Demystifying the Role of Photonics in 5G Networks

Demystifying the Role of Photonics in 5G Networks

The dawn of the 5G era promises a transformative leap in wireless communication, offering unparalleled speeds, low latency, and vast device connectivity. However, to fully realize the potential of 5G, we must overcome many technological challenges. Traditional methods, reliant on electronic signals, face limitations in terms of speed and capacity. This is where photonics, the science of generating, detecting, and manipulating light, emerges as a game-changer.

Photonics offers a promising solution to the hurdles that traditional technologies encounter. By harnessing the unique properties of light, photonics enables us to propel 5G networks to new heights. This article will delve into the intricacies of photonics and its pivotal role in the 5G revolution.

Where to Find Photonics in Mobile Networks

In the intricate web of mobile wireless networks, photonics plays a critical role in the form of optical fibers and components. Optical fibers, slender threads of glass or plastic, are the backbone of modern communication. They transmit data over long distances through light pulses, ensuring minimal signal loss. This feature is particularly crucial in 5G networks, where signals must travel over extended distances with minimal degradation.

Figure 1: Simplified diagram that shows and compares the building blocks of 4G (left) and 5G (right) access networks and the links between these blocks.

Moreover, photonics components find their place in various critical points of a mobile network. For instance, photodetectors are used to convert optical signals back into electrical signals at the receiving end. This process is vital in ensuring that the transmitted data reaches its intended destination accurately and efficiently.

One of the revolutionary applications of photonics in mobile networks is Radio over Fiber (RoF) technology. Traditionally, radio signals travel through coaxial cables, facing signal degradation over long distances.

Conversely, RoF converts these radio signals into optical signals, which can be transmitted via optical fibers with minimal loss. This approach extends the reach of wireless signals and enables more efficient distribution of signals across a network. This means that even in rural areas or distant corners of a city, 5G signals can maintain their speed and strength.

Photonics’ Impact on Latency

Latency, the time it takes for data to travel from its source to its destination, is a critical metric in modern networks. Reducing latency is paramount in the context of 5G and emerging technologies like edge computing. Consider a self-driving car navigating city streets, relying on real-time data from various sensors. Any delay in data transmission could result in traffic accidents or missed turns. The table below shows some of the latency requirements for these edge computing cases.

Types of Edge Data Centres

Types of EdgeData centerLocationNumber of DCs per 10M peopleAverage LatencySize
On-premises edgeEnterprise siteBusinessesNA2-5 ms1 rack max
Network (Mobile)Tower edgeTowerNationwide300010 ms2 racks max
Outer edgeAggregation pointsTown15030 ms2-6 racks
Inner edgeCoreMajor city1040 ms10+ racks
Regional edgeRegional edgeRegionalMajor city10050 ms100+ racks
Not edgeNot edgeHyperscaleState/national160+ ms5000+ racks

Photonics holds the key to mitigating latency issues. Unlike electrons in traditional electronic systems, photons, being massless particles, travel at the speed of light. In the context of data transmission, this speed is unbeatable. This advantage is pivotal in a 5G network where data needs to travel quickly over long distances. Whether it’s in gaming applications, telemedicine, or smart infrastructure, the minimal latency provided by photonics ensures that information reaches its destination almost instantly.

Furthermore, photonics plays a significant role in the realm of edge computing. With edge computing, data processing occurs closer to the data source rather than relying on a centralized data center. Photonics allows for efficient and high-speed communication between these edge devices, facilitating real-time decision-making. This is indispensable for applications like smart cities, where traffic signals, surveillance cameras, and autonomous vehicles must communicate seamlessly, making cities safer and more efficient.

Photonics’ Impact on Capacity

The capacity of a network is defined by its ability to carry information. In this domain, light outshines electronic signals. The fundamental properties of light, specifically its high frequency and bandwidth, allow it to carry an immensely greater amount of information than electrical signals.

To put it into perspective, consider a network transportation system. Traditional electronic signals are akin to single-lane roads, limited in the amount of traffic they can accommodate. Through a technique called Wavelength Division Multiplexing (WDM), photonics transforms this network into a multi-lane highway.

WDM enables multiple streams of data, each encoded in a different wavelength of light, to travel concurrently through the same optical fiber. It’s akin to having several lanes on a highway where each lane carries a different type of vehicle – be it cars, trucks, or motorcycles. This massively increases the network’s capacity, allowing it to handle many users and devices simultaneously.

Optical fiber with DWDM Channels
Figure 3: Example of a bidirectional DWDM system. At the central office, transceiver modules pick different wavelength channels for transmission, and these channels are combined into a single fiber through a device called a multiplexer. A demultiplexer splits the wavelength channels into separate fibers and the receiving modules on the remote end. Since this is a bidirectional system, transmission can go opposite too, from the remote end to the central office.


As we stand on the cusp of the 5G revolution, understanding the pivotal role of photonics is imperative. By harnessing the unique properties of light, we can overcome the limitations that traditional technologies face. Through optical fibers and RoF technology, photonics extends the reach and efficiency of mobile networks, ensuring that even remote areas are connected with the full capabilities of 5G.

Moreover, the impact of photonics on latency and capacity is profound. The speed of light, harnessed by photonics, ensures lightning-fast data transmission, crucial for applications like remote surgery and autonomous vehicles. Additionally, the ability of light to carry a vast amount of information positions photonics as the linchpin of network capacity enhancement.

Corlia van Tonder

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