INTRODUCTION:Embedded systems are computer systems that form part of a larger system. These systems are ubiquitous and diverse, and include mobile phones, entertainment devices, automobiles, toys, smart cards, medical devices, network switching equipment, sensors, and industrial robots. Many embedded systems are real-time systems and have to react to external events within a defined period of time. Other constraints such as size, energy supply and unit price often severely limit the design space, affecting costs and reliability. This has resulted in an emerging trend to integrate previously isolated systems. As embedded systems are increasingly networked and expected to execute downloaded code, they have become subject to attacks by hackers or viruses. This means that they now face many of the resource management and security issues associated with traditional computing systems, and makes operating systems, and compilers and language techniques increasingly relevant in the embedded domain.
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ABSTRACT: WAP – The Wireless Application Protocol – is a communications protocol and application environment for the deployment of information resources, advanced telephony services, and Internet access from mobile devices. The topic that I have chose is the WAP Application Architecture and the main concern here will be –WAP Client WAP Proxy, WAP Gateway Or WAP Server WAP Application Server WAP Internal Structure WAP Protocol Stack The WAP Protocols were designed with the web protocols in mind. The goal of WAP was to use the underlying web structure, but to render communication between content providers and mobile devices more efficient and less time consuming than if the web protocols themselves were used. I will be introducing the elements involved in mobile communications, and their role in the whole picture.wap-the-wireless-application-protocol
Abstract:There has been much work on developing techniques for estimating the capacity and the available bandwidth of network paths based on end-point measurements. The focus has primarily been on settings where the constrained link can be modeled as a point-to-point link with a well-defined bandwidth, serving packets in FIFO order. In this paper, we point out that broadband access networks, such as cable modem and 802.11-based wireless networks, break this model in various ways. The constrained link could (a) employ mechanisms such as token bucket rate regulation, (b) schedule packets in a non-FIFO manner, and (c) support multiple distinct rates. Our evaluation is based on experiments on actual 802.11a and cable modem links. bandwidth-estimation-in-broadband-access-networks
Satellites forms the essential part of telecommunication system worldwide carrying large amount of data and telephone traffic in addition to television signal. They offer a number of features which are not readily available with ther means of communication. Since very large area of earth is visible from a satellite, the satellite can form the star point of communication net linking many users who may be widely separated geographically. Orbit of any satellite depends on it’s application . The defining characteristics of an orbit are its shape, its altitude, and the angle it makes with Earth’s equator. Satellites must operate and survive the harsh conditions of the space so they require durable technologies. The most common source of power for Earth-orbiting satellites is a combination of solar cells with a battery back-up for maintaining orientation attitude thrusters, large spinning wheels that turn the satellite, and magnets that interact with Earth’s magnetic field to correctly orient the satellite are used. For heat radiation radiators in the form of louvered panels are used. Satellites may last for a few years to a few hundred years depending on it’s size and it’s orbital distance from earth.Major application of satellites include communication, navigation, weather
forecast and scientific application.artificial-satellites
Next generation networks are expected to support a wide variety of services. Some services such as video,voice,and plant control traffic have explicit timing requirements on a per-message basis rather than on the average. Therefore we develop a general model of dual-link networks to support real time communication.We examine the desirable properties of this network and the difficulties in achieving these properties.We then introduce the concept of coherence and develop a theory of coherent dual-link networks.We then discuss practical consideration in implementing a dual-link network. analysis-of-dual-link-networks-for-real-time-applications
Once connected, consumers find innumerable uses for their home networks. Sharing in-home appliances to provide faster Internet access has proven to be the main motivator for consumers installing a new home network. Knowledge workers, students, and families are some of the groups of people that are at the forefront of the home networking revolution. The ultimate goal of a home network is to provide access to information, such as voice, audio, data, and entertainment between different digital devices around the house. Home networking allows users to communicate and interact anywhere at anytime. This new and emerging technology will bring the Internet to the hands of the consumers, to every appliance in the house, and help interconnect people across the globe. It allows access to homes via the Internet when one is away, enabling security and energy management. Home networking is really a three part equation offering entertainment, information, and automation services that are distributed between appliances in the home. an-introduction-to-home-networking
