The wavelength of a radio wave is the length of one full wave cycle from start to finish. It is calculated by dividing the velocity of the radio wave (speed of light, c =299 792 458 m/s) by frequency (f). The frequency is the number of cycles generated by the radio wave in one second. Mathematically, Wavelength λ = c/f. In modern networks, the frequencies are generally expressed in GigaHertz (GHz) or MegaHertz (MHz).
Mobile networks employ radio waves for all communication between the base station and the cell phone. One of the most precious resources of a mobile operator is the frequency spectrum which defines what carrier frequencies they may use to roll out their services. For example, if a country wants to use a frequency band ranging from 3.4GHz to 3.8GHz to launch certain 5G services, the carrier frequencies will be in any selected bands within this range. The length of the wave cycle, wavelength for a signal being transmitted at these frequencies will be very short.
As shown by the red lines in the diagram below, the wavelength of a radio wave is the length of one full wave cycle from start to finish. It is the distance between the start and end of the wave cycle and is expressed in metres. The endpoint of a full-wave cycle is the starting point of another wave cycle. When you read a theoretical document, you may come across ‘peaks’ and ‘troughs’ when explaining wavelength, which can be confusing. You don’t have to worry about the peaks and troughs of a wave when measuring wavelength. You can pick any two random points on a wave that have the same position on the wave. For example, look at the green line below, which starts at a random point A and ends at a random point B. For mathematical calculations, you don’t need to look at any diagrams; all you need is the frequency in Hertz and the speed of light, which is 299 792 458 meters per second.
The formula for calculating the wavelength of a radio wave:
Wavelength = λ = c/f;
where f is the frequency in Hertz and c = 299792458 m/s.
Here are some helpful downloads
Thank you for reading this post, I hope it helped you in developing a better understanding of cellular networks. But sometimes, we need some extra support especially when preparing for a new job, or studying a new topic, or maybe just buying a new phone. Whatever you are trying to do, here are some downloads that can help you:
Students & fresh graduates: If you are just starting, the complexity of the cellular industry can be a bit overwhelming. But don’t worry, I have created this FREE ebook so you can familiarise yourself with the basics like 3G, 4G etc. As a next step, check out the latest edition of the same ebook with more details on 4G & 5G networks with diagrams. You can then read Mobile Networks Made Easy which explains the network nodes e.g. BTS, MSC, GGSN etc.
Professionals: If you are an experienced professional but new to mobile communications, it may seem hard to compete with someone who has a decade of experience in the cellular industry. But not everyone who works in this industry is always up to date on the bigger picture and challenges given how quickly the industry evolves. The bigger picture comes from experience which is why I’ve carefully put together a few slides to get you started in no time. So if work in sales, marketing, product, project or any other area of business where you need a high-level view, Introduction to Mobile Communications can give you a quick start. Also, here are some templates to help you prepare your own slides on product overview and product roadmap.