Saturday, May 23, 2015

The Wings of Mercury

Hermes Over Grand Central Station, New York, NY (Source:

The general rule of law is, that the noblest of human productions — knowledge, truths ascertained, conceptions and ideas — become, after voluntary communication to others, free as the air to common use. - Louis Brandeis

The Messenger is a mythological figure that was known by many names in ancient times. His attributes, interestingly, cross far flung barriers of language, culture and tradition. Among the Hindu he was known as Saumya. The Greeks called him Hermes, while the Romans knew him as Mercury. In all three and many others besides, he was not just a messenger between the divine and mortal realms, but also the God of Merchants, Commerce and Trade. 

As merchants of those days sourced and moved their goods between city and countryside, sometimes over sea lanes and by even caravan trails, such ancillary activities became associated with their particular deity of commerce as well, so that he became a God of Travel and Trade Routes, a Trickster and Bringer of Luck. And, as a widely revered god, a broad selection of virtues and virtuous pursuits of particular significance to merchants were attributed to him as well - intellect, eloquence, literature, poetry, oratory and wit. 

Representations of Hermes and Mercury in stone or canvas often included adornments such as winged sandals or a winged helmet. The symbolism of this deity is so captivating that even in the modern era Mercury represented an altogether unique sort of traveler - seven men who pioneered the exploration of the final frontier. They saw Mercury as not just a messenger, but a harbinger of things to come.

All of these representations of the Messenger have one particular factor in common. Selling goods in markets, exporting or importing wares over trade routes, travelling to buy or sell things, employing the art of negotiation and the art of the spoken and written word are all grease for the wheels of commerce and are centered on Communication

The lynchpin of everything in High Tech also falls under Mercury's domain - moving, interpreting and understanding information. By studying how wired and wireless communication are evolving in our industry, we can gain a deeper understanding of High Tech in terms of its general health and prevailing technological directions. It is this topic - Communication - which will be the subject of today's editorial (and likely one or two future ones.)


Observe constantly that all things take place by change, and accustom thyself to consider that the nature of the Universe loves nothing so much as to change the things which are, and to make new things like them. - Marcus Aurelius

The DOCSIS standard is employed by STB makers to permit internet access over cable television networks, which transmit digital information using optical fiber to reach neighborhood nodes and then fan out to customers on coaxial cable (where the data is converted into an RF format.) The latest revision (3.1) is not really all that new, having been released at the end of 2013. Nevertheless, deployment has been gradual and heavyweights like Cisco and Comcast are only starting to get into the game:

It is a backwards-compatible standard to minimize disruption and cost impact to the installed plant and user base. Once fully deployed, 10Gbps downstream and 1Gbps upstream service will be commonplace. 

Some of you might be wondering why this development is of any particular note beyond being an evolution on an existing standard. In and of itself, such gradual enhancements are not all that compelling - until, that is, they reach a tipping point that opens up a whole new landscape of application possibilities. 15 years ago one of the major issues of the day was the 'last mile' - how to get streaming video services to the home. Engineers found one way to do it - make the existing pipes bigger. Improvements to date have already resulted in a radical alteration in how we receive and view content (as anyone who used to work at Blockbuster will tell you.) What further bandwidth improvements offer is setting the stage for a major incursion of the IoT into the home, as the supplementary data burden and accessibility appears poised to come on line as demand for it presents itself.


The condition of all progress is experience. We go wrong a thousand times before we find the right path. We struggle, and grope, and hurt ourselves until we learn the use of things, and this is true of things spiritual as well as of material things. - Felix Adler

Of course, cable TV networks are not the only wired communication medium that are widely deployed today. The truth is that most customers - whether consumer or enterprise - access the internet thru telephone lines offering DSL services. 

The same impetus that drove the definition of the DOCSIS 3.1 standard - namely, to bring improved performance directly to customers over an existing network infrastructure - is present in the enhancement efforts underway with DSL service providers. A very new standard being developed is "G.Fast." Standards were approved in 2014, with deployments targeted for roughly one year from now.

The question is - what does G.Fast bring to the table? The goal is to provide higher bandwidth to subscribers for ADSL or VDSL services, with 1Gb data rates available for terminals within, say, 100 meters, degrading to perhaps 150MHz out to 500 meters. Considering we're talking about a twisted pair transmission medium, this performance is unquestionably attractive.

The applications are immediately evident. For relatively modest range DSL connections to the home, G.Fast offers quite a performance boost. There may be greater performance advantages in moderate size office settings.

There are problems impeding widespread deployment, however. Transmission frequencies overlap with both commercial and government bands. There are further difficulties presenting themselves in terms of ambient noise conditions and crosstalk. Fixing those bugs is creating cost and power complications. 

The installed user base for DSL is enormous, so there is plenty of incentive for service providers to overcome these technical difficulties. Nonetheless, this multiplicity of interdependent problems suggests that connectivity over phone lines may finally be reaching its absolute performance limits.



The best way to predict the future is to invent it. - Alan Kay

The first two standards described in this editorial were improvements on an existing infrastructure. There are, however, some who believe that these sorts of engineering efforts will, in the end, prove pointless. They are betting that the future is one of directly implementing FTTH (Fiber To The Home) - and their vision is to be at the forefront of what they see as an inevitability.

PONs (Passive Optical Networks) have been with us already for quite a while. Cable operators are already familiar with it, as PON support is part of existing DOCSIS specifications for business customers.

The idea of an all-optical network that eliminates electrical-optical conversions has been with us for quite some time. There are, in fact, so many technical and cost advantages in the long term that an optically wired world from the Core to the Home is likely inescapable:

Notwithstanding this, the cost of doing such a thing is still enough to be daunting to the ISP sector. The issue is not simply one of making the capital allocations to extend fiber to homes and businesses. There is a built-in cost savings from doing so, as neighborhood distribution boxes are no longer needed, saving expenses on the equipment and its maintenance (which is a particular problem due to its outdoor deployment.) But an ISP's problems actually begin to proliferate from that.

The central distribution node, no longer relying on a neighborhood box, has to feed data across individual fiber optic lines to each customer terminal. Splitting the optical signals and supporting their transmission requires a major overhaul of equipment in the central node.

Furthermore, customers on the receiving end will be receiving a data stream for ALL of the users at those premises. Any buffering or filtering will have to occur at the reception point for each user and their terminal, posing both equipment and security issues. To add salt to the wound, multiple users relying on the same fiber to their premises may send traffic that is at risk of colliding. A multiplexing system (either time or frequency/wavelength based) will have to be imposed to ameliorate such problems and there is currently no widely agreed upon standard for that. 

One can see from this that the entire infrastructure is affected by transitioning to a pure fiber network, with enough cost and trouble associated with it to make such a switch still too daunting to initiate voluntarily. A fully fiber wired internet is thus likely some years off.
Next week, we'll switch gears and mostly leave the wired world behind us and explore the latest and greatest in the Wireless domain, where Mercury's winged sandals can REALLY show their stuff. ;-)
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