Challenges:Environmental Design for Pervasive Computing Systems
An SAIC Company
Ravi Jain* John R. Wullert II
Autonomous Comm. Lab Applied ResearchDoCoMo USA Labs Telcordia [email protected] [email protected]
*Work performed while at Applied Research, Telcordia
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Outline
Motivation and background Using less Using it longer Smart disposal Conclusions
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Summary
Pervasive computing offers exciting opportunities but also possible negative environmental impacts
We need to treat environmental impact as a first-class design constraint
Increasingly software is a key to reducing environmental impact
We need research in many areas of system design for pervasive computing and communications
Ravi Jain / 19-Sep-02 / 4Recycling Council of Ontario
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Frequently Raised Objections (FRO)
Just throw all the old PCs and cellphones into the sea– Ahem …
This is a naïve and ambitious plot to overthrow the capitalist system– No … we are just promoting environmentally sustainable design– Environmental responsibility has been embraced by many major corporations
and governments This is not really a big problem
– We hope to show data that indicates otherwise This is not my problem … why would I (or anyone) pay for this?
– Legislation and consumer pressure is building– Market-leader advantages
This is not a computer science problem– We believe software, not hardware or materials, is increasingly important
This is not a research problem– We believe environmental factors can affect all layers of system design – Analogy with battery power considerations in mobile computing
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Computer waste (so far …)
Estimate: Over 75% of all computers ever bought in the US are stored in people’s attics, basements, garage … (MCC, 1996)
The growth of electrical/electronic waste is 3 times the growth of other municipal waste (AEA, 1997)
Estimate: By 2004 there will be over 315 million obsolete computers in the US alone (NSC, 1999)– 4 billion pounds of plastics waste alone
Toxic materials in PCs (MCC, 1996)– Lead, Mercury, Cadmium, Arsenic, Chromium– Polyvinyl Chloride (PVC)– Polybrominated Diphenylethers (PBDE) – …– “New personal computers release over 100 different chemical
compounds as gases, adversely affecting the health and performance of office workers”, Technical Univ. of Denmark study, Environment Daily, 9 Sep 2002
Accounts for a significant proportion of U.S. energy consumption
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This is just the beginning
Source: Rainer Malaka, EMLICDE 2001
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Pervasive Computing
Most pervasive computing devices consume less material than traditional PCs
However pervasive computing devices:– Will be far more numerous
Example: 13M Bluetooth devices shipped in 2001; Expect 780M by 2005 (Cahners In-stat) … compare with black phones
– Rapid replacement due to low cost or immature technology– Can be disposable
Example: disposable cell phones (Telespree, HopOn)
– Will be embedded in other products Jewelry, clothing, smart floors, sensor networks, … Makes location, extraction, collection, recycling harder
– More likely to be lost, forgotten, or simply abandoned– Use batteries, likely exclusively– Will bring computer environmental impacts to regions where none exist at
present
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A Challenge
Reduce total-lifecycle per capita computer & communications environmental impacts– Material and energy consumption by 10x– Non-recycled material and non-renewed
energy consumption by 100x– Toxic and harmful byproducts by 1000x
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Design motivations
Not “The sky is falling …”, but pervasive computing does pose a new environmental risk
Design for the environment– Reduction of resource consumption– Reuse of resources and products– Recycling* Needs to be an integral part of the design process, not an afterthought* Recycling is important, but is not the answer* Software is increasingly important
We have an opportunity to do this while still at the start of the technology wave
Legislative and consumer pressure– Extended Producer Responsibility (EPR) in Europe
First-mover advantage (e.g. NEC Eco PC)– Many “socially responsible” advances are first resisted (e.g. Cellular
911)– Foresight sees market opportunities and differentiators
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Using less:Minimizing physical materials
Minimizing physical materials– Doing more with less, not Doing with less
Two parallel trends– Integration: cell phone as pager, organizer, e-wallet, radio, media
player ...– Specialization: different functionality, form factors, power
requirements, connectivity, processing and storage, fashion niches Reducing physical materials within a single device
– Modular design should allow configuration on a per-user basis– Similar to PC configuration options but with smaller option units
Device sharing– Example: Environmental impacts of answering machines ~10x
more than centralized voicemail (Taiariol, 2001)– But voicemail still lacks features (e.g. live screening) and a good UI
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Using less: Device sharing on a larger scale
150M hosts connected to the Internet, mostly underutilized– Have been harnessed for tasks that would be impossible otherwise
Mersenne Prime Search (GIMPS): 130K users, 1.5 TFlops– 213466917-1 (4M digits), Michael Cameron (Age 20), Canada, 800 MHz PC
Two key challenges (Anderson & Kubiatowicz, 2001)– Internet Scale Operating System (ISOS) for resource allocation,
security …– Economic models to provide private owners with incentives
Additional challenge: take environmental concerns into account– Energy: Preferentially utilize computers in cold regions, or those that
are not in dormant mode, or depending on available cycles – Materials: Utilize CPU and storage that would otherwise be wasted
Sharing in enterprise and wireless networks– Pervasive computing environment in user’s home, office, car– Greater device and network heterogeneity, limited resources,
restricted UI
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Using less:Minimizing energy usage Formal models of energy consumption (Big-oh joules)
– Needed to motivate algorithm improvements– Analogy to formal models of disk I/O
Energy-efficient applications and architectures– Example: Half-duplex multiparty calls (“Push-to-talk”) use 50% less
power than voice calls Most 2G/3G systems do not support this feature
Need to consider total-lifecycle energy impacts– Cellphone consumes ~6 kJ/day. Charger: ~110 kJ/day (Nicolaescu, 2001)– Nearly 90% of energy usage in cordless phones and answering machines
is in standby mode (U.S. DoE, 2002)– Consider energy consumed in manufacture, distribution, and disposal
Alternative energy sources– Solar energy– Human energy: wrist movement (Citizen eco-drive watch), footfalls can
generate 50 mW (Paradiso, 2000), keystrokes
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Using it longerProgrammability
Software Sprawl –SLOC = 13992 e0.74 yrs R2 = 0.98
Linux Size(1991-8 data from Forbes; 2000-1 from Wheeler)
y = 13992e0.7428x
R2 = 0.9765
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SLOC = Lines excluding comments and blank lines
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Microsoft Office Requirements
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Release Year
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Using it longerProgrammability
Software Sprawl Again
Office Productivity Suite
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Using it longerProgrammability
Most users do not need all the features of the program (or even know they exist) at any one time
Need mechanisms to – discover system capabilities– discover applications and components– auto-configure software– secure, just-in-time, just-right plug-in upgrades
Hardware requirements should be written not only for entire applications, but based on user-level features
Automated testing techniques need to be developed that support modular hardware
Similar considerations apply to data sprawl
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Smart disposal
Recent increase in recycling PCs–Manufacturer take-back legislation in US
Cellphone recycling in Japan (Belson, 2002)–Gold: 24 micrograms/phone. Total metal extracted: 21 cents/phone
Crushing devices into their raw materials loses the vast majority of their value
In addition, there are significant health and safety risks of recycling itself …
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This is not a problem …
Source:USA Today2/25/02
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Smart disposal
Recycling should focus on– Identifying subassemblies
and larger blocks for reuse RF ID tags
– “Upcycling” or remanufacturing into new products
Close the loop of product information– Provide quantitative
feedback to designers on actual use, upgrade and failure of software and hardware
Product Lifecycle Stage
Production RetailInfo
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Thomas, 2001
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Summary
Lower layers– Hardware requirements specification based on
user-level features– Modularly upgradeable hardware– Identify subassemblies for recycling– Software radios to adapt to new protocols and air
interfaces OS and system software
– Seamless integration of old and new hardware and just-right upgrades
– Environmental parameters to an Internet Scale OS
– Pervasive OS with environmental design– Minimize OS and software sprawl
Low-cost fault-tolerance techniques– Reduced requirements– Intelligent hardware diagnostics and workarounds– Present surviving resources to apps
Applications support– Minimize data sprawl with better knowledge
management, duplicate avoidance, retrieval, and automatic compression
– Discover system capabilities, software component discovery and composition, secure, just-in-time plug in
– Compiler and automated testing techniques Applications and UI
– Just-right software upgrades– Energy-efficient applications and architectures– Improve UI for device sharing– Make energy and toxic byproducts visible to users:
EnergyStar -> NonToxicStar Formal models of energy consumption New design and modeling methodologies Use and management of alternative
energy sources (human, solar)
Environmental impacts need to be treated as a first-class design constraint
If applied consistently, they will have impacts at all levels of software and systems design … a major challenge to integrate total-lifecycle costs into all design aspects
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Barriers
“A threat to growth / capitalism / our way of life”– Sustainable and environmentally responsible design is the best
way to promote long-term growth– Carrots (economic incentives, secondary markets, broker
opportunities) are better than sticks (legislation, consumer disaffection)
No immediate short-term benefits– But see NEC Eco PC, Electric cars, etc
Few professional incentives for R&D in this area– National or international R&D funding programs are needed– No workshops, journals or “tenure-friendly” forums and outlets
Research area is difficult: – need multidisciplinary approach (e.g. air bags)– need precise problem formulations– no established benchmarks