Indoor communications networks realized through hybrid free-space optical and Wi-Fi links

Spencer Liverman; Qiwei Wang; Yu-Chung Chu; Anindita Borah; Songtao Wang; Arun Natarajan; Thinh Nguyen; Alan X. Wang

doi:10.1117/12.2292292

29 January 2018 Indoor communications networks realized through hybrid free-space optical and Wi-Fi links

Spencer Liverman, Qiwei Wang, Yu-Chung Chu, Anindita Borah, Songtao Wang, Arun Natarajan, Thinh Nguyen, Alan X. Wang

Proceedings Volume 10559, Broadband Access Communication Technologies XII; 105590H (2018) https://doi.org/10.1117/12.2292292
Event: SPIE OPTO, 2018, San Francisco, California, United States

Abstract

Recently, free-space optical (FSO) networks have been investigated as a potential replacement for traditional WiFi networks due to their large bandwidth potentials. However, FSO networks often suffer from a lack of mobility. We present a hybrid free-space optical and radio frequency (RF) system that we have named WiFO, which seamlessly integrates free-space optical links with pre-existing WiFi networks. The free-space optical link in this system utilizes infrared LEDs operating at a wavelength of 850nm and is capable of transmitting 50Mbps over a three-meter distance. In this hybrid system, optical transmitters are embedded periodically throughout the ceiling of a workspace. Each transmitter directs an optical signal downward in a diffuse light cone, establishing a line of sight optical link. Line of sight communications links have an intrinsic physical layer of security due to the fact that a user must be directly in the path of transmission to access the link; however, this feature also poses a challenge for mobility. In our system, if the free-space optical link is interrupted, a control algorithm redirects traffic over a pre-existing WiFi link ensuring uninterrupted transmissions. After data packets are received, acknowledgments are sent back to a central access point via a WiFi link. As the demand for wireless bandwidth continues to increase exponentially, utilizing the unregulated bandwidth contained within optical spectrum will become necessary. Our fully functional hybrid free-space optical and WiFi prototype system takes full advantage of the untapped bandwidth potential in the optical spectrum, while also maintaining the mobility inherent in WiFi networks.

Conference Presentation

Citation Download Citation

Spencer Liverman, Qiwei Wang, Yu-Chung Chu, Anindita Borah, Songtao Wang, Arun Natarajan, Thinh Nguyen, and Alan X. Wang "Indoor communications networks realized through hybrid free-space optical and Wi-Fi links", Proc. SPIE 10559, Broadband Access Communication Technologies XII, 105590H (29 January 2018); https://doi.org/10.1117/12.2292292

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available