Introduction to 5G
Mobile communication started with 1G, the first generation of wireless cellular technology, which was based on analog telecommunication standards and provided basic voice services. Later on, it was replaced with 2G, with the main difference from 1G being that the radio signals used for 2G were digital. The shift to digital technology helped improve security and reliability of communication, while also enabling data services and increasing the number of users per MHz of spectrum bandwidth.
With need for more services, mobile networks adopted advanced technologies such as 2.5G, which implemented a packet-switched domain (GPRS) and a circuit-switched domain (HSCSD), and then 2.75G which implemented EDGE (Enhanced Data rates for Global Evolution) networks. These technologies provided improved data transmission rates through extensions on top of standard GSM (Global System for Mobile Communication). 2G introduced many fundamental applications like SMS (Short Messaging System), that we still use today.
3G, the third generation of wireless cellular technology, provided the ability to access internet on mobile devices on-the-go. The faster internet speeds made possible popular applications such as video calls, mobile TV and real-time location-based services such as ride-hailing, although to a limited scale. It heralded the arrival of smartphones that provided new user-experience. 3G is based on International Mobile Telecommunications-2000 (IMT-2000) specifications drafted by the International Telecommunication Union. 3G relies on CDMA (Code Division Multiple Access) standard which evolved to 3.5G (which uses HSDPA – High-Speed Downlink Packet Access) and later to 3.75G (which uses Evolved High Speed Packet Access – HSPA+).
4G, the fourth generation, commonly referred to as LTE (Long Term Evolution), provided even higher data rates and enabled mass adoption of video-streaming, social networking and cloud storage. It marked the proliferation of low-cost smartphones in large volumes that resulted in a surge in data consumption and brought down the per-MB cost of data significantly. 4G uses OFDMA (Orthogonal Frequency-Division Multiple Access) technology. The evolutionary step of 4.5G (which uses MIMO antenna technology – Multiple Input Multiple Output) provides better performance than 4G as a step towards deployment of full 5G capability.
5G, the fifth generation, is currently under development. It denotes the next major phase of mobile telecommunication standards beyond the current 4G/IMT-Advanced standards. With its faster data rates, 5G is expected to enable applications in the B2B (Business-to-Business) space such as Industrial-IoT, Automation in transportation industry and Industrial Process Control which involve strict compliance to SLAs (Service Level Agreement). Also on the horizon are other applications like Remote Surgery and VR-based (Virtual Reality) Sports Coverage.
5G Use Cases
ITU-R (International Telecommunication Union – Radiocommunication Sector) has defined three main use cases :
Enhanced Mobile Broadband (eMBB) – also called Extreme Mobile Broadband.
Use cases include Immersive Virtual Reality for sports coverage and 360-degree video streaming. Peak data rates of 10-20Gbps are envisioned (compared to approximately 1Gbps peak data rate for 4G)
Ultra-Reliable and Low Latency Communications (URLLC)
Use cases include Remote surgery and Autonomous vehicles. These use cases place strict demands on latency and reliability. In 4G systems, latencies are of the order of 100ms, whereas for 5G systems, latencies are of the order of 5ms.
Massive Machine Type Communications (mMTC)
Use cases include Industrial Internet of Things, where a huge number of devices need to be supported in a small geographical area, with data being transferred only sporadically.
Technology
The 5G is expected to provide a new frequency band along with the wider spectral bandwidth per frequency channel. 5G doesn’t merely increase bit-rates, but is also advanced in terms of −
High increased peak bit rate
Larger data volume per unit area (i.e. high system spectral efficiency)
High capacity to allow more devices to connect concurrently and instantaneously
Better connectivity irrespective of the geographic region
Higher reliability of communication
Architecture
A System-level model of 5G architecture is shown in the following figure. 5G will offer contiguous and consistent coverage − “wider area mobility in the true sense.”
This figure illustrates typical blocks in the Physical Layer of a communication system.
Listed in the following table are some of the key differences between technical parameters of 5G networks and 4G deployments.
| Parameter | Unit | 4G | 5G | ||
|---|---|---|---|---|---|
| LTE | Sub-6 | Low mmWave | High mmWave | ||
| Carrier frequency | GHz | 2 | 2 | 30 | 70 |
| Channel Size | MHz | 20 | 100 | 250 | 500 |
| Sampling Rate | MHz | 30.72 | 150 | 375 | 750 |
| Antennas # | — | 4 | 96 | 128 | 256 |
| Modulation order | — | 64 | 1024 | 256 | 64 |
| FFT size | — | 2048 | 2048 | 2048 | 2048 |
| # Active subcarriers | — | 1200 | 1300 | 1300 | 1300 |
| # Data symbols per frame | — | 14 | 70 | 150 | 300 |
Benefits of 5G
Some of the significant benefits are −
A unified global standard.
Network availability everywhere – including connectivity at higher altitudes.
Its cognitive radio technology will help in having different versions of radio technologies to share the same spectrum efficiently.
Facilitating ‘anywhere, anytime’ usage of mobile devices for the general public.
Because of the usage of IPv6 technology, IP addresses will be assigned as per the connected network and geographical position.
Advanced Features
5G has the following advanced features when compared with previous generations −
★ Practically higher data rates 1 to 10 Gbps
★ 1ms Latency (end-to-end round trip).
★ Increased Unit-area bandwidth - around 1000x improvement over 4G.
★ Facility to connect more number of devices (10x to 100x)
★ Worldwide coverage.
★ Significant reduction in Network energy (by about 90%).
Opportunities and Challenges
5G brings many new opportunities as shown in the following image (Courtesy : Ericsson). Some of the key ones are listed below −
Ultra-dense deployments (eg. Immersive VR for event coverage)
Inter-vehicular / vehicular-to-road communications
Massive machine-to-machine communication (eg. Industrial IoT)
Challenges in 5G Technology adoption are −
A lot of the implementation details are still being worked out and much of it is still under research. It is likely to take quite some time to be ready for adoption of the general public.
Many of the old devices would not be compatible with 5G, hence all of those devices need to be replaced with new ones – an expensive deal.
5G deployment requires significant investment in developing new infrastructure.
Key issues related to Security and Privacy are yet to be solved