It’s clear that 5G differs from the G’s that came before it in many ways. More than a network, 5G is an ecosystem that supports numerous applications and industries. The possibilities for telecommunications, internet of things (IoT), and other technologies are virtually limitless, but that comes at a cost.
5G’s capabilities and sophistication lead to more complexity in offering support services. 5G also has unprecedented performance requirements, such as high bandwidth, low latency, connected device density, and coverage area.
If 5G backhaul can address these challenges, however, there’s virtually no limit to its technical and industrial potential.
5G Backhaul Challenges
Mobile backhaul networks connect radio access networks (RAN) at the cell sites to a core network to maintain connectivity. Backhaul traffic from the core network to the transmission network needs high capacity.
In addition, 5G requires network reliability with lower costs. The capacity requirement is only likely to increase as well.
As 5G is used to connect IoT devices, such as IoT and machine-to-machine devices. With so much data that needs to be sent to the core, 5G requires ultra-low latency, increased capacity, decreased traffic, better connectivity, and long-distance reach.
5G Wireless Backhaul Solutions
There’s no one-size-fits-all solution to wireless backhaul. Even before now, all backhaul solutions were about choosing the one with the most advantages relative to its disadvantages, all while considering the factors that can impact the chosen solution itself.
Here are some of the requirements that need to be considered:
- Backhaul architecture – point-to-point (PtP) or point-to-multipoint (PtMP)
- RAN architecture – backhaul, midhaul, or front haul
- Frequency – bands from 4 GHz to 200 GHz
- Reach – from several hundred feet to over 150 miles
- Traffic type – TDM, hybrid TDM-IP, all-IP
Fiber Backhaul Solution
Fiber backhaul is a wired solution and a popular option for high reach, high capacity, and low bit error rate. Fiber isn’t widely available, however, which may prevent its implementation.
That’s not the only disadvantage of fiber. Though it can travel long distances, it needs a pathway to get around obstructions like buildings or natural features like rivers. Fiber also takes a long time to deploy – months – compared to a week like other solutions. It’s also expensive, which can be limiting.
Wireless Backhaul Solutions
Backhaul can be done wireless, which allows for more backhaul solutions to address specific requirements and challenges. Wireless backhaul is reliable and affordable, ensuring end-to-end control for operators and minimal investment from businesses.
Wireless backhaul isn’t perfect, however. Performance can suffer from external factors, such as energy efficiency, environment, traffic, and cell site location.
Wireless backhaul offers several options, including:
Microwave
Roughly half of mobile traffic uses wireless backhaul technology. Microwave radiofrequency is the majority of the wireless backhaul technology, making it one of the most popular options.
While microwave radiofrequency can be costly in its implementation and initial investment, it’s still cost-effective. Deployment is quick, saving time in delays while it’s implemented.
Microwave radiofrequency backhaul isn’t without its challenges. Though it doesn’t struggle with buildings and obstructions, it can struggle with weather conditions and the environment. Operators have the option to adjust the availability requirements for a tradeoff.
For example, they can choose a lower frequency band to improve the reach, though that increases network congestion. Likewise, the higher frequency band can improve the data rate, but that decreases the reach.
Millimeter Wave
Millimeter wave is a high-frequency backhaul method that boasts between 30 and 300 GHz. This is helpful for small cell backhaul solutions, due to its high data transmission rates and wide spectrum.
High frequency does mean a shorter reach, however. Millimeter wave beams are also narrow compared to microwave beams, affecting the line of sight.
Free Space Optics
Free space optics is a similar solution to fiber optics, but wireless. Instead of cable, free space optics use invisible light beams to transmit data. The spectrum for free space optics is single broad computers like the NXP iMX8 running between 300 GHz and one THz, with a rate up to 10 Gbps. It also consumes less power than comparable methods.
Despite the balance between wireless and fiber, free space optics has disadvantages for line-of-sight communications. Ambient light sources, fog, and other environmental conditions can affect the communications, as well as physical obstacles like buildings and natural features.
That said, free space optics is still one of the best options for scalability and flexibility.
Finding a Backhaul Solution
The mobile communications industry is evolving faster than we could’ve imagined. As 5G sees increased adoption and implementation, wireless backhaul methods will be needed to address the unique challenges for the industry and ensure reliable performance. No solution is ideal – or even available – for every situation. It’s important to consider the advantages, disadvantages, and unique factors before choosing the right 5G wireless backhaul solutions.