Price of Anarchy with Heterogeneous Latency Functions

TL;DR

This paper analyzes the price of anarchy in multi-commodity networks with heterogeneous polynomial delay functions, providing bounds for both atomic and non-atomic flows, with implications for traffic prioritization and net neutrality debates.

Contribution

It introduces new bounds on the price of anarchy for networks with heterogeneous polynomial delays, extending previous models to account for commodity-specific delays.

Findings

Derived bounds for heterogeneous polynomial delay functions.

Improved price of anarchy bounds for decomposable delay functions.

Established bounds for uniform latency functions.

Abstract

In this paper we consider the price of anarchy (PoA) in multi-commodity flows where the latency or delay function on an edge has a heterogeneous dependency on the flow commodities, i.e. when the delay on each link is dependent on the flow of individual commodities, rather than on the aggregate flow. An application of this study is the performance analysis of a network with differentiated traffic that may arise when traffic is prioritized according to some type classification. This study has implications in the debate on net-neutrality. We provide price of anarchy bounds for networks with $k$ (types of) commodities where each link is associated with heterogeneous polynomial delays, i.e. commodity $i$ on edge $e$ faces delay specified by $g_{i1}(e)f^{\theta}_1(e) + g_{i2}(e)f^{\theta}_2(e) + \ldots + g_{ik}(e)f^{\theta}_k(e) + c_i(e), $ where $f_i(e)$ is the flow of the $i$th commodity through edge $e$, $\theta \in {\cal N}$, $g_{i1}(e), g_{i2}(e), \ldots, g_{ik}(e)$ and $c_i(e)$ are nonnegative constants. We consider both atomic and non-atomic flows. For networks with decomposable delay functions where the delay induced by a particular commodity is the same, i.e. delays on edge $e$ are defined by $a_1(e)f_1^\theta(e) + a_2(e)f_2^\theta(e) + \ldots + c(e)$ where $\forall j , \forall e: g_{1j}(e) = g_{2j}(e) = \ldots = a_j(e)$, we show an improved bound on the price of anarchy. Further, we show bounds on the price of anarchy for uniform latency functions where each edge of the network has the same delay function.