Long Range 2.4ghz antenna for Legacy Command Base
Here's a long range antenna that easily replaces the stock Legacy Command Base antenna and will improve range if you are having issues, especially with large layouts or irregular shaped rooms with solid obstructions.
2.4GHz 9dBi High Gain Omni Directional WiFi Antenna RP-SMA
In the event this particular item is no longer available, there are many similar listings on eBay for 2.4ghz hi-gain antennas.