Vulnerabilities and integrity of precise point positioning for intelligent transport systems: overview and analysis

Abstract

The implementation of Intelligent Transport System (ITS) technology is expected to significantly improve road safety and traffic efficiency. One of the key components of ITS is precise vehicle positioning. Positioning with decimetre to sub-metre accuracy is a fundamental capability for self-driving, and other automated applications. Global Navigation Satellite System (GNSS) Precise Point Positioning (PPP) is an attractive positioning approach for ITS due to its relatively low-cost and flexibility. However, GNSS PPP is vulnerable to several effects, especially those caused by the challenging urban environments, where the ITS technology is most likely needed. To meet the high integrity requirements of ITS applications, it is necessary to carefully analyse potential faults and failures of PPP and to study relevant integrity monitoring methods. In this paper an overview of vulnerabilities of GNSS PPP is presented to identify the faults that need to be monitored when developing PPP integrity monitoring methods. These vulnerabilities are categorised into different groups according to their impact and error sources to assist integrity fault analysis, which is demonstrated with Failure Modes and Effects Analysis (FMEA) and Fault Tree Analysis (FTA) methods. The main vulnerabilities are discussed in detail, along with their causes, characteristics, impact on users, and related mitigation methods. In addition, research on integrity monitoring methods used for accounting for the threats and faults in PPP for ITS applications is briefly reviewed. Both system-level (network-end) and user-level (user-end) integrity monitoring approaches for PPP are briefly discussed, focusing on their development and the challenges in urban scenarios. Some open issues, on which further efforts should focus, are also identified.

Integration of Context-Aware Services in Smart System Based on Wireless Sensor Networks for Sustainable Cargo Transportation

“…There Tyj is the context data type that we can assess in the range of evaluation points [1][2][3]. The means of such range are 1 for mentioning that comfort, 2 for comfort and safety, 3 for security.…”

“…The means of such range are 1 for mentioning that comfort, 2 for comfort and safety, 3 for security. H is a parameter in the range [0, 1] indicating whether the message should be stored for a longer time, and values of this parameter can be for historical assessment needs (1) or not (0). Ex is a parameter in the range [1][2][3][4] If assignment for message became Pri := 3, it means that the message m tj i priority at the moment tj is critical and must be sent immediately for driver and stored in the corresponding DW; if assignment for message became Pri := 2, it means that the message m tj i at the moment tj has a medium priority; and if assignment for message became Pri := 1, it means that the message m tj i at the moment tj is not important and could be rejected.…”

“…The importance of the message can be assigned in the set range [0, 1], where 1 is with the safety related message and 0 is a comfort / information message. j I is a function for expression of the message age with normalized values which can be choose from the set values in interval [1,2,3], which is calculated according to algorithm expressed in (3), where TM is the difference between the current and the time the message was created.…”

“…Where Tyj is a reduced parameter Ty assigned by values of the range [1,2] (value 1 is assigned for comfort, value 2 is assigned for comfort and safety), Hxj is a parameter for a special non-confidential data set from which values are assigning in the range [0, 1], by indicating whether the data should be stored historically or not.…”

“…Nowadays researchers are concerned with problems of integration of digital transformations into the development of smart systems, which can be applicable for the management of cargo transportation processes [1,2]. Transport management processes became very complex.…”