Application of TRIZ to Wireless MAC System-on-Chip Design: A Case Study Raghunath Govindachari and Kalyan Kumar Banerjee
[email protected] [email protected] MindTree Consulting Limited
42, 27th Cross Road, 2nd Stage, Banashankari Bangalore 560 070
India Abstract
Wireless communication systems are becoming ubiquitous due to the convenience and mobility offered by cable-free devices. Convergence of several wireless technologies into a single device is already happening; advanced mobile terminals today include wireless interfaces for cellular, Global Positioning, Bluetooth and Wi-Fi technologies. Greater integration of multiple interfaces reduces size, power consumption and provides cost advantages.
This paper is a case study in the application of TRIZ techniques including the trends of evolution of technological systems and the elimination of system contradictions. The paper is an attempt by the authors to understand the nuances of applying the above powerful techniques. This is done by considering wireless handheld terminals as the super system with the communication interfaces as the main system of interest. Trends of evolution of the communication interfaces in these terminals are studied with the objective of understanding how the evolution of the overall system influences the evolution of the sub-systems such as the Media Access Control (MAC), the Digital Baseband (PHY) and the RF front end. The trends that emerged are ordered according to the levels of innovation and the higher order trends are considered further. Immediate technical contradictions that may need to be solved for the further evolution of one of the sub-systems viz., MAC is looked into. Applying the TRIZ techniques the principles that offer scope for elimination of these contradictions are identified and mapped to the context of the design of MAC sub-systems.
The results obtained by this case study confirms the power of these techniques in the context of technological systems that exist in the realm of logical systems more than in the realm of physical systems. We found out that logical systems, such as MAC have been evolving naturally in the dimensions of flexibility and adaptability, by means of increasing software or programmability. However, the controllability or speed of operation may deteriorate and hence a system contradiction emerges. We found that the mapping of the inventive principles to the domain specific solutions was not straight forward. We believe that further work must focus on mapping the parameters as well as the inventive principles in this domain of logic systems.
Introduction
The system of interest in the case study is the wireless handset terminal or in short, the handset. Although cellular handsets started out primarily as voice only devices, the immense success of the SMS gave it the thrust in its evolution towards data oriented services such as the GPRS and beyond. With GPRS or WCDMA, multimedia services have come within the reach of the handsets, triggering what is now hyped as triple play services. Mobile handsets have now reached the status of being Personal Mobile Gateway, through which the user not only can communicate with other end users but can actually access a variety of information anywhere, anytime. Similarly, providers of information-based services also in turn can structure their services offering based on the assumption that most users are reachable through their handsets.
Paralleling the convergence of media, the handset has been converging in the dimension of wireless connectivity as well. At least high end handsets today offer multiplicity of wireless interfaces, each with its own purposes and benefits. The central cellular wireless interface provides wide area (or metropolitan area) access, while the WLAN provides high speed data oriented network access, GPS provides location information and Bluetooth provides cable replacement features for audio streaming, remote control or data exchange. Newer wireless interfaces such as NFC are also getting integrated for contact-less authentication and Nokia has already announced Wibree™ – a strap-on wirecontact-less technology for low power, low data rate control applications.
So, what are the implications of these evolutions, on the subsystems that the handset equipment is comprised of? What opportunities are there for a designer of such wireless interface subsystems? What are the challenges and contradictions that may have to be transcended? What is the ideal final design of these subsystems? As a provider of short-range wireless interface solutions we at MindTree Consulting Ltd., are naturally interested in these issues. We decided to approach these issues of predicting the next general directions of evolution and the innovations that we must be harnessing for providing next generation solutions.
The Problem Definition
Today’s wireless terminal unit is a highly sophisticated system that an average user is incapable of mastering. At the same time, the benefits of the convergence of features are required not only for the power user such as professionals of an enterprise but also for lay users. For example, a medical professional may want to take advantage of the seamless connectivity using her mobile terminal across cellular, GPS, Wi-Fi and Bluetooth. As another example, in the event of a catastrophe, a victim requiring medical assistance may reach out using the same mobile terminal even if the cellular mobile signal is unavailable. The important issue is that the terminal should provide seamless connectivity irrespective of the wireless interface being used.
One can view the above requirement as a requirement of versatility or flexibility etc. Such degree of versatility is unachievable in a loose integration of these interfaces in the system.
The main useful function of the wireless terminal is to provide connectivity without wires. The tool is the wireless communication interface, the object is the handset and the field is a wireless communication medium. An ideal wireless interface provides wireless connectivity independent of the nature of the wireless medium.
In moving towards this IFR, we explored the application of various TRIZ processes as summarized below:
1. S-curve analysis 2. Trends of Evolution
3. Identifying one of the contradictions 4. One solution concept development
S-Curve Analysis
At the macro-level, the wireless handset system has evolved considerably from the early days of its birth. During the early adoptions, stand-alone wireless interface devices appeared, designed for stand-alone applications that best utilize the technology. More specifically, in the case of cellular communication devices, the implementations include a Micro Controller Unit (MCU) that caters to the user interface functions and basic voice centric applications. The rest of the wireless protocols were implemented in Application Specific circuitry and software that runs on the same MCU. As the applications got richer, a separate application processor and a wireless processor evolved. The application processors evolved in the direction of richer media handling (like graphics, video, stereo) and ability to run stripped down versions of desktop operating systems and desk top productivity applications. The wireless processor also got enriched with flexibility in terms of ability to handle multiple frequency spectrums, network protocols and sophisticated power management.
Now we look at the wireless interconnect interface subsystem level. Before that, it is important to look at the state of maturity of the different wireless interconnect technologies. Figure 1 shows the relative position of different wireless technologies in the technology maturity curve. It is interesting to see that although this curve is not a simple S-curve, there are piecewise s-curves in this. During the early hype phase of the technology and during the phase of plateau of productivity, the curves resemble S-curves.
Figure 1: Gartner Hype Curve for Wireless Technologies
When a specific interconnect technology is in its early hype phase, its integration into the wireless subsystem is loose but when it enters the plateau of productivity, then the integration is tighter. First generation products had multiple chipsets – usually the RF separate from the Baseband and the MAC. Quickly these were integrated into modules – which reduce the complexity of designing RF circuitry on the mother board. The next stage is when these were integrated in a single package (called System in Package or SIP). The advances in CMOS RF technology has resulted in true single chip wireless devices.
The evolution of the system in the dimension of physical parameters like size and power is not unique to these systems but is a resultant of the general improvements in the field of semiconductor design and manufacturing techniques. Today’s wireless chips are being designed for deep submicron processes (45 nm and 65nm) with the immediate benefits of smaller area being lower manufacturing cost and lower power dissipation.
We may now observe that a single wireless communication subsystem has fairly evolved and is likely to be close to the peak of its optimal performance. Further improvements in the functionality, integration and physical geometry would be incremental in results. For example, as more powerful MCUs are added or smaller geometries are used and further migration of analog circuits to CMOS processes could result in faster, power efficient and
smaller wireless subsystems. However, any fundamental breakthroughs will have to happen through investigation of evolution potential of these systems in other dimensions and resolving conflicts that will facilitate such evolution.
We therefore look at the opportunities for evolution in other dimensions than the above. As a starting point we use the laws of technological system evolution.
Trends of Evolution
In this part of the case study we look at the laws of evolution of the wireless subsystem and predicate possible evolution potentials from applying these laws. Then we map these to the hierarchy of invention levels to see the effort and impact of inventions that may result when evolving in the promising directions. We then select a couple of these trends to identify the improving parameters and the contradictions that need to be resolved to achieve the improvement.
Law of Increasing Ideality
According to this law, the system evolves towards either performing its functionality better or more functionality is achieved using less or same resources or both. Looking at it in the line of more functionality seems natural in the case of the wireless subsystem. Going by the earlier definition of IFR, we seek a wireless subsystem that provides seamless, unrestricted, universal connectivity in a variety of heterogeneous environments.
This kind of evolution is already happening in the wireless subsystems. For example, single chip Bluetooth and GPS, Bluetooth and Wi-Fi solutions are being designed. Similarly chip designers are integrating FM transceivers with either Bluetooth or cellular devices to provide a single integrated solution. Next generation GSM/GPRS/WCDMA/CDMA basebands are being designed which integrate Bluetooth with the cellular basebands. Evolving from the FM integration, next generation cellular chips may integrate TV tuners along with Digital Video Broadcast services gaining popularity. Similar integration of WiMAX and Wi-Fi chips may happen in the next couple of years, to exploit the heterogeneous deployment of broadband wireless services. Natural outcome of this multi-technology capability is the synergistic use cases for these otherwise disparate or apparently competing technologies. For example, Wi-Fi enabled handsets may benefit from Bluetooth for the last meter cable replacement. Thus the wireless subsystem is getting into multi-protocol capabilities on its natural path of evolution towards universality ideal. Figure 2 shows a system with multiple wireless interfaces attached to a common application processor.
Figure 2: Integration of Multiple Wireless Interfaces
Application
Processor
MCU
FLASH/
ROM
Peripherals
SRAM
Digital
Cellular
Baseband
Digital
GPS
Baseband
Digital
BlueTooth
Baseband
AFE & RF
AFE & RF
AFE & RF
Law of non-uniform evolution of subsystems
According to this law, we expect that while the overall wireless subsystem may be evolving forward towards its ideality as articulated above, one or more components that constitute this wireless subsystem may evolve rather regressively, at least temporarily, until this is corrected sooner or later. For example, the integration of GPS and Bluetooth into the system using a single IC may actually worsen the IC in terms of its overall performance in comparison to stand alone BT or GPS functionality, or power consumption or may take more resources such as RAM or FLASH. However, the integrated component will evolve on its own to resolve the conflicts that cause the above degradation of functionality, power or performance. It is our interest to actually look at such components with regressive trends and apply TRIZ to resolve their contradictions. The hierarchy of a wireless subsystem consists of a Processing subsystem that execute protocol software stack, a media access control (MAC) processor, a Baseband signal chain processor (PHY) and an RF analog front end system (AFE). Integrating multiple wireless technologies moves the wireless subsystem overall towards its ideality, but may pose challenges to the designer of each of these component subsystems. For example, it is a non-trivial challenge to run multiple protocol stacks, each with its own demands on the memory and MIPS. At the MAC and PHY levels as well the latency constraints of each of the wireless interfaces make it harder to integrate. At the RF level the challenges are huge considering the diversity of the RF communication channels involved.
We predicate that the integration may start with common MCU for protocol processing and culminating in a rather idealistic single RF front end. Figure 2 illustrates a common Application processor attached to multiple wireless single chip components.
Law of increasing dynamism
This law indicates the need for increasing flexibility. Among the several lines of evolution that can be investigated such as transition to continuously variable systems, adaptive and self-adaptive systems did not throw up fundamental improvements. On the other hand, following the line of increasing flexibility of physical structure and transition to fluids and fields seemed to offer promise.
For example, in the realm of logical systems such as the wireless interfaces, digital circuits are fundamentally more flexible than analog circuits and in turn software is more flexible than digital circuits. We see this line of evolution to happen rapidly, transforming the communication interfaces into predominantly software systems executing on predominantly digital hardware.
Evidences towards this trend are already being seen. For example, Baseband signal processing has more or less become all digital implementations and in several cases is beginning to be DSP based software implementations as well. Similarly, several analog front end functionalities such as filters and synthesizers are being implemented in digital domain using the emerging discrete time signal processing techniques.
The culmination of this trend may be in the Software Defined Radios (SDR) where in a single wide band analog front end with corresponding data converters will constitute a common RF subsystem controlled by software and the rest of the signal processing and protocol processing may also be in software executing on appropriate processing subsystems. There are substantial technological challenges such as the processing power, the energy dissipation and battery life and also the precision control that have to be overcome before this ideality is achieved at least in mobile devices.
Law of Transition to Higher Level Systems
With this trend initially the wireless subsystem increases in diversity of components. It is now at a stage where the system (mobile device) has as much as 6 wireless interfaces. At the subsystem level, it is now at a stage of convolving to decrease complexity. Integrated multi-protocol wireless chips such as GPS+BT, BT+Wi-Fi and CDMA+BT not only reduces the number of chips, but also makes efficient use of on-chip resources such as CPU and memory. Further evolution in this line of decreasing complexity can be expected to yield a single chip with multi-protocol MAC and Baseband processing capability.
Following the line of increasing non-uniformity of materials leading to functional zones, we can foresee that the ICs will have multi-core, multi-element structures each with specialized capability for MAC, Baseband and RF processing. Once again, convolution will result in rationalization of redundancies within the structure, resulting in a simplified structure.
Law of Transition to Micro Levels
This law closely follows on the heels of convolution. We believe that in the case of the functional specialization of processing of MAC layer and Baseband layer, there may be fundamentally identical processing elements that can be micro-programmed to perform the different processing requirements for MAC and Baseband layers.
Law of Completeness
An autonomous technological system consists of the four principal parts viz., working means, transmission, engine and control means. Within the wireless interface we map the engine to be the Baseband, the transmission to be the RF circuitry and the working means to be the antennae. The control means is with the MAC processor.
The line of completion suggests that non-automatic aspects get increasingly automated. For example, emerging techniques of smart antenna systems, that uses diversity combining techniques and space-time signal processing techniques, or paving the way for MIMO radios.
Law of Shortening of Energy Flows and Law of Harmonization of Rhythms In the context of communication systems, we equate energy flow with information flow. Then, this law implies that information traverses shorter paths. This implies that front end components (like sensors, actuators and In our case the transceivers) will become intelligent enough to process specific information locally instead of having to pass all information to a central processor as is the case with dumb sensors, actuators and transceivers. Thus, this law too highlights the smart antenna systems.
Corollary to this law is the synergistic existence of systems. For example, in devices where both Wi-Fi and Bluetooth interfaces are co-located, in current systems, the control of usage of either interface is far removed from the interfaces and is placed at the application processor. However, when these interfaces are implemented in a single chip, flow of information can happen directly between these two interfaces resulting in much better and finer coordinated action, resulting in superior performance or functionality. Thus this law enables the harmonization of rhythms at a finer granularity, resulting in better controllability.
When the communication is happening between several such dual interface devices, there is a possible synergistic use of these two interfaces. For example, an application can seamlessly switch from one interface to another depending on the bandwidth, power equations. When a connection is in less intense use, a lower bandwidth, power efficient Bluetooth interface can be used. But when the intensity of activity increases dramatically, the application can switch to the higher bandwidth Wi-Fi interface.
For example, both Wi-Fi and Bluetooth operate in the same frequency bands and can interfere with each other. Although, Bluetooth has mechanisms for co-existence in an environment with Wi-Fi transmitters, the overall performance might degrade. This conflict is resolved when a coordinated action or rhythm is introduced. This means that the system will have adequate control on the periods during which the Bluetooth and
Wi-Fi transmitters are active. This control is easy to achieve when these interfaces are integrated into a single chip. Further benefits result due to such integration as well.
Looking at this law in conjunction with the law of completeness, we can see that the control interface requires information from all of the rest of the parts of the system. Direct flow of information between these parts (engine, transmission and working means) to the control means will result in better controllability, in comparison to a strictly layered system.
Law of Increasing Controllability
This law observes that systems evolve towards increasing substance-field interactions, with completeness of su-fields, complex su-fields and intensified su-fields.
Although, we have not constructed a formal su-field model for the wireless system, we conjecture that this could be applied at each of the functional constituents of the interface – MAC, PHY and RF. An intensified su-field will result in universal wireless interface comprised of software defined radios systems, with a wide band antenna and front end system, digital filter structures, micro-programmed MAC engines, all controlled through software.
Invention Levels
Altshuller has propounded organizing innovations in a hierarchy to assess their degree of novelty and impact [1]. We look at some of the future directions of the wireless subsystem that emerged as a result of applying the various laws of evolution to compare where each may be positioned in the hierarchy of invention levels. For the sake of understanding, we reproduce here the definition of the invention levels [1]:
Invention Level 1 These are typically slight modifications of existing systems that usually do not resolve any system conflicts and result in localized changes to a subsystem.
Invention Level 2 These resolve some system conflicts (that may already have been resolved in other systems).
Invention Level 3 These resolve system conflicts by an original approach within one discipline. They also radically change at least one system component.
Invention Level 4 These give birth to new systems using interdisciplinary approaches. The developed concepts can usually be applied to many other problems at the lower levels.
Invention Level 5 These are really pioneering inventions usually based on recently discovered phenomena and they result in creation of new engineering disciplines.
Table 1 shows such a comparison. Invention
Level
Trends identified through laws of evolution
Issues and Enablers Level 1 Module level integration of multiple
wireless ICs
Multiple RF circuitry layout issues are overcome using well known techniques.
Level 2 Integrated multi-protocol ICs The design challenges are usually moderate, restricted to the typical chip design issues of power, die area, pin counts and packages (the last three translating to cost). The challenges are overcome by design techniques that optimize these parameters (through optimizing the gate area, memories etc.).
Level 3 All digital processing, Advanced CMOS Processes, Discrete time signal processing Level 4 Smart Antennas, micro programmed
engines
semiconductor processes, radio signal processing algorithms, analog and digital design techniques, protocol implementation techniques and software and chip architectures Level 5 Software Defined Radios (SDR) At the system level Issues of
processing power, power dissipation remain to be solved, at least for battery powered, hand held equipment.
Table 1 Invention Levels and the Emergent Trends
From the above mapping, we can clearly see that the software defined radios is the one strong theme that takes us closest to the IFR of universal wireless interface. SDRs are being adopted for wireless infrastructure equipments such as base stations where the issues of power dissipation can be resolved using traditional design techniques that attempt to optimize rather than resolve contradictions. Same is the case with the processing power requirements, which is addressed by over-provisioning of processing capacity using banks of very high end DSP chips.
When transitioning to battery-powered hand held consumer oriented devices like mobile terminals, such techniques will not provide breakthrough solutions that do not compromise power, form factor and cost constraints.
We have not yet investigated these issues using TRIZ techniques. But in what we believe to be a first step, we are focusing on the design of advanced Multi-protocol MAC engines that can be a component of future SDR-based systems.
The rest of the paper briefly analyzes the contradictions that emerge in designing such a MAC component. A detailed description of the process of contradiction elimination and resultant solution is intended to be captured in a sequel paper.
Solution concept development
In discussing the law of non-uniform evolution we mentioned that as the wireless interface subsystem evolves towards its ideality (viz., SDR), some of its components may take regressive steps. We now focus on the MAC layer of a wireless interface that implements the SDR architecture.
The MAC processor is required to perform the Media Access Control functionality of multiple wireless protocols, often concurrently. So, it must have the flexibility to process the diverse MAC layer functionalities as specified by the respective wireless MAC standards. At the same time, it must have the ability to not violate the stringent timing required for correct operation of the protocols. It must also be sufficiently fast to sustain the peak performance of the respective protocols. As part of battery operated devices, the MAC processor should operate efficiently in terms of clock frequency and occupy less foot print in terms of memory and logic circuits.
A Media Access Control layer of a communication system is responsible for the following main functions:
1. A well-defined access control procedure to avoid or arbitrate conflicting requests to access a shared physical medium.
For example, several protocols use time slots for this purpose. Others use CSMA-CD.
2. Framing of packets that are transmitted over the physical medium
3. Ability to detect errors in the received packet (both in the header part and the payload part)
4. Ability to inform the transmitting device about errors detected in reception. (ACK)
5. Ability to retransmit the erroneous packets (individually or in blocks)
6. In most high speed protocols, ability to correct certain types of errors (Forward Error Correction or FEC) is used to avoid or minimize retransmissions.
7. In most wireless communication, security of the packets is critical. Hence, the ability to encrypt and decrypt packets sent between trusted devices.
8. In certain cases, a large packet may have to be segmented into optimal size packets at the transmitter and later reassembled at the receiver side. (Segmentation And Reassembly SAR)
The above functions can be grouped into two categories: those which are control oriented requiring timely handling of control information (in the header) and those which are data oriented which require computational steps involving the payload (such as CRC, FEC or encryption). These functionalities typically get partitioned for implementation into hardware and software.
A typical contradiction is that a hardware implementation is more efficient, accurate in timing and faster than software implementation, but is less flexible. This is further intensified when MAC functionality for multiple protocols is required. There is an enhanced need for flexibility in order to reduce the hardware complexity. But this has to be done without hampering controllability and performance.
Thus the improving parameters are Device Complexity (36), adaptability or versatility (35). The worsening parameters are Speed (9), Loss of Time (25) and Loss of Energy (22).
Looking up at the contradiction matrix, we get the following principles to pursue: Worsening
Parameter Improving Parameter
Speed (9) Loss of Energy (22) Loss of Time (25) Adaptability/Flexibility (35) 35, 10, 14 18, 15, 1 35, 28 Device Complexity (36) 34, 10, 28 10, 35, 13, 2 6, 29
The frequency of references to principles highlighted by the contradiction matrix is below: Frequency of Reference Principle ID 1 1, 2, 6, 13, 14, 15, 18, 29, 34 2 28 3 10, 35
Between Principle 10 and 35, which appear most frequently, Principle 10 (preliminary action) does not seem to offer fundamental solutions, but could be useful in the scheduling of work load once MAC architecture is in place.
Principle 35 (Parameter Changes) appears across all the rows and columns of the contradiction matrix and seems to be a good candidate for offering a fundamental solution. The parameter changes could be change of physical state, concentration or consistency. Still, the mapping to the specific solution is not obvious. In the context of logic systems such as the MAC (in contrast to physical systems), we could consider the
functional units to be hard-wired fixed function logic (solid state) or fully programmable general purpose logic (like a CPU) or a micro-programmed functional block.
Micro programmed functional units implement very basic level logic in hardware circuitry and define micro instructions that map to these basic logic steps. Then a higher level functionality could be constructed by composing the basic steps in sequence, iteration or conditional sequences.
This solution direction also seems to be corroborated by Principle 28, Mechanics Substitution. According to this principle, a mechanical aspect (such as a circuit) can be replaced by a subtler material (such as a field). Mapping this notion to logical systems, we get the same result, viz, the basic circuit is mapped to a micro instruction and the complex circuit is achieved as a “program” resulting from composing the micro instructions. It is important to note that in this process, there emerge two kinds of instructions – those instructions that are directly mapped to useful computations performed by the underlying circuitry and the meta-instructions that control the flow or sequence of computations.
This solution direction emerging here is similar to the invention disclosed in WIPO Patent Application # PCT/US2003/034537, US Provisional Application # 60/422 [3]. The above invention proposes a highly programmable MAC architecture for handling protocols that require precision timing and demand very short response times. According to this invention, a HardMAC module is introduced in between a general purpose CPU that runs the protocol software and a hardwired DSP block that handles PHY layer signal processing. The HardMAC is a programmable coprocessor module including pre-defined operation hardware blocks having parameterized functions whose parameter values are programmable. A portion of the coprocessor module controls timing and the clock cycle rate is a programmable parameter. The programmability of the HardMAC avoids the necessity to make hardware changes involving pre-defined operations performed at a communications transceiver whose parameters may vary based on changes on regulatory requirements or the like.
The programmability of the above solution is based on the parameterization of the pre-defined operations as well as a sequencer. The programmability allows the reuse of the MAC engine to diverse MAC protocols. However, in actual application, the solution needs to be dynamically used in real-time to switch between simultaneous occurrences of different protocols. To make this happen, we believe additional facets of how the programming is to be done needs to be nailed down. We think that the other principles highlighted by the contradiction matrix will be of real use.
For example, the Segmentation principle may have to be applied to allow contexts and packets of differing protocols to be maintained in separate memories. Applying Principle 18 (Mechanical Vibration), we may arrange the functional elements of the MAC in a different fashion as opposed to a simple bus topology to decrease or increase the clock rates of operations as needed.
Conclusions
The above case study helped us with first hand opportunity to applying systematic problem solving steps such as S-curve analysis, trends of evolution and elimination of technical system contradiction.
We have looked at the evolution of a wireless communication handset from the point of view of ideality, i.e., universal connectivity. We used S-curve analysis in 3 dimensions of functionality, physical parameters and complexity. The dimension of complexity reduction appeared to provide maximum potential for maturing.
We have further looked specifically at the wireless interface subsystem of such a system and applied the different laws of evolution. The resulting trends have been organized using the concept of levels of inventions, in order to look for higher degrees of evolution. We found that for convergence of wireless interfaces to happen, the corresponding components should enable flexibility/adaptability. At the same time, the evolved system should overcome the initial inferior performance (in terms of speed, power or timing accuracy) before becoming main stream in usage, especially in portable/hand-held devices.
We then, used the TRIZ contradiction matrix to identify a set of principles that may help us resolve the above technological conflict at the MAC layer. The principles generated by the contradiction matrix were explored in the order of frequency and spread of applicability across the different rows (improving parameters) and columns (worsening parameters) of the contradiction matrix. The major solution that emerged was confirmed by the existence of a recently patented invention. The additional principles have indicated further improvements over the main solution.
Through this case study, the following new insights were gained:
• There is a distinct class of technological systems which we call Logical Systems in contrast to physical systems.
• We think that logical systems already are mature in certain aspects of evolution such as flexibility/adaptability.
• Certain physical parameters such as weight, length, geometry may have to re-interpreted in the context of logical systems.
• From the point of applying TRIZ principles, the mapping of the principles to the domain specific solutions is not direct or obvious.
We conclude therefore that further work must focus on addressing these differences. Although some work has been directed at software systems by TRIZ researchers, we think that the approach has been limited to suggesting software analogies for the 40 principles. We think that by looking at systems as logic systems, there is a wider and seamless coverage of digital systems that may be purely hardware or software or combinations of both. Any progress made in bridging these gaps may be very productive, given the predominance of logical systems in the digital age.
References
1 “Innovation on demand: New Product Development using TRIZ”, Victor Fey, and Eugene Rivin, Cambridge University Press, 2005.
2 “Hands-on Systematic Innovation”, Darrel Mann, CREAX Press, 2002.
3 “Highly Programmable MAC Architecture for Handling Protocol That Require Precision Timing and Demand Very Short Response Time”, Oleg Logvinov and Fred Skala, WO/2004/040425, WIPO, 2004.
