Thread: Electric Line Interference problem (need professional help)

Hi all

Based on my experience and extensive troubleshooting, i have come to know that mains electric line can cause interference/noise in bsnl line leading up to splitter. I have proved this practically, i was downloading at 110 KBps(1350 UL plan is upgraded to 1mbps till 30 april) constant on utorrent on ups power, through ZTE ADSL ZXDSL 531 B wireless modem. suddenly when light came the speed dropped to zero, & the speed graph instantly came down like a mathematical curve azymptote down to zero like an xy graph of 1/x to x. so definitely electricity is the problem. i did not check but it definitely affects my SNR.

Now what i want to know here (any experts in wireline communication here??) is that can i myself solve the problem by bringing my phone line seperately from the pole away from electric line and reducing number of open joints, or the problem is beyond the pole that means it is not possible to solve this problem from my end since the phone line passes through many high voltage electric lines while reaching my house. and can we cover open joints with cellotape?? coz i heard it induces noise in the line

Please give advice based on some experience or professional expertise only. If u have no idea about it then it is no use giving ur opinion like changing DNS server, since i have tried all other options.


For information, my military type RJ phone line is through underground from pole onwards in an unshielded PVC pipe alongwith the mains electric wire
cheers

Sorry I cant help you, But yes even I have proved this and I was soon going to create a thread in this matter.

My Observation:

I had just put the routers power cable and my ADSL cable close to each other and my SNR values went down and when they are very well seperated the values are good enough.Power cable really affects the ADSL one and causes much interference.
If anyone doubts my observation they can try themselves.

Supportive Information:

Anyone Ever has wondered why the power cord jack and the ADSL cable jack are on a two seperate ends of a router?
Ex: Take any router and you will find the same everywhere.

I had just put the routers power cable and my ADSL cable close to each other....

Which is the modem/router you use ?
Usually the power supply ( from the adapter ) cable to the modem carries D.C at a very low Voltage say 12V to. 5 V.
Effect of the magnetic field in this cable may not be significant.

90% of interference is before the splitter from mains power line. i figured out that for max SNR u hav to:

1. Keep as less open joints as possible, ie the line from pole to splitter should be in one piece.

2. Keep the line as short as possible, take the shortest path to the modem, and the line from splitter to modem should not exceed 4 ft (standard RJ)

3. Keep the line away from all sources of interference like high freq tubelight chokes, preferably a separate underground wire housing, and avoid running it parallel to electric line at any point.

@syedtalha
You can post as Annexure the SNR Attn page of your modem ( mention/make/number) here.
When you post Click "Go Advanced " scroll down .
manage Attachments.

Statistics -- ADSL

Mode: T1.413
Type: Fast
Line Coding: Trellis On
Status: No Defect
Link Power State: L0

Downstream Upstream
SNR Margin (dB): 10.8 13.0
Attenuation (dB): 61.0 31.5
Output Power (dBm): 11.6 15.9
Attainable Rate (Kbps): 928 416
Rate (Kbps): 896 384
K (number of bytes in DMT frame): 29 13
R (number of check bytes in RS code word): 0 0
S (RS code word size in DMT frame): 1 1
D (interleaver depth): 1 1
Delay (msec): 0 0

Super Frames: 70268 70268
Super Frame Errors: 12 0
RS Words: 0 0
RS Correctable Errors: 0 0
RS Uncorrectable Errors: 0 N/A

HEC Errors: 8 0
OCD Errors: 0 0
LCD Errors: 0 0
Total Cells: 2524400 0
Data Cells: 193677 0
Bit Errors: 0 0

Total ES: 10 0
Total SES: 0 0
Total UAS: 31 0


This is when electricity is on. & when it electritity is off, SNR jumps to 16 or 17. Attenuation remains same, since it depends of distance from exchange which is const. to put it simply, my net gets suddnely disconnected when electriticy comes, & then after some time i am able to reconnect, but with significantly lesser speed than before....SNR is to blame off course, but can i prevent this and how??

Modem ZTE ZXDSL 531 B
Soft. Ver : ZXDSL 531BIIV7.3.0f_D09_IN

Downstream Upstream
SNR Margin (dB): 10.8 13.0
Attenuation (dB): 61.0 31.5
very bad. complain to BSNL CC.

@syedtalha
Your Line Download Rate are lower then the usual.
At this line rate you never get the full DL speed of 2Mbps ( If you are in 2Mbps Plan )

For getting the Download Rate at 2048Kbps instead of 896 Kbps only check on the G.DMT mode and uncheck all others mode.

I think it will also increase the SNR Margin.

Your SNR and attenuation values are poor. Get you line checked by the line man. Ask him to change joints and put a single cable. This will give you an idea