Ready to Test 5G Data Throughput?

Ready to Test 5G Data Throughput?

With mobile operators fast-tracking their 5G deployment plans, the realization of 5G is rapidly approaching. To keep pace, chipset and device manufacturers will need to accelerate their own development activities. If these efforts pay off, 5G will deliver new and powerful capabilities to support use cases requiring much faster data rates, ultra-reliable low latency (uRLLC) and massive machine-type communications (mMTC). However, that is easier said than done, given the challenge that comes with testing 5G’s high data rates.

5G Use Cases

There are three main use cases for 5G. They are enhanced mobile broadband (eMBB), uRLLC and mMTC. The eMBB use case is targeted in the Verizon 5G Technical Forum (5GTF) specification, as well as phase 1 of the 3GPP new radio (NR) specification. Due to strong industry demand, this use case and its definition have been accelerated. 3GPP has agreed to the early completion of the nonstandalone (NSA) 5G NR mode for eMBB. In NSA mode, the connection is anchored in LTE with 5G NR carriers used to boost data rates and reduce latency. Data rates up to 20 Gbps in the downlink and 10 Gbps in the uplink are on the horizon for network rollouts in the next few years.

The 5G eMBB use case provides functionality to support high speed data rates, improved connectivity and system capacity. That is critical, since consumers want the ability to connect to the network wherever they are, such as attending a sports event, traveling in a car or riding on a high speed train or other public transport. High data rates and greater capacity are essential to using virtual reality (VR) and augmented reality (AR) applications, which include new video formats with increased resolutions (8K+) and higher frame rates (HFR). For interactive AR and VR applications, low latency is a key requirement. With the number of users increasing and simultaneously consuming or sharing premium content, 4G networks will struggle to provide the capacity. That underscores the necessity of improved capacity with a 5G network.

To achieve the higher data rates, improved connectivity and greater system capacity for eMBB than is available using sub-6-GHz frequencies, 5G is also being deployed in the higher frequency mmWave spectrum, which offers significantly greater bandwidth. While LTE operates at frequencies up to 6 GHz, mmWave frequencies up to 100 GHz are under consideration for 5G. 5GTF specifications covering 28 and 39 GHz are also being considered by other operators. At higher frequencies, propagation and penetration losses increase. To overcome the high path loss and improve connectivity to users at the cell edge, beamforming techniques will be employed. Beamforming increases the signal level received by a device, which results in a stronger signal-to-noise ratio, by providing high gain in specific spatial directions.

eMBB Test Challenges

The introduction of beamforming in the 5GTF and 3GPP NR specifications creates several new test challenges. Adding to these are the changes in the physical layer (PHY)—the frame structure, new reference signals and new scheduling and transmission modes—to support the eMBB use case. Understanding the new frame structure and beamforming concept is critical. To aide in this discussion, consider Table 1, which compares the PHY characteristics among the LTE, 5GTF and 3GPP 5G NR specifications. Note that all changes from the LTE standard are denoted in red. As shown in the table, the 5GTF frame structure parameters (e.g., subcarrier spacing and carrier bandwidth) are fixed compared to the 3GPP NR values. The 3GPP NR values are scalable to accommodate a wider range of use cases. As previously mentioned, 5GTF targets the eMBB use case. In this specification, higher subcarrier spacing, carrier bandwidth and use of higher frequencies all contribute to a higher data rate and improved connectivity, compared to LTE.