile networks, consisting of radio base stations with large antennas. The main purpose of the RAN is to connect user equipment wirelessly. According to the standard, mobile phones and other wirelessly connected devices are referred to as user equipment, terminal equipment, mobile stations, etc. 

Cell phones use radio waves to communicate by converting your voice and data into digital signals that are sent as radio waves. In order for your phone to connect to a network or the Internet, it first connects through a radio access network (RAN). RAN uses radio transceivers to connect you to the cloud. 

Most base stations (or transceivers) are primarily connected to the mobile core network via fiber optic backhaul. RAN functions are typically provided by silicon chips located in the core network and user equipment. 

The Radio Access Network (RAN) is part of the mobile telecommunications system. It implements radio access technology. Conceptually, it sits between devices such as mobile phones, computers or any remotely controlled machines and provides connectivity to its core network. 

- How does RAN Work?

The RAN provides radio access and assists in coordinating network resources across wireless devices. Devices primarily connect to cellular networks via LTE or 5G NR. Silicon chips in the core network, along with user equipment such as mobile phones or laptops, help enable the functionality of the RAN. 

• In the RAN, the radio unit (Radio Unit, RU) processes digital radio signals and transmits, receives and converts signals for the RAN base station.
• When the RU receives signal information from the antenna, it communicates with the baseband unit (BBU) using the common public radio interface (CPRI). 
• The BBU takes the signal information and processes it so that it can be forwarded to the core network. Data is returned to the user through the reverse process.
• The amount of area that a RAN node can cover varies depending on the capabilities of the node's antennas, RAN hardware, and software.

In mobile networks, RAN accounts for 60% to 65% of the total cost of ownership of the network.

As the mobile communications industry moves toward a 5G future, the amount of data traffic traversing networks is exploding. One of the ways MNOs are responding to reality and preparing for the further onslaught 5G will bring is by transforming the RAN. 

The RAN is a key component to enable fast data transfer to the core network and user equipment. With distributed, centralized, virtualized and open infrastructure, the RAN can be modified and modified to suit the requirements of different operators and technologies.

- RAN and 5G Technologies

The amount of data available every day is growing rapidly, and as devices become more interconnected and networks grow larger, so is the amount of data being generated and transmitted.

5G networks require RAN virtualization (vRAN) because 5G requires visibility, automation, and adaptability that traditional hardware-based RANs cannot provide.

The ability to scale and intelligently adjust the network to changing conditions is important as demand from mobile phone users and more importantly IoT (Internet of Things) devices increases on 5G networks.

Network administrators must be able to update vRAN remotely, as it can improve as technology advances. This is a key component of 5G RAN as the component technologies involved are expected to change in the coming years.

- Edge Router

Edge routers are gateways that accept inbound traffic into your network. Edge routers work to secure the network edge and protect the core by characterizing and securing IP traffic from other edge routers as well as core routers. They differ from core routers in that core routers forward packets between routers to manage traffic and prevent packet loss, often using multiplexing. 

An edge router uses static or dynamic routing to send or receive data from other networks. Data transfer between the network and Internet or WAN edge typically use Ethernet, such as Gigabit Ethernet via copper or over single or multimode fiber optic. 

- The RAN Edge

The RAN edge is located outside the network core, closer to end users. 5G RAN incorporates virtualization and edge computing into its infrastructure. 

RAN nodes at the edge connect users to the core network, the cloud, the Internet more generally, and to other users without requiring user data to travel great distances before reaching the nearest RAN node. Adding a general-purpose server to a RAN node gives the node more compute, network, and storage resources to use. 

The type of RAN node can be a traditional cell tower, a rooftop antenna, or the more common small cell deployment in 5G RAN. An alternative to installing servers on nodes is to use a local data center to serve multiple nodes. Serving multiple nodes in this manner is often associated with Cloud RAN (C-RAN), but is not the only defining characteristic of C-RAN architecture; nor is it used only for C-RAN.

The benefits of deploying RAN at the edge include lower latency, improved user experience, optimized network efficiency, reduced network congestion, and local computing capabilities for devices. These benefits enable or improve use cases including autonomous vehicles, mobile gaming and support for the Internet of Things (IoT).

[More to come ...]