The book and PDF file are published un. Holonic and Multi-Agent Systems for Manufacturing ,. Wireless Mesh Networking. Thomas G. Dietterich: Pages: This.
|Published (Last):||8 November 2010|
|PDF File Size:||12.11 Mb|
|ePub File Size:||6.57 Mb|
|Price:||Free* [*Free Regsitration Required]|
Ciencias Exactas, Universidad Nacional de. La Plata, 47 y , C. Many heads of the families are unemployed and although children have access to schools it is common that they do not finish their basic instruction. In many cases NGOs play a fundamental role in changing this reality. In this presentation we detail the implementation of a test bed where 14 families and a school were provided with computers, Internet access and were educated out of digital illiteracy.
The deployment of WMN in a such a broad area, aimed to define the possible lowest cost implementation, and conforms an important part of the research activities. The project was financed through an award given in a public competition by Microsoft research and CentralTech, a leading Argentinean educational center. It was the sum of these factors which happened in conjunction with some very particular political events. In resume, a more planar world has been generated, where information is a click away.
Some underdeveloped countries are somehow better prepared than others after the technological changes of the last years. And these countries could obtain immediate benefits from the use of ICTs.
They have acquired the necessary physical infrastructure as optical 39 fiber and possess the human capital required to operate the associated systems. Its use cannot bring any other consequence than economical growth and improved standards of living. But access to internet and the many ingredients that made the earth flat modified this situation, transforming a problem into a challenge.
The same tools of IT and advances in telecommunication today nearly convergent gave the tools to solve the problem. There is no doubt that the opportunity is there, the important issue is to know how to take advantage of it.
Some countries like India are already immersed in big changes. In Africa the problem is still more complex since huge investments in physical infrastructure are needed. But, the fact that the earth is flat, the free access to libraries and their content offered by Internet, thousands of developers willing to help in open-source projects, the multiplicative effects for education and many other areas makes it possible to perform a radical change in poor countries.
Simple: start tackling problems. Its main objective is to investigate the design and implementation of new technologies that favour underdeveloped regions. The great majority of this type of projects use technologies developed in countries with intellectual, economical and educational wealth.
The sheer implementation of many of them simply fails since no questioning is made on costs, feasibility of implementation, energy problems or the need to orchestrate the appropriate educational support and study these technologies within the local eco-systems.
ICT4D-AR tackles problems related to hardware, software, connectivity and its influence in education and work opportunities. The project, finally, pretends to give a diagnosis, promote the proper technologies that eventually might be adopted by governments and corporations. One of the pre requisites of any new project is that it should be carried out in real environments pilot tests, test-beds. This is vital, since it provides the answer to its feasibility and gives a diagnosis for scalability.
They addressed the question of how one could give access to internet and connectivity to those places not included in the commercial plans of telecom companies or if the connectivity was there, how it could be provided at a low cost.
One of their main arguments in their analysis was the need to have a decentralized connectivity infrastructure. In this manner one avoided a single point of failure. Another, that the technology would be sufficiently simple and low cost so that it could be maintained and expanded by local participants with very little technological experience.
It basically proposed the use of low cost hardware, home constructed antennas and ubiquitous technologies simple to implement. Wi-fi In the last years the group of Dr. In the project won a RFP made by Microsoft Research for the implementation of the test bed described in this paper using the technologies developed by Dr.
In the full mesh topology, each node is connected directly to each of the others. When we speak of mesh networking, we understand a network that has connections many to many and capable of dynamically updating an optimizing these connections.
The nodes can be mobile or not. In our case they are not mobile since their position as a function of time does not change. Figure 1 shows a diagram of a possible mesh implementation. The biggest challenge for any mesh configuration is the administration of the complex information from the routing tables since they must include external networks and the internet gateways.
Some of the outstanding issues, adapted to our scenario, as pointed by Krag and Buettrich , are: Price: Ease and simplicity: In our case each node is a PC running Windows XP with wireless mesh software and uses standard wireless protocols such as Organization and business models: The decentralized nature of mesh networks. Network robustness: Mesh topology and ad-hoc routing should provide more stability in the face of changing conditions or failure at single nodes.
The challenge is a low cost implementation. The idea of Grameen Bank started by Muhammad Yunus, has helped improve millions of peoples life worldwide. Our project rested on the NGO as the way for selecting the families that received the computers, give them support in education and guiding the participants as a community. For months the families received courses and several very interesting experiences and positive returns emerged.
The project put up the whole infrastructure, serviced the antennas and connectivity and provided funds for IT education. Could it be possible to implement this at a very low cost in a real environment and not as an experimental laboratory? This was basically the question that made us implement the project. Our 15 nodes were distributed as shown in Figure 3: two groups of nodes and 4 nodes at the border.
In parallel to the study of connectivity and as already stated each family assisted to training in basic informatics tools Word, Excel, PowerPoint.
They were in charge of deployment and monitoring of the network. Each node consisted of a PC running windows XP, a wireless network card A coaxial RG8 cable of little loss was used for connecting the antenna and the PC.
The antenna was held together with the TV antenna of each home. Although not optimal due to losses in the cable, this solution was decided due to cost. Use of a bi-directional amplifier or LNA would have increased total cost. It was always in the spirit of the project a search for lowest cost implementation. Although commercial antennas were used, the final aim was to replace them by home made ones.
Connectivity was achieved between all 15 nodes but several factors attempted against the stability of the network. This brought many problems. If a node needed to be reset, it would modify some parameters and technical personal needed to be called to reconfigure.
Given the small number of nodes, the disappearance of one of them would leave several others without connectivity. Zero configuration was finally eliminated in the inst.
WIRELESS MESH NETWORKING BY THOMAS KRAG PDF
Sazragore This makes them valid locations for network nodes. Since routes are configured dynamically, it is often enough to simply drop the box into the network, and attach whatever antennas are required for it to reach one or more existing neighboring nodes assuming that we can solve the wirfless of IP address allocation. With a power consumption of 4W and potentially lowerit is wireless mesh networking by thomas krag for deployment with an autonomous sustainable power source. Power generating units are typically connected to points of infrastructure and human presence. Obviously, combining the two characteristics of a mesh topology and ad hoc capabilities is a very attractive proposition. It shows a graphical view of the current Mobile Mesh network topology.
wireless mesh networks-paper
Kagabar December 24, File size: From this database, a routing table is calculated by constructing a shortest-path tree. Each wireless device uses different standards, data formats, protocols, and access technologies. It is designed to networkjng run internal to a single Autonomous System. It may also be worth checking out the mmrpviz package that comes with the Mobile Mesh tarball.
WIRELESS MESH NETWORKING BY THOMAS KRAG EBOOK DOWNLOAD