On the Context-Aware, Dynamic Spectrum Access for Robust Intraplatoon Communications

Table 4

Summary of selected properties of the proposed management architectures.

Property	Centralized	Distributed	Hybrid
SM location	Central management server	Platoon leader	RSU/BS
CADB location	Central CADB	Central CADB and RSU/BS	Central CADB and RSU/BS
SM-CADB connection	Intra-CADB interface (backbone network)	Car-CADB interface (V2X communications) and intra-CADB interface (backbone network)	Intra-CADB interface (backbone network)
SM-platoon connection	Car-CADB/SM interface (V2X communications) and intra-CADB interface (backbone network)	Direct access (leader)	Car-CADB/SM interface (V2X communications)
Advantages	Global knowledge of the network status, joint optimization of spectrum allocation, and lower management load of the RSU/BS	Lowest latency, decreased load of the network with management data, and deployment of an additional server not required	Lower network load and latency than those in the centralized system, partial (regional) coordination of spectrum allocation, and deployment of an additional server not required
Disadvantages	High load of the management server, high latency, increased network load with management data, and dedicated management server (hardware) required	Incomplete information on spectrum availability, no coordination between platoons (interference), and increased vehicle cost (SM inside the vehicle)	Inter-RSU/BS interface needed for coordination of neighbouring SMs and additional load of the RSU/BS with management tasks