The FCC filing once again doesn't actually have the Nexus branding on it, but it is an HTC-made tablet, which narrows down the field quite a bit. The device ID for this filing is also quite similar to the Wi-Fi only Nexus 9 that we saw before. This filing shows a tablet with support for LTE bands 2, 4, 5, 7, 12, 13, 17, 25, 26, and 41, which covers all U.S. carriers; and, it also includes GSM850/1900 support and WCDMA bands 2, 4, and 5 for global roaming.
We can't say exactly when the LTE Nexus 9 will go on sale, but it should be clear to do so, now that the FCC approval has been done. The LTE Nexus 9 is listed on the Google Play Store only as a 32GB model for $599. We'll keep an eye out and let you know when it goes up for sale.