new to docsis |

You are here

new to docsis

6 posts / 0 new
Last post
Anonymous (not verified)
new to docsis
Microsoft Office document icon diagram.doc28 KB

i have recently done Master in Computer Science. One of my friend has cable tv network in pakistan. Please see the attachments. which has the existing network diagram. we have 7 sub offices. now we want provide internet facility to our customers. the amount of customers is round about 10000. initially we want to start with some hundreds of users. and then we will go on as the users incerases. i am reading about HFC networks for 1 month. i want to know how we can start this project. what will be feasible for us by cost and performance. what kind of cmts we should use. please anyone can help me out with detail diagrams. please.


Arshid Milad

Allot to plan

Just to confirm, you estimate 10k users? how is the rf configured in the head end (downstream and upstream)?
What is the signal to noise at the customer's home and at the head end from the customer's home? what do you plan to offer for services, speed to and from the internet?
there are 4 flavors for docsis. docsis 1.0, 1.1, 2.0 and 3.0. 1.0 is the first, basic and best effort. 1.1 you can guarantee rates or speeds. both support 256qam and 64qam downstream. qpsk and 16qam upstream. 6Mhz wide downstream and 800Khz to 3.2Mhz wide upstream. on average, 3.2Mhz wide running 16Qam upstream will give you around 7 or 8 Mbps shared bandwidth. that's for all the customers on the receiver port of the cmts. docsis 2.0 the return can go up to 6.4Mhz wide and adds atdma and scdma modulation on the return. docsis 3.0 is the new version where you can bond downstream and upstream channels to increase speed. Cable providers in Asia and Canada for example offer 100 and 160 Mbps speeds with docsis version 3.0
What does the current downstream and upstream support ( the ampr and nodes in the field, downstream goes to 550Mhz or 750Mhz? upstream is 5 to 30Mhz or 42?) Euro downstream is an 8Mhz carrier downstream and upstream goes to 65Mhz. so there's allot more question for you before the group can say what's best for what you want to do


can i confirm something too

can i confirm something too ?

Does your HFC have return path already ? i think the Pakistan is euro channel plan
you should use Euro-DOCSIS , but some area , they use the DOCSIS , even they use eruo channel plan....

i am very happy to talk about this , my e-mail

arshadmilad (not verified)
No. if you look at diagram

No. if you look at diagram of our existing network we just have transmitters of prevail company. we don't have return path.. and we want to build the network from scratch.

thanks for reply i am adding you in my mailing list in yahoo.


Arshid milad

Start from scratch

I know there was allot of questions and your starting from scratch, but you can email me and take this offline.

yes , i had look the diagram

yes , i had look the diagram , but i don't have see return path , so i asked this question .
then i think you need upgrade your HFC 1st .
maybe you need change node , and amp.
maybe you need calculate the downstream , upstream for your design.
and also you need add some revicer in your headend.

but i think you can chose 1 node to do this job frist. it's will more easy and sample .
about the CMTS , you have 2 those.
1. buy layer-2 cmts , it is cheap , but not goot for future (some layer-2 cmts only DOCSIS 1.0 plus....)
2. buy layer-3 cmts , like casa , cisco , arris . some vender maybe is the best , but price is one the top too....and in the future , you still need to do some monitor system by your self , they also have some different like function and price. but the price is the most important for you now ....
just make some money , then you can buy more

so the step is
1. upgrade twoway HFC
2. build the cmts .
3. buy the bandwidth from isp.( also you can save the cost in the future.)
4. build a monitor system for cable modem quality .
5. make the the money form your subscriber ....

also you can find some company , they have total solution , and they have HFC know how.
sometimes you buy the CMTS , but they don't know HFC so they can't support you in the HFC.
sometimes you buy the HFC production , but they don't know about CMTS....

maybe you will spent a lot of money in this.

Log in or register to post comments