Microwave Backhaul: Critical for Leveraging 5G Innovation

By Nitin Bansal

With the buildout of LTE, the appetite for mobile broadband backhaul capacity has increased, as expected. This will continue to increase with the arrival of 5G. It is forecasted that, by 2022, the typical backhaul capacity for a high-capacity radio site will be in the 1Gbps range, rising to 3–5Gbps by 2025. It is also predicted that 80 percent of sites in an advanced mobile broadband network will still be operating under 350Mbps in 2022, though by 2025 this will have increased to 600Mbps.

In the future, microwave share will continue to be high, supporting the requirements of LTE and 5G. Due to the increasing number and size of LTE deployments in India, microwave share is now forecast to be higher than previously estimated, exceeding 65 percent in 2022 (excluding China, Korea, Japan and Taiwan). The planned introduction of 5G in networks with as high as 80 percent microwave-based backhaul, shows that microwave is highly relevant for 5G. Globally, mobile network backhaul continues to evolve with a mix of fiber and microwave.

With the introduction of 5G in microwave bands, the availability and usage of microwave spectrum for fixed services will go through a major transformation in the next few years. E-band will grow in importance and in usage, and we will see an introduction of new bands around and beyond 100GHz.

The evolution of 5G new radio (NR) is rapidly progressing as more parts are being standardized by the 3rd Generation Partnership Project (3GPP) and other organizations, with a focus on both enhanced and new services. This requires a closer look at the demands that will be put on the transport networks to achieve the desired results. Transport networks need to support new types of radio networks and additional interfaces with different requirements on bandwidth and latency, but the diverse deployment possibilities in 5G RAN causes actual transport demands to vary more than in typical 4G networks.

Ahead of 5G’s rollout, improvements in operational simplicity, efficiency and cost are necessary. Looking ahead, one way in which this can be done is to integrate transport further into the radio domain, as transport capabilities will impact the overall network performance for future 5G use cases.

Trends in spectrum

Greater capacity requirements are driving the introduction of 5G in microwave bands, meaning the availability and usage of microwave spectrum for fixed services will go through a major transformation in the next 5 to 10 years. E-band will grow in importance and in usage, and we will see an introduction of the new W- and D-bands.

India has the world’s largest installed base of microwave in traditional bands. Once E-band is introduced in India , it is likely to become the world’s largest E-band market, assuming it will have a low-spectrum fee approach, like most countries. The main drivers for E-band in India are: traditional spectrum fees; a lack of broad channels (max 28MHz) in traditional bands hampering capacity growth; and many short hops.

Already today, multi-band booster can be installed using two antennas – one in each band. However, to reduce load and rental cost of tower space, there is a clear need for dual-band antennas. The global high-volume bands 15, 18 and 23GHz are the most relevant for dual-band antennas, for combined use with 70/80GHz. In certain markets, 26 and 28GHz will also be relevant.

E-band was established in the US over 10 years ago. With E-band now open in more than 85 countries, growth has accelerated in 2017 and a significant further growth is expected in the next 5 years. The main drivers for E-band are high capacities and low spectrum fees. Eastern Europe is still the largest E-band market, mainly driven by low spectrum fees and simplified licensing. In Poland, the replacement of existing links with E-band

Conclusion

Global mobile network backhaul continues to evolve with a mix of fiber and microwave. There are two major trends influencing backhaul deployments around the world, as operators are in very different phases in the evolution of mobile broadband.

The advanced mobile broadband operators are starting to plan for the introduction of 5G, while most operators are in a phase of expanding LTE networks. According to the Ericsson Mobility Report Q4 2017, 3.3 billion mobile broadband subscribers will be added in the next five years, and a clear majority of these will come from LTE and 3G/HSPA in microwave-centric markets. The addition of an Indian greenfield LTE/4G operator and the densification needed to support proper MBB services will increase the number of sites, stabilizing microwave share on a global basis. The large-scale 5G volume

Deployments are initially expected in areas with high fiber penetration, such as China, Korea, Japan and US. There are also operators in Western Europe that have a combination of microwave and fiber, and are looking at introducing 5G. Larger volume rollouts of 5G networks are planned for a later point in the next few years. Regional variations Regional differences are expected to continue over the next five years. For operators evolving their LTE Networks, the focus will be on improving total cost of ownership and time-to-market in order to outperform competitors.

In mature mobile broadband regions such as Western Europe, there are examples of large operators using up to 80 percent microwave that now plan for 5G introduction using existing microwave networks. Microwave technology has evolved to manage the demand of mobile networks, and can do so from any macro site.

(The author is Head of Network Solutions , Market Area South east Asia , Oceania and India)