What is mmWave and how does it work?

What is mmWave and how does it work?

The increased usage of smartphones, tablets, and IoT devices around the world is creating a growing demand for more reliable network coverage and higher and faster data transmission. Cellular networks such as 4G LTE use frequencies between 600MHz to 700MGz and 2.5GHz to 3.7GHz bands, allowing for waves to travel further and cover more area, but at the cost of lower speeds. As technological innovation persists, data consumption is only going to increase, and we need a way to make data transmission faster and more efficient. A promising technology that can be used for this purpose is millimetre wave, also referred to as mmWave.

Millimetre wave is the band of spectrum with frequencies between 30GHz to 300GHz. Compared to the frequencies used for cellular networks and Wi-Fi today, mmWave has significantly higher frequencies, which allows for higher data transfer speeds.

How does mmWave's higher frequencies increase data transmission speeds?

Well, higher frequency transmissions have greater bandwidth, which measures the data transfer capacity of a network in bits per second. This means that with mmWave technology, a greater amount of data can be transferred per second, resulting in much higher network speeds.

Millimetre Wave technology gets its name from the fact that the wavelengths of the 30GHz to 300GHz frequencies span a distance of 1 – 10 millimetres. This wavelength is significantly shorter than the radio waves currently used by smartphones, whose wavelengths are around several dozen millimetres. Currently, the mmWave technology is primarily used by radar systems and satellites, with its reach rapidly expanding to 5G cellular networks and remote sensing. Before we discuss the uses of mmWave technology and how it's affecting the transmission of data, let us consider some of the advantages and disadvantages of using mmWave technology. 

Advantages of mmWave Technology

Millimetre wave technology has various applications, spanning industries like radio astronomy, remote sensing, satellites, military weaponry, security screening and telecommunications. Further advancements in mmWave open up the possibilities of creating many unique technologies more effective and efficient. 

From a wireless communications' standpoint, mmWave does support faster transmission. However, due to its shorter wavelength, its signal propagation of mmWave is relatively short, meaning it can travel less distance when compared to more lengthy radio waves. These characteristics of mmWave prove to be beneficial. Shorter transmission paths limit interference from neighbouring mmWaves that might overlap, which helps maintain high data transmission speeds. The short propagation distances can also increase the number of required access points in a given area, reducing the number of devices sharing bandwidth. Shorter wavelengths allow access point antennas to be smaller in size than other frequencies, making them useful for smaller data-transmitting devices. 

Disadvantages of mmWave Technology

 

The main disadvantage of mmWave technology is that they are strongly affected by gases and moisture in the air, negatively affecting their range and strength. Rain and humidity reduce the waves' signal strength and propagation distance. The propagation distance of mmWaves is already not as high as other frequencies, so all these obstacles prove to be quite damaging. Moreover, physical objects such as trees, walls, buildings, and people can weaken wave strength and reduce propagation. This disposition to signal loss is why mmWave technology is currently mostly used by devices that need to transfer data over shorter distances or devices that are located in obstacle-free areas.

Promising Uses of mmWave Technology 

Let's further look into some of the more specific uses of mmWave technology in terms of 5G cellular network and remote sensing:

5G Cellular Network

There are two types of 5G networks. The first one being mmWave, which is the type of 5G that is talked about in reference to high and improving network speeds. The second type is sub-6Hz, which is the 5G that most people worldwide are connected to today. 

As discussed previously, mmWave refers to higher frequency bands in the 30GHz to 300GHz (although for 5G, mmWave will refer to frequency bands between 30GHz to 40GHz). Comparatively, sub-6Hz refers to lower frequencies under 6Hz. mmWave bands can transmit data faster, which is why they can support breakneck network speeds. Even though mmWave 5G networks are fast, the shorter wave propagation prevents them from being used in suburban and rural areas. People, walls, trees, and other obstructions in these areas make this issue worse. To use mmWave 5G, you must be within a block of a 5G tower, which isn't a feasible thing for most communities. For the mmWave 5G network to be available for people in suburban and rural areas, there would need to be many more 5G towers installed, which is a considerable cost most carriers are unwilling to take on.

Because of mmWave's limited range, it has been challenging to implement mmWave 5G in most areas around the world. Nonetheless, the technological advancements related to data transmission devices and antennas have allowed for mmWave to show lots of potential for 5G users in the future. Theoretically, mmWave 5G can deliver speeds up to 5Gb/s, compared to the current average of 40mb/s.

Remote Sensing: 

remote sensing

mmWave remote sensing incorporates the usage of mmWave radars, which are a type of sensing technology used to detect the movement and position of objects, and determine the velocity and angle of those objects. There are many different uses of remote sensing using mmWave radars. For example, mmWave radars are used by many automotive companies for traffic control. Moreover, mmWave radars can determine the distance between adjacent vehicles, which can help prevent collisions. The rate at which the mmWaves are reflected off a neighbouring vehicle could help determine the distance to the next vehicle.

Another use of mmWave's remote sensing capabilities is health monitoring and human motion detection. mmWave signals are so sensitive that they can detect subtle changes in an environment, including some of the biological functions of the human body. For example, you could use a device that uses mmWave technology to monitor a user's heartbeat and breathing without the use of sensors, wearables or implants. This is a unique technology in which the user would not have use any wearables to gather data. 

remote sensing 

Let's also consider respiration rate monitoring. A signal is sent from the mmWave device out into the environment. When you inhale, your chest inflates, making the distance from the signal's origin to its destination a tiny bit shorter. When you exhale, the signal needs to travel a little further. By monitoring these variances in the signal, your system could deduce and monitor your respiration rate. Over time, the algorithms in the system will learn what is normal for you and take motion into account (e.g. during exercise). So, for instance, if you have an allergic reaction and your respiration rate suddenly changes drastically, your system could be programmed to respond by dialing the emergency services.

For more information on Mercku's remote sensing, check out our upcoming product: Mercku Wireless Intelligence Sensing (WISe)

Want to learn more about wireless sensing? Read more about our latest partnership with Aerial to provide best-in-class WiFi Sensing Services!

For more information about Mercku's Connectivity Suite, our hardware and how you can partner with Mercku, please reach out to the team at connect@mercku.com

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