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Fluke Networks: Minimize Wi Fi Network Downtime

Aruba: Packets never lie: An in-depth overview of 802.11 frames

ATM15 Ten Talk “Wifi drivers and devices”

Houston Methodist Innovates with Wireless Technology

Bruce Frederick Antennas (1/2)

 

Bruce Frederick dB,dBi,dBd (2/2)

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2.4 GHz Channel Overlap

EXAMPLE 1  

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See inside Cisco's latest wireless gear!

LWAPP QoS Packet Tagging

 

 

CWSP RELEASE DATE 2/08/2010
  • CWSP Certified Wireless Security Professional Official Study Guide: Exam PW0-204
    CWSP Certified Wireless Security Professional Official Study Guide: Exam PW0-204
    by David D. Coleman, David A. Westcott, Bryan E. Harkins, Shawn M. Jackman

    Shawn Jackman (Jack) CWNE#54 is a personal friend and has been a mentor to me for many years.  I've had the pleasure and opportunity to work with Jack for 4 years. Jack is a great teacher who takes complex 802.11 standards and breaks them down so almost anyone can understand the concept at hand. I'm excited for you brother. Great job and job well done! Put another notch in the belt!

Interference Types

BLUETOOTH
 

Microwave Oven
 

Cordless Phone

JAMMER!
 

IEEE 802.11a/g/n Reference Sheet

 

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Sunday
Nov082009

Wireless NIC problem or just poor quality? 

This evening I did benchmark testing on a wireless client which I want to share. I was working on a Samsun NQ unit with an integrated Atheros AR5007EG wireless NIC. I was told by the user the client would lose connectivity and had a slow network connection when connected. So I go through the normal check list, do I have signal for data- check, is the noise floor low -  check, do I have expected PHY data rates - check.  But this test was conducted right under the access point.

As I get distance between the client and the access point (also know as free space path loss) I see the wireless client signal strength nose dive hard.

So I check all the normal things, antenna connection, driver update, NIC config. All these check out OK. So I do side by side benchmark testing with a known good wireless NIC and notice an almost a 20 dBm difference. As you know all wireless NICs will hear (receive sensitivity) differently. But with advancements today, you will see most NICs are all generally in the same ballpark. I say that lightly and tip toeing.

Below is a snap shot of both clients, Samsung has the Atheros AR5007EG and my laptop Intel2915AG. Both clients are side by side at the same distance from the access point. I did further testing by adding another laptop for consistency. I also added a Cisco Linksys WUSB600N to the Samsung.

I don’t have another Samsung to test and it’s not my unit so I wont be taking it apart to investigate further. But the moral of the story, never ever discount the client. Each client will hear differently, and soemtimes a client may have issues or be a poor design.

 

 

 

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