Tuesday, November 13, 2012

Wireless Is Not Always The Answer

Everywhere we look these days, something is wireless.  It started with an infrared remote control, and now we can send vast amounts of data at incredible speeds.  The latest wireless innovation I'm taken aback by is AirFiber from Ubiquiti Networks, which allows a point to point wireless link at over 1.4Gbps for under $3000!  With all these wireless solutions around, why do we even need wires anymore?  Wires / cables should be all gone soon, right?  Wrong...

Wireless has its place, just like a jet engine has its place.  Each is a tool to perform a function.  Take Bluetooth based headsets for example.  Before they  came about, we had wired headsets that connected to our cell phones.  They got the job done and worked well.  But when Bluetooth headsets came out, it got better.  No more cumbersome wires to get tangled up in, and one less thing to plug in.  Sure, they have to be charged nightly, but so does the phone itself.  Bluetooth in this case is a perfect fit for this job.  Bluetooth cannot transfer a large amount of data, and encoded voice is very low bandwidth.  This means that replacing the cable with a Bluetooth connection will not induce any loss of quality, making the replacement acceptable.

Next look at Wireless Ethernet.  Instead of having a big infrastructure of wires measured in dozens of miles of cable, dozens of switches, etc...you can use one WiFi access point to deliver network access to multiple end users at once.  This makes for a faster, easier network deployment.  Sounds good, right?  Well, not always.  If your users are simply browsing the web, yes.  But if they are doing large file transfers, not so good.  WiFi has much more limited throughput then wired computers.  So like the Bluetooth solution, Wireless Ethernet has it's place.  It's not the end-all be-all solution to networking.

Outside use cases, there are also logistical considerations.  I've had several people ask me this question recently: "I'm remodeling and want to install some speakers in this room of my house.  What do you think of wireless speakers?".  Now, it should be said that in these questions, these are people that are going as far as taking the rooms/buildings down to the studs.  Stop and think about this for a second.  Wireless speakers are rarely 100% wireless, unless they run on batteries.  They have to plug in somewhere for power.  So if you have to put power where you want the speaker, it would be a lot easier to instead put in speaker cable.  Power / 110VAC circuits are more complicated to run in most cases, and more dangerous for the typical home owner to try on their own.  Speaker cable is harmless.  Wireless in this case is simply a buzz word, so you can say you have "wireless speakers".  (This is all of course ignoring that I've never been happy with the audio quality of wireless speakers.)

Now lets consider the fundamentals of what something means to be "wireless".  Wireless connectivity is as simple as it sounds: creating a point to point (or point to multipoint), connection between two (or more) devices to send some form of data.  This can be as simple as a set of kid's walkie-talkies, or as complex as data communications bouncing through satellites orbiting Earth.  Most of the basic principals we're be discussing here apply to both.

The first thing that is obvious but you must keep in mind is that with all forms of wireless communications, you are not in control of the medium.  It's air.  With wired communications, you have a physical connection from point A to point B that has only certain devices and certain data on it.  When wireless is used, it is a free-for-all.  Think about an apartment complex or a densely packed neighborhood.  You can turn on your laptop's WiFi card and see your neighbor's wireless network.  We've all grown used to this, but keep this in mind: anything that's out there on wireless, anyone can see/hear.

Let's take it one step further.  Using those walkie-talkies I mentioned earlier, what happens when two people try talking at once?  You can't hear either one well, or at all.  That's a simple example of interference.  Interference can come from literally anywhere because, again, you are not in control of the medium.  Most WiFi networks work in the 2.4Ghz band.  And guess what.  There are LOTS of other devices that work in that same band.  Bluetooth, video game controllers, RF TV remote controls, most cordless phones, and microwaves (yes...the things that you use to warm your lunch), all operate in the 2.4Ghz band.  This means that when a cordless phone rings or someone warms up their leftovers, your WiFi connection can become very slow or drop out completely.  (This happens to me when I'm on my laptop in my living room and my wife fires up the microwave, which is physically located between me and the access point.)  So from a reliability standpoint, wireless just can't compare to wired, due to the lack of control of "outside influences".

Speaking of outside influences that are outside the realm of control, anyone with the right tools can hear what's going on.  Some of you may recall back in the 80s when cordless phones hit the market, they were purely analog devices.  No digital encoding was done to the data stream...it was pure FM (frequency modulation).  That meant that anyone with an off the shelf radio scanner from Radio Shack could eavesdrop on their neighbor's phone conversations without anyone knowing.  Things are different now with digital coding and encryption being done, but it's still possible.  In the early days of WiFi, most networked used a security protocol called WEP (Wired Equivalency Privacy).  It was decent at the time, but with today's computing power, WEP networks can be easily hacked and a 3rd party can easily see your traffic.  Even some of the newer protocols like WPA and some implementation of WPA2 are susceptible to decryption hacks.  Not to mention simply having a week password (like "1234") on the wireless network.  The point: if your network must be secure, wireless is NOT the answer.

I like wireless sometimes, but most of the time, I think it's a hack.  For example, several companies are developing wireless HDMI solutions, so you can connect a TV to a video source within ~20 ft.  To me this is silly.  The TV has to be powered anyway, and the HDMI cable can go further for a lot less money.  There's a time and place to use wireless, and there's a lot more times to not use it.  Before getting sucked into the wireless hype that everything wireless is better, take time to consider how it's better then what you have now, and what the risks/loses are. Every time wireless is used, something is compromised.  WiFi can be really convenient for mobile users, but for the love of all that is holy, please don't rip out all your Cat5 jacks and switch to 100% wireless "just because" (yes...people have done this, and I died a little inside when it happened).


  1. My workplace got rid of most of the Cat5 jacks a year or two ago, promising lightning fast wireless. It is anything but.

    And it's especially brutal for me, who creates HD videos and has to upload them to YouTube, Vimeo, etc.

    I'm definitely not a fan of wireless-only offices, especially when everybody is just sitting at a desk near a jack and has to be tethered to the wall for power anyway.

    1. Oh my! You're a video guy. The few video guys I know that do it in offices / professionally typically have some of the best machines in the office. Sounds like you got the short end of the stick. You need a gigabit connection! Do they think your videos are only 50MB in size? That's exactly what I was talking about though. Why rip out the wired infrastructure when it already exists, you've paid for it, and in your case, it's even very accessible! In the case I hit where they did that, the customer was complaining it was taking too long to Ghost 20-30 laptops over 11Mbps wireless with a 5GB image...all at once...


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