@inproceedings{de9dabf0a4034494aa01c8e5238d1460,
title = "Layering as optimization decomposition: Questions and answers",
abstract = "Network protocols in layered architectures have historically been obtained on an ad-hoc basis, and much of the recent cross-layer designs are conducted through piecemeal approaches. Network protocols may instead be holistically analyzed and systematically designed as distributed solutions to some global optimization problems in the form of generalized Network Utility Maximization (NUM), providing insight on what they optimize and on the structures of network protocol stacks. In the form of 10 Questions and Answers, this paper presents a short survey of the recent efforts towards a systematic understanding of {"}layering{"} as {"}optimization decomposition{"}. The overall communication network is modeled by a generalized NUM problem, each layer corresponds to a decomposed subproblem, and the interfaces among layers are quantified as functions of the optimization variables coordinating the subproblems. Furthermore, there are many alternative decompositions, each leading to a different layering architecture. Industry adoption of this unifying framework has also started. Here we summarize the current status of horizontal decomposition into distributed computation and vertical decomposition into functional modules such as congestion control, routing, scheduling, random access, power control, and coding. We also discuss under-explored future research directions in this area. More importantly than proposing any particular crosslayer design, this framework is working towards a mathematical foundation of network architectures and the design process of modularization.",
keywords = "Adaptive coding, Congestion control, Cross-layer design, Distributed algorithm, Lagrange duality, MAC, Network architecture, Network utility maximization, Optimization, Power control, Reverse engineering, Routing, Scheduling, Stochastic control, TCP/IP",
author = "Mung Chiang and Low, {Steven H.} and Calderbank, {A. Robert} and Doyle, {John C.}",
year = "2006",
month = jan,
day = "1",
doi = "10.1109/MILCOM.2006.302293",
language = "English (US)",
isbn = "1424406188",
series = "Proceedings - IEEE Military Communications Conference MILCOM",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
booktitle = "Military Communications Conference 2006, MILCOM 2006",
address = "United States",
note = "Military Communications Conference 2006, MILCOM 2006 ; Conference date: 23-10-2006 Through 25-10-2006",
}