When WiFi was first launched in the 1990s (based on the growing set of IEEE 802.11 standards, for those who care about provenance), it had a small range at the 2.4 Gigahertz (GHz) radio frequency. In 1999, a more capable range at 5GHz range was added. And now 6GHz is just appearing on the market.
Radio waves are sort of all the same, no matter the space between their peaks. Therefore, the differences between 2.4, 5, and 6 GHz are a matter of quantity and the trade-offs they make. We shouldn’t expect a sudden new capability just because we’re in a new frequency band. On the other hand, the quantitative differences each new band brings can open up new possibilities for the institutions employing it.
I talked to Roger Sands, CEO and Co-Founder of Wyebot, about the capabilities of the new radio band and how it can benefit hospitals. We’ll start with some radio basics, then look at applications of the band to clinical institutions.
The technical reasons for advantages of 6 GHz
Radio waves make a trade-off: Higher-frequency waves carry more information but travel less far.
The higher waves have more information because the more vibrations they make per second, the more bits you can fit into one second (thinking digitally for a moment). It’s just like you can name twice as many people if you speak the names twice as fast. Think about an auctioneer’s pitch.
However, the rapid vibration of the frequencies uses up energy, so higher waves lose energy faster and don’t travel as far. (I am trying to use concrete language and simplify concepts here, so I offer apologies to electrical engineers and physicists among the readership.)
Higher waves also have trouble passing through walls or other barriers (even a steady rain).
Another aspect of radio we need to evaluate is the width of the band allocated to a service. In order to send an orderly set of waves that an antenna can pick up, and that won’t interfere with other transmissions, each transmission stays within a limited range of frequencies called either a band or a channel.
That’s why TV stations, even with cable TV, occupy numbered channels. In AM and FM radio, the numbers assigned (such as 100.1) correspond to actual measurements of the frequencies they occupy. The measurements are in kilohertz (KHz) for AM and megahertz (MHz) for FM.
The 5GHz WiFi band has more channels than the 2.4GHz band, partly because higher-frequency waves can convey the same operation in less space, and partly because of the width assigned by regulators (which means the FCC in the US). The 6GHz band has even more channels.
How wide is a channel? For the sake of analogy, on FM radio, a channel occupies 200KHz: That’s why the 100.1 channel and 100.3 channel (measured in MHz) can carry separate radio stations.
In the original 2.4GHz space, users had a choice of 20MHz or 40MHz channels. If you chose 40MHz, you got only half as many channels. And for practical reasons, most installations used a maximum of two channels.
With 5GHz, you could also have 80MHz channels. In the new 6GHz WiFi, you can go even bigger and choose 160MHz channels. Thus, if you have a device emitting lots of data (MRI images, perhaps) you can choose a wide channel.
A posting from Wyebot lists a lot of useful geeky specs about 6GHz WiFi. Because the range assigned to that band is large, it provides a lot of channels: 14 channels if you choose 80MHz or 7 channels if you choose 160MHz.
At the time I’m writing, only a few manufacturers make 6GHz access points (often called “hubs”). To use 6GHz, the devices at the other side of the communication also have to be upgraded. Therefore, Sands explained, there are three parallel evolutions going on: access points, devices, and the users upgrading their hospitals or other facilities. I’ll return to the question of adoption later.
Possibilities of 6GHz in hospitals
Just as when you expand your physical building, you have to think about how to divide up your bandwidth needs when you expand your WiFi capacity. Locating access points and choosing channels for WiFi is a little like spacing out walls when you architect a building. Who’s hogging space now? How many people are competing for space?
A lot of hospitals are OK without 6GHz. Each network administrator should monitor usage of their WiFi networks and see whether they tend to run out of capacity. (Parenthetically, that’s part of the service Wyebot offers.)
But bandwidth needs are on the rise. First, more and more devices are getting “smart” (Internet-connected). Carts and tablets are becoming Internet-enabled. Many patients now wear tracking devices. Children will be playing video games, and so on. The hospitals also have sensors for temperature, security, and other general purposes besides patient care.
Some devices also send a lot of data, such as the MRI images mentioned earlier.
By the way, RFID chips (which are popular for tracking items in hospitals) use different frequencies from WiFi.
Because 6GHz has trouble with walls and has a shorter reach, you will need more access points in order to be within the range of the devices. That limitation increases costs (including the cost of monitoring and administering access points). But it also means you can squeeze more devices into your facility, because you need to put fewer on an access point.
Hospitals are likely to adopt 6GHz gradually
Sands says that hospitals tend to upgrade each access point every 4 to 5 years. This is the time to re-evaluate requirements, including those for bandwidth.
Thus, he says, we should see a bit of early adoption in 2023. As more hospitals become familiar with 6GHz and replace more devices, he thinks 2024 will be the year when we can say that the band becomes mainstream.
In so many areas, quantitative change can lead to a qualitative one. Proponents for 6GHz WiFi think it will put us closer to having a fully connected hospital, unloading from staff some of the burdens of monitoring patients and their environments.
