High-band spectrum is what delivers the highest performance for 5G, but with major weaknesses. It is often referred to as mmWave. High-band spectrum can offer peak speeds up to 10Gbps and has extremely low latency. The main drawback of high-band is that it has low coverage area and building penetration is poor.
AT&T, T-Mobile, and Verizon are all rolling out high-band spectrum. 5G coverage for the carriers will piggyback off LTE while they work to build out nationwide networks. Since high-band spectrum sacrifices building penetration and coverage area for high speed, it will rely on many small cells. These are low-power base stations that cover small geographic areas and can be combined with beamforming to bolster coverage.
How fast is 5G?
The International Telecommunication Union (ITU) is a specialized agency at the United Nations that develops technical standards for communication technologies, and it sets the rules for radio spectrum usage and telecommunications interoperability. In 2012, the ITU created a program called “IMT for 2020 and beyond” (IMT-2020) to research and establish minimum requirements for 5G. After years of work, the agency created a draft report with 13 minimum requirements for 5G in 2017.
Once the ITU set the minimum requirements for 5G, the 3rd Generation Partnership Project (3GPP), a collaboration of telecommunications standards organizations, began work on creating standards for 5G. In December 2017, 3GPP completed its non-standalone (NSA) specifications, and in June 2018 it followed up with its stand-alone specifications (SA).
Both NSA and SA standards share the same specifications, but NSA uses existing LTE networks for rollout while SA will use a next-generation core network. Carriers are starting with the NSA specification, which means you will fall back on 4G LTE in a non-5G environment.
The standards set by 3GPP closely correspond with IMT-2020 performance targets and are somewhat complex, but here’s a general rundown:
- Peak data rate: 5G will offer significantly faster data speeds. Peak data rates can hit 20Gbps downlink and 10Gbps uplink per mobile base station. Mind you, that’s not the speed you’d experience with 5G (unless you have a dedicated connection) — it’s the speed shared by all users on the cell.
- Real-world speeds: While the peak data rates for 5G sound pretty impressive, actual speeds won’t be the same. The spec calls for user download speeds of 100Mbps and upload speeds of 50Mbps.
- Latency: Latency, the time it takes data to travel from one point to another, should be at 4 milliseconds in ideal circumstances, and at 1 millisecond for use cases that demand the utmost speed. Think remote surgeries, for instance.
- Efficiency: Radio interfaces should be energy efficient when in use, and drop into low-energy mode when not in use. Ideally, a radio should be able to switch into a low-energy state within 10 milliseconds when no longer in use.
- Spectral efficiency: Spectral efficiency is “the optimized use of spectrum or bandwidth so that the maximum amount of data can be transmitted with the fewest transmission errors.” 5G should have a slightly improved spectral efficiency over LTE, coming in at 30bits/Hz downlink, and 15 bits/Hz uplink.
- Mobility: With 5G, base stations should support movement from 0 to 310 mph. This means the base station should work across a range of antenna movements — even on a high-speed train. While it’s easily done on LTE networks, such mobility can be a challenge on new millimeter wave networks.
- Connection density: 5G should be able to support many more connected devices than LTE. The standard states 5G should be able to support 1 million connected devices per square kilometer. That’s a huge number, which takes into account the slew of devices that will power the Internet of Things (IoT).