They are a slate gray on the top and white underneath. I thought of a titmouse, but these birds don't have the tuft on their heads. They are agressive, fighting off other birds and even sometimes their own species. Maybe all birds are this way, but these little gray ones seem more agressive than others at the feeders.
Figure 3.6 An independent BSS (IBSS) is the most basic type of 802.11 wireless LAN. Figure 3.7 An Extended Service Set (ESS) 802.11 wireless LAN consists of multiple cells interconnected by access points and a distribution system, such as ethernet.
BTS is short for base transceiver station. In mobile communications, a BTS holds the radio transceivers that define a cell and coordinates the radio-link protocols with the mobile device. The BTS is the networking component of a mobile communications system from which all signals are sent and received.