VM Architecture Questions?

[collangm]

Would anyone on this forum be able to answer or direct me to alternative webpages in relation to the questions about the Virgin Media network below?

1. What is the (useable) RF Frequency range (from the RF spectrum) used for the tranmission of upstream & downstream EuroDOCSIS 3.0 (Data) content (Note: Not the stated edge-to-edge range of 5-862MHz)?

2. How does VM provide telephone services to cable customers - i.e how is the siamese cable fed to the customer physically distributed once it arrives at the local distibution point/street cabinet? Do they route these back to BT exchanges or use softswitches in the cabinets back to the VM Headend and then out to the PSTN via a gateway?

3. What Fibre modulation methods are employed on the VM fibre cables - WDM, DWDM or CWDM, and how many separate frequencies (of light) are typically sent down each fibre to the optical node?

Note: I'm writing a thesis on modern HFC/CATV systems and Virgin are the prime candidate for reference to U.K distributed systems. I have already queries 'Media Boy' on the above but was unfortuantely unable to asnwer any of these questions.


Thanks in advance,

COLLANGM.

[RobboEdin]

Given that you are writing a thesis, I would suggest that you do not base it on hearsay from the internet.

Perhaps a direct approach to Virgin Media would be more fruitful and give you more accurate and corroborated information on which to base a thesis.

collagm, as as Robbo states above, you would be better off contacting VM direct - may I suggest your first port of call to be the Press Office, who may be able to point you in the right direction for technical information of this sort.

This would also enable you to provide source references, if you are using Harvard Referencing.....

[Buffalo2102]

I can't really help with 2, but the answer to 1 and 3 is "it depends". Unfortunately, the architecture varies from region to region due to the different networks that have been acquired over the years so there is no simple answer to either question.

[weesteev]

1 - Varies by region, the 3 distinct franchise areas use different frequencies.
2 - Siames from customers property > DP > Secondary Mux (trasnfer from copper to Fibre) > Major Mux > Headend. This can still vary from region to region and is again dependant on the legacy architecture.
3 - Varies, especially if business services are fed from the same Fibre node as residential (which is the case on pretty much every fibre node in the field). As for modulation, this can vary depending on capacity requirements in any given area as far as im aware.

You wont get a clean cut answer on this, and if your writing a thesis and basing it on VM's network then you could write 100k words and still not be done! The network is massive with many different technologies being delivered.

Hope this helps