A Mobile Transient Internet Architecture

This paper describes a new architecture for transient mobile networks destined to merge existing and future network architectures, communication implementations and protocol operations by introducing a new paradigm to data delivery and identification. The main goal of our research is to enable seamless end-to-end communication between mobile and stationary devices across multiple networks and through multiple communication environments. The architecture establishes a set of infrastructure components and protocols that set the ground for a Persistent Identification Network (PIN). The basis for the operation of PIN is an identification space consisting of unique location independent identifiers similar to the ones implemented in the Handle system. Persistent Identifiers are used to identify and locate Digital Entities which can include devices, services, users and even traffic. The architecture establishes a primary connection independent logical structure that can operate over conventional networks or more advanced peer-to-peer aggregation networks. Communication is based on routing pools and novel protocols for routing data across several abstraction levels of the network, regardless of the end-points’ current association and state. The architecture also postulates a new type of network referred to as the Green Network. The Green Network has protocols to coordinate routing traffic and to allow for the identification and authentication of devices, services, users and content characterized as Digital Entities. Transmission is assumed to initiate and terminate at transient physical locations. The network implements every reasonable effort to coordinate a prompt delivery to the transient end-points using whatever means available. This paper is a conceptual logical model of the intended architecture and specifics about its particular components and their implementations will be discussed in future papers

Efficient User Controlled Inter-Domain SIP Mobility Authentication, Registration, and Call Routing

Over the past decade, multimedia services have gained significant acceptance and played an important role in the convergence of IP networks. The proliferation of mobile devices and the nomadic user and computing lifestyles on current networks make mobility support a crucial ingredient of current IP-based multimedia systems. The Session Initiation Protocol (SIP) presents one approach towards supporting IP mobility. Additionally, SIP is increasingly gaining in popularity as the next generation multimedia signaling and session establishment protocol, and the SIP infrastructure is anticipated to be extensively deployed all over the Internet. We have lately proposed an approach to inter-domain SIP mobility which we call H-SIP. H-SIP is a user-controlled mobility scheme that improves personal and terminal mobility. H-SIP uses persistent identifiers and leverages the traditional SIP architecture to abstract any domain binding from users. This paper expands on our previous work and experimentally proves the efficiency of H-SIP in achieving inter-domain authentication and call routing through modeling and real-time measurements

Wireless Camera and Site Survey Issues over an IEEE 802.11 b based wireless network test bed

Wireless LAN systems based on IEEE 802.11 have been a proved and sought after technological innovation, over the past few years. In this paper, we discuss some of the technical aspects for testing and deploying a wireless LAN system at the University of New Mexico, Albuquerque, New Mexico. This shall serve as a model test bed for future research and development, under the aegis of Ibero American Science and Technology Education Consortium (ISTEC)

An Application of the Mobile Transient Internet Architecture to IP Mobility and Inter-Operability

We introduce an application of a mobile transient network architecture on top of the current Internet. This paper is an application extension to a conceptual mobile network architecture. It attempts to specifically reinforce some of the powerful notions exposed by the architecture from an application perspective. Of these notions, we explore the network expansion layer, an overlay of components and services, that enables a persistent identification network and other required services. The overlay abstraction introduces several benefits of which mobility and communication across heterogenous network structures are of interest to this paper. We present implementations of several components and protocols including gateways, Agents and the Open Device Access Protocol. Our present identification network implementation exploits the current implementation of the Handle System through the use of distributed, global and persistent identifiers called handles. Handles are used to identify and locate devices and services abstracting any physical location or network association from the communicating ends. A communication framework is finally demonstrated that would allow for mobile devices on the public Internet to have persistent identifiers and thus be persistently accessible either directly or indirectly. This application expands IP inter-operability beyond its current boundaries

Experimental studies of the cross-excitation instability in a relativistic backward wave oscillator

Our group first reported the operation of a relativistic backward wave oscillator (BWO) in the so-called “cross-excitation” regime in 1998. This instability, whose general properties were predicted earlier through numerical studies, was a consequence of using a particularly shallow rippled-wall waveguide (slow wave structure – SWS) that was installed in the experiment to diagnose pulse shortening in a long pulse electron beam-driven high power microwave (HPM) source. This particular SWS was required to accommodate laser interferometry measurements during the course of microwave generation. Since those early experiments we have further studied this regime in greater detail using two different SWS lengths. We have invoked time-frequency analysis, the smoothed-pseudo Wigner-Ville distribution in particular, to interpret the heterodyned signals of the radiated power measurements. These recent results are consistent with earlier theoretical predictions for the onset, voltage scaling, and general behavior for this instability. This paper presents data for a relativistic BWO operating in the single frequency regime for two axial modes, operating in the cross-excitation regime, and discusses the interpretation of the data, as well as the methodology used for its analysis. Although operation in the cross-excitation regime is typically avoided due to its poorer efficiency, we discuss how it may be exploited in HPM effects studies

HPV types and cofactors causing cervical cancer in Peru

We conducted a hospital-based case-control study in Peru of 198 women with histologically confirmed cervical cancer (173 squamous cell carcinomas and 25 cases of adenocarcinoma/adenosquamous carcinoma) and 196 control women. Information on risk factors was obtained by personal interview. Using PCR-based assays on exfoliated cervical cells and biopsy specimens, HPV DNA was detected in 95.3% of women with squamous cell carcinoma and in 92.0% of women with adenocarcinoma/adenosquamous carcinoma compared with 17.7% in control women. The age-adjusted odds ratio was 116.0 (95% Cl = 48.6–276.0) for squamous cell carcinoma and 51.4 (95% Cl = 11.4–232.0) for adenocarcinoma/adenosquamous carcinoma. The commonest types in women with cervical cancer were HPV 16, 18, 31, 52 and 35. The association with the various HPV types was equally strong for the two most common types (HPV 16 and 18) as for the other less common types. In addition to HPV, long-term use of oral contraceptives and smoking were associated with an increased risk. HPV is the main cause of both squamous cell carcinoma and adenocarcinoma in Peruvian women. © 2001 Cancer Research Campaignhttp://www.bjcancer.co

Human Papillomavirus type distribution in invasive cervical cancer in Uganda

<p>Abstract</p> <p>Background</p> <p>We conducted a study aiming to describe Human Papillomavirus (HPV) type distribution in invasive cervical carcinoma in Uganda.</p> <p>Methods</p> <p>191 archival cervical carcinoma samples diagnosed in the Department of Pathology, Makerere University in Kampala between 1968 and 1992 were analysed using a sensitive PCR-Reverse Hybridization Line Probe Assay.</p> <p>Results</p> <p>Out of the 186 cases of confirmed invasive cervical cancer in the study paraffin blocks, 114 were positive for HPV DNA. Specific HPV genotypes were identifiable in 109 cases: HPV 16, 18, 31, 35, 39, 44, 45, 51, 52 and 70. These occurred as single infections in 105 cases (96.3%) and as multiple infections in 4 cases (3.7%). HPV 16 or 18 accounted for 80% (84/105) of cases with single infection.</p> <p>Conclusion</p> <p>The results of this study confirm the role of HPV 16 and 18 in cervical cancer pathogenesis in the Ugandan population. The results suggest that the currently available HPV vaccines against HPV 16 and 18 could possibly prevent the majority of invasive cervical cancers in Uganda.</p