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Will WiFi replace ethernet cable ?

posted Feb 2, 2012, 4:00 AM by David Khorram   [ updated Feb 2, 2012, 4:00 AM ]

From: Paul Dover  and  Scott Harris 




It has always been possible to provide wireless LAN’s. But, what has always hampered their use has been the physical environment. For example, concrete walls full of rebar constitutes an antenna array and the only way thru with high speed is via a perpendicular angle of attack otherwise dispersion becomes an issue for very low angles of attack. Second issue is security… anything wireless is unsecure (remember my old saying “if it was conceived by a man another man can figure it out”) WEP/WPA can be breached. So, my neighbor could ride my IPTV but he has to have a set top box which are available on the black market (and have always been). MIMO is a complicated technology and is heavily dependent on stable inputs to produce stable outputs (it’s nothing more than a multiplexing technology). It is heavily used at cellular sites and works pretty good…. in the home or office? Long way to go for that.


Last thought, any wireless RF is heavy on protocol overhead, don’t be fooled by the stated throughput. An excellent cabled Ethernet system can get a maximum of 95%, the rest is eaten up by Ethernet overhead. Wireless requires more overhead capacity due to the interference that may be encountered, extra security, compression, MIMO processing, etc.


There’s more but think Greenfield versus Brownfield environments. How many times has AP’s been installed and additional ones had to be installed because of unforeseen signal strength issues that weren’t uncovered in the modeling?


Also notice the limited applications; streaming video, large file transfers, etc. Very expensive… as a user it doesn’t help me type faster nor read faster… to me, to try and fit to the individual is a waste of bandwidth; that’s why plain old cabled Ethernet has always won out in the end for the last 35 years….


Add to that, I can’t tell you what sources of interference I would encounter today in the 5ghz range must less tomorrow…. How about with my neighbors? Every source of interference is added overhead…