Coffee Shop Gets a 5G Boost
by Melroy Machado, Technical Product Manager
Pivotal’s 5G Test Lab blog describes how Pivotal conducts its product testing. "The Lab" uses a Pivot 5G outdoor network repeater to extend mmWave coverage from a gNB to the otherwise shadowed side of a nearby hotel. Doing so provides enough signal at each room window to allow an Echo 5G subscriber repeater to gently flood it throughout the room inside. This blog describes how Pivotal used The Lab to test its new Echo 5G Boost product at a coffee shop across the street. The Boost was designed to propagate mmWave indoors through low emissivity (low-e) glass windows.
The Set Up
Figure 1 shows how one of the Pivot wide-beam service units (SU) for the hotel was replaced by a narrow beam SU and swiveled 90 degrees towards the coffee shop across the street. Total distance between gNB and coffee shop is about 600 feet. The coffee shop windows are made of one-inch thick, dual pane, low-e glass.
Low-E
Estimates of low-e glass in U.S. households and businesses approximate 25% and 35%, respectively. But recently, says the Department of Energy, more than 50% of window sales in the commercial market and 80% of the sales in the residential market incorporate low-E coatings. That’s good news for saving energy, but bad news for acquiring a mmWave signal indoors.
Echo 5G Boost
Figure 2 shows mmWave penetration, or the lack of it, inside the coffee shop. Without an Echo attached to the window, no mmWave coverage penetrated indoors. When an Echo 5G for standard glass was attached, the signal penetrated just a few feet inside. When the Echo 5G Boost for low-e glass was attached, indoor mmWave coverage spanned wall-to-wall. By adding an additional gain stage indoors, the Boost overcomes low-e glass loss up to 50 dB.
What about 4G, you might ask. Table 1 breaks it down. The coffee shop’s own Wi-Fi download speed clocked in at 5 Mbps.
| KPI | 4G | 5G mmWave | Improvements over 4G |
|---|---|---|---|
| DL speed | ~300 Mbps | 700 MBps - 1.4 Gbps | 2x - 5x |
| UL speed | ~20 Mbps | 30-66 Mbps | 1.5x - 3x |
| Ping | ~25 ms | 7 - 8 ms | 70% faster ping |
| Jitter | 3 - 6 ms | 2 - 4 ms | 50% improvement in jitter |
Another First
Pivotal introduced the first 5G mmWave subscriber repeater, Echo 5G, in 2020. Echo 5G Boost is another first, and evidently, it can really make a difference in the presence of low-e glass windows. Figure 3 depicts a happy future for the coffee shop patron wearing augmented reality (A/R) glasses. Pivotal apologizes in advance to coffee shops for encouraging longer loitering.
