CSCE 491 – Homework #2 Page 1
CSCE 491 – Fall 2002
Homework #2
Using the Rose model (the file you download off the HW#2 link on my webpage), make the following
extensions to the different diagrams as indicated in the following specifications. We will use this design
model for the next few homework assignments, so make your changes and extensions carefully. And make
sure you save and backup this file. I’d hate to see you lose any work (and I won’t accept explanations to
this affect as to why you don’t have your homework).
1. Use Case diagram:
We want to add several new cases and actors to the model in a new Use Case Diagram: (1) Add new
Actors: ShiftController, WordCounter, FrameStateCounter, PipelineDecoder; (2) Add new Use Cases:
ShiftInWord, CycleFrameState, BufferFrameWord, CycleFrameWord, DecodeFrameTargetBlock. These
should be created in a separate Use Case diagram. You’ll need to create one using the Browse->Use Case
and selecting New… then name your new diagram “WordShifterController”. You will be creating a
diagram, like the one below, but with 4 Actors and 5 Use Cases. Try and indicate the directions of
association arrows accordingly.
PHY_Layer
TransmitFram e
ReceiveFrame
Deco deFrameHeader
DecodeAddres ses
DecodeDurationID
DecryptFrameData
DecodeFrameCheck
DecodeSequenceControl
MAC_Layer
2. Class Diagram
Given the class diagram below, I want you to list the statements that are captured in the class diagram. I
want to check your understanding of how to read these diagrams, so make a list of each statement that can
be read from the diagram.
Here’s a few to start with:
1. a Station has_state of exactly one OperationState.
2. a MAC_Layer ResidesIn exactly one Station.
3. a Station has exactly one MAC_Layer. (Note we can read these association links in both
directions.)
4. a PHY_Layer Received&Converts one to many Frames.
