5G Test, Measurement, and Assurance
VIAVI is here to help with all your 5G testing needs.
While the advent of 2G in the 1990s made text messaging possible, the leap to 3G subsequently supported data transmission. The 4G LTE platform built upon those capabilities, with improved bandwidth, speed and reliability.
New innovations such as self-driving cars, the “Internet of Things” (IoT) and virtual reality are driving the next paradigm shift, and 5G will provide the exponential improvement in bandwidth and latency reduction to power these advancements.
With speeds up to 100 times faster than existing cellular connections and latency in the 1 millisecond range, 5G will even surpass the current capabilities of physical fiber optics. To support a successful transition, 5G test practices are being developed and refined to ensure the consistent performance that end users demand. The collective tools, software, protocols, and practices required for all 5G deployment phases form the core of the emerging 5G testing field.
Why 5G Testing Is Important
Since 5G is not simply an incremental update to existing communication standards, 5G test practices are dictated by the inherent complexity of the new technology. The expected enhancements will be the result of multiple elements performing seamlessly in tandem. Failure at any level could instantly lead to dissatisfied end users. Prediction and maintenance of this optimal performance can only be achieved through innovative and robust 5G testing practices.
New Radio (NR)
5G NR refers to the new OFDM-based wireless standard that will supersede LTE as the de facto standard for 5G operation. The 3rd 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.
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, will be 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.
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.
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 integrated arrays of 100 or more individual antennas.
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.
Challenges in 5G Network Testing
The combination of millimeter wave utilization, MIMO, and beamforming provides the infrastructure of 5G and the pathway to incredible performance enhancements. The added complexity introduced by these innovations can also pose challenges for the 5G testing process. MIMO essentially means (many) more antennas, which represents a higher test burden to ensure that all integrated antennas are fully operational. Measurement connectors for each antenna will no longer be feasible based on the compact architecture and density.
The utilization of the millimeter wave and beamforming at super-high frequencies presents additional obstacles. Since these frequencies are much more susceptible to propagation loss from environmental conditions, over-the-air (OTA) testing may be less consistent and more complex. However, since conducted mode testing cannot be performed without discrete connection points, OTA will be required more frequently.
Channel emulation becomes more complex with 5G, since the number of necessary RF channels will exponentially increase, as opposed to the linear expansion experienced with 3G and 4G releases. For 5G test equipment to be practical, the electronics technology must advance rapidly to compensate for the intricacy. Creative solutions that minimize chamber testing and other expensive test elements, without compromising test coverage and accuracy, should continue to be explored.
5G Deployment Phases
The deployment of 5G is a complex and challenging endeavor, requiring careful planning and seamless execution. Within each individual deployment phase, prudent application of an optimized 5G test toolkit is the best way to guarantee success. In many cases, these phases will be compressed and overlapping.
5G Deployment Phase #1 – Technology Verification and Validation
An essential precursor of successful 5G 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.
Scalable 5G test systems with integrated data services are required to measure the complete performance of the network and simulate real-world user behavior in 5G field trials. Software capable of emulating and measuring millions of unique data flows is another indispensable element of 5G V&V which can enhance load/capacity testing and benchmarking capabilities.
5G Deployment Phase #2 – Deploy, Activate & Scale
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.
Advanced fiber testing has not lost its relevance with the advent of 5G. For example, through fiber optic cable runs, Centralized Radio Access Networks (C-RAN) can co-locate baseband unit locations away from busy antenna sites. C-RAN architecture can also help to facilitate real-time radio resource coordination.
5G Deployment Phase #3 – Assure, Optimize, Monetize
The opportunities for monetization through 5G connectivity are limitless. More so, 5G is about business transformation, not just network transformation. Subscription fees for ultra-fast mobile broadband, mobile HD videos, virtual reality gaming and widespread IoT applications are just a few of the obvious avenues.
Each will require excellent customer quality of experience (QoE) to maintain viability. A real-time intelligence platform connected to virtual agents throughout the network lifecycle is an effective way to meet the challenges of 5G traffic density head-on, thereby assuring and optimizing QoE on a continuous basis.
5G Testing Best Practices
While the 3GPP has released the preliminary standard for 5G NR, there are still many areas in need of further refinement. Non-standalone (NSA) mode has been addressed in the 2017 release, although details regarding 5G standalone (SA) mode specifications, absent the convention of LTE coverage as an anchoring technology, have yet to be established.
Standardization is ultimately the key to developing accurate 5G test models, which in turn lead to more harmonized test practices. With the LTE standard now adopted worldwide, there is every reason to anticipate a similar evolution for 5G testing best practices.
Given the enormous frequency range and high-bandwidth services inherent to 5G technology, standardization of best practices will continue to progress as the technology, tools, and applications develop.
Preparing for the 5G Revolution
The technological advancements that 5G will enable were once the stuff of science fiction. Autonomous cars, virtual reality gaming, “smart cities” and the IoT are just a few of the futuristic innovations with a long head start as they prepare for the bandwidth and latency improvements that 5G will soon deliver. As with any advancement in functional capability, the unlimited potential of 5G will spawn more creativity and a continuous stream of new applications.
Due to the high frequencies inherent to 5G, initial deployment might occur in pockets where solid obstructions can be avoided. 5G transmitters will be located closer to the ground than previous generations, meaning more hardware at the ground level to ensure data quality.
As the deployment of 5G networks propagate and the requirements for standalone mode begin to take shape, the demand for innovative and cost-effective 5G testing tools will continue unabated. These powerful yet versatile tools will tacitly support the greatest technology revolution of the 21st century.
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