A framework and source model for design and evaluation of Robust Header Compression

摘要

Robust Header Compression (ROHC) is a specification being developed by the Internet Engineering Task Force (IETF) for compressing protocol headers robustly over wireless channels to improve bandwidth efficiency. Traditionally, header compression schemes are designed based on qualitative descriptions of source headers. This is inadequate because qualitative descriptions do not precisely describe the effect of different source and deployment scenarios, and it is difficult to perform optimization using this methodology. In addition, due to the use of qualitative descriptions, most studies on header compression performance do not take into account the tradeoff between performance metrics such as robustness and compression efficiency. In this paper, we present a modeling framework for header compression. For the first time, a source model is developed to study header compression. Modeling the way packets are generated from a source with multiple concurrent flows, the source model captures the real-world behavior of the IP Identification header field. By varying the parameters in the source and channel models of our framework, different source and deployment scenarios can be modeled. We use the framework to define and establish the relationship between performance metrics, offering new perspectives to their current definitions. We then introduce the objective of scheme design and the notion of optimal schemes. Based on this new paradigm, we present a novel way to study the tradeoff dependencies between performance metrics. We demonstrate how a scheme can be designed to optimize tradeoffs based on the desired level of performance.