MMDS Box

TCP/IP

Hi there,

I have recently moved to Newbridge and they have Chorus through MMDS, can somebody tell me how it works, what the set top box looks like and what chanells are on it.

Many thanks
TCP/IP

zilog_jones

They'll need to put an aerial on your roof, and connect that to an STB. Dunno what STBs they're using now but they used to supply Sagem ones - pretty small, 2 SCARTs, etc. I think there's about 50 channels - the usual crap (don't know exactly).

AFAIK they need one aerial per TV (that's what they seem to do in Limerick anyway), which is a bit gammy.

5h4mr0(k

zilog_jones wrote:

AFAIK they need one aerial per TV (that's what they seem to do in Limerick anyway), which is a bit gammy.

Just 1 aerial per house. They can put in a splitter which allows the DC up on one side of it. Each extra digital box is €8 a month (I think...could very well be wrong on that price). No charge at the moment for an extra analogue box.

zilog_jones

Really? Maybe Chorus in Limerick are just dumbasses or something - I know several people who had to get several aerials on their roof for multiple rooms - the rooftops of some MMDS areas are complete messes thanks to this.

5h4mr0(k

It was Chorus in Limerick that did mine....

TCP/IP

Is the box that you get the same as a cabled NTL box or becasue it is MMDS a different box

Aquos76

It is the very same box for both(NTL cable & MMDS), its just the default frequency that differs.

watty

zilog_jones wrote:

They'll need to put an aerial on your roof, and connect that to an STB. Dunno what STBs they're using now but they used to supply Sagem ones - pretty small, 2 SCARTs, etc. I think there's about 50 channels - the usual crap (don't know exactly).

AFAIK they need one aerial per TV (that's what they seem to do in Limerick anyway), which is a bit gammy.

Still sagem till the analog MMDS is scrapped and they change to same as NTL MMDS.

maxg

watty wrote:

Still sagem till the analog MMDS is scrapped and they change to same as NTL MMDS.

Why should they change ex chorus mmds?
A move would cost several millions for nothing.

watty

Because running two different systems is expensive and Sagem DVB-T boxes are about twice the price of DVB-c boxes (Thomson or Pace).

DVB-T is good for VHF/UHF or mobile. Tiny advantage at MMDS 2.5GHz fixed links.

Also UPC need to double the headend gear at each MMDS site to have the 120 digital only instead of current 60+ digital & 11 analogue. So no doubt they will upgrade MMDS one site at a time.

It isn't a cheap bit of work!

zilog_jones

So Chorus use DVB-T for MMDS and NTL use DVB-C? Confusing...

maxg

watty wrote:

Because running two different systems is expensive and Sagem DVB-T boxes are about twice the price of DVB-c boxes (Thomson or Pace).

DVB-T is good for VHF/UHF or mobile. Tiny advantage at MMDS 2.5GHz fixed links.

Also UPC need to double the headend gear at each MMDS site to have the 120 digital only instead of current 60+ digital & 11 analogue. So no doubt they will upgrade MMDS one site at a time.

It isn't a cheap bit of work!

With other words only speculation.
I don't think UPC is willing to waste money with such a move.
Replacing the analgoue channels with a digital signal in DVB-T modulation is easy.
I don't think the cofdm modulator from ex chorus is limited to a 16mhz frequency spacing.

steveon

MMDS reception for chorus via Wire Mesh requires a level of approx 70 to 72db for a stable digital picture. U can run a number of boxes off one Mesh Depending on the Signal received on the roof. For two boxes a signal of about 75-76db is required as A Splitter will be used which will drop the signal by approx 4db out of each lug.

For 3 boxes to run off one mesh a signal of about 77-78 db or higher is required. A 3 way splitter loses 4bd from the first lug, and approx 7db from the 2nd and 3rd lug.

However another advantage of using a 2nd aerial is that the second box is not ran as a slave, which means if the downconvertor on the first aerial packs in u will still have a working system until A service technician comes round...

Regards,
Steve

watty

maxg wrote:

With other words only speculation.
I don't think UPC is willing to waste money with such a move.
Replacing the analgoue channels with a digital signal in DVB-T modulation is easy.
I don't think the cofdm modulator from ex chorus is limited to a 16mhz frequency spacing.

It's not speculation.
DVB-c will work with some older MMDS P.A.
DVB-t needs a highly linear amplifier, DVB-c needs better linearity than Analogue, but not as much as DVB-t

Upgrade of analogue MMDS to either system is expensive and often needs new backhaul too. NTL fully upgraded their MMDS, Chorus didn't, even though that might have been a breach of licence (Speculation).

In both systems there is no built in "spacing" in the modulator. The modulator is programable on frequency and bandwidth (number of possible channels at a given bitrate), though commonly only 6MHz (USA) or 8MHz (Europe) channels are supported.

nilhg

I'm in west Kildare and Chorus are currently replacing the analogue (Jerrold) with Sagem digital boxes, the installer who did mine told me that the plan is to have all the switchover complete by mid April.

steveon

All Analog MMDS boxes are being replaced at present in Limerick as the analog signal is due to be shut down in the coming months.:mad:

maxg

watty wrote:

It's not speculation.
DVB-c will work with some older MMDS P.A.
DVB-t needs a highly linear amplifier, DVB-c needs better linearity than Analogue, but not as much as DVB-t

Upgrade of analogue MMDS to either system is expensive and often needs new backhaul too. NTL fully upgraded their MMDS, Chorus didn't, even though that might have been a breach of licence (Speculation).

In both systems there is no built in "spacing" in the modulator. The modulator is programable on frequency and bandwidth (number of possible channels at a given bitrate), though commonly only 6MHz (USA) or 8MHz (Europe) channels are supported.

Only the half side of a ex chorus mmds transmitter should be able to transmit dvb-t. That makes not much sense.
Btw. you should know the frequency space currently in use for chorus digital mmds. The gaps are filled with analogue mmds.

Solair

I seriously doubt that they'll be in any major rush to change tens of thousands of boxes. Is it possible it could be moved over to DVB-C with a firmware upgrade?

Are Chorus cable networks also using DVB-T signalling over the cable system? The Sagem boxes look identical in Cork to the MMDS ones.

Bare in mind the Chorus version of the sagem boxes are a custom job specifically for chorus. They don't necessarily have the same specs at the ones on Sagem's website even though they may be very similar to the commercial DVB-T boxes.

What is the maximum channel capacity of either system?
DVB-T vs DVB-C
Given the bandwidth constraints of MMDS i.e. you don't have the full range of cable bandwidth.

steveon

Digital MMDS boxes used in Limerick Clare area etc are used on the cable system in places such as Clonmel and Thurles to name but a few.

maxg

Its not possible to change the tuner via a software update.
Sagem boxes with ITD in the name got DVB-T tuners and sagem boxes with ICD in the name got cable tuners.
In some areas the subscribers get a mmds signal via a central mmds antenna and thats the source for some misunderstandings.
There is not much difference between DVB-T and DVB-MC in the maximum bandwidth.
DVB-MC is the name for a cable signal being broadcast in a frequency range other than 40 to 860 mhz.