1. Problem 2: The In-Car Radio Navigation Case Study Marcel Verhoef (Chess Information Technology, NL) Ernesto Wandeler, Lothar Thiele (ETH Zürich, CH) Paul Lieverse (Siemens VDO Automotive, NL)

2. The In-Car Radio Navigation System Car radio with built-in navigation system User interface needs to be responsive Traffic messages must be processed in a timely way Several applications may execute concurrently

3. System Overview – Change Volume NavigationRadio User Interface Database Communication 50 msec 200 msec

4. Application A: Change Audio Volume Performance RequirementsInput Data RateCommunication Resource DemandComputation Resource Demand

5. System Overview – Handle TMC NavigationRadio User Interface Database Communication 1000 msec

6. Application B: Handle TMC

7. Application C : Address Lookup

8. Proposed Architecture Alternatives NAVRAD MMI 22 MIPS 11 MIPS113 MIPS NAVRAD MMI 22 MIPS 11 MIPS113 MIPS RAD 260 MIPS NAV MMI 22 MIPS RAD 130 MIPS MMI NAV 113 MIPS MMI 260 MIPS RAD NAV 72 kbps 57 kbps 72 kbps (A) (E)(D)(C) (B) kbps = kilo bit per second, mips = 10 6 instructions second caveat: deploying app. B on arch. B needs an extra task to move data from rad to nav; assume 1000 instructions

9. Task priorities & scheduling Assume FP scheduling for all resources Priorities are ordered as follows (ordered highest → lowest) 1.MMI.HandleKeyPress 2.Radio.AdjustVolume 3.Navigation.DatabaseLookup 4.MMI.UpdateScreen 5.Radio.HandleTMC 6.Navigation.DecodeTMC

10. Analysis – Design Question 1 How do the proposed system architectures compare in respect to end-to-end delays? consider the following application combinations ChangeVolume and HandleTMC AddressLookup and HandleTMC

11. Analysis – Design Question 2 How robust is architecture A? Where is the bottleneck of this architecture? NAVRAD MMI 22 MIPS 11 MIPS113 MIPS 72 kbps (A)

12. Analysis – Design Question 3 Architecture D is chosen for further investigation. How should the processors be dimensioned? RAD 130 MIPS MMI NAV 113 MIPS 72 kbps (D)

13. Full details can be found at http://www.mpa.ethz.ch