A wireless computer network is a set of components that allows a computer to access a computing network, and the Internet, without being connected to the building through a wire. The most popular reason for participating in a wireless network is because we own a portable notebook computer, and frequently use it from many locations on campus - and connecting the notebook to a data jack is inconvenient or simply not possible. When we are part of a wireless network, our computer communicates to one or more "wireless access points" installed in a building. As we move around, we may fall outside the range of these access points and disconnect from the network, or our computer may automatically switch from the access point currently in use to one that is now closer (it may help to compare the wireless network to experiences you may have had with cellular phones - their signals get weak as we get farther away from the cellular tower, and then get better if our phone switches to a different cellular site). Assuming that we have a notebook computer and want to use the wireless network installed on campus, we will have to purchase an appropriate wireless adapter card for your notebook, register your wireless card with Information Services, and use our notebook in an area covered by the wireless network. While it is possible to get a wireless card for a desktop personal computer, this option is generally not recommended for a variety of reasons (cost, speed ...).
T. Mohan Babu
Development of 3rd Generation Cellular Wireless (3G) Technologies is well underway within Network Equipment Manufacturers. Most major wireless Service Providers are beginning technology trials, but production networks will not be rolled out until 2001 at the earliest. This paper introduces 3G Wireless technology, standards and protocols.
Wireless network refers to the systems connected without any physical medium. The communication is possible between the networks using Radio or Infrared rays. LAN(Local Area Network) means connection of computers on a short distance together for the purpose of exchange of information and sharing the data. The exchange of information is done by Electromagnetic waves.The development of wireless aware applications will allow to demonstrate the concept and to expand the wireless extensions with the needs of those applications. Mobile IP seems an obvious target.
This paper is intended to give you a few tricks on how to install that beast and will mostly redirect you to a lot of literature explaining the things much better way. Then, we will see some of the difference of Wireless LANs compared to Wired technology from the user point of view.
Wireless refers to not using wire for networks. So, communication is possible between the networks using radio or infrared rays. LAN(Local Area Network) means connection of computers on a short distance together for the purpose of exchange of information and sharing the data. The communications between the computer system is done by electromagnetic waves.
Installing and using a Wireless LAN is not such a big deal, and is not much different from other kind of networks. In this paper we will give you a few tricks on how to install that beast and will mostly redirect you to a lot of literature explaining the things much better way. Then, we will see some of the difference of Wireless LANs compared to wired technology from the user point of view and why it reacts sometime differently.
3.What is wireless LAN ?
A radio network is a collection of nodes communicating together through radio devices, using radio waves to carry the information exchanged (obvious, isn't it ?). It is sometime called a radio Ethernet, by analogy of the wired technology. Most radio devices are a card (ISA, Pcmcia) to plug in a PC (or workstation), and interact directly with the standard networking stack on it (no need of PPP or any specific protocol stack).
There is far too many people buying a Wireless LAN and discovering only after that it is not supported under Linux. Most Wireless LANs are designed to work well in most configurations, but my experience tells that some Wireless LANs or some environment may be capricious.
The performance of different Wireless LANs may vary widely, depending on may factors. The throughput of two Wireless LANs advertising the same bit rate may vary by a factor 5. Range also can have wide variations, even between similar cards. So, be warned and benchmark your Wireless LAN...
4. Spread Spectrum techniques:
Spread spectrum is a technique (mainly pioneered by the army) trading bandwidth for reliability. The goal is to use more bandwidth than the system really needs for transmission to reduce the impact of localized interferences (bad frequencies) on the system. Spread spectrum, as it prevents one system to use the full bandwidth capacity, also force independent systems to share the bandwidth. In the 2.4 GHz band, the regulation specifies that systems have to use one of the two main spread spectrum techniques: Direct Sequence or Frequency Hopping.
The principle of Direct Sequence is to spread the signal on a larger band by multiplexing it with a signature (the code), to minimize localized interference and background noise
Understanding wireless LAN and wireless allows you to plan and design the effective deployment of wireless networks whether at home or using WLAN External long-term Internet users in rural network connectivity.Wireless allows computers and devices to communicate with high frequency - (RF) rather than the conventional cable network.