What is 5G technology and how does it work?

5G is the latest generation of mobile networks and is already live in many countries. It stands for fifth-generation mobile networks and uses a technology called New Radio – NR to offer cellular services. NR (New Radio) is to 5G as LTE (Long Term Evolution) is to 4G. Like 4G is often written as 4G LTE, 5G in most documentation is referred to as 5G NR. 5G NR is a flexible technology as it allows a single physical mobile network to cater to a wide range of use cases across many different customer segments.

NR is the only technology in the world that enables 5G services, and it is the upgrade path for all 4G LTE networks across the globe. From a consumer perspective, 5G NR can offer extremely high data rates (in Gbps), and it also offers extremely low latencies as low as 1 millisecond. For industries, 5G can offer support for billions of low-powered IoT devices. In addition, its ultra-low latencies can help digitise many market verticals, including manufacturing factories and self-driving cars, its real-time communication capabilities.

How is 5G technology different from 4G?

LTE – Long Term Evolution provided the 4G upgrade path to all key 3G technologies, including UMTS and CDMA2000. The key difference between 5G and 4G is the technology focus which in 5G is targeting three distinct use case classes: eMBB, uRLLC and mMTC. eMBB stands for Enhanced Mobile Broadband which from a use case perspective is the closest match to 4G LTE networks. But unlike 4G LTE, 5G has a strong focus on two additional areas, uRLLC – Ultra-Reliable Low Latency Communication and mMTC – Massive Machine Type Communication. In addition, 5G can work alongside 4G LTE by using the existing 4G mobile core network, EPC (Evolved Packet Core), in a deployment model called non-stand-alone 5G – 5G NSA. 4G LTE and 5G NR are expected to co-exist for a long time to address many mobile broadband use cases together. The other model for 5G, the standalone model, is the full end-to-end 5G network with its own dedicated 5G cloud-native core network that caters to a wide variety of enterprise-level use cases.

Is 5G technology already in use?

The fifth generation of mobile networks – 5G is already live in many countries. In the UK, 5G networks were launched in 2019 and even though the initial deployments have mostly been non-standalone 5G (NSA), the standalone 5G networks are yet to be widely deployed. At the moment, 5G networks can offer average download speeds of around 150-200 Mbps in the UK through the NSA deployment model. However, speeds of between 300 Mbps-500 Mbps have also been witnessed by our tests in the area of Reading, UK.

How does a 5G network work?

The 5G mobile networks require two key network components to offer their full potential (i) a radio network using the New Radio -NR technology (ii) a cloud-native 5G core network – 5GCN. Since 4G LTE networks are currently the most widely deployed networks and as LTE Advanced and LTE-Advanced Pro can comfortably support many enhanced mobile broadband use cases, 5G and 4G networks will work together. 5G and 4G can work in dual-connectivity scenarios where a user device can be connected to both 4G and 5G networks at the same time to offer bigger bandwidths and, therefore, higher data rates to customers. This is where non-stand-alone 5G networks come in as they can support both 4G and 5G user devices by supporting both 4G LTE and 5G NR radio networks. The non-stand-alone 5G model requires the 5G radio network to connect to the 4G LTE core network – EPC. The standalone 5G networks have their own cloud-native core network which uses a service-based architecture and enables network virtualisation for many network functions. One key capability that utilises network virtualisation is network slicing. Network slicing allows mobile operators to offer “virtual” sub-networks. It means they can create individual network slices for specific market verticals (sectors). For example, they can create a very targeted network slice using the millimetre band to achieve ultra-low latency for a manufacturing unit. At the same time, they can create another slice for the rest of the population in the same area for general 5G mobile coverage. Have a look at our dedicated post on network slicing to learn more.

What is the frequency band for 5G?

5G networks are not tied to a single frequency band and they can operate in various band types. According to this web page on GSMA’s website, 5G spectrum guide, the majority of commercial 5G launches rely on the 3.3-4.2 GHz frequency range. In the UK, for example, all mobile operators use the 3.4-3.6 GHz band for 5G which falls in the mid-band range. The three(3) band-classes for 5G are as follows:

  • Low band: Below 1GHz e.g. 700 MHz.
  • Mid band: 1 to 6GHz e.g. 3GHz.
  • High or Millimetre band: Over 6GHz especially 24-30 GHz.

5G networks operate in various frequency bands in order to provide nationwide network coverage with high data speeds and low latency.

According to the laws of physics, the wireless signals that have higher frequencies experience higher losses as they travel, which means they offer limited coverage. In comparison, the signals that use lower frequencies can travel much further due to experiencing lower losses. Higher frequencies are, however, more suitable for improved (reduced) latency and higher throughput. Therefore, in 5G, lower frequency bands can be used for providing wide-area nationwide coverage. The higher frequency bands can provide more targeted coverage in smaller areas with low latency and high throughput. Lower frequency bands are also useful for services that require always connected low-powered devices. The lower frequency band for wide-area 5G coverage in Europe is the 700 MHz band. The equivalent in the US is the 600 MHz band.

What are small cells in 5G?

5G networks use various frequency bands including the millimetre bands. Since higher frequency bands (millimetre bands) offer limited coverage, they need to operate in a small-cell architecture for situations that require targetted coverage. Examples of that can include urban areas, office buildings, and manufacturing facilities etc. However, the wider coverage with 5G will require larger cells (macrocells) that can make use of lower frequency to provide better coverage. But that doesn’t mean that macrocells can’t use higher frequencies. With the beamforming technology that 5G employs, the wireless signal travels to the receiver in a more targeted way with more energy. Since higher frequencies offer higher antenna gains, they also form higher beams, leading to extended coverage.

What multiplexing does 5G use?

5G uses OFDM (Orthogonal Frequency Division Multiplexing), which is the same access technology that LTE uses for the air interface. In 4G LTE, the sub-channel spacing is 15 kHz, but 5G NR is more flexible and can use sub-carrier spacing in the multiples of 15 kHz, e.g. 30 kHz, 60 kHz etc. From a bandwidth perspective, LTE uses a maximum carrier bandwidth of 20 MHz, and by using multiple carriers, it can use up to 5 carriers to achieve a maximum bandwidth of 20 MHz x 5 = 100 MHz. In 5G NR, the maximum channel bandwidth is 400 MHz, and with multiple carriers, 5G can use up to 16 carriers. That allows the maximum bandwidth to be 400 MHz x 16 = 6400 MHz or 6.4 GHz. Higher bandwidth leads to higher data speeds which allows 5G to offer much higher speeds as compared to LTE.

Is 5G TDD or FDD?

5G networks can work in both TDD and FDD duplex schemes. FDD uses two separate frequency bands; one for the uplink and one for the downlink. TDD uses the same frequency band for uplink and downlink and separates the transmission through different timeslots. In earlier mobile technologies, including 4G LTE, 3G UMTS and 2G GSM, Frequency Division Duplex – FDD has been the primary duplex scheme for uplink and downlink. 5G networks use a slightly different approach. In 5G NR, the millimetre frequency band can use Time Division Duplex (TDD) while the lower frequency bands (low and mid) may still use FDD.

How does 5G Internet work?

The 5G home internet is based on the use case category eMBB – Enhanced Mobile Broadband. In marketing documentation, the abbreviation eMBB is also expressed as Extreme Mobile Broadband. A 5G home broadband set-up may comprise a 5G data-only SIM inserted into a 5G broadband router to create WiFi coverage just like a regular DSL or Fibre connection. Have a look at this detailed post on 5G high-speed internet services. Also, just like in the 4G LTE networks, mobile hotspotting is also an option if you want to use your 5G smartphone for tethering.

Here are some helpful downloads

Thank you for reading this post, I hope it helped you in developing a better understanding of cellular networks. 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 the challenges considering 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.

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