T-Mobile has successfully tested the world's first 5G standalone (SA) data session with New Radio Carrier Aggregation (NR CA) on a commercial smartphone. Carrier aggregation lets a mobile device on a wireless network use more than one frequency band simultaneously, boosting available bandwidth and therefore increasing data speeds. Carrier aggregation has long been a standard feature of 4G (LTE) networks, but is just now coming to 5G (NR) networks. T-Mobile's test used an LG Velvet phone with a MediaTek Dimensity 1000C chipset to connect to Ericsson network equipment over two bands: band 41 (2.5 Ghz, AKA mid-band) and band 71 (600 MHz, AKA low-band). T-Mobile says CA boosts download speeds on its band 41 by 20 percent on average initially.