Association, Blockage and Handoffs in IEEE 802.11ad based 60GHz Picocells- A Closer Look

TL;DR

This paper provides a detailed quantitative analysis of IEEE 802.11ad 60GHz WLANs, focusing on link alignment, blockage effects, and handoff mechanisms, with high accuracy measurements and practical insights for future millimeter wave networks.

Contribution

It offers the first comprehensive quantitative evaluation of 60GHz WLANs, including blockage differentiation, handoff strategies, and real-world experimental data.

Findings

High accuracy blockage differentiation (96-97%) between temporary and permanent obstructions.

Quantitative measurements of link alignment and association overheads.

Successful demonstration of intelligent handoffs using commodity IEEE 802.11ad devices.

Abstract

The link misalignment and high susceptibility to blockages are the biggest hurdles in realizing 60GHz based wireless local area networks (WLANs). However, much of the previous studies investigating 60GHz alignment and blockage issues do not provide an accurate quantitative evaluation from the perspective of WLANs. In this paper, we present an in-depth quantitative evaluation of commodity IEEE 802.11ad devices by forming a 60GHz WLAN with two docking stations mimicking as access points (APs). Through extensive experiments, we provide important insights about directional coverage pattern of antennas, communication range and co-channel interference and blockages. We are able to measure the IEEE 802.11ad link alignment and association overheads in absolute time units. With a very high accuracy (96-97%), our blockage characterization can differentiate between temporary and permanent blockages caused by humans in the indoor environment, which is a key insight. Utilizing our blockage characterization, we also demonstrate intelligent handoff to alternate APs using consumergrade IEEE 802.11ad devices. Our blockage-induced handoff experiments provide important insights that would be helpful in integrating millimeter wave based WLANs into future wireless networks.