Tag Archives: RF

The Rule of 10s and 3s

A while back I wrote a blog post explaining how an antenna works when it is connected to a wireless access point. Today I’m going to add to that lesson by explaining The Rule of 10s and 3s. Essentially, you can use this rule to figure out what your transmit power is going to be when you add various connectors, cables, and external antennas to your access points. Without further ado:

Please remember that using The Rule of 10s and 3s does not give you exact figures. It should only be used to perform rough calculations. Also, this video is not intended to be a technical deep-dive into the field of RF mathematics. Instead, my goal is to explain the basics of a complex topic so that almost anyone can understand it. (I’ve assumed knowledge of milliwatts and decibels though).

Dan C.

Bonus marks if you can explain why having this knowledge is important for anyone working with WLANs. Leave your answer in the comments section and share this video with anyone you think might benefit from knowing this rule.

Having difficulty making the RF connection?

For some people, learning the RF antenna connector names can sometimes be the most complicated thing about deploying a wireless network. If you are doing an indoor WLAN deployment and your access points have integrated antennas then you have spared yourself the joy of learning connector naming conventions. For those organizations requiring external antennas, the task of keeping all the connector types and names straight can be a somewhat confusing task to say the least.

With this post, I hope to provide a bit of clarification for anyone who is struggling to determine the connector types needed in their WLAN deployment. Here are a few connector types/names accompanied by some tips on how to identify them. (My apologies for the relatively limited selection of connector types but I’m writing this from a hotel room and using my phone to take pictures of the gear I have with me.) :

1. RP-SMA Plug (RP = Reverse Polarity and SMA = Sub-Miniature Type A). You’ll note that it has a female inner-receptacle and inner-threading. 

2. RP-SMA Jack. This connector has a male inner-pin and outer-threading. Another name you might see associated with this connector is: RP-SMA Socket.

3. Type N Plug. This connector has a male inner-pin and inner-threading. Another name you might find associated with this connector is: N-Type Plug.

4. Type N Jack. It has a female inner-receptacle and outer-threading. Other names you might find associated with this connector are: Type N Socket, N-Type Socket, N-Type Jack.

5. RP-TNC Plug (RP = Reverse Polarity and TNC = Threaded Neill-Concelman). This connector has a female inner-receptacle and inner-threading.

6. RP-TNC Jack. It has a male inner-pin and outer-threading. Another name you might see associated with this connector is: RP-TNC Socket.

Properly deploying a healthy and secure WLAN can sometimes be a confusing task for the uninitiated. Hopefully, this post can clear away a bit of that confusion by helping to put a name to a few of the different connectors you might encounter.

Dan C.

If anyone has any images of SMA, or TNC connectors, and is willing to share them, please let me know and I will be happy to update this post.

How Your Wifi Antenna Does What it Does

Most of the people I have spoken to lately have had a minor misunderstanding about how their wireless antennas actually work. Everyone gets the part about “extending the range of the signal” correct but it is usually incorrectly attributed to active gain instead of passive gain. In the picture, below, you can see a flashlight bulb, and a flashlight. These two items can serve as pretty decent analogies for how your standard omni-directional and directional antennas work.

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Wireless Networking for the Rest of Us

Wireless networks are everywhere and have become a part of our everyday lives because they allow people to remain connected without sacrificing mobility.Their popularity really skyrocketing in the past six months and I couldn’t be happier about that since I am a bit of a wireless junkie.  

I think a large contributor to the success of wireless networking is their relative ease-of-use. It is very easy for someone with very little wireless knowledge to setup and connect to a basic wireless network; this makes them very attractive.  Unfortunately, it is the apparent ease-of-use that masks the fact that wireless networks are incredibly complex and that they require a lot technical skill and planning to fully understand and deploy properly. With that in mind, consider this my first post in a series designed to explain the inner-working of wireless networks in language that anyone can understand. Basically, I want to take the technical-mystery out of wireless networks and help people understand how they work.

The remainder of this post is actually a republishing of a post I created for my, now retired, personal blog several months ago. Posts to follow will contain explanations of how antennas work, understanding radio frequencies (RF), and authentication and encryption. Without further ado, I give you “What You Thought You Knew About Your New 802.11n Router”: Continue reading