Promoting Efficient Infrastructure Competition through Vectoring and Enlarged DSL Bandwidth

The most effective way to promote Next Generation Access coverage and ultra-broadband penetration is through infrastructure competition. In Countries having well-developed cable networks this market condition preexists. Where CaTV is limited or null, one way to surrogate its powerful procompetitive effect is through the VDSL2/FttC architecture stimulating competition among operators. This has been the approach finally selected in Italy to promote the 30 Mbit/s Digital Agenda for Europe objective for year 2020 (DAE-2020). However, some technical intricacies make hard using “vectoring” while the NRA imposes a regulatory remedy known as SLU (Sub Loop Unbundling). In particular, as we verified with extensive computer calculations on the Italian copper network, in a Multi-cabinet architecture the current VDSL2 17a standard profile having 17.6 MHz bandwidth is unable to provide the 100 Mbit/s DAE-2020 policy target. This paper introduces one possible solution to the problem of providing more than 100 Mbit/s coverage to a large population extent (e.g., 70%), useful for a Country, such as Italy, characterized by a set of severe constraints – i.e., geographic, demographic and urbanistic constraints. In the paper, we describe SBV (Sub-band Vectoring) solutions to boost the data-rate under multi-operator conditions, while the NRA encourages infrastructure competition. The SBV solution allow sharing bandwidth, typically between two or more operators independently implementing vectoring. SBV allows the simultaneous use of UBB data transmission of co-sited operators not coordinated nor synchronized with each other. The paper shows results of coverage with SBV in the presence of two and three operators at the same street cabinet using Italy as a case study. —————————————— Work sponsored by KRUPTER SrL, Rome, Italy.