The UE48JS8580 supports an 802.11n wi-Fi standards which is newer than most 4K and 8K TVs that have been around for more than a year. Most 4K and 8K TVs that were launched around the same time as it support an 802.11a wi-Fi standards. In addition, this television support 802.11ac and 802.11b and 802.11g wi-Fi standardss.
An 802.11n wi-Fi standards is actually the best supported WiFi standard across all 4K and 8K TVs that have been available for around the same time as the UE48JS8580.
The worst supported WiFi standard across comparable types of TV is IEEE 802.11n.