[elektro-etc] Ez álom vagy valóság =3F?=

[Leto Tokarev]

Ja hogy 30MHz alatt MEGY az internet, de nem ott JON :)




Leto


On Fri, 25 Aug 2006, hwsw famulus wrote:

> Leto Tokarev wrote:
> >> A NET joval  a TV/Radio alatt jon frekiben
> >> Talan az also ~10 Mhz-ben ...
> >> valami extrem modulacioval
> >
> > Ez biztos?
> 
> Nem biztos, de ilyesmi remlik...
> 
> Rakerestem lasd alabb.
> 
> Ahogy elnezem nagysebessegu cabelnet
> eseten mar belelog a NET a VHF savba
> es  az URH radioba is...
> Ezert lehet gond a szures a
> szokasos kabelTV kiosztas eseten...
> 
> KJ
> 
> > Leto
> 
> 
> Cable TV networks are one way broadcast networks, based on coax cable. We 
> distinguish between the download and the upload band-width. Today the 
> following frequencies can be used:
> 
>   a.. download: 47-450 MHz
>   b.. upload: 5-30 MHz
> In the future the  so called "Full Service Networks" will increase the 
> band-width:
>   a.. download: 47/80-862 MHz
>   b.. upload: 5-30/65 MHz
> The today existing cable TV networks usually do not dispose a backward 
> channel.  To use the cable TV networks as a door to Internet, this feature 
> has to be implemented first. Since the band-width of the backward channel is 
> limited and may not be big enough in a big network island, the cable TV 
> provider has to grow up the capacity of the backward channel from some 
> distribution centers to the main network via xDSL connections or other added 
> connections. In most cases, this connections do not exist yet and they have 
> to be built up first. These are the reasons, why this new service is coming 
> up step by step from region to region.
> With this cable modem technology we can reach speed up to 36MBit/s. The real 
> installed modems will allow us maximal download rates between 2 and 4MBit/s. 
> On the backward channel upload rates between 64kBit/s and 10MBit/s are 
> theoretically possible. In the practice these values are depending on the 
> used modems. At present most modems allow down streams up to 3MBit/s and up 
> streams between 100 and 800kBit/s. The "Home Works Universal" made by Zenith 
> as a special case can work with 4MBit/s in both directions (duplex).
> 
>