Information Theoretic Operating Regimes of Large Wireless Networks

TL;DR

This paper develops a new theory for large wireless networks, identifying fundamental operating regimes based on key parameters, and proposes a hybrid scheme to achieve capacity in a previously unrecognized power and bandwidth limited regime.

Contribution

It introduces a novel scaling law formulation for wireless networks, revealing a new capacity-limited regime and proposing a hybrid scheme to attain optimal performance.

Findings

Identifies four distinct operating regimes based on network parameters.

Discovers a unique regime where capacity is limited by both power and bandwidth.

Proposes a hybrid scheme that achieves capacity in this new regime.

Abstract

In analyzing the point-to-point wireless channel, insights about two qualitatively different operating regimes--bandwidth- and power-limited--have proven indispensable in the design of good communication schemes. In this paper, we propose a new scaling law formulation for wireless networks that allows us to develop a theory that is analogous to the point-to-point case. We identify fundamental operating regimes of wireless networks and derive architectural guidelines for the design of optimal schemes. Our analysis shows that in a given wireless network with arbitrary size, area, power, bandwidth, etc., there are three parameters of importance: the short-distance SNR, the long-distance SNR, and the power path loss exponent of the environment. Depending on these parameters we identify four qualitatively different regimes. One of these regimes is especially interesting since it is fundamentally a consequence of the heterogeneous nature of links in a network and does not occur in the point-to-point case; the network capacity is {\em both} power and bandwidth limited. This regime has thus far remained hidden due to the limitations of the existing formulation. Existing schemes, either multihop transmission or hierarchical cooperation, fail to achieve capacity in this regime; we propose a new hybrid scheme that achieves capacity.