5G Network Testing and Performance

5G NR refers to the new OFDM-based wireless standard that will supersede LTE as the de facto standard for 5G operation. The 3^rd Generation Partnership Project (3GPP) released the preliminary NR standard in December 2017. The New Radio spectrum will include frequencies from less than 6 GHz up to 100 GHz. Much of this wide spectrum will consist of space vacated by decommissioned 2G, 3G, and PCS frequency bands for the sub 6GHz band. The first application to be addressed and standardized will be mobile broadband. Additional capabilities, such as massive machine type communications (MMTC) and ultra-reliable low latency communications (URLLC) will be rolled out later.

5G NR is driving a new paradigm in 5G test methodology. An elevated degree of sophistication is required to verify beam tracking and acquisition at higher frequencies with more complex channel aggregation. Flexible 5G RAN architecture produces an exponentially larger set of test cases and diverse fiber network configurations. At the same time, coexistence with 4G in non-standalone mode creates interference and handoff issues that must also be emulated, tested and verified, and monitored through innovative 5G test practices.  

The super-high frequency spectrum that includes the 100 GHz upper limit defined by NR is known as millimeter wave. Large amounts of available bandwidth in hundreds of MHz at higher frequency translates to higher speed; the millimeter range, defined as 24 GHz to 100GHz, is an essential element of 5G testing and deployment. While the speed is faster, the range is much shorter, and obstacles such as buildings and walls will blunt the signal, whereas lower frequencies can simply travel through these objects. These higher frequencies and wider channel bandwidths have necessitated test solutions with improved dynamic range and signal-to-noise ratios (SNR) to demodulate signals in the millimeter wave accurately.

Multiple input, multiple output, or MIMO refers to antenna technology that can be used to increase the data rate (spatial multiplexing) instead of improving robustness. A system that incorporates a much larger number of radio antennas into arrays on cellular towers is referred to as massive MIMO. At high frequencies, radio wavelengths are so small that a large array of antennas can be integrated into a much smaller form factor to allow massive MIMO operation.

Massive MIMO can overcome some of the drawbacks associated with millimeter wave by transmitting data streams in parallel and enabling the device to reconstitute them into a single message. Massive MIMO array density and elimination of connector ports has prohibited traditional cabled testing and ushered in new standards for over-the-air (OTA) testing.

This advanced functionality has landed synchronization testing requirements for 5G MIMO arrays into the most stringent (A+) category of tests. Fronthaul transport network node (FTN) testing with the T-BERD/MTS-5800-100G can effectively validate synchronization requirements by performing throughput, delay and packet jitter measurements.

Another advanced technology that is essential to the success of 5G testing and deployment is beamforming. This is a method whereby an algorithm is used to focus wireless signals into a directed beam. This approach provides a way to avoid obstacles that can interfere with high-frequency transmissions and can also strategically focus transmissions directly to the end user.

The use of massive MIMO will further enable this personalization through the propagation of dynamic arrays including 256 or more individual antennas. Validating these active antenna configurations along with channel performance requires an innovative 5G cell site test solution. The CellAdvisor 5G verifies and monitors channel stability, modulation quality and cell ID from controlled field trials through large-scale 5G deployments.

The concept of network slicing refers to intelligently utilizing portions of the spectrum based on the specific needs of the individual device or application. For example, a self-driving car may require extremely low latency for safe operation, whereas IoT applications may encompass a large number of devices with very low throughput demands. The mobile network will adeptly configure resources to optimize traffic flow and resource utilization.

5G network performance verification of multiple, virtual elements in the real world can be augmented by testing and validating diverse network slicing use cases in the lab environment. End-to-end solutions for RAN-to-Core testing and validation can emulate 5G core networks in total and verify network slice node selection and functionality.

An essential precursor of successful 5G network deployment is robust verification and validation (V&V). This phase includes verification of virtual network functions and network services to ensure immediate quality and reliability once the network is deployed.

Once the rubber of 5G deployment hits the road, an appropriate suite of 5G test tools for activation and scalability is imperative. Base station analyzers augmented to analyze the spectrum and interference of 5G signals in the millimeter wave range are an important centerpiece for this deployment phase. Software to monitor and ensure network performance and verify Service Level Agreements can augment the 5G activation, performance monitoring, and troubleshooting activities.

The opportunities for monetization through 5G connectivity are limitless. More so, 5G is about major business transformation, not just network transformation. Subscription fees for ultra-fast mobile broadband, mobile HD content and videos, virtual reality gaming, media streaming, and widespread IoT applications are just a few of the obvious avenues.