Ad-hoc networks are not restricted to any special hardware. But today such networks are most likely to consist of nodes utilizing so-called WLAN interfaces. These are wireless interfaces operating according to IEEE specifications 802.11a, 802.11b or 802.11g. Throughout this document it is assumed that ad-hoc networks consists of links made up by either WLAN or Ethernet interfaces.
IEEE 802.11 does not support multi-hop communication by it self. Two modes are defined for communication using WLAN devices:
The Ad-hoc mode is obviously the mode to use when setting up a MANET, but it lacks one basic requirement: multi-hop. Traffic is only transmitted to neighbors within radio range when using the ad-hoc mode, therefore there is a need for MANET routing protocols to set up and maintain traffic paths.