There are 8 total wires inside a modern Ethernet twisted-pair cable with an 8P8C connector, braided into 4 pairs. All of the 8 wires can be put to work for 1000Base-T/GigE signaling at rates up to 1 Gbps, but only 4 are needed for either 10Base-T signaling at rates up to 10 Mbps or 100Base-T/Fast-E signaling at rates up to 100 Mbps. Additionally, the blue wires alone can be used on recrimped Cat5e cables for telephony, changing the connector from 8P8C to RJ11.
Using 100Base-T or lower frees up wires for other uses. In the 802.11af Power over Ethernet standard, wires 4 and 5 are ground wires, and wires 7 and 8 are live power wires. Ethernet cables can also be used with HDMI-over-Ethernet adapters as an in-place cabling method when lower signaling rates are acceptable. You could even peel off 2 pairs (for 4 total wires) to support 100Base-T Ethernet and 2 separate phone lines.
There are no “wireless” wires in an Ethernet cable, that is to say there are no wires in an Ethernet cable specifically used for wireless transmission
Ethernet cable, like CAT5e or CAT6a Cable, has 4 twisted pairs of 2 wires each, resulting in 8 total wires
Each pair has a distinctive color, Blue, Orange, Green and Brown, one of the two wires in the pair will typically have a white stripe or band (or on some cable will have a white cable with a colored band selecting it’s matched pair), the other wire in the pair will be a solid color
So what does each wire actually do?
Well, in each pair, one wire is typically a positive and the other is negative (aka Tip and Ring)
So now what does each pair actually do?
Well, this depends on the network
On 10/100 based networks (10Mb/100Mb), only the Orange and Green pairs are used, the Blue and Brown pairs go unused, in some creative wiring, you may see the Blue and Brown pair used for another Ethernet connection, and in some cases used for phone wiring alongside the Ethernet
Sometimes either the Blue or Brown pair is used to deliver DC electrical current, this is known as PoE or Power over Ethernet
In 1000Mb Ethernet, aka 1Gb or Gigabit Ethernet, all 4 pairs (8 wires) are used for data transfer, it is still compatible with PoE like 10/100 networks are, but there is also data being sent down the line that the DC current is traveling down
This is all related to a wired network
Okay, so if this is all for a wired network, how to you send a wireless network through Ethernet?
Well, simply put, you don’t, you add wireless networking to a wired network, it’s converted from a wired signal over the Ethernet cable to a wireless signal over the air and vice versa
So how is this done?
With a device called a WAP or Wireless Access Point, this device has an Ethernet port on the back and connects to a wired network like any other device (like a computer with an Ethernet port), a wireless device (like say a laptop) communicates to the WAP and the WAP communicates to the Ethernet network like any other wired device
No WAP, no Wi-Fi
