Virtual Machine Abstractions for Nomadic Pervasive Computing (NPC) Environment Presented by: Hen-I Yang, Nov. 29, 2006

Outline Nomadic Pervasive Computing (NPC) Environment Problem Definition and Analysis Presenting Various Abstractions Comparison Conclusion

Pervasive Computing Environment Integrates computation into the environment, rather than having computers which are distinct objects. Embedding computation into the environment and everyday objects to enable people to interact with information-processing devices more naturally and casually than they currently do, and in whatever location or circumstance they find themselves. -- Wikipedia

Elements in a Pervasive Computing Environment Sensor Actuator Service Applications User Space System Support

Nomadic Pervasive Computing Environment Smart spaces, where ubiquitous computing services are available will become much more widespread in the near future, but will not be joined seamlessly or continuously. Nomadic Pervasive Computing encompass a federation of isolated smart spaces and the mechanisms that allow users to be continuously served as they move around.

Problems in supporting NPC Binding issues –Separating goals and means. –Deciding where binding occurs –Interoperability and compatibility –Ownership of space and authentication of entities Quality of Service (QoS) –Conflict resolution: priority and scheduling –Criteria of QoS –Service level agreement –Mobility Scalability –Service delivery –Scalability of data and processes Security and Privacy -- UbiSys 06

Goal of this Project Find suitable virtual computer abstractions that can solve the following issues in NPC: Binding issues –Separating goals and means. –Deciding where binding occurs –Interoperability and compatibility –Ownership of space and authentication of entities Quality of Service (QoS) –Conflict resolution: priority and scheduling –Criteria of QoS –Service level agreement –Mobility Scalability –Service delivery –Scalability of data and processes Security and Privacy

Scenarios Medicine Reminder Climate Control Follow-me Display

Abstraction I: System (Space) Transcoder and I/O binding Authentication Migrate VM Abstract Device Driver VMM O/S Hardware VMM O/S Hardware Transcoder and I/O binding Authentication Transcoder and I/O binding Authentication

VM Scenario using Abstraction I Medicine Reminder Timer Service Timing Device Context-aware Transcoder Svc Mobile Audio Device Stationary Audio Device Stationary Video Device Location Service Follow-me Display Svc Personal Tag Device Climate Controller Temp Sensing Device Hum. Actuating Device Abstract Device Driver Temp Actuating Device Clock Cell Phone Speaker Desktop Monitor Kitchen Small TV HDTVHeaterA/CThermometer Transcoder and I/O binder Ultrasonic Tag User Preference

Abstraction II: Service VMM O/S Hardware VM Service 1 VM Service 2 VM Service 3 VM Service 4 VM Service 5 Secured Shared Buffer Data Insertion Data Reading VMM O/S Hardware Secured Shared Buffer Abstract Device Driver Transcoder and I/O binding Transcoder and I/O binding Migrate VM Service 3’ VM Service 4’ Migrate

Scenario using Abstraction II Medicine Reminder Timer Service Timing Device Context-aware Transcoder Svc Mobile Audio Device Stationary Audio Device Stationary Video Device Location Service Follow-me Display Svc Personal Tag Device Climate Controller Temp Sensing Device Hum. Actuating Device Abstract Device Driver Clock Cell Phone Speaker Desktop Monitor Kitchen Small TV HDTVHeaterA/CThermometer Transcoder and I/O binder Ultrasonic Tag User Preference Do not Migrate Temp Actuating Device

Abstraction III: User VMM O/S Hardware VM/User User Preference Service Inflator Necessary Devices Inflated Service Logic Service Implement. Discovery Service Transcoder and I/O binder VMM O/S Hardware Discovery Service Transcoder and I/O binder Migrate VM/User User Preference Service Inflator

VM/User User Preference Service Inflator Required Device Service Logic VM/User User Preference Service Inflator Scenario using Abstraction III … …. … Service Inflator Required devices: Temperature actuator (a) Temperature sensor (s) Service Logic: while (TRUE) Retrieve reading from s if s > 75 send lower to a else if s < 70 send higher to a end if end while VM/User User Preference Service Inflator Required Device Service Logic Service Inflator (Generic Program Engine) Discovery Service Executables VM/User User Preference Service Inflator Required Device Service Logic Executables query + bind

Comparison Approach I: Space Approach II: Service Approach III: User Type of VM SystemProcessSystem Primary Mechanism Authenticator, Transcoder and I/O rebinder Everything in I + Secured Shared Buffer and Dependency Analyzer Service inflator and discovery service Suitable Scenario Relocation Summer House Frequent migrator with critical services Simple best-effort personal preference maintenance Challenges Clash of space (e.g. public space) Service conflict/redundancy detection More complicated service logic Migration Cost Very highhighlow Advantage Easy migrationLighter weight, User involved service hoarding Personal crash isolated, Private and secure, ultra light weight

Conclusion Virtual Machine provides many desirable properties that are suitable for NPC environment Difficulties in communications as a result of isolation maybe costly in highly dependent NPC environments Different abstractions provide various benefits depending on the applications and the characteristics of the space Implementation and actual deployment is necessary to verify the design using these abstractions and the benefits