The Apple MacBook Pro Early 2015 has an 802.11n WiFi standard which is better than most notebook PCs of this age and type. Most MacBooks that were released one year ago have an 802.11a WiFi standard. In addition, this notebook PC have 802.11ac and 802.11b and 802.11g WiFi standards.
This notebook PC's Wi-Fi standard (802.11n) is in fact the best Wi-Fi standard amongst all portable PCs that have been on the market for a comparable time to the MacBook Pro Early 2015.
An 802.11a WiFi standard is the worst Wi-Fi standard amongst similar types of notebook PC.