Vectoring in DSL Systems: Practices and Challenges

Crosstalk cancellation, also known as vectoring, is a promising technique that significantly increases the capacity of digital subscriber line access networks. In this paper, the potential of vectoring to boost the capacity in a realistic copper access network is demonstrated. Deployment of vectoring becomes challenging when not all crosstalk can be eliminated due to the presence of uncontrolled lines or due to limited cancellation resources. Lines can be outside of the vectoring group because of technological constraints or regulation. As a result, the performance of vectoring degrades as compared to full cancellation. Based on representative simulations and lab measurements, different deployment guidelines are proposed along with a discussion on their practicality.