Undergrad Why does a kinked wire reduce data throughput?

[greypilgrim]

Hi.

I read that every kink in a data wire reduces throughput. What's the physical reason for this? Does the resistance of the wire increase at a kink or is this an inductive effect or something else?

 

[Bystander]

Does the resistance of the wire increase at a kink or is this an inductive effect or something else?

Both?

 

[greypilgrim]

And why does resistance increase? And why would this affect the data rate?

 

[Bystander]

Bending/kinking work hardens the wire. Increased losses, lower throughput.

 

[tech99]

Hi.

I read that every kink in a data wire reduces throughput. What's the physical reason for this? Does the resistance of the wire increase at a kink or is this an inductive effect or something else?

I think you are referring to a transmission line with two conductors. I think the main effect is to add inductance at the kink, and this will create a mismatch, reflecting some of the pulse energy. The received pulse will then be accompanied by echoes, which make detection of 0s and 1s more difficult.

 

[jbriggs444]

Hi.

I read that every kink in a data wire reduces throughput. What's the physical reason for this? Does the resistance of the wire increase at a kink or is this an inductive effect or something else?

Kinks in data wire do not reduce throughput directly. They may decrease the intensity of the received signal or create unexpected reflections or noise, but that does not, by itself, reduce throughput. The rate at which bits go into a length of wire is still the same as the rate at which they come out.

If the kink is severe enough, the data connection will simply fail. That could be viewed as a 100% decrease in throughput. That is actually the preferred mode of failure.

If the kink is only severe enough to produce errors, there can be a serious throughput degradation as a result. This degradation will be more serious than one might naively imagine. A packet loss rate of one percent is enough to cripple a circuit and degrade end to end throughput by over 50% as upper layer protocol endpoints resort to timeouts and retransmissions to preserve communications integrity.

 

[tech99]

I think we can say that a kink will slightly reduce the maximum distance at which error free transmission can be obtained.