Wireless Network Components

in Power

Client Software and Adapter

Any client computer, laptop or wireless device with a compatible wireless client adapter allows connectivity with an access point. The client adapter is a radio transmitter with firmware that supports any of 802.11a/b/g signaling. That is needed before the device can associate and authenticate with the access point. Some access points have a no client mode that doesn't allow any association from clients extending network distance. Client wireless software included with the adapter must be implemented with specific Windows platforms. The client adapter will be integrated with the laptop, PCMCIA slot or desktop PCI bus slot. They will support specific wireless standards, antenna characteristics, WiFi certification, WDS, network range and security. The wireless manufacturer software must be implemented for all available features. The following is a list of some client adapter configured settings.

Access Point

As the name suggests an access point allows connectivity between the wireless client or wireless device and the wired network. The access point takes wireless data packets from a client and translates them to standard Ethernet data frames before transmitting across the wired network. Standard category 5 twisted pair cabling will connect the access point Ethernet port with a catalyst switch Ethernet port. The maximum distance between access point and network switch is 100 meters standard with Ethernet design.

WLAN Controllers

Wireless designs with hundreds of root access points on an enterprise network will sometimes deploy wireless LAN controllers. The design specifies lightweight access points connecting to a network switch. The 4404 WLAN controller device acts as a hub connecting 4 network switches supporting 100 access points. Cisco wireless control system (WCS) wireless network management software is sometimes deployed with WLAN controller design for planning, configuring and optimizing the network.

Power Injector

Cisco access points have a variety of power options such as AC adapters, power over Ethernet and power injectors. The placement of access points is such that in some situations an AC power outlet isn't available. Should your Ethernet switch not support power over Ethernet, an option such as power injectors extends the distance from an AC outlet. Distances of 1.24 miles are available with a fiber optic media converter.

Power over Ethernet

Cisco access points can be deployed with power over Ethernet (PoE) should the network switch modules support that feature. The distance of 300 feet is the same with Cisco prestandard and 802.3af. The Cisco prestandard use Cat 5 cabling pins 1, 2, 3, 6 for powering devices while 802.3af uses 1, 2, 3, 6 with 10/100/1000BaseT signaling and 4, 5, 7, 8 with 10/100BaseT. Select a network switch module with the power over Ethernet standard your access point has implemented and has a power wattage rating per port for your specific devices. The network switch power supply should be upgraded to support additional power draw from multiple devices. Deploying power over Ethernet will decrease implementation costs with deployment of IPT, wireless and Gigabit. See network switch documents at Cisco web site for information on what network switching modules support PoE and wattage ratings. 802.3af defines powered device class 2 at 3.84W - 6.49W and class 3 at 6.49W - 12.95W.

Power Patch Panel

Cisco inline power patch panels can be deployed where Ethernet switches don't support power over Ethernet and power injectors aren't an option. The patch panel does no switching. It powers the devices through a Cat 5 cable that is a maximum 300 feet at a specific rated wattage per port. The patch panel connects the access point to the wired switch with a patch cable.

The book Cisco Wireless Network Design Guide is available at amazon.com

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Shaun Hummel has 1 articles online

Shaun Hummel is an author of various technical books, web hosting provider and manages a web site focusing on job search solutions.

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Wireless Network Components

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This article was published on 2010/04/03