The decision that symbolized the apparent ungluing of the Dallas Cowboys, Switzer's unsuccessful call at his own 29 that led directly to an embarrassing loss at Philadelphia on Dec . 10, is now little more than an amusing footnote to a difficult season.
12.
The main reasons for unsuccessful call setups in mobile networks are lack of radio coverage ( either in the downlink or the uplink ), radio interference between different subscribers, imperfections in the functioning of the network ( such as failed call setup redirect procedures ), overload of the different elements of the network ( such as cells ), etc.
