Today's mobile network operators (MNOs) are in a tricky situation. They need to invest to meet growing demand for higher speeds, wider coverage and attractive new offerings. But spending big to harness the untapped potential of connected things, people, homes and businesses at a time when revenue opportunities are only beginning to emerge is a risky strategy.

First of all, MNOs need to make a choice about which 5G opportunity they want to address. In case of long access links, existing residential copper infrastructure offers little opportunity to scale bandwidth, and so fixed wireless access could be a very promising business model. On the other hand, with the potential for billions of connected sensors and smart devices, IIoT and wireless enterprise services could offer the most value. Or does an MNO see the greatest opportunities in providing more bandwidth for the mobile user?

Open architectures for agility and growth

Each of these business opportunities comes with its own set of requirements. Fixed wireless access requires mmWave radio frequencies and high bandwidth, while enterprise services can leverage midband spectrum but require low latency and high reliability. And new MIMO technologies applied in the low band offer an efficient way to provide more bandwidth to mobile users.

Obviously, MNOs will invest only in the technologies required to support their targeted business model. This comes at the risk of creating 5G stove pipes and, in the worst-case scenario, could mean entering a dead-end road.

Here the connectivity network is the major concern. As shown in the diagram, investment in new technologies must not outweigh revenue from new business opportunities. This objective can only be met if the mobile transport network is designed to easily adapt to any future mobile user, enterprise or IIoT service.

New connectivity for 5G

The Open RAN model is a sensible starting point for defining a mobile connectivity target architecture and selecting the most suitable technologies for it. Defined by major service providers and mobile infrastructure suppliers, the Open RAN approach combines the most flexible X-Haul architecture with the value of ETSI-defined NFV technology. The open, software-defined networking approach assures ease of integration and adaptability to any future mobile requirements. 

A closer look at the connectivity requirements of the Open RAN model reveals some mobile-specific characteristics. User services require more bandwidth at the Fx interface than at the F1 interface, and timing requirements are more stringent at Fx compared with F1. In combination with the need for a significantly higher number of cell sites and more capacity per cell, the following technologies are a promising approach for future-proof 5G connectivity networks:

• Disaggregated packet networking separates the physical forwarding plane from the control software by means of open interfaces. This results in a highly scalable architecture that can easily be enhanced in functionality and complements open disaggregated optical transport solutions.
• Segment routing and SDN control reduce operational complexity of MPLS and supporting interworking among different technology and vendor domains.
• NFV and edge hosting transform previously monolithic, single-vendor networks into an open cloud-native architecture, which can also host enterprise applications in addition to virtualized mobile network functions.
• Precise synchronization is key to spectral efficiency in 5G but also an essential requirement for many mission-critical mobile applications. A combination of PTP-optimized optical transport and timing assistance in the packet forwarding plane with ultra-precise core clocks has significant advantages over satellite-based cell site timing with all its vulnerabilities and operational challenges.

TIP is at the forefront of 5G new connectivity commercialization

TIP has provided a framework for mobile network operators, hardware suppliers and software vendors to jointly commercialize the technologies listed above – technologies that are essential for the new breed of 5G connectivity networks. From specification to implementation, demonstration and field trials in live networks, solutions have matured at unprecedented pace.

An open, disaggregated cell site gateway solution has recently been trialed by several MNOs. ADVA’s carrier-grade Ensemble Activator network operating systems has proven true multi-vendor interoperability, including demonstrations with three different hardware suppliers (ODMs).

With the work of TIP and companies such as ADVA supporting it, MNOs can now implement future-proof 5G connectivity solutions designed for any business opportunity and developed for the further growth.