The Latitude 14 E7440 has an 802.11n wi-Fi standards which is better than most portable PCs of this spec and age. Most ultrabooks that have been around for a similar time to it have an 802.11g wi-Fi standards. In addition, this portable PC have 802.11a and 802.11ac and 802.11b wi-Fi standardss.
An 802.11n wi-Fi standards is actually the best Wi-Fi standard across all ultrabooks that have been on the market for more than two years.
The worst Wi-Fi standard across comparable types of laptop is 802.11a.