Look to Apple to Deliver a Fix Under Your Warranty
Further tests using a Fluke Networks WiFi Tester showed that the WiFi signal strength at 5GHz in the area where the third-generation iPads were unable to connect was -66 dBm. The signal strength at 2.4GHz was somewhat stronger because the lower frequency has less attenuation through walls or foliage. These signal levels are high enough that the iPads should have been able to connect without problems.
Next, eWEEK performed tests with a Lenovo T-410 computer equipped with a 3x3 antenna system, which enables it to use three spatial streams, and the Fluke WiFi tester, which is a 2x2 system. Both devices were able to demonstrate reliable connections at 5GHz at distances ranging up to 150 feet for the Fluke tester before it showed packet loss, and distances up to 200 feet with the Lenovo. The first-generation iPads demonstrated proper operation at distances that varied between 75 to 100 feet of free space with one exterior wall.
The third-generation iPads completely lost their 5GHz connection between 20 and 25 feet. The iPad that could connect at 5GHz showed packet loss at virtually every distance over 10 feet. We were unable to test for packet loss in the third-generation iPad that wouldn't join the network.
Apple reportedly is investigating the WiFi issues, but most of the complaints have been with WiFi-only devices, which either don't connect to WiFi at all or have poor or unstable connections. Apple has instructed its staff to "capture" those devices, according to a report in 9to5Mac, which has obtained an internal Apple memo.
While reports of WiFi issues in LTE-equipped iPads are rare, they do exist. This is likely because relatively few people use 5GHz WiFi, and of those who do, many have WiFi routers that operate on both the 5 and 2.4GHz bands, but which have the same SSID, making identification of which band is being used difficult to determine without specialized test equipment.
Users trying to find out if they have a problem with 5 GHz operation on their iPads can change the service set identifier (SSID) of the 5GHz portion of their WiFi router so that it's different from that on the 2.4GHz portion. Once that's done, both should show up as separate access points in the list of WiFi devices on the iPad's WiFi screen in the Settings menu.
If you don't see both SSIDs, but then see the 5GHz access point appear as you approach it, then you may have a problem. While it's normal for the 5GHz signal to have less range than the 2.4GHz signal, it should still be a distance of 50 feet or so, depending on conditions.
Because your third-generation iPad is still within its warranty and because Apple is already trying to figure out the problem, it's a good idea to contact Apple support if you are experiencing this issue. At least that way, you'll know when there's a fix.