Two-way group voice communications, otherwise known as teleconferencing are common in commercial and defense networks. One of the main features of military teleconferences is the need to provide means to enforce the Multilevel Security (MLS) model. In this paper we propose an architecture and protocols facilitating MLS conferences over Public Switched Telephone Network (PSTN). We develop protoc...

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the exposure to electromagnetic field emitted by mobile telephones is increasing rapidly worldwide that causes side effects, including thermal and non thermal side effects. ear proximity to electromagnetic source may lead to greater damage and side effects, including hearing loss. this study was performed to assess the chronic effect of exposure to electromagnetic field of mobile telephones on ...

Assisting during emergencies is one of the important functions of the telephone system. Emergency communications has three components: summoning help during emergencies, coordinating emergency response and notifying citizens and public officials of local emergencies. As we transition to an Internet-based telecommunications system, these functions need to be provided, but there is also an opport...

This paper presents the survivability issues relevant to ATM group communications and outlines the tradeo s between restoration techniques that can be extended from circuit-switched communications. Current models proposed by the ATM Forum for group communications (VC Mesh and Multicast Server) are compared and restoration techniques for all possible single fault scenarios are examined. It is co...

The nature of competition in the United States’ communications sector changed significantly over the past two decades. Before the 1990s, ‘‘competition’’ referred to the fight among providers of discrete services, such as the contest among AT&T, MCI, and Sprint over the longdistance slice of the communications pie. Today, competition is much more likely to describe the fight over the entire pie,...

This research is aimed at understanding the dynamics of collaborative multi-party discourse across multiple communication modalities. Before we can truly make significant strides in devising collaborative communication systems, there is a need to understand how typical users utilize computationally supported communications mechanisms such as email, instant messaging, video conferencing, chat ro...

Over the last eight or nine years a new commercial marketplace has been emerging. Called spread spectrum, this field covers the art of secure digital communications that is now being exploited for commercial and industrial purposes. In the next several years hardly anyone will escape being involved, in some way, with spread spectrum communications. Applications for commercial spread spectrum ra...

one of the most important challenges for researchers is deciding on how to collect their data. there are various views on using telephone interviews. conducting telephone interviews on women of 40 years old and older in isfahan about mammography screening behavior showed that it could be an appropriate method for data collection when there is a combination of effective communication process and...