1 basic telecommunications wireless fidelity 802.11x

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BASIC TELECOMMUNICATIONS

Wireless fidelity802.11x

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The WiFi standards are still evolving, the technology was first introduced in 1985 and the first wireless products were introduced in 1991

In 1999 the WiFi Alliance was formed and the official term WiFi was coined along with the WiFi logo

Wireless networks use RF transmission and they are based on the IEEE (Institute for Electrical and Electronic Engineers) 802.11 standards


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Wireless networks have gained a great deal of popularity in both residential and commercial environments

Access points (Aps) are increasingly being designed into the LAN networks and are an integral part of the network topology

In addition to being part of the building infrastructure many service businesses are implementing free indoor and outdoor WiFi access called “hot spots”


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To access the hot spot your laptop or electronic device must have a built in WiFi card, or a user can use a PCMCIA (Personal Computer Memory Card International Association) card that inserts into a laptop


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WiFi networks or WLANs (Wireless Local Area Network) are not necessarily wireless

To the end user it’s wireless, however to have a dependable high speed network it requires UTP cable to each WAP (Wireless Access Point)


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Many AP manufacturers suggest the use of either ScTP or STP, CAT 5e or CAT 6, 4 pair cable to each location

The shielded cable helps to eliminate interference that might slow down through put on the wireless network

Each AP is cabled the same as any network location in a star topology


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WAPs are active devices which means in addition to a CAT 6 cable they also need power

Since WAPs are usually placed above drop ceilings in most locations finding a power outlet close by is very unlikely

This means that an electrician will have to install power outlets at all the WAP locations


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The best way to work around this problem is to use PoE (Power over Ethernet) switches

PoE is defined in the 802.3af standard which provides up to 15.4 W of DC power (minimum 44 V DC and 350 mA[) to each device, only 12.95 W is assured to be available at the powered device as some power is dissipated in the cable


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The updated IEEE 802.3at-2009 PoE standard also known as PoE+ or PoE plus, provides up to 25.5 W of power

Some manufacturers are claiming up to 50W, 48VDC at 350mA

With these new PoE standards we can power remote CCTV cameras, PTZ controllers and VoIP phones which are currently utilizing PoE solutions to power the phones


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Another alternative is to use a PoE injector which can be placed in the TC where power is readily available

The CAT 6 link plugs into the injector from the network switch and the WAP cable is also patched into the injector

Just like the PoE switch the PoE injector sends power over the two un-used pairs of the CAT 6


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Below is an example of a PoE injector used to provide power over two of the four pairs in a CAT 6 cable to a remote WAP


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If two pairs in a CAT 5e/6 cable are used for data transmission then which two pair do you think are used for power over Ethernet?


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WAPs should not be confused with a wireless router which is a multi-function device that serves as a router, wireless access point and network switch

Wireless routers work well in a home but in order to have complete coverage in a business environment multiple WAPs or APs (Access Points) are required


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The wireless router allows for hard wired devices to be connected to the LAN ports such as a desktop computer and/or printer that will then be networked with other wireless users


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Wireless routers need to be set up or configured when they come out of the box.

Manufacturers have made it fairly simple to set up a wireless router using the step by step menu instructions included with the router

Most are set up with a DHCP IP (Internet Protocol) and then hand out DHCP (Dynamic Host Control Protocol) IPs to clients on the network


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DHCP means that the device’s IP address will always change when a new connection to the internet is established

A static IP is a fixed IP address that never changes

Most devices connecting to the internet will be configured to obtain a DHCP address


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A computer’s IP address is typically 192.168.X.1 thru 200 the X denotes the gateway number

Most out of the box wireless routers have an IP address of 192.168.1.1, when this number is put into the URL (Uniform Reading Line) it will get you to the login page of your router

The URL is where you type in web addresses


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Of course you will want to encrypt your router so others can’t access it.

One option is WEP (Wired Equivalent Privacy) encryption, WEP is the easiest to set up but is the least secure because it has a fixed key code size that is used over and over when sending info

WPA(WiFi Protected Access) and WPA-2 offer higher levels of security because you can set your own encryption pass code


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With WPA and WPA-2 encryption you can have up to 250 characters for an encryption code which will be scrambled every time info is sent from your router

When using the WPA-2 encryption choose “personal”

You will also be asked to create an SSID (Set Service Identifier) name that will be broadcasted for all to see


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When setting up a wireless router you will need the IP address of the ISPs (Internet Service Provider) modem

One way to find this info (it’s required by the router) is to run a DOS (Disk Operating System) command

In the start menu go to the search line and type cmd, this will bring up the DOS window


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Once you have this window up type in “ipconfig /all” and hit enter this will give you all of the IP information needed for the router


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You will now have your IP address, the default gateway address the subnet mask and the DNS server information to set up your router


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After configuring your router, if any problems arise with connectivity or it “freezes up” (this is problem with idle APs) you can power it down and power back up after approximately a 30 second wait

If needed all wireless routers can be reset by taking a paper clip and holding down the little black button on the router for 10 seconds


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You will need to remember your user name and password to get into your router, the reason why most people reset their routers is because of forgotten passwords.

For WEP encryption you will also need the pass key or phrase to access the network, this should be written down somewhere


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You can go in a make changes to your router at any time, and view logs of sites that have been visited by anyone on the network

In your routers settings page you can also restrict access to web sites (to keep kids from surfing in the wrong place)

For further security measures you can also MAC authenticate all computers allowed access through your router


1 basic telecommunications wireless fidelity 802.11x

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