1. Software Engineering Group, Motorola India Electronics Pvt. Ltd.,
SDL Language Relevance to Protocol/Telecom Application Development: Case Study By
Bhaskar Rao.G,
Software Engineering Group,
Motorola India Electronics Pvt. Ltd.,
Bangalore, India
World of Communication

2. SDL, Is it only Auto Code Generation?
Integrated Methods and Tools for Software Development (Methodology)
Requirements - MSC
SAD - State Charts/UML/SDL
Coding - SDL, C <AUTO CODE >
Unit and Integration Testing - Simulation & Validation
System Testing - TTCN/SDL
Code generation for multiple targets: pSOS, Vrtx, VxWorks, NT, UNIX, Classic, OSE etc…
Separates Functionality from Implementation and Environmental aspects
Design, Implementation and Test Development (with environment) language

3. Product development with SDL
Req Analysis
System analysis and design
Object design
Verification and Validation
Auto code generation
System testing

4. MIEL: Projects Infrastructure projects Control Network projects
Other Projects

5. Benefits of using SDL at MIEL
Average test effort for SDL projects reduced due to V & V
No noticeable performance overhead
SDL Based test automation was very effective
Unit, Integration, Load, Conformance and Performance testing
Less dependency on tools, Good Environment support
Auto code is Scalable

6. Major Concerns Technical Concerns Managerial Concerns Customer Related
Impact on Code Size & Performance <Lack of effective code generators: Hand-written code>
Data Handling Problems <Addressed in SDL-2000>
No Support for Global Data and No effective ways to write Algorithms
Difficulty in Understanding Auto Generated Code <SDL to be maintained>
Managerial Concerns
Familiarity with Current Practices <Learning Curve>
Estimation and Tracking need improvement < New approach>
Cost of the tools
Customer Related
Not Willing
Other Modules are in C <C code integration: External procedures>
On Site Maintenance
Timely Delivery due to projected risk of using new technology <Not a Risk, Faster>

7. Challenges ahead Good and Effective Code Generators
Code size and Performance
Direct executable instead of code generation
SDL-2000 supporting tools
Gap between the standard and implementation should be small
Portable across tools
Enhancing the SDL to support General Application Development
Cost considerations

8. Case Study

9. Specifications: Data Link Layer
The Data Link Layer shall get packets from the Network Layer, Thease packets have to be segmented and converted Frames and sent to the Physical Layer
Does Framing and Error Control
Note: Please Refer to ISO-OSI specs for the detailed specifications

10. Interaction with the environment
System
Ack, Nack
Packet L2
L3, L1
L3Chnl
L2Chnl
Frame
FrAck

11. Simplified FSM for L2 Start Idle WaitRsp Init
Packet/Call BreakN_SendM_Timer(N)
FinalAckFrame/Ack
WaitRsp
TimeOut/Retransmit

12. SDL System Architecture
SignalsPack
DataDefPack E N V I R O M T E N V I R O M T
External C Code
System
BlockType
Block 1
ProcessType
Process 1

13. Simulator <System>
V &V
Test Engineer
Test Data
SDL
Simulator <System>
Traces
SDL
MSC
Text
Breakpoints

14. Application Integration
Other Applications
Glue Logic
Generated Application
(Single Thread)

15. Application Integration
Other Applications
Glue Logic
Generated Application
(Multi-Threaded)

16. Conclusions SDL Suitability and Promises Application Perspectives
Product Development Process
Case Study

17. Motorola India Electronics Pvt Ltd,
Q &A
Bhaskar Rao.G
ext: 3091
Motorola India Electronics Pvt Ltd,
Banglore

18. Backup Slides

19. SDL Promises
Facilitates Development of the Product from Requirements to End
MSC, UML(State Charts), SDL, TTCN, Simulation, Validation, Auto code, Auto Test Case generation ….
Separates Functionality from Implementation and Environmental aspects
Designs captured at higher levels of abstraction
Verification of functionality (“Make sure it is correct”)
Specialization to a particular environment and platform
Code generation for multiple targets
pSOS, Vrtx, VxWorks, NT, UNIX, Classic, OSE etc…
Re-targeting: 2-3 staff months effort (ONE TIME)
Integrated approach with integrated methods

20. SDL Promises (2) Graphical Representations
Availability of major implementation concepts as primitive types in the language
Timers
Messaging
State Machine
Sending and Receiving
Structuring mechanisms
Targeting specifications
Entire system as task
Multiple tasks
OS and NON OS communicating mechanisms

21. Usage Perspectives of SDL
Design language
Used as primarily the design language to capture high-level details
Telecom, Real Time and major protocol development
Implementation language (with code generation)
SDL, MSC, TTCN, Simulation, Verification, Code Generation, C ...
Completely formal SDL representation
Takes extra 30% effort
Minimizes the need for extra coding phase
Early verification and validation

22. Usage Perspectives of SDL (2)
Test case development language
Proved to be very good for medium and high complex systems
Unit, Integration, Performance, Conformance, Stress testing
Features enable suitability
FSM, Timers, Messaging, Logging, Tracing and Reply with tool
Concurrency
Ability to simulate the non-existing modules

23. SDL Deployment at MIEL
The SDL methodology at MIEL uses integrated methods and tools for protocol stack software development
Requirements - MSC
System Analysis and Design - State Charts/SDL
Coding - C, SDL (Code Generation)
Unit and Integration Testing - Simulation & Validation
System Testing - TTCN/C
Not used for incremental changes to legacy products

24. Requirements Analysis
Importance levels
Critical, Medium, Low
Separate guidelines to be followed
Effectiveness of the code generator
implementation/Design aspects influence the performance and code size
Evolvability
Performance
Code
Attribute
level

25. V&V Discrete, Real Time and Remote target simulation
Validation of MSCs
Automatic detection of deadlocks and dynamic errors
Generation of MSCs

26. Code Generation Environment
Run Time Library
UNIX, NT, pSOS, VxWorks, …
SDT Auto
Code Tool
SDL Code
Gen. code
Compiler
H2SDL
SDT
Simulation
Executable
C Headers
Manual
C Code

27. Case Study

28. Problem Solving Stages
Requirement Analysis
MSCs are helpful
Interface Specification
State Charts
System Analysis and Design
HLD with SDL
LLD
Detailed SDL and C code
Logging
Simulation
Verifying the correctness wrt to Requirements
Code Generation and Application Build

29. HLD Environment Data structures Timers Messages
Network Layer, Physical Layer
Data structures
Packet, Frame and other internal data structures
Timers
A timer (set) is required for very frame
Messages
Packet, Frame, Ack, Negative Ack

30. Issues Application Building Process Maintenance
Separate Application, Part of the application, Part of the existing application, Run on a particular target, Multi Threading VS Single Threading
Process
Estimations and Actuals
Cycle Time, IPF, Productivity
Tracking and Controlling issues
Lack of sufficient data
Maintenance
Adding New Features, Corrections, Changing the implementations