5G specs announced: 20Gbps download, 1ms latency, 1M devices per square km

ITU LogoThe total download capacity for a single 5G cell must be at least 20Gbps, the International Telcommunication Union (ITU) has decided. In contrast, the peak data rate for current LTE cells is about 1Gbps. The incoming 5G standard must also support up to 1 million connected devices per square kilometre, and the standard will require carriers to have at least 100MHz of free spectrum, scaling up to 1GHz where feasible.

These requirements come from the ITU's draft report on the technical requirements for IMT-2020 (aka 5G) radio interfaces, which was published Thursday. The document is technically just a draft at this point, but that's underselling its significance: it will likely be approved and finalised in November this year, at which point work begins in earnest on building 5G tech.

I'll pick out a few of the more interesting tidbits from the draft spec, but if you want to read the document yourself, don't be scared: it's surprisingly human-readable.

5G specs announced: 20Gbps download, 1ms latency, 1M devices per square km

The specification calls for at least 20Gbps downlink and 10Gbps uplink per mobile base station. This is the total amount of traffic that can be handled by a single cell. In theory, fixed wireless broadband users might get speeds close to this with 5G, if they have a dedicated point-to-point connection. In reality, those 20 gigabits will be split between all of the users on the cell.

Speaking of users... 5G must support at least 1 million connected devices per square kilometre (0.38 square miles). This might sound like a lot (and it is), but it sounds like this is mostly for the Internet of Things, rather than super-dense cities. When every traffic light, parking space, and vehicle is 5G-enabled, you'll start to hit that kind of connection density.

Similar to LTE and LTE-Advanced, the 5G spec calls for base stations that can support everything from 0km/h all the way up to "500km/h high speed vehicular" access (i.e. trains). The spec talks a bit about how different physical locations will need different cell setups: indoor and dense urban areas don't need to worry about high-speed vehicular access, but rural areas need to support pedestrians, vehicular, and high-speed vehicular users.

The 5G spec calls for radio interfaces that are energy efficient when under load, but also drop into a low energy mode quickly when not in use. To enable this, the control plane latency should ideally be as low as 10ms—as in, a 5G radio should switch from full-speed to battery-efficient states within 10ms.

Under ideal circumstances, 5G networks should offer users a maximum latency of just 4ms, down from about 20ms on LTE cells. The 5G spec also calls for a latency of just 1ms for ultra-reliable low latency communications (URLLC).

It sounds like 5G's peak spectral efficiency—how many bits can be carried through the air per hertz of spectrum—is very close to LTE-Advanced, at 30bits/Hz downlink and 15 bits/Hz uplink. These figures are assuming 8x4 MIMO (8 spatial layers down, 4 spatial layers up).

Finally, despite the peak capacity of each 5G cell, the spec "only" calls for a per-user download speed of 100Mbps and upload speed of 50Mbps. These are pretty close to the speeds you might achieve on EE's LTE-Advanced network, though with 5G it sounds like you will always get at least 100Mbps down, rather than on a good day, down hill, with the wind behind you.

The draft 5G spec also calls for increased reliability (i.e. packets should almost always get to the base station within 1ms), and the interruption time when moving between 5G cells should be 0ms—it must be instantaneous with no drop-outs.

The next step, as shown in the image above, is to turn the fluffy 5G draft spec into real technology. How will peak data rates of 20Gbps be achieved? What blocks of spectrum will 5G actually use? 100MHz of clear spectrum is quite hard to come by below 2.5GHz, but relatively easy above 6GHz. Will the connection density requirement force some compromises elsewhere in the spec? Who knows—we'll find out in the next year or two, as telecoms and chip makers start developing draft 5G tech.

Source: Ars Technica

Tags: 5G, mobile communications

Comments
Add comment

Your name:
Sign in with:
or
Your comment:


Enter code:

E-mail (not required)
E-mail will not be disclosed to the third party


Last news

 
Galaxy Note10 really is built around a 6.7-inch display
 
You may still be able to download your content
 
Facebook, Messenger and Instagram are all going away
 
Minimize apps to a floating, always-on-top bubble
 
Japan Display has been providing LCDs for the iPhone XR, the only LCD model in Apple’s 2018 line-up
 
The 2001 operating system has reached its lowest share level
 
The entire TSMC 5nm design infrastructure is available now from TSMC
 
The smartphone uses a Snapdragon 660 processor running Android 9 Pie
The Samsung Galaxy A5 (2017) Review
The evolution of the successful smartphone, now with a waterproof body and USB Type-C
February 7, 2017 / 2
Samsung Galaxy TabPro S - a tablet with the Windows-keyboard
The first Windows-tablet with the 12-inch display Super AMOLED
June 7, 2016 /
Keyboards for iOS
Ten iOS keyboards review
July 18, 2015 /
Samsung E1200 Mobile Phone Review
A cheap phone with a good screen
March 8, 2015 / 4
Creative Sound Blaster Z sound card review
Good sound for those who are not satisfied with the onboard solution
September 25, 2014 / 2
Samsung Galaxy Gear: Smartwatch at High Price
The first smartwatch from Samsung - almost a smartphone with a small body
December 19, 2013 /
 
 

News Archive

 
 
SuMoTuWeThFrSa
  12345
6789101112
13141516171819
20212223242526
27282930   




Poll

Do you use microSD card with your phone?
or leave your own version in comments (15)