Two Motorola divisions got some interesting insights into Japan's broadband access plans this fall, and it might have a lot to tell us about the future of xDSL, passive optical networks and the multiprotocol label-switching standard. And for the Japanese consumer, Nippon Telephone and Telegraph may finally have discovered a way to bring its national fiber network to end users, thereby relieving that notorious last-mile bottleneck.

At the MPLScon show in Washington at the end of October, the NetPlane Systems product unit within Motorola Computer Group unveiled its work with NTT Network Services Systems Labs on a new multicast version of MPLS. M-MPLS already has gained official status within the Internet Engineering Task Force, and the demonstrations Motorola and NTT gave in Washington sparked a lot of interest in using M-MPLS for distributed consumer applications.

Seisho Yasukawa, senior research engineer for the M-MPLS program at NTT, said the impetus came from the need to find low-cost ways of scaling streaming video to millions of residential users. Unicast protocols for traditional MPLS could not scale to such massive networks, so NTT and Motorola revolutionized MPLS routing by designing Tree Explicit Route Objects to define arbitrary forwarding trees in the last mile.

Meanwhile, a primary driver for the broadband passive optical network (PON) chip set work in Motorola's Semiconductor Products Sector (see story, page 50) had been NTT's interest in using ATM PON as a last-mile fan-out service from an optical network unit, the neighborhood terminal used in fiber-to-the-curb or fiber-to-the-building architectures. Niket Jindal of Motorola's semicustom-products group said that "multicasting services" were a primary reason Japanese carriers are considering this technology in the last mile.

NTT's decision to combine PON and MPLS in the last mile suggests that a worldwide shift may be taking place concerning full-service access network architectures. Digital subscriber line copper networks that take advantage of optical fiber-to-the-curb topologies, including VDSL and ADSL-2+, may still have the upper hand when copper is in the ground. But PON interest is accelerating, and the NTT experience may be an example that many last-mile architectures will emulate.

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