Abstract-Long propagation delays and low bit rates of the problem of hidden terminals and exposed terminalsarises underwater acoustic networks make these systems fundamentally in ad-hoc networks due to the lack of connectivity between different from the packet radio networks. As a consequence, certain nodes. many of the network protocols designed for radio channels are either not applicable, or have extremely low efficiency over A situation of a hidden terminal occurs when one station underwater acoustic channels. These facts necessitate a dedicated cannot sense one or more nodes that can interfere with its design of protocols for an underwater acoustic network. transmission. A situation of an exposed terminal occurs when A medium access control (MAC) protocol suitable for an a station delays transmission because of another overheard underwater acoustic network is proposed and analyzed. The transmission that would not collide with it. Figure 1 illustrates protocol is based on a channel access discipline called floor acquisition multiple access (FAMA) which combines both carrier a situation in which nodes A and C are hidden from each sensing (CS) and a dialogue between the source and receiver other. A situation of exposed terminals would occur if C were prior to data transmission. During the initial dialogue, control transmitting to D and B wanted to start a transmission to A. B packets are exchanged between the source node and the intended would listen to the channel and it would defer its transmission destination node to avoid multiple transmissions at the same time. Special attention is paid to the networks that are not fully alt
In REF , Molins and Stojanovic propose the classic slotted FAMA protocol, which is based on a channel access protocol called floor acquisition multiple access (FAMA).
Slotted FAMA: a MAC protocol for underwater acoustic networks
OCEANS 2006 - Asia Pacific
OCEANS 2006 - Asia Pacific
Engineering