Mitsubishi

FTTH Optical Networks

GE-PON system

Requirement for very high bit rate

[ FTTx networks ]

[ Mitsubishi Electric GE-PON system ]

Where does the need for very high bit rate come from?

Increasing demand of subscribers for very high bit rate

Penetration rate of high bit rate is increasing rapidly in France (34% of home). ADSLis the main technoilogy enabling high bit rate access. Cable operators are also an alternativebut they can only address customers that live in the centre of big cities

At the beginning, high bit rate was mainly used to navigate quicker on Internet. After some time, new services appeared such as videoconference, electronic surveillance, networks interconnection, teleworking, TV programs distribution (6 Mbit/s for digital TV, up to 25 Mbit/s for HDTV). Subscriber is now willing to use all these services from his home or his office.

Download time is also a decisive factor for the migration to the very high bit rate. Indeed, the files and applications the user needs to download, are becoming larger and larger.Without adequate bandwidth, download time is not acceptable. The following figure represents download time for different kind of files/applications, according to the bandwidth offered to the customer

Furthermore, with Internet penetration at home, heavy expanditure of digital pictures, digital video and audivisual software, custmers are now generating contents themselves. In order to share these contents, the user needs to upload large files on some servers accessible from his friends and family. Very high bit rate requirements are thus becoming symmetric (upload and download)

With triple-play (voice, video, Internet access) and HDTV, bit rates offered by ADSL are not enough anymore, hence a migration towards the Very High Bit Rate. With copper wires, it is not possible to reach VERY high bit rates unless using VDSL et be located very close (less than 300 m) from the DSLAM. Optical fibre thus appears as the ideal media to provide very high bit rate