5G Mobile Networks

As with the previous 2G, 3G, and 4G mobile networks, 5G networks are digital cellular networks. In addition to providing cell phone service, 5G networks are intended to interwork with wired internet and cable networks and provide service to the home and office. 5G envisions a single platform seamlessly providing a plethora of diverse services.

5G networks use high-frequency radio waves in the millimeter wave band, instead of the lower-frequency microwave band the earlier generations use. The goals of 5G are to provide:

  • Higher data rates – up to 10 Gbps which is faster than current cable internet, and 100 times faster than 4G LTE
  • Reduced latency – response times below 1 millisecond, compared with 30 – 70 ms for 4G
  • Massive connectivity – for the Internet-of-Things devices
  • More system capacity
  • Cost reductions
  • Energy savings

5G networks are expected to be used for consumer and private networks, with applications in industrial IoT, enterprise networking, and critical communications.

5G rollout will be phased over several years with all major carriers onboard, including AT&T, Verizon, Sprint, Deutsche Telekom, Vodafone and China Telecom, all South Korean telecoms, and Telefónica Deutschland. 2018 saw some demonstration deployments and select deployments such as in South Korea. Worldwide commercial launch is expected in 2020.

Infrastructure for 5G and Millimeter Waves

Millimeter waves lack the multiple-mile range of microwaves. Walls, buildings, and even gases in the atmosphere can interfere with millimeter waves. Instead of cell towers, millimeter wave antennas, which are a few inches long, will be mounted on buildings, telephone poles, and other urban infrastructure. The size of millimeter-wave 5G cells will typically be equal to a city block. Sub 6 GHz frequencies can also be employed for enhanced 5G coverage.

The local antennas connect to the Internet and telephone network through a high bandwidth optical fiber or wireless backhaul connection.

Spectrum for 5G

5G will use spectrum in the existing LTE frequency ranges 600 MHz – 6 GHz and 24 – 86 GHz in the millimeter wave bands. New spectrum is been allocated to 5G by the Federal Communications Commission, European Union, and other regulatory agencies. Much of it is high-band frequencies that are currently underutilized.

Additional 5G Performance Techniques

5G networks can transmit more data per second because they have more bandwidth available to them and can use wider frequency channels to communicate up to 400 MHz compared with 20 MHz in 4G LTE. There are several techniques that are being used to further improve speed and reduce latency:

  • OFDM (orthogonal frequency division multiplexing) modulation – multiple carrier waves transmitted in same frequency channel, so that multiple bits of information are transferred concurrently
  • MIMO (multiple-input multiple-output) – multiple antennas in a cell communicating with a device, over separate frequency channels, so that data is transmitted concurrently
  • Beamforming – continuous calculation of the best route for radio waves to reach any given device, and the organization of the antennas to work together to service the device
  • MEC (multi-access edge computing aka mobile edge computing) –a n architecture that enables IT and cloud application services to run closer to the cellular customer at the “edge” of the network, such as cellular base stations, to reduce congestion and improve performance. Cellular operators can open their radio access network (RAN) to third-party application developers and content providers.

5G Standards

The term “5G” was originally defined by the ITU in theIMT-2020 standard. It set requirements for peak download capacity among other things which are in the table below. Multiple standards bodies are now involved including IEEE and 3GPP.

3GPP

3GPP (3rd Generation Partnership Project), a collaboration between groups of telecommunications standards associations, has done much recent work on 5G standards.

  • 3GPP Release 14 contains mission-critical enhancements including LTE support for Vehicle to everything (V2x) services, enhanced use of unlicensed bands, 4 band Carrier Aggregation, inter-band Carrier Aggregation and more.
  • 3GPP Release 15 includes work on the 5G System, Machine-Type Communication, V2x improvements, etc. 5G NR (New Radio) is standardized in Release 15 as the 5G physical-layer communication standard. 5G NR can include lower frequencies below 6 GHz, and higher frequencies in the 24 to 40 GHz range.
  • 3GPP Release 16 will enable the ITU’s IMT-2020 vision.

IEEE

IEEE covers several areas of 5G with a core focus in wireline sections between the Remote Radio Head (RRH) and Base Band Unit (BBU). IEEE 1914 Working Group is standardizing the Next Generation Fronthaul Interface. 1914.1 standards focus on network architecture and dividing the connection between the RRU and BBU into two key sections.

  1. Radio Unit (RU) to the Distributor Unit (DU) being the NGFI-I (Next Generation Fronthaul Interface)
  2. DU to the Central Unit (CU) being the NGFI-II interface allowing a more diverse and cost-effective network

NGFI-I and NGFI-II have defined performance values so that they can ensure transport of different traffic types defined by the ITU.

The 1914.3 standard is creating a new Ethernet frame format capable of carrying IQ data in a much more efficient way depending on the functional split. Also, multiple network synchronization standards within the IEEE groups are being updated to ensure network timing accuracy at the RU is maintained to a level required for the traffic carried over it.

ITU

The ITU has divided 5G network services into three categories:

  1. Enhanced Mobile Broadband (eMBB) or handsets: Initial deployments will focus here, including fixed wireless, which uses many of the same capabilities as eMBB
  2. Ultra-Reliable Low-Latency Communications (URLLC), which includes industrial applications and autonomous vehicles
  3. Massive Machine Type Communications (MMTC) or sensors

The table below lists eight key parameters of IMT-2020 5G and which of the three ITU services will primarily benefit from the parameter specification.

ITU 5G Performance Requirements
Capability Meaning Target Specs Target Services
Peak data rate Maximum achievable data rate 20 Gbit/s eMBB
User experienced data rate Data rate achievable across the coverage are 1 Gbit/s eMBB
Latency Radio network contribution to packet travel time 1 ms UTLLC
Mobility QoS and hand-off maximum speed requirements 500 km/h eMBB/URLLC
Connection density Total number of devices per unit area 10/km MMTC
Energy efficiency Data sent/received per unit energy consumption (by device or network) Equal to 4G eMBB
Spectrum efficiency Throughput per unit wireless bandwidth and per network cell 3–4x 4G eMBB
Area traffic capacity Total traffic across coverage area 1000 (Mbit/s)/m2 eMBB

Broadband Forum

The Broadband Forum has studied network slicing and fixed-mobile convergence (FMC). BBF SD-420 was developed jointly with 3GPP to define the architecture for FMC. More work on 5G in the BBF is on the Control and User-Plane Separation (CUPS) protocol and BNG disaggregation.

ASSIA is closely following all of these 5G activities and working to make wireline/Wi-Fi and mobile convergence a reality, so the customers of the future get the services they want with high satisfaction and without worrying about network problems.