From 50Mbps to 50Gbps: A 30-year journey of point-to-multipoint Fiber Access.

My colleague and old friend Byron Vlaskamp from RSA found an old picture from May 1997 and took the time to digitalize and send it to me.

It was taken in the Sun City resort in RSA during a weekend break while we were integrating the first Alcatel TDM PON fiber access system, the Alcatel 1570NB, with Telkom South Africa’s Alcatel E-10 Telephone switches.

In 2024, Nokia enabled operators across the Globe to trial 50G PON over their networks, and this picture reminded me that 30 years ago, in 1994, we were also enabling customers across the Globe to trial the first FTTH/FTTC/FTTB TDM PON system ever built: the Acatel 1570NB. This was an Access Node with two optical interfaces (LT cards) each enabling the transmission over fiber of any mix of data services (at that time TDM leased lines or ISDN) and voice services (POTS or PABX) to 32 ONUs located between 0 and 20 km from the OLT, each of them supporting up to 32 subscribers. In 1994 I was leading the Optical Interfaces team that designed the first point to multipoint commercial transmitters and receivers, as well as ASICS for clock and amplitude recovery in TDMA receivers and to accommodate the resulting data streams over the PDH DS1/E1 interfaces to data and telephone core nodes. Our commercial product exceeded the performance of AT&T Bell Labs experiments and those of our only competitor: a shortly-after disappeared Israeli company, which name I cannot remember. The line rate was 51.84Mbps, a seemingly arbitrary number, but those of my generation would recognize the SONET OC-1 bit rate, for which one could find compatible chips, xtal oscillators, lasers and receiver preamplifiers.

When the photo was taken in 1997, I had become the Alcatel FITL R&D Leader, and my main responsibility, the 1570NB, had incorporated in the release 2.0 single fiber bi-directional transmission, DBA, support to 64 ONUs per PON, and new ONU models supporting 1, 16, or 64 subscribers.

The product was discontinued at the transition of the century, when the success of ADSL (where Alcatel also pioneered) removed the need to replace copper by fiber in the subscriber loop. But the inventions of that group of engineers, indeed status-quo misfits doing crazy things, can be easily recognized in later BPON, GPON and subsequent standards up to 50G PON HSP.

This note is in memory of so many brilliant brains that randomly fell together in Madrid, Spain in the 90’s decade. I am talking about the leadership and direction of Emilio and Pedro, the creativity of Damian, Charles and David, the ASIC design mastership of Pedro-Jesus, Pepe and a few others, the planning and execution ability of team leads Miguel, Jorge, Manuel, Pedro, those who sacrificed so many days to be abroad far from family and friends supporting worldwide integrations and trials like Luis, Miguel Angel, Angel, Justino and a many others, the German connection Bernd, Gert, Marcello and Thomas, product managers Alberto and Javier who gave everything to put us in the Telcos' map, and most heartfully the optical interfaces team, Juan Carlos, Moises, Pedro-Jesus, Raquel, Esteban and assistants Conchi and Herminia. So many others were involved in that exciting spirit of tireless innovation and entrepreneurship that would fill pages, please, forgive me for not mentioning all of you.

Since then, Alcatel merged with Lucent, including former knowledge-competitor Bell Labs. After touching almost all areas of the business, I left the company to move to the USA, and in 2017 I joined a Nokia that had absorbed Alcatel-Lucent, where I resumed Fiber Access activities, now enabling the first 50G PON trials. Nokia wisely inherited the global leadership in Fiber Access PON technology.

In the picture, left to right signaling SW senior specialist Miguel Angel Cano (Macano), RSA Delivery Leader Byron Vlaskamp and I. Good old times! Thanks Byron!

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Acronyms:

ASIC: Application Specific Integrated Circuit

BPON: Broadband Passive Optical Network, ITU G.983

DBA: Dynamic Bandwidth Allocation

ISDN: Integrated Services Digital Network, ITU Q.921, ETSI 300 325

FITL: Fiber In The [subscriber] Loop

FTTB: Fiber To The Building

FTTC: Fiber To The Curbe/Cabinet

FTTH: Fiber To The Home

GPON: Gibabit-capable Passive optical Networks, ITU G.984

HSP: Higher Speed PON or 50G-capable PON, G.9804

OLT: Optical Line Termination

ONU: Optical Network Unit

PABX: Private Automatic Branch Exchange (a business telephone switch)

PDH: Plexiochronous Digital Hierarchy: DS1 (ANSI) and E1 (ETSI) correspond to the 2Mbps hierarchical level.

ON: Passive Optical Network

POTS: Plain. Old Telephone Service

RSA: Republic of South Africa

TDM: Time Division Multiplexing (a point to pint multichannel grouping technology)

TDMA: Time Division Multiple Access (a multipoint to single point multichannel grouping technology)

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