Millimeter-wave wireless LANs are targeted for use with bandwidth-intensive applications such as virtual/augmented reality and real-time high-definition video. To maintain high throughput while addressing mmWave signal blockages, multiple access points (APs) within one room to improve line-of-sight conditions is considered a promising approach. In a scenario with fixed and mobile (human) obstacles, we mathematically analyze LoS blockages produced by mobility, and use the analysis to develop a multi-AP association scheme. Our scheme statically assigns primary and backup APs in order to maximize blockage robustness and perform load balancing among APs. Simulation results show that: 1) our static approach can provide blockage tolerance close to that of an expensive dynamic probing approach while achieving higher throughput, 2) the use of client mobility patterns, if known, can improve our static approach even further, and 3) our approach achieves significantly better fairness and load balancing than existing approaches.
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Optimal Access Point Placement for Multi-AP mmWave WLANs
mmWave communication in 60GHz band has been recognized as an emerging technology to support various bandwidth-hungry applications in indoor scenarios. To maintain ultra-high throughputs while addressing potential blockage problems for mmWave signals, maintaining line-of-sight (LoS) communications between client devices and access points (APs) is critical. To maximize LoS communications, one approach is to deploy multiple APs in the same room. In this paper, we investigate the optimal placement of multiple APs using both analytical methods and simulations. Considering the uncertainty of obstacles and clients, we focus on two typical indoor settings: random-obstacle-random-client (RORC) scenarios and fixed-obstacle-random-client (FORC) scenarios. In the first case, we analytically derive the optimal positions of APs by solving a thinnest covering problem. This analytical result is used to show that deploying up to 5 APs in a specific room brings substantial performance gains. For the FORC scenario, we propose the shadowing-elimination search (SES) algorithm based on an analytic model to efficiently determine the placement of APs. We show, through simulations, that with only a few APs, the network can achieve blockage-free operation in the presence of multiple obstacles and also demonstrate that the algorithm produces near-optimal deployments. Finally, we perform ns-3 simulations based on the IEEE 802.11ad protocol at mmWave frequency to validate our analytical results. The ns-3 results show that proposed multi-AP deployments produce significantly higher aggregate performance as compared to other common AP placements in indoor scenarios.
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- Award ID(s):
- 1813242
- NSF-PAR ID:
- 10167652
- Date Published:
- Journal Name:
- Proceedings of the 22nd International ACM Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems
- Page Range / eLocation ID:
- 35 to 44
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1145/3345768.3355914
