After identifying the general structure of a POTS (Plain Old Telephone System) Switching System we model individual components as communicating-nite state machines. Formulating the nite state machines in Promela (Process Meta Language) allows us to verify general and speciic properties of the model using the model-checker Spin. Modelling operational systems imposes design decisions, which we wi...

The GSM system has become the most popular system for mobile communication in the world. Criminals commonly use GSM phones, and it is therefore a need for forensic investigators to understand which evidence can be obtained from the GSM system. This paper briefly explains the basics of the GSM system. Evidence items that can be obtained from the Mobile Equipment, the SIM and the core network are...

by Patty Cleary D u e t o the obso lescence of the m a i n t e l e p h o n e switch, the Rice t e l e p h o n e sys tem is having serious p r o b l e m s , a c c o r d i n g t o D r . Wi l l i am Akers , Vice Pres ident fo r A d m i n i s t r a t i o n . P r e l i m i n a r y e s t ima te s for r e p l a c e m e n t of the swi tch , tenta t ive ly set fo r th is s u m m e r , a re in the $1.5 t...

Dialog management is of particular importance in telephone-based services. In this paper we describe our recent activities in dialog management and natural language generation in the LIMSI RAILTEL system for access to rail travel information. The aim of LEMLAP project RAILTEL was to assess the capabilities of spoken language technology for interactive telephone information services. Because all...

The rapidly increasing demand for PCS has provided the impetus to design adaptive antenna arrays to improve spectral efficiency and enhance system capacity. With increasing data rate in some PCS application like DECT( Digital European Cordless Telecommunications), higher BER would degrade the system performance further. An adaptive antenna array testbed using 12 elements was built to evaluate i...

In this paper, a mixer topology selection for a multi-standard high image-reject front-end is presented. The receiver is intended to work for Digital Enhanced Cordless Telephone (DECT) systems (at 1.9 GHz and 2.4 GHz) and for Bluetooth (at 2.4 GHz). It will be implemented in 0 18 μm CMOS technology. A double-quadrature low-IF architecture is employed because it can provide a high image rejectio...

The focus of this research has been the development of a low power, radio frequency transmitter architecture. Specifically, a technique for in service automatic calibration of a modulated phase locked loop (PLL) frequency synthesizer has been developed. Phase/frequency modulation is accomplished by modulating the feedback divide value in a phase locked loop frequency synthesizer. A digital prec...

The objective of this study was to investigate the effects of two sources of electromagnetic fields (EMFs) on the proteome of cerebellum, hippocampus, and frontal lobe in Balb/c mice following long-term whole body irradiation. Three equally divided groups of animals (6 animals/group) were used; the first group was exposed to a typical mobile phone, at a SAR level range of 0.17-0.37 W/kg for 3 h...