exchange or remote concentrator site. In the UK this would require 100 of
these core edge nodes with long-reach spans of 100 km and bit rates of at
least 10 Gbps.
CWDMA/OCDMA PONs: Coarse WDM (CWDM) allows low-cost WDM to
be deployed (as device cooling is not required); CWDM uses channel
spacing of 20 nm, so only eight or so channels can normally be
deployed. OCDMA (see below) has been demonstrated [25, 26] as a
robust complementary technology that could als o be deployed in
conjunction with CWDM to increase the number of users. As with
WDM, OCDMA offers the possibility of translation from one channel
to another (code translation), opening many interesting possibilities.
Transmission speed
Current networks employ amplified DWDM systems with individual ...