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A Comparative Survey of Optical Wireless Technologies: Architectures and Applications

Mostafa Zaman Chowdhury, Md. Tanvir Hossan, Amirul Islam, Yeong Min Jang

arXiv:1810.02594v1cs.NI

TL;DR

Growing 5G and beyond capacity demands exceed what current RF systems can fulfill. This survey reviews optical wireless communication and compares wireless technologies, finding clear differences in their principles, architectures, and application scenarios.

  • Problem

    Current RF systems cannot fulfill the exponential growth in wireless-capacity demand for 5G and beyond communications.

    Source: §V · p. 18

  • Method

    The paper surveys emerging optical wireless technologies and compares wireless systems across their principles, architectures, and application scenarios.

    Source: A. Summary · p. 15, §V · p. 18

  • Results

    The comparison shows clear differences among wireless technologies in basic principles, architectures, application scenarios, and advantages and disadvantages.

    Source: A. Summary · p. 15

  • Takeaways & Limitations

    VLC, LiFi, and OCC are identified for 5G small-cell hotspots, while FSO, LiFi, and VLC can provide high-capacity backhaul.

    Source: C. OWC for 5G and IoT · p. 2

    Outdoor VLC remains an area needing further research, with ambient-light noise and sunlight complicating LED/photodiode detection.

    Source: C. Optical Camera Communication (OCC) · p. 10

Abstract

from arXiv · show

New high-data-rate multimedia services and applications are evolving continuously and exponentially increasing the demand for wireless capacity of fifth-generation (5G) and beyond. The existing radio frequency (RF) communication spectrum is insufficient to meet the demands of future high-datarate 5G services. Optical wireless communication (OWC), which uses an ultra-wide range of unregulated spectrum, has emerged as a promising solution to overcome the RF spectrum crisis. It has attracted growing research interest worldwide in the last decade for indoor and outdoor applications. OWC offloads huge data traffic applications from RF networks. A 100 Gb/s data rate has already been demonstrated through OWC. It offers services indoors as well as outdoors, and communication distances range from several nm to more than 10000 km. This paper provides a technology overview and a review on optical wireless technologies, such as visible light communication, light fidelity, optical camera communication, free space optical communication, and light detection and ranging. We survey the key technologies for understanding OWC and present state-of-the-art criteria in aspects, such as classification, spectrum use, architecture, and applications. The key contribution of this paper is to clarify the differences among different promising optical wireless technologies and between these technologies and their corresponding similar existing RF technologies

I. INTRODUCTION … E. Contribution of This Paper

Growing 5G and IoT capacity demands strain the regulated RF spectrum, while optical wireless communication (OWC) offers complementary high-data-rate connectivity across indoor and outdoor settings. This survey compares OWC technologies, their architectures and applications, and their distinctions from related RF technologies.

I. INTRODUCTION

  • 5G and IoT growth intensifies demand for high rates and massive connectivity, while RF spectrum below 10 GHz is nearly exhausted and constrained by limited bandwidth, regulation, and interference.The paper notes 5G projections of 1000 times the mobile data volume per area and 100 times the connected devices of existing networks.Source: §I · p. 1

A. What are the OWC Technologies?

  • OWC uses visible, infrared, or ultraviolet light; VLC, LiFi, OCC, FSO, and LiDAR differ in their transmitters, receivers, operating bands, functions, and communication ranges.VLC can combine communication, illumination, and localization; OCC uses a camera or image sensor, FSO uses narrow intense beams, and LiDAR supports 3D mapping.Source: A. What are the OWC Technologies? · p. 2

B. OWC Application Platforms

  • OWC supports diverse platforms and link types, from homes, transport, and underwater settings to space, with suitable technologies depending on application, speed, and platform.Links include device-to-device, machine-to-machine, vehicle-to-infrastructure, point-to-point, and multipoint configurations.Source: B. OWC Application Platforms · p. 2

C. OWC for 5G and IoT

  • VLC, LiFi, and OCC can provide dense 5G hotspot cells, while FSO, LiFi, and VLC can support high-capacity backhaul and low-power, secure connectivity for diverse devices.The paper presents OWC as a means to support reliable connections, network densification, area spectral efficiency, and low-power IoT connectivity.Source: C. OWC for 5G and IoT · p. 2

D. Related Review Literatures

  • Earlier reviews –,,, – addressed OWC technologies and topics such as standards, deployment, integration, and VLC challenges, but a comparative survey was missing.Existing reviews also covered optical broadband and wireless access, as well as OWC modulation, MIMO, channel modeling, and capacity analysis.Source: D. Related Review Literatures · pp. 2–3

E. Contribution of This Paper

  • This survey compares OWC technologies with one another and with similar RF technologies across spectrum, technology, scenarios, devices, architecture, operating principles, and applications.The paper is organized into an OWC overview and classification, technology and application discussions, future research issues, and a conclusion.Source: E. Contribution of This Paper · p. 3

II. OVERVIEW · A. OWC Classification

The overview presents the optical spectrum as a large, mostly available resource for OWC complementary to RF, while the classification organizes OWC applications by communication distance, from chip-scale links to inter-satellite communications.

II. OVERVIEW

  • The optical spectrum offers OWC a large unregulated bandwidth complementary to RF, and researchers have demonstrated high data rates using OWC, –.Source: §II · p. 4
  • Incoherent front ends enable relatively straightforward intensity modulation and direct detection (IM/DD), supported by baseband techniques and available high-bandwidth components.Source: §II · p. 4
  • OWC’s advantages include security, low power and cost, high SNR, and lighting integration, while obstacles, sudden blocking, and limited transmitted power constrain systems,.Source: §II · p. 4
  • IR is invisible and usable without illumination, UV supports LOS and NLOS links at specified distances, and NIR and visible light behave qualitatively similarly,.Source: §II · p. 4

A. OWC Classification

  • OWC is classified into five distance categories: ultra-short chip-to-chip links at nm/mm scales, short-range WBAN, WPAN, and underwater links, and medium-range VLC WLANs and outdoor V2X [37], –.Source: A. OWC Classification · p. 4
  • Long-range OWC includes km-scale inter-building connections, while ultra-long-range links include inter-satellite, satellite-airplane, airplane-airplane, and ground links,,.Source: A. OWC Classification · p. 4
  • The application classification spans WBAN, WPAN, WMAN, and WAN, with communication ranges extending from ultra-short inter-chip links to ultra-long inter-satellite links.Source: A. OWC Classification · p. 5

B. Infrared vs VL vs Ultraviolet for OWC · C. NLOS Communications

OWC uses infrared, visible-light, and ultraviolet bands, with different technologies drawing on these spectra; although OWC is mainly used for LOS links, NLOS communication is also possible, including high-data-rate UV links.

B. Infrared vs VL vs Ultraviolet for OWC

C. NLOS Communications

  • Although OWC is widely used for LOS communication, NLOS links are also possible, including high-data-rate communication using UV.Source: C. NLOS Communications · p. 6
  • Reflections of IR and VL enable low-data-rate NLOS communication, while UV can provide high-data-rate NLOS communication.Fig. 4 depicts these IR/VL and UV NLOS configurations.Source: C. NLOS Communications · p. 6, Figure 4 · p. 7
  • For NLOS UV links, an omnidirectional transmitter points upward at an elevation, and the receiver must intersect its beam.The transmitter uses a xenon flashtube inside a searchlight dish.Source: C. NLOS Communications · p. 6
  • The UV receiver requires high gain and low noise and uses a photomultiplier tube and counter; ozone and oxygen strongly absorb UV light.Source: C. NLOS Communications · p. 6
  • Knowing transmitted and received beam positions is important for higher data rates, lower latency, and reduced transmitted power.Source: C. NLOS Communications · p. 7

D. LED vs LD for OWC · III. ENABLING TECHNOLOGIES · A. Visible Light Communication (VLC)

The paper contrasts LED- and LD-based OWC and describes VLC’s architectures, performance, limitations, and applications. VLC uses rapid light modulation for communication alongside illumination, while its suitability depends on the transmitter, receiver, and communication medium.

D. LED vs LD for OWC

  • LEDs’ rapid intensity switching supports simultaneous energy-efficient illumination and very-high-speed communication.The paper also notes LED use for localization and a bandwidth–optical-efficiency tradeoff; LDs are proposed as an alternative for better visible-light spectrum utilization.Source: D. LED vs LD for OWC · p. 7, A. Visible Light Communication (VLC) · p. 8
  • LD coherence concentrates light for long-distance, high-data-rate links with less interference, but low aperture limits LDs to point-to-point communication.The paper also notes laser safety concerns, cost, color-mixing complications, and uncertain suitability for illumination.Source: D. LED vs LD for OWC · p. 7

III. ENABLING TECHNOLOGIES

  • OWC technologies differ in transmitter, receiver, and communication medium: they use LEDs or LDs, PDs or cameras (or ISs), and IR, visible-light, or UV spectra.Fig. 5 presents basic architectures, including downlink and uplink communication.Source: §III · p. 7, Figure 5 · p. 8

A. Visible Light Communication (VLC)

  • VLC offers 10,000 times more bandwidth capacity than RF-based technologies and opportunities across homes, offices, vehicles, aircraft, trains, and roads, but is less effective outdoors and cannot communicate long distances.The paper also describes VLC as non-harmful to humans and potentially useful in high-density, high-capacity 5G networks and IoT.Source: A. Visible Light Communication (VLC) · pp. 7–8
  • 100 Gbps is achievable with LD-based VLC at standard indoor illumination levels.The paper also reports potential LED-based VLC rates over 10 Gbps and 3 Gbps achieved using a single-color LED,.Source: A. Visible Light Communication (VLC) · p. 8
  • VLC applications include smart lighting, secure high-speed connectivity, vehicle links, hospital communications, and RF spectrum relief.The paper also identifies aircraft media services and underwater data transfer as applications where RF is undesirable or unavailable.Source: A. Visible Light Communication (VLC) · p. 8
  • Other VLC applications include information-bearing LED signboards, location-based services, high-speed local area networks, and sound transmission using different-colored LEDs.Source: A. Visible Light Communication (VLC) · p. 8
  • VLC connects user equipment to a core network through LED or LD transmitters, camera, IS, or PD receivers, and wired or wireless backhaul.Indoor backhaul is normally wired, whereas outdoor vehicular cases use wireless backhaul; LiFi and OCC use similar connectivity.Source: A. Visible Light Communication (VLC) · p. 9, Figure 6 · p. 9

B. Light Fidelity (LiFi)

LiFi is a bidirectional, multiuser optical networking system that supports seamless mobility, forming small attocells within heterogeneous networks. It can deliver very high data rates and support indoor and outdoor applications, but has limited suitability for outdoor and long-range communication.

B. Light Fidelity (LiFi)

  • LiFi is bidirectional, supports seamless user mobility and multiuser communication, and uses visible light forward with IR, visible light, or UV possible on the return path –, –.Unlike VLC, LiFi is a complete wireless networking system that can form a small attocell layer in heterogeneous networks; a VLC system is LiFi only if it has these features, while LiFi is VLC only when visible light is the transmission medium.Source: B. Light Fidelity (LiFi) · p. 9
  • Over 3 Gbps from a single microLED and 56 Gbps using a VCSEL have been demonstrated for LiFi,.LiFi transmitters can use existing LEDs or laser diodes combined with optical diffusers.Source: B. Light Fidelity (LiFi) · p. 9
  • LiFi and VLC applications include indoor communication with illumination and outdoor street-light communication, while vehicle-to-infrastructure and vehicle-to-vehicle examples are VLC [Fig. 7].Outdoor scenarios may combine communication and illumination, as with street lamps and vehicle headlamps, or provide communication only, as with traffic signals and rear lamps; street light–smartphone communication may use VLC or LiFi depending on uplink media and features.Source: B. Light Fidelity (LiFi) · p. 9, Figure 7 · p. 10
  • LiFi offers fast data rates, lower cost, available spectrum capacity, and better security than WiFi, but is less effective outdoors and cannot provide long-range communication.Its security makes LiFi promising for electromagnetic-sensitive locations such as hospitals, nuclear plants, and aircraft cabins.Source: B. Light Fidelity (LiFi) · p. 9

C. Optical Camera Communication (OCC)

OCC uses a camera or image sensor to receive optical signals, distinguishing it from VLC in its supported light spectrum, transmitters, and receivers. Its pixel-level spatial resolution supports source separation and diverse indoor and outdoor applications, but conventional camera frame rates and line-of-sight links constrain communication.

C. Optical Camera Communication (OCC)

  • OCC uses LEDs with a camera or image sensor as receiver and can use infrared or visible light, unlike VLC’s visible-light medium and LED or laser-diode transmitters.VLC with LEDs and a camera/image sensor also fits the OCC definition; OCC using visible light can be considered VLC.Source: C. Optical Camera Communication (OCC) · p. 10
  • A camera’s millions of pixels spatially separate signals from different directions and can reject background-light pixels, supporting interference-free, reliable outdoor communication,,.Camera/image-sensor reception can address LED/photodiode VLC limitations including short range, ambient-light noise, and difficulty detecting LEDs under direct sunlight.Source: C. Optical Camera Communication (OCC) · pp. 10–11
  • OCC applications include V2X and drone communication, cm-level localization, indoor positioning, digital signage, motion recognition, and augmented or virtual reality.Unique LED identification codes can enable camera-equipped smart devices to locate people, objects, or devices indoors.Source: C. Optical Camera Communication (OCC) · pp. 11–12
  • A one-pixel LED image can maintain stable communication as distance changes, provided the image remains at least as large as a sensor pixel,.The incident light power per pixel remains unaffected by distance changes under this condition.Source: C. Optical Camera Communication (OCC) · p. 12
  • OCC links require line of sight, while conventional cameras’ low frame rates limit data rates and can cause visible flicker with low-frequency visible-light signals,.Common image sensors operate at 30 fps, and the data rate in bps/pixel must be no greater than half the frame rate to satisfy the Nyquist requirement.Source: C. Optical Camera Communication (OCC) · p. 12

D. Free Space Optical Communication (FSOC)

FSOC uses focused optical beams—typically in the NIR—to provide high-bandwidth wireless links over distances from nanometers to thousands of kilometers. Its broad application range is tempered by reliability losses from weather, turbulence, and obstructions.

D. Free Space Optical Communication

  • Typically using NIR, FSOC can also use visible or UV light; IR has lower attenuation, illumination is unnecessary, and transmitters often use laser diodes.Focused, narrow beams support high-data-rate links between fixed points over distances from a few nanometers to several thousand kilometers.Source: D. Free Space Optical Communication… · p. 12
  • FSOC encodes and modulates data before optical transmission, then collects and focuses the received beam onto a photodetector for filtering and demodulation.Transmission may use OOK, PM, or OFDM; optical amplification is optional. The receiver converts photodetector current to voltage and uses a low-pass filter to limit thermal and background noise.Source: D. Free Space Optical Communication… · pp. 12–13
  • FSOC supports long-distance links at 10 Gbps and a 40-Gbps link over 20 m, with recent data rates comparable to fiber optics.FSOC uses spectrum above 300 GHz, described as unregulated worldwide, and offers substantially more bandwidth than RF-based communication.Source: D. Free Space Optical Communication… · p. 13
  • FSOC links serve cellular backhaul, disaster recovery, campus connectivity, surveillance, underwater and ship-to-ship communication, and satellite and aircraft links.Other applications include inter-chip and network connectivity, broadcasting, and fiber backup; Fig. 11 illustrates several scenarios.Source: D. Free Space Optical Communication… · p. 13, Figure 11 · p. 13
  • FSOC reliability, especially over long ranges, is vulnerable to weather-related attenuation, atmospheric turbulence, and temporary beam blockage by physical obstructions.Examples include fog, rain, haze, smoke, sandstorms, clouds, snow, scintillation, birds, trees, and tall buildings.Source: D. Free Space Optical Communication… · p. 13

E. Light Detection and Ranging (LiDAR)

LiDAR uses optical light to sense distant targets, measure their range and other properties, and support high-resolution 3D mapping. Its systems operate from ground, airborne, and space platforms and share some ranging principles with RADAR while using a different type of energy.

E. Light Detection and Ranging (LiDAR)

  • LiDAR is optical remote sensing for finding target range or other information,, –, using NIR and visible light to image diverse materials.Its targets include rain, dust, non-metallic objects, chemical compounds, aerosols, clouds, and individual molecules.Source: E. Light Detection and Ranging (LiDAR) · p. 13
  • 30 cm or better terrain resolution is possible with an aircraft-mounted laser, while scattered-light measurements generate points for 3D mapping.Source: E. Light Detection and Ranging (LiDAR) · p. 14
  • LiDAR systems comprise a laser, photodetector and receiver electronics, scanner and optics, and position and navigation subsystems; unlike RADAR, they transmit optical light rather than microwaves.Both technologies use reflected energy to determine target distance, size, and other characteristics, but differ in how they work and the targets and applications best suited to each.Source: E. Light Detection and Ranging (LiDAR) · p. 14
  • Ground, airplane, and space platforms collect LiDAR data, with airborne LiDAR the most commonly used platform.Airborne collection scans the ground, uses GPS for aircraft altitude and x-y location and an inertial measurement unit to track tilt, then combines the data to calculate range-related information.Source: E. Light Detection and Ranging (LiDAR) · p. 14, Figure 12 · p. 14

DIFFERENCES BETWEEN LiDAR AND RADAR

The supplied passages describe LiDAR as a 3D sensing technology used alongside radar in vehicle control and across several other applications, but do not directly compare LiDAR with radar.

DIFFERENCES BETWEEN LiDAR AND RADAR

  • LiDAR measures the distance between a car and an object and builds a 3D environmental image; combined with radar, its data informs onboard steering, braking, and acceleration decisions.Fig. 13 shows a vehicle scene and the LiDAR-mapped 3D image for that same scenario.Source: DIFFERENCES BETWEEN LiDAR AND RADAR · p. 14, Figure 13 · p. 15
  • LiDAR supports archaeological mapping and elevation models, military target identification, and rock-mass characterization using 3D point clouds.The cited rock properties include discontinuity orientation, aperture, and persistence.Source: DIFFERENCES BETWEEN LiDAR AND RADAR · p. 15
  • In robotics, LiDAR is used to observe environments and classify objects; precise 3D elevation maps can also help calculate safe landing velocities.Source: DIFFERENCES BETWEEN LiDAR AND RADAR · p. 15

IV. SUMMARY, OPEN ISSUES, AND FUTURE RESEARCH DIRECTIONS · A. Summary

The summary compares OWC technologies by their capabilities and limitations, contrasting them with RF communication and recommending coexistence to address their complementary constraints.

A. Summary

  • OWC reaches 100 Gbps versus RF communication’s 6 Gbps, with longer communication distance, lower interference, and higher security, but is sensitive to obstacle blocking.The paper presents OWC and RF coexistence as an effective future solution.Source: A. Summary · p. 15, Table VII · p. 16
  • VLC supports illumination, communication, and localization, while LiFi supports illumination and communication; both provide high data rates but are limited outdoors and over long distances.The comparison also identifies short-distance communication and outdoor unsuitability as limitations for VLC and LiFi.Source: A. Summary · pp. 15–16
  • OCC supports communication, imaging, and positioning, including comparatively long-distance outdoor communication, but conventional cameras’ low frame rates constrain its data rate.Source: A. Summary · p. 15
  • FSOC supports high-data-rate, ultra-long-range communication, although environmental conditions affect its performance.Source: A. Summary · p. 15
  • LiDAR enables very-high-resolution 3D mapping, but it is currently very expensive and its performance is affected by the environment.Source: A. Summary · p. 15
  • The technologies differ in standards, modulation, transmission media, transmitters, receivers, operating principles, attenuation, and security, so their application areas should be chosen accordingly.The comparison summarizes differences in basic principles, architectures, and application scenarios.Source: A. Summary · p. 15

B. Open Issues and Future Research Directions

The section identifies technical challenges and research directions for OWC, spanning hybrid networks, link performance, mobility, and applications.

Hybrid network architecture

  • Hybrid OWC/RF networks can improve load balancing, link reliability, connectivity in remote settings, and interference reduction, but require smooth adaptive switching between systems.Examples include WiFi/LiFi, VLC/femtocell, VLC/FSO, and LiFi/OCC,.Source: B. Open Issues and Future Research… · pp. 16–17

Propagation and underwater links

  • Future link research should assess NLOS UV performance across atmospheric and geometric conditions, mitigate atmospheric losses, and adapt underwater modulation and coding to the environment.A 405 nm blue-light LD is identified as a potential route to long-range underwater links.Source: B. Open Issues and Future Research… · p. 17

Backhaul and spectrum

  • The passage identifies extending the optical spectrum beyond the UV band as a challenging issue for future wireless communication, with potential benefits from high power and low cost sources.Source: B. Open Issues and Future Research… · p. 17

Mobility and interference

  • Seamless OWC mobility needs horizontal and vertical handovers, while dense VLC small cells must manage inter-cell optical interference.LiFi currently provides seamless connectivity; proposed handovers include LiFi-to-LiFi and LiFi-to-WiFi.Source: B. Open Issues and Future Research… · p. 17

MIMO optical wireless communications

  • MIMO can improve OWC power efficiency, reliability, and capacity, but IM/DD channel properties, added complexity, narrow receiver fields of view, and misalignment hinder deployment.The section calls for accurate channel models across OWC technologies; MIMO applicability is under investigation,,,.Source: B. Open Issues and Future Research… · p. 17

Applications

  • Research directions include LED-based OWC for RF-sensitive healthcare devices, vehicular traffic management, drone localization and communication, and accurate outdoor positioning.LED positioning is noted for accuracy, license-free operation, lack of electromagnetic interference, and low-cost frontends.Source: B. Open Issues and Future Research… · p. 17

OCC, dimming, and flicker

  • OCC research should improve its reported 55 Mbps data rate and develop RGB-LED parallel VLC,,, while OWC needs effective dimming and flicker-avoiding modulation.Flicker is described as harmful to human health.Source: B. Open Issues and Future Research… · pp. 17–18

V. CONCLUSIONS

The survey presents optical wireless communication (OWC) as a complement to RF for 5G and beyond, where RF spectrum cannot meet growing wireless-capacity demand. It compares major OWC technologies, their architectures, applications, advantages, limitations, and challenges.

V. CONCLUSIONS

  • The optical spectrum, spanning infrared, visible, and ultraviolet bands, can support 5G and IoT connectivity while complementing RF to relieve spectrum-shortage problems.The paper notes efforts to adapt applications currently based on RF communication to OWC.Source: §V · p. 18
  • The survey covers VLC, LiFi, OCC, FSOC, and LiDAR technologies, which support communication from ultra-short to ultra-long distances.Their distinct advantages and limitations make their application areas different.Source: §V · p. 18
  • The paper categorizes OWC systems and clarifies differences in their basic principles, architectures, and application scenarios, while explaining each technology's challenges.It presents OWC as relevant to settings including industry, healthcare, transportation, residences, underwater communication, and space.Source: §V · p. 18

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