Zbigniew Piotrowski

Multimedia transmission over HF links

This paper presents tests results of long distance HF link and structure of used radio workstations for e-mail exchange, analog and digital voice transmission. Tests results are: average transmission time for short and long messages and percentage ratio of speech intelligibility for different speech transmission modes.

Mobile application for driver's health status remote monitoring

This article describes implementation of the DHSRM mobile application interfaced with a hardware Data Logger fitted on board of a vehicle. The Data Logger gathers data from sensors located in the vehicle and on the drivers body. The application is designed to monitor the quality of acquired signals in real time and dramatically shorten the time to estimate the drivers health status, including his/her fitness for driving vehicles.

Drift Correction Modulation Scheme for Digital Audio Watermarking

The article describes a new method of embedding and extracting the digital watermark in an acoustic signal, which operates in the frequency domain and uses a drift correction modulator of the watermark’s phase angle, as well as a precise correction procedure of the watermark signal to the minimum masking threshold. This method does not require synchronization reproduction at the receiving side in order to extract the watermark. The Drift Correction Modulation (DCM) is characterized by a high normalized data payload of the watermark signal and may be implemented in applications of hidden and secure data transmission. The method has confirmed its robustness against degrading factors: lossy compression, resampling, A/D and D/A conversion, noisy VHF channel. The paper presents the results of auditory tests according to the ITU-R 1116-1 standard; moreover, results of the watermark’s extraction tests in the VHF radio link, with the use of military tactical radio stations have been presented. The DCM scheme can be also use for OFDM based radio systems for OFDM output signal watermarking to create hidden or additional service channels.

Architecture of car measurement system for driver monitoring

This paper addresses the todays social needs to ensure security in road traffic, a task which becomes difficult due to the growing number of drivers and, therefore, increasing traffic intensity. The rising need for mobility constitutes a huge challenge for the institutions responsible for improving the road traffic safety. The paper describes selected hardware components which can be used to build an integrated warning system. Its measuring modules supply data on the road traffic environment parameters, the vehicle dynamics, and psychophysiological behavior of the drivers. An important aspect of interoperation of such hardware components is reliable communication and data synchronization. The presented solutions are based on the CAN, WiFi, ISM 2.4 GHz, and GSM/GPRS interfaces. To minimize the risk of data loss, the data is stored redundantly in the local memory structures, as well as in a remote archiving system to which the data is transmitted through wireless communication protocols.

The National Network-Centric System and its components in the age of information warfare

This paper describes the new model of information warfare system based on a data hiding platform. This concept is based on the assumption that data hiding technology is the most effective mechanism for creating the new inter-layer, called the stego layer, in the known Internet Protocols. The main idea is to create network botnet bases on standard client-server architecture using specific agents – Hidden Protocol Interpreters (HPI). The HPIs are responsible for bidirectional hidden and secret communication with the administrator’s workstation. The HPI serves as a passive monitoring station of the Internet infrastructure, intercepts points for remote control commands and finally plays the role of an active element in order to take control of allocated IP mechanisms (computers, routers, etc.). In this paper, a likely new attack on telecommunications links called a voice spoofing attack, in the form of, for example, a subscriber’s voice impersonation, and a method of protection against this attack – Personal Trusted Terminal (PTT) – is also described.

Drift Correction Modulation scheme for digital signal processing

Abstract The article describes a new method of embedding and extracting the digital watermark in an acoustic signal, which operates in the frequency domain and uses a drift correction modulator of the watermark’s phase angle, as well as a precise correction procedure of the watermark signal to the minimum masking threshold. The Drift Correction Modulation (DCM) has been worked out for the needs of the watermarking system with a large data payload and robustness against degrading factors which occur during signal processing. The digital watermark embedded in the original signal using the DCM method is inaudible and robust against the majority of degrading factors. The DCM method may be used in Digital Signal Processing applications, e.g. for a hidden authentication of subscribers in telecommunication channels or for determining the output phase mistuning of devices. DCM is characterized by a high normalized data payload of the watermark signal and may be implemented in applications of hidden and secure data transmission. The paper presents the results of auditory tests according to the ITU-R 1116-1 standard; moreover, results of the watermark extraction tests in a VHF radio link, with the use of military tactical radio stations have been presented.

Wireless driver and vehicle surveillance system based on IEEE 802.11 networks

The paper presents a complex system for driver and vehicle surveillance. System uses many different sensors such as acceleration sensors, ECG and blood pressure measuring devices, eye movement recorders, video cameras, GPS and wireless IEEE 802.11 networks for transmission of recorded data in real time. The paper presents also two experiments with their results and a method to calculate a metric characterizing the drivers technique that uses signals recorded during the experiment.

Novel Hybrid Blind Digital Image Watermarking in Cepstrum and DCT Domain

The problem of affine transform attacks refers to many watermarking algorithms. A slight change in the geometry of watermarked image can disable the decoding of embedded information; therefore the advanced watermarking methods should be robust against the above-mentioned procedures. This paper contains a description of the algorithm consisting of two complementary methods of image watermarking. The watermark is encoded in the luminance and chrominance components in the spatial and frequency domains. The decoding process takes place in the two-dimensional Cepstrum and the discrete cosine transform. The algorithm makes the watermarked image robust against the following affine attacks: scaling shearing and translation. Also the following image distortion processes like JPEG lossy compression, adding noise to the watermarked image, median filtering and majority cropping do not cause any loss of hidden information.

Correspondent authorization in the GSM telephony using watermarking technology

This paper describes conception of the correspondent authorization in the GSM link. Watermarking technology gives support for additional data hiding in the host signal. This additional data is known as a watermark signal. Watermark should be robust for loose compression in GSM 6.10 standard codec and should be transparent for human auditory system (HAS) in the host signal background. OFDM technology together with psychoacoustic MPEG model can be used for dedicated GSM authorization system. Several modes of watermark signal processing in the GSM link were presented. Results of the decoding as well as results of the ITU-R BS1116-1 subjective quality estimation tests were illustrated and commented

The proposal of IEEE 802.11 network access point authentication mechanism using a covert channel

The paper presents a concept of using a covert channel to authenticate access points. The covert channel is performed using Beacon frames and Timestamp fields and takes advantage of the least significant bits of these fields.