OT: Wireless Network Strength Dependent On Wired Network?

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1

Okay, a small, offtopic question. (I figured you guys were a far more
reliable source than my local ${electronics_store} salesperson...)

Consider the following setup:
internet pipe -> wired network -> (wireless router) wireless network ->
computer1, computer2

Suppose the signal coming in on the pipe is good, but the signal
deteriorates rapidly in wired network (old & bad wiring). Now, the two
computers are connected via the wireless network only. computer1 has a great
connection (it's in the same room as the wireless router), but computer2 is
far away and drops the wireless connection frequently.

Now, a former electrical engineer is claiming that if we improve the wired
network so that the signal comes across better, then computer2 won't drop
the wireless connection so frequently. (He says that the signal emitted by
the wireless router will be improved by feeding it a better source signal.)

I argue that there are two separate signals: the internet connection signal
coming in on the pipe, and then the wireless network signal being emitted
from the wireless router; and their strengths are independent. In other
words, if we improve the wiring, the wireless signal will not get any
stronger.

So...basically, who's right? (Or are neither of us?) Any thoughts, comments,
corrections?

2

He doesn't know what he's talking about. The two signals have nothing to do with one another - there is no direct connection between wired ethernet and wifi. You can not just plug an antenna into the end of a cat5e cable and expect it to work.

In an easier to visualize path... if you have an ethernet card, and a 802.11g card in your desktop, yes, they may be attached to the same PCI bus, but the packets still have to come in one interface, be handled by the hardware on the card, passed down the PCI bus to the CPU where the software handles processing of the data, then passed back down the PCI bus to the other card, processed by that card, then transmitted by that card over whatever transport it uses. There's a few conversions going on during the path, throwing out garbage data, retransmitting, etc.

If you shut off the antenna of the wifi card, it doesn't affect the ethernet card, and it will continue passing data for the computer to the LAN. If you unplug the cat5e, the wifi can still pass data between devices that communicate over wifi.

I can go into alot more detail here, but moral of story, is don't let a electrical engineer that has no clue about how ethernet and wifi work tell you how packets get from one place to another, and how ethernet relates to wifi.

3

Consider the following setup:
internet pipe -> wired network -> (wireless router) wireless network ->
computer1, computer2

Suppose the signal coming in on the pipe is good, but the signal
deteriorates rapidly in wired network (old & bad wiring). Now, the two
computers are connected via the wireless network only. computer1 has a great
connection (it's in the same room as the wireless router), but computer2 is
far away and drops the wireless connection frequently.

Now, a former electrical engineer is claiming that if we improve the wired
network so that the signal comes across better, then computer2 won't drop
the wireless connection so frequently. (He says that the signal emitted by
the wireless router will be improved by feeding it a better source signal.)

I argue that there are two separate signals: the internet connection signal
coming in on the pipe, and then the wireless network signal being emitted
from the wireless router; and their strengths are independent. In other
words, if we improve the wiring, the wireless signal will not get any
stronger.

Your EE friend is highly confused.

Get a stronger WiFi transmitter or repeater.

4

Neil wrote:

Okay, a small, offtopic question. (I figured you guys were a far more
reliable source than my local ${electronics_store} salesperson...)

Consider the following setup:
internet pipe -> wired network -> (wireless router) wireless network ->
computer1, computer2

Suppose the signal coming in on the pipe is good, but the signal
deteriorates rapidly in wired network (old & bad wiring). Now, the two
computers are connected via the wireless network only. computer1 has a great
connection (it's in the same room as the wireless router), but computer2 is
far away and drops the wireless connection frequently.

Now, a former electrical engineer is claiming that if we improve the wired
network so that the signal comes across better, then computer2 won't drop
the wireless connection so frequently. (He says that the signal emitted by
the wireless router will be improved by feeding it a better source signal.)

I argue that there are two separate signals: the internet connection signal
coming in on the pipe, and then the wireless network signal being emitted
from the wireless router; and their strengths are independent. In other
words, if we improve the wiring, the wireless signal will not get any
stronger.

The source signal is the device itself, not the wired portion. To prove
it unplug the wired Ethernet and the signal will still be there (unless
the radio goes down with loss of link).

~Seth

5

Okay, a small, offtopic question. (I figured you guys were a far more
reliable source than my local ${electronics_store} salesperson...)

Consider the following setup:
internet pipe -> wired network -> (wireless router) wireless network ->
computer1, computer2

Suppose the signal coming in on the pipe is good, but the signal
deteriorates rapidly in wired network (old & bad wiring). Now, the two
computers are connected via the wireless network only. computer1 has a great
connection (it's in the same room as the wireless router), but computer2 is
far away and drops the wireless connection frequently.

Now, a former electrical engineer is claiming that if we improve the wired
network so that the signal comes across better, then computer2 won't drop
the wireless connection so frequently. (He says that the signal emitted by
the wireless router will be improved by feeding it a better source signal.)

If you are running a digital network, no. Digital doesn't work like that. The
packets get through intact, or they are dropped. Dropping the wireless connection means that
you are having trouble communicating between the wireless router and computer 2.
Since computer 1 is close and works and computer 2 is far away, that strongly suggests that you have
a SNR problem. To fix that, you need either a stronger
access point (wireless router), another access point closer to computer 2, or a wireless repeater. Note that the AP also has
to receive the signal from computer 2, and you probably can't boost computer 2's power, so you may
not be able to fix this by just boosting the access point's power.

There is a possibility that the problem is with computer 2. You might try swapping
computer 1 and 2 to confirm that the problem is distance related, or (what I generally do)
use a laptop as a test probe to confirm a good signal at computer 1, and a poor one at computer 2.

I argue that there are two separate signals: the internet connection signal
coming in on the pipe, and then the wireless network signal being emitted
from the wireless router; and their strengths are independent. In other
words, if we improve the wiring, the wireless signal will not get any
stronger.

In the spacecraft world, what the wireless router is doing is called regeneration. It is
not just amplifying the wireline signal it receives, it receives it, decodes it, turns it into
bits, and then puts those bits out as a radio encoding. Any noise in the signal
received is irrelevant, as long as it is not enough to cause the entire packet to be dropped.

Regards
Marshall