Dynamic Cognitive Self-Organized TDMA for Medium Access Control in Real-Time Vehicle to Vehicle Communications

Table 2

Qualitative comparison of the analyzed protocols.

Type	CSMA/CA	Slotted-Aloha	RR-Aloha	STDMA	VeSOMAC	NCC-TDMA
	Contention	Contention	Scheduled	Scheduled	Scheduled	Scheduled
Topology-independent	Yes	Yes	Yes	No	No	No
Signalling	No	No	Yes	Yes	Yes	No
Message exchange required	No	No	Yes	Yes	Yes	No
Possibility of collision	Yes	Yes	Yes	Yes	No	No
Time synchronization required	No	Yes	Yes	Yes	No	Yes
Reason for access schedule reconfiguration	N/A	Collision	New users, new transmissions.	Periodic reconfiguration	Collision with other system users	Detection of channel occupation, whether by another user or due to outside signal interference
Oriented at application	No	No	No	Yes: vehicle localization and movement	Yes: vehicle localization	No