# Investigation of Data Quality Assurance across IoT Protocol Stack for V2I Interactions
## 7 Conclusions  
Despite the unique capabilities of the various protocols within our tri-layered study, there exists a gap in the traceability and validity dimensions. Addressing these gaps would involve incorporating additional methodologies, such as logging and monitoring systems, data validation rules and implementing anomaly detection techniques. Furthermore, adopting a cross-layer fusion approach by leveraging the synergy between protocols and layers, such as network conditions from the Internet layer, can enhance validity checks in the application layer. While all these approaches can potentially improve DQ across all layers, they could also lead to potential violations of the existing layered architecture principles. Thus, these strategies might introduce trade-offs, such as increased computational overhead or system complexity. Hence, achieving an optimal balance between DQ, security, system performance and efficiency in a protocol fusion approach is a compelling future research direction.  
Conceptualisation, D.S. and K.A.; methodology, D.S.; validation, D.S., K.A., and R.S.; formal analysis, D.S.; investigation, D.S.; resources, D.S.; data curation, D.S.; writing--original draft preparation, D.S.; writing--review and editing, D.S., K.A., and R.S.; supervision, R.S. and K.A. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Data Availability Statement: Not applicable. Conflicts of Interest: All authors have declared no conflict of interest. Abbreviations  
3 GThird Generation  
4 GFourth Generation  
6 LowPANPv6 over Low-Power Wireless Personal Area Networks  
ACKAcknowledgement  
AMQPAdvanced Message Queuing Protocol  
C-ITS Cooperative Intelligent Transportation System  
C-V2X Cellular Vehicle-to-Everything  
CoAP Constrained Application Protocol  
DCCP Datagram Congestion Control Protocol  
DDSData Distribution Service  
DNSDomain Name Server  
DQData Quality  
DSRCDedicated Short-range Communication  
FTPFile Transfer Protocol  
GNSSGlobal Navigation Satellite System.  
HTTPHypertext transfer protocol  
IETFInternet Engineering Task Force  
IoTInternet of things  
IPInternet Protocol  
IPv4 Internet Protocol version 4  
IPv6 Internet Protocol version 6  
LLNsLow-Power and Lossy Networks  
M2 MMachine-to-Machine  
MANETMobile Ad Hoc Network  
ModQUICModified Quick UDP Internet Connections  
MQTTMessage Queuing Telemetry Transport  
MQTT-SNMessage Queuing Telemetry Transport-Sensor Network  
PDRPacket Delivery Ratio  
PSNRPeak Signal-to-Noise Ratio  
QoSQuality of services  
QUICQuick UDP Internet Connections  
RESTRepresentational State Transfer  
RPLRouting Protocol for Low-Power and Lossy Networks  
RTTRound Trip Time  
SCTPStream Control Transmission Protocol  
SMTPSimple Mail Transfer Protocol  
STDSpatial-Temporal Data  
TCPTransmission Control Protocol  
TCP/IPTransmission Control Protocol/Internet Protocol  
TFRCTCP-Friendly Rate Control  
UDPUser Datagram Protocol  
V2 IVehicle-to-Infrastructure  
V2 VVehicle-to-Vehicles  
V2 XVehicle-to-Everything  
VANETVehicular Ad Hoc Network  
XMPPExtensible Messaging and Presence Protocol