The Zipper prototype: a complete and flexible VDSL multicarrier solution

This article presents the prototype developed to prove the Zipper concept and contribute to VDSL standardization. This solution includes the hardware and software needed to demonstrate that the VDSL multicarrier is a feasible, flexible, high-performance, competitive solution. The prototype provides the network management and telemetry software needed to simplify system setup and performance evaluation, respectively. It includes two interfaces: one to plug a twisted pair cable or a cable simulator, and the other to connect the ATM transport protocol. A 155 Mb/s (OC-3 rate) ATM-SDH/SONET interface is provided too. The first measurements performed between two VDSL modems, with injected noise of 20 VDSL equivalent lines, show that it is possible to transmit (in downstream and upstream directions) payload bit rates up to 48 Mb/s at 300 m and up to 25 Mb/s at 1500 m using 0.5 mm copper cables. The prototype has been designed using a modular and flexible architecture able to allow future VDSL modem extensions. The reuse of this prototype is expected for other applications where OFDM technology applies.