Thursday, June 22, 2006

Wireless mesh networking is mesh networking implemented over a Wireless LAN.

This type of Internet infrastructure is decentralized, relatively inexpensive, and very reliable and resilient, as each node need only transmit as far as the next node. Nodes act as repeaters to transmit data from nearby nodes to peers that are too far away to reach, resulting in a network that can span large distances, especially over rough or difficult terrain. Mesh networks are also extremely reliable, as each node is connected to several other nodes. If one node drops out of the network, due to hardware failure or any other reason, its neighbours simply find another route. Extra capacity can be installed by simply adding more nodes.

The principle is similar to the way packets travel around the wired Internet — data will hop from one device to another until it reaches a given destination. Dynamic routing capabilities included in each device allow this to happen. To implement such dynamic routing capabilities, each device needs to communicate its routing information to every device it connects with, "almost in real time". Each device then determines what to do with the data it receives — either pass it on to the next device or keep it. The routing algorithm used should attempt to always ensure that the data takes the most appropriate (fastest) route to its destination.

The choice of radio technology for wireless mesh networks is crucial. In a traditional wireless network where laptops connect to a single access point, each laptop has to share a fixed pool of bandwidth. With mesh technology and adaptive radio, devices in a mesh network will only connect with other devices that are in a set range. The advantage is that, like a natural load balancing system, the more devices the more bandwidth becomes available, provided that the number of hops in the average communications path is kept low.

To prevent increased hop count from cancelling out the advantages of multiple transceivers, one common type of architecture for a mobile mesh network includes multiple fixed base stations with "cut through" high-bandwidth terrestrial links that will provide gateways to services, wired parts of the Internet and other fixed base stations. The "cut through" bandwidth of the base station infrastructure must be substantial for the network to operate effectively. However, one feature of wireless mesh networks is that an operator need only deploy a minimal base station infrastructure, and allow the users themselves to extend the network.

Since this wireless Internet infrastructure has the potential to be much cheaper than the traditional type, many wireless community network groups are already creating wireless mesh networks.

ELECTRONIC DEMOCRACY. The concept uses electronic communications technologies, such as the Internet, in enhancing democratic processes within a democratic republic or representative democracy. It is a political development still in its infancy, as well as the subject of much debate and activity within government, civic-oriented groups and societies around the world.

Electronic direct democracy is a form of direct democracy in which modern communication media are used to ameliorate the bureaucracy involved with referenda on many issues. Many advocates think that also important to this notion are technological enhancements to the deliberative process.

While pirate radio began as a defamatory term in Britain, it later became accepted as having a secondary meaning to describe adventurous forms of licensed broadcasting that had roots in true offshore unlicensed broadcasting.

P2PTV refers to peer-to-peer software applications designed to redistribute video streams on a p2p network. The draw to these applications is significant because they have the potential to make every TV channel in the world global. These applications are also controversial because they give content piracy a new avenue, that of live television.

from Wikipedia article on P2PTV
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posted by u2r2h at Thursday, June 22, 2006


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