Wi-Fi vs. Cable Connection?

Network Connections

We regularly get asked whether an organisation should use a cabled network or a Wi-Fi to connect their computers. So, can Wi-Fi equal a cabled LAN network?

The simple answer is yes it can but you may need to accept a reduction in reliability and bandwidth.

  • The most common Wi-Fi standard currently available, (802.11g) isn't full duplex (it cant send and receive data at the same time), 802.11n can but it is more expensive,
  • Wi-Fi can be subject to interference/cross-talk from other Wi-Fi transmitters (including some DECT wireless phones) and there is nothing to stop someone putting one in right next to you,
  • Wi-Fi is rarely as good in PCs as in laptops. This may be due to the PC itself creating more interference,
  • The speed you get across Wi-Fi networks is only a fraction of that in cabled Local Area Networks (LANs). Doesn't matter so much for pure internet access but if files are being shared between computers, it will be noticeable,
  • Wi-Fi just isn't as reliable as cabling; signal tends to fluctuate and may drop out,
  • Wi-Fi signal degenerates through walls & ceilings,
  • Wi-Fi is ephemeral and doesn't have any other uses - cabling is a long term investment in infrastructure which has many uses such as telephone system and means that PCs & phones can be set up anywhere where there are points. Every time you add a PC or move PCs in a wireless network you have to think whether the signal will reach,
  • Lastly you nearly always need some cabling anyway - routers, phones, printers and NAS drives probably could be converted to Wi-Fi but they are bound to work better and be more reliable on CAT5 cabling.

If you do decide to proceed with a wireless connection, we suggest you do a Wi-Fi survey of the premises using a program such as NetStumbler or similar. People sometimes put their Wireless Local Area Network (WLAN) on a unique channel thinking they'll get a clearer signal - in fact the opposite can happen. Multiple WLANs can share a channel and time-slice seamlessly between them, but a transmitter on an adjacent channel will interfere with them. That's why the convention is to only use channels 1, 6 and 11 so there's the maximum separation. If you are on channel 11 and somebody starts using 10 nearby then your signal will start doing weird things like fading in and out.

If you are wiring up desktop computers in different rooms, consider using a wireless card with a separate antenna rather than standard PCI cards. As having the card in the back of the PC with all the other stuff degrades the signal. A USB dongle on a breakout cable can be positioned to get the best signal (and is much easier to fit).

It is also worth noting that old buildings with plaster walls and wooden floors are Wi-Fi friendlier than buildings built of brick or pre-stressed concrete.


From those Friendly People at DOT-COMmunICaTions