Cell Phone Reception: Quality Getting Worse

Alex Mindlin reports in the New York Times http://www.nytimes.com/2011/03/21/technology/21drill.html that J.D. Power and Associates has announced that  cell phone quality has hit a plateau after steady improvement from 2003 to 2009.  The article cites the trend of indoor usage as people replace or supplement landlines being responsible for this quality plateau.  Regardless of where the calls were made or over what handsets, the quality of calls have declined over the last 6 months.  The article does not differentiate between carriers, but indicate the worst city for reception is Washington with 18% problem calls, three times the rate for Pittsburgh or Cincinnati which have the best call quality.

Those of us who have worked in the indoor coverage niche for years have seen this coming.  Improvements in technology and additional spectrum have been overwhelmed both by subscriber growth and the bandwidth thirst of smart phone applications.  Wireless technology was keeping pace with demand until the introduction of the iPhone.  On the consumer behavior side of the equation, cell phones have evolved from the family road emergency tool to the personal communications device.  Consequently, if I want to reach the individual, I call the cell and most of the time that person and phone are indoors.  The only solution to the problem is frequency reuse by cell splitting and the new cells need to be inside office buildings, public venues and residential buildings.  The most efficient architecture for indoor cell service is the combination of a picocell and a distributed antenna system.  This allows for separating the geographical aggregation engineering from the traffic aggregation engineering within buildings.

Over the last 5 years, both the carriers and the OEMs have indulged in wishful thinking and have avoided directly confronting these trends in the serving architecture... they have continued to upgrade and build macro towers and have treated indoor as an afterthought at best or something that might go away somehow (700 MHz may fix it, smart antennas may fix it, better coding may fix it, etc.)

There has been a move by AT&T in the last year to recognize the importance of indoor, particularly for large venues, however, there is not consensus in the industry.  One could expect a bad quality report to motivate carriers, however, with the continued consolidation of the carriers, quality as a competitive differentiator may become less important http://dealbook.nytimes.com/2011/03/20/att-to-buy-t-mobile-usa-for-39-billion/.

What’s your view... has the time come for indoor wireless coverage and capacity to take center stage and have well architected solutions?  Or will wishful thinking and market power continue to delay a solution to this problem?

Technology Trends: Transmission Systems

I attended OFC-NFOEC a couple of weeks ago and listened to a panel talk on the issue of “what next beyond 100 Gbps systems.”  This is a familiar issue from the early 1990s when I was involved in transmission planning for Ameritech.  It was also a critical issue in the late 1990s when I helped plan transmission system products for Alcatel.  In the 1980s and 1990s, there were two parallel universes: Transmission systems and data ports, both evolving aggressively as silicon and optical technology improved.  The transmission rule of thumb was 4x while the data port rule was 10x... that is, the next generation of transmission systems technology needed to be 4x in speed (and usually only about 2x in price) to justify transition of whole networks to the new technology.  OC3 systems were replaced by OC12 systems which were replaced by OC48 (2.4 Gbps) systems which were replaced by 10 Gbps systems.  Meanwhile 10 Mbps Ethernet ports were replaced by 100 Mbps ports were replaced by 1 Gbps ports were replaced by 10 Gbps ports.  Why 4x and why 10x?  Coming from carrier transmission planning, I knew that the 4x rule had its basis in transmission deployment business cases, comparing the cost of upgrade to the higher speed (Up) vs. building additional systems at the same speed (Out.)  Up vs. Out business cases had different results for short haul compared to long haul deployment.  The 4x rule was for long haul, but ushered in improved economics for short haul systems whenever long haul upgrade hit volume deployment.

The data port 10x rule had its own Up vs. Out business cases, however, the ports were much more rapidly commoditized and depreciated than transmission systems and the cost of cabling in the business cases were negligible compared to the cost of laying new fiber routes.  I also think the 10x rule was a kind of self fulfilling prophecy... once people got on the 10x band wagon, it was hard to get off.

Back to OFC-NFOEC: the curious thing about this panel was the absence of any discussion of these underlying business cases, rather, the subjective impressions of customers and technologists were explored and people seemed to be equally divided between continuing the 4x rule (carrier planners and their fellow travelers) and continuing the 10x rule (data networking folks and their allies.)

There is, however, an additional factor that may be more important than either traditional Up vs. Out business cases or subjective impressions of the people with the purchase power... fundamental limitations of optical technology.  Transmission systems are beginning to reach fundamental limitations of glass media and optical coding.  Beyond 100 Gbps, we reach the Shannon limit for single channels and the power limit for glass fiber (before the lasers melt the core of the fiber.)  It may not be possible to achieve either 4x or 10x capacity increases in the future, but rather the more modest 20 to 40% improvements of a mature technology.  The future may well be multi-fiber or require new higher power wave guide technology.

What are your impressions of the future of optical transmission systems?  Are you a 4x or 10x technologist?  How does that color your perspective on the march of optical systems?

Modular Design: Product Architecture Value-add

One of the disciplines I learned as a network architect was to explore alternative functional architectures... that is, to be deliberate in the choice of where a function is performed in the network.  For example, restoration on failure of a fiber optic link is a function that can be performed centrally (manual restoration coordination, or automated restoration using an operational support system) or in a distributed manner (rerouting in switching or routing vehicles or more rapid restoration using 1-1, ring or mesh transport systems.) Each approach has its strengths and weaknesses, some work well together and many do not.

In product design, electronic systems architects generally do a good job of thinking through the functional architecture because there is a tradition of modular design in both hardware (backplanes, boards/blades, daughter boards, etc.) and software (operating system, services, applications, stacks, frameworks, etc.)  However, in the design of mechanical systems, the modular approach is less traditional and sometimes counter-intuitive.  The benefits of standardization of parts and subassemblies are clear from a procurement and manufacturing perspective, however, for simple products the additional planning, coordination and overhead of modularization may not be justified, particularly where the volumes of a new product are hard to predict.

Modular design for mechanical products requires a change of thought... the designer should be planning for success and expecting larger volumes, product evolution and related products.  That is, the designer should be planning a product family over time, not just one product to solve one problem for one customer.  That approach will identify components of the product that will be common over the product family, components that will evolve over time, components that will need to change to address different scales of applications and components that should be customizable to address different operating environments and operational procedures.  The result will be a product family with many variations, built from a smaller number of components.

The pioneers of this type of design for mechanical products have been Scandinavian engineering and manufacturing companies.  There are good economic and cultural reasons for this discipline developing in these countries... design traditions are strong, but also, these companies recognized early that to create a sustainable differentiation in a global market where the competition has much lower labor and material costs, they needed to create designs that used material more efficiently, could be shipped more cost effectively and addressed fundamental customer problems in unique ways.  I find a walk through an IKEA store is an education in modular mechanical design and global competition.

What are your perspectives on modular design, particularly for mechanical products?  Do you own any Scandinavian products?  If so, why?

3-D Printing: Is it ready for prime time?

Every few years, there is a rush of enthusiasm regarding 3-D printing technologies (see for example http://www.economist.com/node/18114221.) Each time this topic comes around, I have the same set of questions and wonder if this is the time it will experience explosive growth and substitution for conventional fabrication technologies.   My questions are usually around materials, precision/resolution and cost.  What range of materials are suitable to this type of 3-D printing technology (plastics, metals, composites, etc.)?  How precise is the “machining” and how reproducible are successive pieces?  How much does it cost per piece (setup, first piece, first 10, 100, 1000, 10000, etc.) and how does this cost compare to conventional fabrication technologies?  What are the technology trends for 3-D printing (cost, precision, materials) compared to the steady improvement in CAD/CAM?

Earlier 3-D printing technologies were dependent on the peculiar properties of particular classes of polymers or gels.  The object formed by the printing was the right shape, but usually the wrong material.  The subsequent step of creating a mold from the printed object and molding in the preferred material reduced the appeal of the 3-D printing process.

This most recent economist article, like many I’ve see over the years, is fully of vision and technology salesmanship, however, there are a couple of details that are more than just boosterism that may indicate that more widespread adoption will happen in a few years.  The first is a material... titanium.  Titanium has always been a problem material.  Light, strong, creep and crack resistant, with a high melting temperature, it has been a preferred material for supersonic airframes since the days of the SR-71 Blackbird.  However, it is difficult to machine (requiring an inert atmosphere and special tooling) and one fabrication technique for titanium has involved sintering...  placing titanium powder in ceramic molds at very high temperatures until the powders fuse at the edges into a solid material.  The quality of the piece is dependent on process trade secrets.  My understanding is that there is a lot of art in the fabrication of titanium.

EADS engineers in Bristol, have been using lasers and/or electron beams to print 20-30 micron layers of titanium power into fused structures and then add layer by layer to make titanium parts.  This sounds like a technology that could work for any powdered metal that you might want to fabricate.  Aerospace parts using titanium or titanium alloys could be the breakthrough application for the technology.

The second detail is an interview with Dr. Neil Hopkinson at Loughborough University that discusses an ink-jet technology his team has invented that prints an infra-red-absorbing ink on polymer powder and then uses infra-red heating to fuse the powder layer by layer.  This is sintering (at low temperatures) applied to polymers and should be useful for a variety of polymer compounds.  Dr. Hopkinson thinks their process is already competitive with injection-molding at production runs of around 1000 items and expects it to be competitive on 10,000 to 100,000 item runs in about 5 years.  This is the key economic comparison for adoption.

What do you think of 3-D printing?  Is the time now, soon or much later in your technological crystal ball?

Geoengineering: Technology of Last Resort?

As a resident of planet earth with children, I have been watching the long, painful public discussions relating to greenhouse gas emissions for decades with a mixture of hope and despair... hope that increasing scientific evidence would galvanize action to address the problem and despair that this is a problem too difficult for human beings to solve before an ecological disaster kills significant numbers.   I have written previously that in the 1980’s one of my colleagues from Harwell Labs had identified this as the most significant threat to human beings and that one solution was to introduce stratospheric aerosols to cool the earth and counteract the effects of additional greenhouse gas in the troposphere.  This concept, now called geoengineering, is getting more serious consideration in technical and policy communities (see for example, http://www.economist.com/node/18175423.)

My current thoughts on the subject:

1. Ecological impact of increased greenhouse gas emissions has already happened, however, most people can’t connect the human causes (fossil fuel burning) with the human effects (crop failures, starvation, population dislocations, war and genocide.)
2. Our current political and economic systems are too local and too short term to adequately address this problem... they have failed us and are not likely to change soon.  Furthermore, it is more cost effective for interested parties to inject noise into the public debate than to change the economic behavior that has created the problem.
3. Independent of whether action is taken or whatever action is taken to reduce emissions, there is enough CO2 in the atmosphere and enough inertia in the economy these consequences will continue for decades or generations.
4. Since we can’t cure the disease, we are then forced to treat the symptoms.
5. The only proposal that can be implemented quickly and cost effectively is a geoengineering solution that creates sufficient cloud cover in the stratosphere to reflect sunlight back into space to counterbalance the greenhouse effect in the troposphere.
6. This is an action that can be taken by a few technologically advanced countries that find it in their best interest to stabilize planetary climate to reduce the cost and risk of the human consequences of greenhouse gas emissions.
7. Although the politics of this solution are difficult, this solution is less difficult than previous attempts to limit emissions.  This will not require most people to change their lives and jobs.
8. Because this is an entirely new technology, there will be a learning curve while cloud creation and control systems are developed.  This will take years to develop, but not decades.  I believe the solution can be developed quickly enough to address the problem.

What are your thoughts on geoengineering?  Are there other approaches to treating the symptoms of global warming that hold more promise?

3-D Audio: New Tricks for an Old Dog

In the March 2011 edition of The Atlantic, Hal Espen interviews Princeton professor Edgar Choueiri about his pure stereo filter (http://www.theatlantic.com/magazine/archive/2011/03/what-perfection-sounds-like/8377/).  He promises “truly 3-D reproduction of a recorded soundfield.”  Espen’s description of the demo in an anechoic room evokes an acoustic experience that surpasses all previous technologies for presence... both for natural sound and music.

The problem that Prof. Choueiri identified and claims to have solved is a filter which removes cross talk between stereo channels without audible spectral coloration.  His approach was documented in a 24 page paper described by Mr. Espen as “fiendishly abstruse.”   Since then, Prof. Choueiri obtained Project X funding at Princeton to code his filter and test it in his 3-D audio lab (not his primary work at Princeton... he teaches applied physics and develops plasma rocket engines for spacecraft propulsion.)

Human hearing, including the audio processing in the human brain, is sensitive and sophisticated.  When we hear a conventional stereo recording, with channel cross talk, we have to “work” to process and interpret the signal.  This “work” creates a barrier between the listener and the audio experience the technology was trying to reproduce.  Prof. Choueiri: “The most tiring part of stereo is the fact that the image spatially doesn’t correspond to anything that you ordinarily hear.”  “That’s what drove me to create this thing.  Your brain is getting the right cues, and you relax.  Your brain stops trying to recreate reality.”

I love this story because spatial sound reproduction is considered by most technologists to be a solved problem.  Most development since the introduction of the CD has been development of multi-speaker technologies that use brute force to add sound to action-adventure cinema experiences.  There has been some work on digital audio signal processing to allow customization of a stereo audio signal to reproduce different concert spaces or to correct artifacts from earlier recording technologies, but Prof. Choueiri’s work goes back to the fundamental problem of stereo fidelity, the focus of audio engineering before 1980.

I’m neither an audio engineer, nor an audiophile, however, I have a strong preference for live music over reproduced music because of the quality of the experience.  I’ve assumed that the problem with reproduced music has been the cost of creating a good audio environment in my home, not the fundamental technology.  This work causes me to reexamine that assumption.

What’s your perspective on Prof. Choueiri’s invention?  Is a great leap forward or just an over-hyped incremental improvement?

Decision Support: The Multi-Variable Ranking Systems

In the most recent issue of The New Yorker, Malcolm Gladwell takes on the US News & World Report’s annual “Best Colleges” guide in The Order of Things: What college rankings really tell us (http://www.newyorker.com/reporting/2011/02/14/110214fa_fact_gladwell) (sorry, subscription required for the full text article.)  He dissects the US News college ranking system with other examples of ranking systems: Car and Driver’s ranking of three sports cars, a ranking of suicide rate by country, a ranking of law schools and a ranking of geographical regions by level of civilization.  He makes the point that these systems are highly arbitrary and can be best understood by inspecting the categories and weights against the needs of various audiences that will make decisions based on the information provided.  Most ranking systems reflect the prejudices of the people doing the ranking and less frequently serve the needs of the people seeking advice.

I have also used multi-variable ranking systems to assist in decision making in the past.  These systems were used to help sort out alternative architectures, product portfolios investment decisions or alternative corporate strategies and as such often stimulated intense political positioning and lobbying before, during and after decisions were made. My experience has been that to drive good decisions, there are a number of best practices that have their origin in the politics of shared responsibility in corporate organizations.  Here they are in no particular order:

1. Score criteria that are naturally quantitative, quantitatively, for other criteria, use qualitative ranking, e.g., project cost or profitability should be scored in $, while strategic alignment can be High, Medium or Low. 
2. Get political adversaries to participate in the structuring of the number and weights of criteria... be sure to include the top two or three things each cares most about in the system.
3. Be prepared to explain everything: the structure of the system and the reasoning behind the scores.  To the extent that a score is controversial, it should have its origin and ownership in the organizations that bear the greatest responsibility for execution after the decision is made.
4. Find several different points of view to cross check the results of the ranking system.  If you use choose certain proxies for cost, quality, flexibility, etc., cross check with other proxies.
5. Run sensitivities on the number of variables and weights chosen to see how dependent the outcome is on the particular variable set and weights.  When a sensitivity changes the outcome, study what you have to believe to use different variables and weights that drive a different outcome.
6. Recognize that it is impossible to put every decision criteria into the system and that ultimately an executive will make a decision based on the system and other factors outside the system.  Also recognize that an important function of the system is to get the participants to develop common language and models, not to drive a particular result.

What are your experiences with multi-variable ranking systems in support of decision making?  How do you react to Gladwell’s discussion of the limitations of these systems for making difficult apples to oranges comparisons?