Thread: how to increase SNR

i am getting the following values.. is this ok..
how to increase it..

the snr u r getting is fine and u cannot change it a it from ur isp.

Originally Posted by m222

i am getting the following values.. is this ok..
how to increase it..

ur attenuation is too high,but if ur getting good speeds than u dont need to worry abt snr


if u r having slow speeds ,then do u hear any noises or disturbance on your telephone while using internet ?

then contact bsnl customer care and make them check your line

Broadband speed is low during night(2am-8am)

same thing here dude ,during daytime i get stable 2mb speed,but during 2am to 8m the speed decrease ,exactly at 2:10 am ,

i am also from bangalore,jeevan bhima nagar

complaint to bsnl customer care 1800-424-1600,make sure the operator registers your complaint and the docket no ,

if nothing happens ,you can use the docket no for future reference

if still the problem continues ,then contact the area manager or divisional manager,in ur bsnl exchange

I had done that too.. a month or so back..

I logged a complaint saying that the speeds are too slow.. The person in charge of Broadband came and checked the line.. They later told that the cable has been changed.

My SNR/Attenuation for Downstream was, 35/32.5.. It shot up to 60/32.5 and i saw immediate effect..

But again.. from past two weeks.. Im facing Low speeds..

And now when i check it... SNR/Attenuation is back to 35/32.5

Can the BSNL folks really control the speeds from the exchange???.. More importantly can WE do something about it other than log a complaint each time???

They can easily come in the mornings and check to say that speeds are fine and get away with it!!!...

if i change my adsl configuration to ADSL2+. I am getting low snr value(7.5)
if its ADSL ONLY then snr is 10.
which mode is better

Originally Posted by m222

if i change my adsl configuration to ADSL2+. I am getting low snr value(7.5)
if its ADSL ONLY then snr is 10.
which mode is better

Use G.dmt.

Originally Posted by m222

if i change my adsl configuration to ADSL2+. I am getting low snr value(7.5)
if its ADSL ONLY then snr is 10.
which mode is better

it doesnt matter if u change the mode

put it to adsl+2 only,that's the default mode

speed of your connection is determine by the line quality and the servers of bsnl

dont just keep on changing settings on modem,

i complained to customer care once againr egarding low speeds after 2am,he said he will call me back after checking the connection

there was noise in my land line phone.i complained it. the bsnl guy came n checked it.now he has replaced the wire.now there is no noise....But when i am using the net..when modem is on..there is lot of noise in phone.
now my snr values is this..WHATS THE MAXIMUM SNR VALUE BSNL PROVIDES.

Originally Posted by m222

there was noise in my land line phone.i complained it. the bsnl guy came n checked it.now he has replaced the wire.now there is no noise....But when i am using the net..when modem is on..there is lot of noise in phone.
now my snr values is this..WHATS THE MAXIMUM SNR VALUE BSNL PROVIDES.

The problem is that your phone line is not connected to the splitter. A splitter should be the first device connected to the line running from outside.

There is no max value of SNR. You should have an SNR margin value from 20 db to 35 db on an average. SNR Margin value also depends upon the distance of your home from the exchange - the greater the distance the lower is the SNR Margin.

i have used the splitter ..where i connect to modem..
i use 2 phones .for the first one i have used splitter where i connect both modem n first phone. for the second phone splitter is not used..
SHOULD I USE SPLIITER FOR BOTH THE PHONES??

Originally Posted by m222

i have used the splitter ..where i connect to modem..
i use 2 phones .for the first one i have used splitter where i connect both modem n first phone. for the second phone splitter is not used..
SHOULD I USE SPLIITER FOR BOTH THE PHONES??

There should be only one splitter in the circuit as follows:

1. Outside line --> splitter
2. Splitter's voice output --> all telephones including parallel lines
3. Splitter's data output --> modem --> PCs

Imp: No parallel lines running to telephones before splitter.

See attached diagram.

If this is how your home network is connected and you still have noise issues, then splitter may not be working.

thanks very much.but......
i have connected similarly as shown..but only in my room where my pc is..
but the other phone is connected to phone point directly in the hall.
so should i remove the connection which is in hall??

If you have it connected like this, then it's fine. It will not cause any problems for internet (Broadband) even if you connect parallel phones connected after the splitter.

thanks a lot ..for giving visual help

The rates were taken from a post by Oblivian on overclockers.co.nz. So obviously, credit goes to him

Attenuation Rates:
20bB. and below = Outstanding
20dB-30dB. = Excellent
30dB-40dB. = Very Good
40dB-50dB. = Good
50dB-60dB. = Poor and may experience connectivity issues
60dB. and above = Bad and will experience connectivity issues



For S/N Margin Readings:

6bB. or below = Bad and will experience no line synchronisation or intermittent synchronisation problems.
7dB-10dB. = Fair but does not leave much room for variances in conditions.
11dB-20dB. = Good with little or no synchronisation problems
20dB-28dB. = Excellent
29dB. or above = Outstanding

@all -- I couldn't attach the link of the original post as this is my first post and i'm not allowed to attach links to external URL until i have made 15 posts. Still you can try googling "ADSL Line rate/SNR - a newb guide. - Overclockers NZ Forums"

Edit: There is a similar article by just4kix on this forum but i'm not allowed to link to it....

Hope this helps....

Thank a lot!
Repped!

Originally Posted by just4kix

Imp: No parallel lines running to telephones before splitter.

Well, it doesn't necessarily have to be like this...here is an alternate if you already have pre-existing parallel lines in your house and you don't want to pull an external wire, to your room, from outside....

Config:
I've a telephone line that comes directly to a junction box on ground floor in my house. From there a total of 6 parallel lines are divided accross 3 floors(incl. ground floor)....and i've attached my modem in one of those rooms, on 2nd floor, w/o splitter.

And here are my values.....

Downstream Upstream
SNR Margin (dB): 22.1 25.5
Attenuation (dB): 29.5 10.8

Speed averages around 1.7 Mbps day time...while at night it can reach upto 2.5 Mbps(average) and one of my friend is lucky enuf to get speeds upto 4 Mbps at night. FYI, we both have Home 500 plans...

Now, since I have parallel lines all accross the house and a fax on ground floor, using a splitter at modem end would be useless as a splitter is a typical 3.5KHz low pass filter that blocks out signals above 3.5 KHz(ADSL systems use typically frequencies between 25 kHz and around 1.1 MHz.) leaving your telephone line noise free at telephone end. So, I'm using splitters at the telephone and fax end to filter out the noise generated by the ADSL signals over the line...Try googling "ADSL filters explained epanorama.net" for a detailed description on splitter..

This is what wikipedia tells...

Typical installation for an existing home involves installing DSL filters on every telephone, fax machine, voiceband modem, and other voiceband device in the home, leaving the DSL modem as the only unfiltered device.

So, if you already have house with pre-existing parallel connections, all you have to do is use splitter or a 3.5KHz low pass filter at each telephone (and fax incase you have one like me) end..

Hope this helps....

What is your downstream and upstreams speeds as listed in the modem web interface?

From Post No 19.

using a splitter at modem end would be useless as a splitter is a typical 3.5KHz low pass filter that blocks out signals above 3.5 KHz(ADSL systems use

SEE
http://i34.tinypic.com/s4c0me.jpg

From the Telephone junction the RJ11 short cable can go the modemDIRECT without any filters so that there is no attenuation/degradation of the signal. An Adsl splitter
does just this. ( see diagram above)

Due to DC present in the line, the surge affects the modem
connection, when the handset is lifted or there is an incoming call.

Better Idea will be to have a telephone number dedicated to BB and another for incoming and outgoing calls.
Some Home Plans have no telephone rental.
There is also some limit ( seems 5 telephones) that can be
connected in BB ADSL connection line.
( Impedance matching)

@Noisysilence
Pictures can be attached as annexures. Click Go Advanced.
links can be given hxxp or h t t p ://
or just bbservice.bsnl.in

Wow. Thanks for that post. I was also of the impression that some kind of filtering is done in the splitter. Now i know that for ADSL purposes no filtering is done, but it is done only for the phone purposes..

Repped for the informative post..

So, I'm using splitters at the telephone and fax end to filter out the noise generated by the ADSL signals over the line.

also refers.
@cool_techie_tvm
I think this topic was discussed threadbare somewhere else.

Anyway trying a different modem CAN improve/DEGRADE
SNR/ATTN also .
I found AIRTEL connection better,.I.R.O snr/attn.
even though BSNL Exchange is very near .(usual oxidisation/rusting/blackening of contacts due to proximity to sea .
FLASH
Advance congratulations for being No 1 in the contest

Hi!everyone ......
i ws just wondering are the values for SNR and attenuation of my modem good ...... ?? ....... actually i'm having a ZTE ZXDSL 831 AII modem ........... but there is visible two attenuation and SNR values under it ................... the values are listed below .............
Local SNRMargin 32.5 dB
Local Line Attn 12.5 dB
&
Remote Line Attn 6.0 dB
Remote SNRMargin 25.5 dB

so which one among these above listed to check for .............. b'coz i'm still suffering from DC at random intervals ............. and for additional info i'm listing my downstream line rate and upstream line rate : -
Downstream Line Rate 7997 kbps
Upstream Line Rate 510 kbps

U need to worry about the Local SNR and Attenuation only. What is your current ADSL modulation ?