Search

The Assisted Commercial Authentication Service (ACAS) is a semiassisted signal authentication concept currently being defined for Galileo, based on the E6-C encrypted signal. Leveraging the assumption that the true E6-C encrypted signal always arrives before any inauthentic signal, we define user concepts for signal detection, including vestigial signal search. We define three mitigation levels, each level defending against an increasing set of threats, incorporating the described concepts and additional checks. The concepts are analyzed and implemented in a simulation environment, and tested in both nominal conditions and under advanced spoofing attacks. The results suggest that even advanced attacks can be detected and mitigated by ACAS receivers.

A semiassisted global navigation satellite systems (GNSS) authentication concept is proposed, with two main advantages. First, it can be implemented in a GNSS without modifications to the signal plan, provided that the GNSS can transmit an encrypted signal and an open signal with unpredictable and verifiable bits regularly. Second, it can work in a receiver for up to several days without any assistance or the possession of a private key, at the expense of some authentication latency. In this concept, parts of the encrypted signal to be transmitted in the future are re-encrypted, published, and downloaded in the receiver. Some seconds after transmission, the satellite openly broadcasts the decryption key, and the receiver performs the a-posteriori correlation with the encrypted signal. The concept is particularized for the Galileo system as Galileo assisted commercial authentication service, based on OSNMA in E1B for the decryption keys and E6C for the encrypted signal. An end-to-end procedure for measurement authentication is proposed and tested, showing its viability.

A SYNTHETIC APERTURE? WHAT'S THAT? Well, an aperture in optics is just a hole or opening through which light travels. Those of us into photography know that the amount of [...]

An important market step for Galileo will be timely availability of hybrid Galileo/GPS receivers in combination with wireless communications network positioning capabilities for consumer applications. The GAWAIN project has investigated [...]

Rules imposed by regulatory agencies and commercial interest in wireless location-based services have stimulated efforts to find affordable methods for determining the location of callers. These German researchers found that, [...]

Proposes some strategies for integrating global navigation satellite systems and communications technologies to achieve positioning capability without a large investment in infrastructure. Positioning methods; Realization of the measurements; Global System for Mobile Communications (GSM) and Universal Mobile Telecommunication System ranging techniques; Position domain and geometry.