Wireless network refers to any type of computer network that is wireless, and is commonly associated with a telecommunications network whose interconnections between nodes is implemented without the use of wires.[1] Wireless telecommunications networks are generally implemented with some type of remote information transmission system that uses electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes place at the physical level or "layer" of the network.[2]
Wireless PAN
Wireless Personal Area Networks (WPANs) interconnect devices within a relatively small area, generally within reach of a person. For example, Bluetooth provides a WPAN for interconnecting a headset to a laptop. ZigBee also supports WPAN applications.[3]
- Wi-Fi: Wi-Fi is increasingly used as a synonym for 802.11 WLANs, although it is technically a certification of interoperability between 802.11 devices.
- Fixed Wireless Data: This implements point to point links between computers or networks at two locations, often using dedicated microwave or laser beams over line of sight paths. It is often used in cities to connect networks in two or more buildings without physically wiring the buildings together.
[edit] Wireless MAN
Wireless Metropolitan area networks are a type of wireless network that connects several Wireless LANs.
- WiMAX is the term used to refer to wireless MANs and is covered in IEEE 802.16d/802.16e.
[edit] Wireless WAN
Wireless Wide Area Networks are wireless networks that typically cover large outdoor areas. These networks can be used to connect branch offices of business or as a public internet access system. They are usually deployed on the 2.4 GHz band. A typical system is as per the one deployed by Gaiacom Wireless Networks contains base station gateways, access points and wireless bridging relays. Other configurations are mesh systems where each access point acts as a relay also. When combined with renewable energy systems such as photo-voltaic solar panels or wind systems they can be stand alone systems.
[edit] Mobile devices networks
With the development of smart phones, cellular telephone networks routinely carry data in addition to telephone conversations:
- Global System for Mobile Communications (GSM): The GSM network is divided into three major systems: the switching system, the base station system, and the operation and support system. The cell phone connects to the base system station which then connects to the operation and support station; it then connects to the switching station where the call is transferred to where it needs to go. GSM is the most common standard and is used for a majority of cell phones.[4]
- Personal Communications Service (PCS): PCS is a radio band that can be used by mobile phones in North America and South Asia. Sprint happened to be the first service to set up a PCS.
- D-AMPS: Digital Advanced Mobile Phone Service, an upgraded version of AMPS, is being phased out due to advancement in technology. The newer GSM networks are replacing the older system.
See also mobile telecommunications.
THE WIRELESS DEVICE THAT I LIKE MOST IS:
2.1 Lucent Wavelan & DEC RoamAbout DS
| Driver status : | stable |
| Driver names : | ISA : wavelan.o Pcmcia : wavelan_cs.o |
| Version : | v19 (20/4/99), v20 (29/7/99) or v23 (10/10/00) |
| Where : | ISA : Linux kernel (2.0.37, 2.2.11 & 2.3.15) Pcmcia : Pcmcia package (3.0.11) |
| Creators : | Bruce Janson (ISA) and Anthony D. Joseph (Pcmcia) |
| Maintainer : | Jean Tourrilhes |
| Web page : | http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/Wavelan.html |
| Mailing list : | http://lists.samba.org/pipermail/wireless/ |
| Documentation : | man pages, headers |
| Configuration : | Wireless Extensions |
| Statistics : | Wireless Extensions |
| Modes : | Ad-Hoc |
| Security : | DES (only for hardware with the DES option) |
| Scanning : | No |
| Monitor : | Yes (nwid off + tcpdump) |
| Multi-devices : | isa : up to 4 pcmcia : yes |
| Interoperability : | proprietary protocol, interoperate with Windows |
| Other features : | module, hardware multicast, Wireless Extensions, SMP |
| Non implemented : | roaming |
| Bugs : | see release notes on web page :-( |
| License : | GPL & OpenSource |
| Vendor web pages : | http://www.wavelan.com/ http://www.networks.digital.com/dr/wireless/ http://www.cabletron.com/dnpg/dr/npg/lanfm-mn.html |
2.1.1 The device
The Wavelan has been around for quite a while now, and this product is now discontinued (and replaced by the Wavelan IEEE/Orinoco - see section 3.1). The Wavelan is a radio LAN, using the 900 MHz or 2.4 GHz ISM band (Direct Sequence). It is built by Lucent, formerly AT&T, formerly NCR, and there is a few OEM version (for example the DEC RoamAbout DS). The Wavelan comes in two flavours, an ISA card and a PCMCIA card (plus the access point).The Wavelan appears to the PC as a standard network card and interfaces naturally with the networking stack. The configuration includes setting the frequency (10 different channels), Network ID (16 bits). Hardware encryption is optional (DES or AES - 64 bits key).
This product is built around a standard Ethernet controller (that may be found in some 3Com and Intel Ethernet cards), and the Ethernet physical layer is replaced by a radio modem. The ISA and Pcmcia cards share the same basic architecture, have the same modem, but have different Ethernet Controllers and bus interfaces (the pcmcia has only one transmit buffer). Because the Wavelan doesn't use a specific radio MAC (no MAC level retransmissions for example), it uses very efficiently the bandwidth, but is more sensitive to packet loss and collisions.
There is two versions of the modem, a 900 MHz and a 2.4 GHz version. Revision 2 of the 2.4 GHz modem allows the user to set the frequency (from a set of predefined channels - the availability of each channel depend on the regulation). The Wavelan is Direct Sequence Spread Spectrum (11 chips encoding), using a 2 Mb/s signalling rate (using effectively 22 MHz of bandwidth) and diversity antennas.
2.1.2 The driver
The ISA driver has also been around for quite a while now in the kernel and is pretty stable. The last set of modifications were to solve a few remaining small problems and add Wireless Extensions and some other features, so the driver is fairly complete now. The only things remaining to do is the implementation of the roaming protocol (but it might come, if I'm not too lazy...).The Pcmcia driver has caught up with the ISA one to offer the same level of functionality and reliability. The only difference are the pcmcia specific functions (auto loading, auto unloading, crude power saving).
The latest releases of both drivers (v23) adds SMP support.
The drivers use the card EEprom to save the configuration changes for subsequent reboots. Wireless Extensions let you configure the NWID, the frequency, the sensitivity and the encryption key (optional). Statistics include the signal quality, signal level, noise level and the count of packet received with an invalid NWID (see Wavelan documentation). Private Wireless Extensions include the setting of the quality threshold.
LIFE WITHOUT WIRELESS DEVICES?
Oh life without wireless devices? well it would be a miserable one if we dont have it.
for me, life will be boring without it. There will be also a nuissance in sending and communicating messages to our love ones. Also, there wold be no internet that im using right now.
If there's no internet, well i wont be able to do blogging.
heheheheh..............
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