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Scalability and Development of Space Networks. Vincenzo Liberatore, Ph.D. Disclaimer: the views expressed here are solely the author’s, not the presenter’s. Scalability. Definition Ability of a system to sustain seamless operations when certain parameters increase Dimensions
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Scalability and Development of Space Networks Vincenzo Liberatore, Ph.D. Disclaimer: the views expressed here are solely the author’s, not the presenter’s
Scalability • Definition • Ability of a system to sustain seamless operations when certain parameters increase • Dimensions • Specified across four dimensions
Scalable Terrestrial Networks • Scalability is Primary Concern • Exponential increases of key parameters • Quality Assurance • “If it scales, it must be working” [O’Dell] • Expandable and Reusable Solutions • Convergence layers • E.g., Internet Protocol (IP) • Support multiple link, transport layers • Middleware • E.g., Resource Discovery • Simplifies design, development, and deployment of complex distributed applications • Reduces costs • Improves system quality
Scalable Space Networks • Assumption • Combined approach more powerful than each in isolation • Leverage on high readiness terrestrial technology • Only a working hypothesis • Gap Analysis • Terrestrial assumptions may be inappropriate for space networks
Gap Analysis • Example • Numerical scalability • Vast numbers of terrestrial assets • Fewer and sparser space assets • Objective • Reconcile gaps
Process • Resolve Gaps • Needs explicit process • Spiral Development • Cycle steps to resolve gaps • Cycle steps to evaluate alternatives • Milestones to resolve gaps
Spiral Development Reprinted from [Bohem 89]
Determine Objectives Flexibility Sustainability Affordability Autonomy Others? Determine Constraints Computation Power Delays and errors Others? Hypothetical Example: Development Scalability
Hypothetical Example: Development Scalability • Determine alternatives • Terrestrial Networks • Sensor Networks • Common architectures, interfaces, substrates (on-going at NSF NeTS) • Alternative Approach I • Highly optimized systems • Hooks for flexibility • Alternative Approach II • Reference model: • Common architectures, interfaces, and substrates • Compile into highly optimized implementation • Analogy: distributed shared memory • Alternative Approach III • Anyone?
Hypothetical Example: Development Scalability • Remaining spiral stages • Evaluate alternatives, identify resolve risk • Develop, verify next level product • Plan next phases
Conclusions • Concern with scalability central to terrestrial networks • Reconcile with space objectives • Identify and resolve gaps • Process: Theory W spiral