Consumer and enterprise customers demand higher-speed connections, greater reliability, more visibility, and faster response times. These demands have led to the development of 5G, built to support an Internet of Things (IoT), higher capacity, and very-low-latency connections. Service providers will need many network tools to address connections to 5G base stations that support this low latency, high bandwidth, and high reliability. Microwave has traditionally been one of the leading technologies for mobile backhaul because of its high reliability, high capacity, and low cost. Recently, microwave providers have combined high-capacity E band with midbands to improve reliability while addressing 5G's requirements.
Applications driving the need for greater reliability
Enterprise, consumers, and governments are looking for new 5G solutions to solve problems and deliver new levels of service. There has been a great deal of hype around 5G and the applications it addresses, including self-driving cars. Figure 1 reflects the new 5G applications, their requirements (e.g., scale, high availability, or low latency), and their mode of operation (e.g., human to human or human to machine). Customers are looking for new video, gaming, and training experiences that use virtual reality on extreme mobile broadband. These same customers also demand an ultrareliable low-latency service for healthcare monitoring, vehicle-to-infrastructure, or industrial automation applications. These ultrareliable low-latency applications and massive IoT applications are driving new requirements for the network.
Latency is critical for industrial automation, while reliability is critical for healthcare monitoring, public-safety applications, and vehicle-to-infrastructure communications. Standards for 5G have tightened the latency requirement from 50ms for 4G to 1ms for 5G while expanding bandwidth capabilities to 10Gbps. Enhanced network slicing with 5G allows users to buy a slice of functionality to better control for reliability or performance. Smart grids and public-safety networks must stay connected during emergency situations. Table 1 outlines some of the ultrareliable applications and their requirements.
Table 1: Table 1: Applications driving ultrareliable low-latency networks
|Application||Enhanced broadband||Ultrareliable low latency||Massive machine connections||Benefits|
|Vehicle to infrastructure||Yes||Yes||Provide suggestions on routes to avoid congested areas. Allow traffic lights to flow traffic through cities avoiding congestion.|
|Public safety||>1Gbps||Yes||Frequently||Emergency responders need fast and reliable networks to save people's lives.|
|Healthcare monitoring||Yes||Yes||Monitor patients' critical health conditions, detecting any deterioration. Provide monitoring when hospital services are remote.|
|Remote surgery||>1Gbps||Yes||No||Allow skilled surgeons to provide care to people in remote areas (this will be a much later application).|
|Vehicle to vehicle||Yes||Yes||Avoid accidents and warn of upcoming hazards.|
As people around the world have more visibility based on smartphone capability, they expect more from their providers. Governments and enterprises must adopt solutions that can give similar visibility to critical infrastructure and communications. Most of these applications require a network that is ultrareliable with low latency.
Microwave has historically been used for low latency and network resilience
Microwave technology has been around for a long time. Microwave systems have been relied on to provide network resilience against natural disasters. In hurricane-prone areas, regional and municipal governments and service providers rely on microwave systems as the reliable path when the wireline infrastructure is damaged.
Microwave also benefits from unique characteristics that lower network latency. Microwaves travel through the air in a direct line, whereas fiber tends to follow existing infrastructure, which is never a straight path. Microwaves, because of their propagation through the air, also enjoy a lower delay than fiber: fiber-optic cables propagate light more slowly than air does. The benefits of microwave systems led brokerage firms to build microwave networks for high-frequency trading.
The limitations of microwave systems were spectrum availability and high-capacity performance. Microwave systems in the middle band have had high availability but are limited to speeds up to 2.5Gbps depending on channel availability and distance. Microwave systems in higher bands such as the 80GHz E band can deliver high-capacity backhaul but are affected by weather, which increases their downtime. As service providers looked for greater reliability and higher speeds, microwave manufacturers created a multiband microwave solution.
Multiband solutions for ultrareliable high-capacity networking
80GHz E-band frequency bands were set up for fixed point-to-point connectivity for higher-speed connections. For many years microwave manufacturers offered E-band technology, but it has struggled to gain widespread adoption because of weather-related performance issues. The 80GHz band is susceptible to degradation due to rain and high-wind mast movement. These issues hurt performance with more link failures and increased customer dissatisfaction. Microwave vendors have worked on various solutions to improve performance and reliability. The multiband solution appears to improve reliability with E band, and it steps down to a more reliable frequency when conditions warrant.
Combining midband frequencies (18–23GHz) with 80GHz E band as shown in Figure 2, a multiband solution can provide a reliable connection. It will work in bad weather while addressing high-bandwidth 5G backhaul applications in more moderate conditions.
Multiband can be deployed to an existing midband microwave system by adding E-band radios and couplers to an existing system where capacity requirements drive this upgrade. Multiband can also be deployed during planning for 5G where capacity needs to be added upfront but reliability is critical. This scenario combines the reliable midband solution with high-capacity E band, delivering the necessary capacity for 5G while maintaining availability at five nines.
We will discuss this topic in depth during a webinar on October 23.
— Don Frey, Principal Analyst, Transport & Routing, Ovum firstname.lastname@example.org