On the CEH 10 videos on video Wireless Hacking Concepts at 19:29 they go into antennas. A few things that where a little off. Omni directional antennas do not give off a dome signal pattern it is more of a do-nut. After that they talk about dipole antennas. Dipole are Omni directional not bidirectional. In fact the access point he uses as an example used dipole antennas.