11
V. Liberatore
Pervasive Computing
Why layering?
lDealing with complex systems:
*Explicit structure allows identification, relationship of complex system’s pieces
nLayered reference model for discussion
*Modularization eases maintenance, updating of system
nChange of implementation of layer’s service transparent to rest of system
nE.g., change in gate procedure doesn’t affect rest of system
*Layering considered harmful?