DSL Advances

11.4. Vectoring

Coordination within a common DSLAM or modem unit allows co-generation (or co-reception) of multiple (preferably all) lines at the DSLAM. Such situations occur naturally as DSL evolves to remote/line terminals fed by fiber. In such DSLAMs at remote terminals, it is possible and feasible to coordinate signals because all or most of the lines are terminated on common equipment. In downstream transmission, joint generation of a vector of transmit signals over a common packet period is feasible (and possibly more cost-efficient than individual generation). This is the downstream broadcast vectored system of Figure 11.32. Vectored multiple access for upstream signals occurs at the receiver as in Figure 11.33.

Figure 11.32. Vector broadcast ...