Keywords network university remote learning HomeNet
1． The Background
With the extension of internet in application area, from academies, enterprises to the government departments, the network reaches variable aspects of our society. From knowledge learning, message obtaining to e-commerce, the digital network is all proved a strong pushing strength. With network, the difference of time and space are eliminated, the exchange and communication among people, the resources sharing are becoming much more easier, based on that, more and more applications are developed, and one of which is the network university and remote learning which will be a great revolution to the traditional teaching and learning way. People can study online, exchange thoughts interactively with teachers and schoolmates through network rather than special classrooms in the campus, this will provide a chance to learn knowledge all the life for those who are in work or can’t go into colleges, perhaps the network university will be the most important model to study in a not long future.
The network university consists of three infrastructures: the education center stations which include multimedia courseware, sound and image material etc., the high speed backbone and user terminal network. Our government has made the remote learning a strategy to promote the quality of the nation, the CERNET 2.5GBPS backbone are in construction , and the education center stations have already been implemented successfully in some campuses, so the key to employing the remote learning project lies in the third part---the user terminal network.
The network brings us great flexibility to study online , no doubt , the most often place for people to learn is at home , and with the development of life standard , many families will have more than one set of computer and HDTV sets, and study is not only the thing of children , but also the need of parents , and additionally , remote medical treatment , ordering online, home automation controlling are all the future requirements in the family[1], so it is a necessary condition to digitalized the families in the information society to construct a perfect HomeNet( home terminal network) which provide all above functions , in the following sections , we will discuss the structure, the key technologies and access media of HomeNet.
2. The Key Technologies in HomeNet
The home network is a special LAN, in logical structure, they have some resemblance, but the home network has its own special features in application environment, operational functions and system physical construction. The implement of home network requires several key technologies to support as following[2]: the embodied operate system and embodied custom IC(ASIC) , API level interoperable specifications, the final use interface design and access technology.
2.1 There are various devices at home, and the difference between them is large in controlling model, computation ability and intelligent level. Most of them are less performance products except a few such as computers, thus, to enable the whole home network, the embodied OS and IC is the kernel technologies. Current prevailing embodied OS are WINDOWS CE, 3COM Palm OS, JAVA2, JAVA2 Micro Edition, Pjava, Ejava and our own embodied Hopen OS designed by KAISI Cooperation. The embodied IC includes LonWorks’ Neuron ICs and Intel’s micro controllers such as 8051 family and the like.
2.2 API is application program interface, due to the media is various in the network physical layer, in order to get the interoperability on the program interface layer, API lever interoperable specifications must be defined, it’s the foundation to develop home network application, it shields the under layer protocols, and provide a identical interface to application developer. The current APIs are Microsoft UPnP, SUN JINI, Home PNP, Home API and so on.
2.3 User interface(UI) determines the easy degree of operation, and then&n
