COMB: Cell Based Orientation Aware MANET Broadcast MAC Layer

The design of a collision avoidance system for trains implies the design of a MAC layer for their specific requirements. It should be efficient, reliable, use broadcast and support wireless mobile ad hoc networks (MANETs) with high user speeds. Therefore we are using awareness techniques, which allow a certain channel assignment, despite the absence of infrastructure. This paper presents a new MAC layer protocol designed for broadcast MANETs called COMB (Cell-based Orientation-aware MANET Broadcast). In principle, COMB allows the realization of a collision free transmission, high speed is supported and no handshake is required. COMB is based on localization aware cross layer dimensioned CDMA cells, and uses the SOTDMA protocol as intra cell scheme, while the inter cell scheme relies on direction and speed awareness.