The vision of a broadly unified and pervasive communication paradigm where people can freely communicate with wide range of devices (phones, PDAs, palmtops etc.) using networks of wired and wireless links is gradually taking shape [3], [11], [12]. Applications that will run over a communication infrastructure composed of heterogeneous links (wired and wireless) will be susceptible to the vagari...

With the increasing usage of mobile devices to ubiquitously access heterogeneous applications in wireless Internet, the measurement and analysis of Internet traffic has become a key research area. In this paper, we present the results of our measurements for VBR traffic over UDP in 802.11g and GPRS networks. We focus on Inter-Packet Arrival Time (IPRT) and Inter-Packet Transmission Delay (IPTD)...

We investigate performance improvements through TCP window size optimisation achievable when TCP Reno is used over a highly heterogeneous network, such as an 802.11b Wireless LAN or a GPRS-based internet connection. Initially, our modelling focuses on a constant rate, buffered access link, based on a loss-less wireless channel and with a bandwidth at least one order of magnitude less than its f...

Mobile IP provides mobility support in heterogeneous wireless networks where mobile nodes change the point of attachment. The mobility is handled within the network layer and depends on either receiving router advertisements or sending solicitations. However, this movement detection is not appropriate to provide lossless connectivity during handovers. This paper presents a so-called proactive h...

We demonstrate experimentally a periodic array of differently-sized and circularly-shaped gap plasmon resonators (GPRs) with the average absorption ~94% for unpolarized light in the entire visible wavelength range (400-750 nm). Finite-element simulations verify that the polarization insensitive broadband absorption originates from localized gap surface plasmons whose resonant excitations only w...

The aim of this paper is to investigate the influence of different probability distributions that can be applied in user data source models. We compare their effect on the user perceived performance of a simulated GPRS system. Four different distributions of the time between two consecutive web page requests have been investigated and compared. We also consider non-probabilistic models of the w...

This paper presents three different mechanisms to provide Quality of Service (QoS) to General Packet Radio Service (GPRS) users. These mechanisms include a Call Admission Control (CAC), a Radio Resource Reservation and Scheduling in the radio interface. Video, voice and data integration are expected by mobile users. However, these media have different QoS requirements in terms of bandwidth and ...

According to the needs of the security operation taxi, a kind of vehicle monitoring terminal device which takes C8051F040 microcontroller as the core, combining GPS, GPRS and LCD was proposed. This device will show the superiority of C8051F040 microcontroller, which is high-speed, low-power, and has rich interface. Through the application of GPS, LCD, and the GPRS module which communicate with ...