Microwave Transport Path to 5G Network Slicing

- Overview

If anyone doubts that microwave transport will be ready for 5G, think again. With carrier aggregation and mmWave deployments, microwave networks provide the high throughput and low latency to meet even the most demanding 5G service. With carrier Software Defined Networking (SDN), microwave networks are managed automatically and dynamically to provide extreme reliability and maintain performance whatever the demand. 

Together, these technologies enable a third capability that will give 5G a business-winning sizzle for Communications Service Providers (CSPs) – network slicing. With network slicing, end users get capacity, latency, reliability, coverage, security and other network performance characteristics tailored to their needs. The user experience will be the same as if they were being served by their own dedicated physical network built just for them. 

Network slicing enables the creation and delivery of innovative services that will drive CSP business growth for the next decade and beyond. CSPs will be able to offer innovative services not possible with 3G/4G networks, allowing them to win revenue from new customer segments. 

- Microwave Paths

Point-to-point microwave transmission is a critical component of the national communications infrastructure. Microwave paths enable broadband data transmission that supports telephone, cellular, and personal communication service (PCS) networks, wireless internet providers, audio and video transmission from television studios to transmitter sites, as well as many other industry/utility applications. 

Microwaves are widely used for point-to-point communications because their small wavelength allows conveniently-sized antennas to direct them in narrow beams, which can be pointed directly at the receiving antenna. This allows nearby microwave equipment to use the same frequencies without interfering with each other, as lower frequency radio waves do. This frequency reuse conserves scarce radio spectrum bandwidth. Another advantage is that the high frequency of microwaves gives the microwave band a very large information-carrying capacity; the microwave band has a bandwidth 30 times that of all the rest of the radio spectrum below it. A disadvantage is that microwaves are limited to line of sight propagation; they cannot pass around hills or mountains as lower frequency radio waves can.

Microwave radio transmission is commonly used in point-to-point communication systems on the surface of the Earth, in satellite communications, and in deep space radio communications. Other parts of the microwave radio band are used for radars, radio navigation systems, sensor systems, and radio astronomy.

The next higher frequency band of the radio spectrum, between 30 GHz and 300 GHz, are called "millimeter waves" because their wavelengths range from 10 mm to 1 mm. Radio waves in this band are strongly attenuated by the gases of the atmosphere. This limits their practical transmission distance to a few kilometers, so these frequencies cannot be used for long-distance communication. The electronic technologies needed in the millimeter wave band are also in an earlier state of development than those of the microwave band.

Wireless transmission of information

• One-way and two-way telecommunication using communications satellite
• Terrestrial microwave relay links in telecommunications networks including backbone or backhaul carriers in cellular networks

More recently, microwaves have been used for wireless power transmission.

- Plotting A Path Through the Network

Microwave transport networks support around half of all base stations globally. Empowering them to support network slicing helps CSPs to re-use existing investments as they deploy 5G. 

This is achieved by implementing carrier SDN to dynamically create a path, with the specific capabilities needed for the network slice, through the transport network from Radio Access Network to the core network or edge application servers. Carrier SDN uses open interfaces to automatically discover the network topology and use the performance characteristics of each physical link in the network to figure out an end-to-end route. Adding a new base station site as part of network densification, for example, becomes a simple task. The new site is assigned an IP address and the SDN automatically provisions all the other end-points with routing information to reach the new destination. 

Implementing a Layer 3 Virtual Private Network (L3VPN) approach to network slicing ensures that traffic on one slice is prevented from interfering with traffic on another slice. Putting the VPN on Layer 3 also benefits from the high level of flexibility and scalability of IP with automated routing.

[More to come ...]