Performance Analysis of mmWave Ad Hoc Networks (1412.0765v2)

Abstract: Ad hoc networks provide an on-demand, infrastructure-free means to communicate between soldiers in war zones, aid workers in disaster areas, or consumers in device-to-device (D2D) applications. Unfortunately, ad hoc networks are limited by interference due to nearby transmissions. Millimeter-wave (mmWave) devices offer several potential advantages for ad hoc networks including reduced interference due to directional antennas and building blockages, not to mention huge bandwidth channels for large data rates.. This paper uses a stochastic geometry approach to characterize the one-way and two-way signal-to-interference ratio distribution of a mmWave ad hoc network with directional antennas, random blockages, and ALOHA channel access. The interference-to-noise ratio shows that a fundamental limitation of an ad hoc network, interference, may still be an issue. The performance of mmWave ad hoc networks is bounded by the transmission capacity and area spectral efficiency. The results show that mmWave networks can support much higher densities and larger spectral efficiencies, even in the presence of blockage, compared with lower frequency communication for certain link distances. Due to the increased bandwidth, the rate coverage of mmWave can be much greater than lower frequency devices.

• The paper presents an analytical framework using stochastic geometry to evaluate mmWave ad hoc network performance considering directional antennas, blockages, and interference.
• Analysis shows random blockages significantly impact SINR by differentiating LOS/NLOS paths, highlighting challenges in NLOS communication despite reduced interference from directional beams.
• The study calculates transmission capacity and area spectral efficiency, indicating significant performance gains over lower frequencies, especially under LOS conditions, enabling high spectral efficiency.

Performance Analysis of mmWave Ad Hoc Networks

This paper presents a robust analytical framework for evaluating the performance of millimeter-wave (mmWave) ad hoc networks, considering factors like interference, signal-to-interference ratio (SIR), and area spectral efficiency (ASE). The work employs stochastic geometry principles to model and analyze these networks, particularly focusing on networks utilizing directional antennas, random blockages, and an ALOHA channel access method.

Key Contributions

1. SINR Distribution Analysis: The authors derive the signal-to-interference-plus-noise ratio (SINR) distribution for mmWave ad hoc networks by accounting for line-of-sight (LOS) and non-line-of-sight (NLOS) communication. The approach delineates the effects of interference and noise in the presence of random blockages and directional beamforming.
2. Blockage and Interference: The analysis uses a blockage model to differentiate between LOS and NLOS paths, significantly affecting the network's SINR and performance. The paper finds that while mmWave technology benefits from reduced interference through directional antennas, NLOS communication still poses a substantial challenge due to higher path-loss exponents.
3. Transmission Capacity and ASE: The transmission capacity, defined as the maximum user density supporting a target SINR with specific outage constraints, is calculated. Results indicate significant gains in mmWave networks compared to lower frequency networks, particularly under conditions favoring LOS communication. The ASE, which quantifies the network's efficiency in bits/sec/Hz/m², demonstrates that mmWave networks can achieve drastically higher efficiency thanks to their large bandwidth.
4. Two-Way Communication: The paper extends the analysis to account for two-way communications using bandwidth allocation between forward and reverse links, showcasing the flexibility and potential efficiency improvements in mmWave networks compared to simpler, fixed allocations.

Implications and Future Directions

The implications of this research are both practical and theoretical. Practically, strategies to enhance mmWave ad hoc network deployments become evident, such as aggressively pursuing LOS communication to harvest the immense mmWave capacity. Theoretically, the findings push forward the understanding of network capacity limits under realistic interference and blockage conditions.

Future developments may address optimizing bandwidth allocation in two-way communication settings, exploring dynamic antenna beamforming strategies to mitigate interference further, and improving network models to consider user mobility and changing environmental conditions.

This paper establishes an analytical baseline for evaluating mmWave ad hoc networks' performance, guiding future network design and implementation to capture the full potential of mmWave technology.