- A TechNote on Wireless and Mobility
- Michael Finneran, President
- dBrn Associates
Some important developments in the Wi-Fi arena were highlighted in my last TechNote, following my recent return from the Interop trade show in New York City.
The CEO of the Wi-Fi Alliance, Edgar Figueroa moderated a panel "Wi-Fi: Gigabit Performance (and a whole lot more!)" The Director for Standards and Business Development at Realtek, Sean Coffey talked about 802.11ac and the Marketing VP at Wilocity, Mark Grodzinksy outlined developments with 802.11ad. We're going to talk about the latter of those two standards in this TechNote.
So Where Does IEEE 802.11ad Fit?
Most of the talk has been about 802.11ac, which fits into the current model of Wi-Fi and will be the successor to the current 802.11n. By combining wider channels (up to 160 MHz versus 20- or 40 MHz in 802.11n), more efficient coding (256QAM versus 64QAM in 802.11n), and additional multiple input-multiple output (MIMO) streams (eight streams versus four in 802.11n) 802.11ac will push the maximum Wi-Fi data rate from 600 Mbps to a potential 6.934 Gbps. That's a 10x increase in capacity.
The 802.11ad is a second gigabit Wi-Fi standard, but it takes Wi-Fi in a different direction and will serve a new and different set of applications. Wilocity's Grodzinksy acknowledged this standard is in a much earlier stage of development and that it's still unclear when the first products will appear.
The big difference is that 802.11ad will operate in the 60 GHz band. There are few applications in the 60 GHz band primarily because the signal loss is so high relative to 2.4 GHz and 5 GHz. Higher loss translates into a much shorter transmission range. As a result, 802.11ad will not be capable of supporting transmissions between access points and devices dozens of meters apart. Rather, 802.11ad will be used for in-room wireless connections.
One major advantage of moving to 60 GHz is that there's a lot of spectrum to work with in that band. Mr. Grodzinksy says there is roughly 7 to 9 GHz available throughout most of the world, versus about 0.5 GHz in the 5 GHz band and 0.0835 GHz in the 2.4 GHz band. His company, Wilocity currently makes the Wireless PCI Express (wPCIeTM) cable replacement solution that also runs in the 60 GHz band.
Potential for 802.11ad
The current plans for 802.11ad will have it operating on a 2 GHz channel, meaning a single 802.11ad channel will have more bandwidth than what's available in the entire 2.4 GHz and 5 GHz bands combined. While it will operate in a very wide channel, the initial implementations will use a relatively simple modulation scheme and no MIMO capability. The result is that 802.11ad will deliver data rates up to around 7 Gbps at the outset. Mr. Grodzinksy pointed out that you can do uncompressed 1080P HD video in around 3 Gbps.
Longer term they expect to increase the efficiency of the modulation scheme much as we saw with the progression from 802.11b, to g, then a, and n. As those more efficient techniques are brought to bear, the data rate could potentially go to 25 Gbps.
To compensate for the high signal loss, 802.11ad will use directional antennas that can focus the radio beam into a six-degree angle. Even with that narrow beam, 802.11ad still can only be used for in-room applications. A six-degree beam means that you may have to aim the devices at one another, though there is an option to incorporate beamforming so the two devices could "find each other" and aim the beam automatically.
Two applications are leading the way in discussions centering on 802.11ad.The first is wireless connections for computer peripherals that would not only clean up the mess of cables we find behind our desks, but also allow more flexible peripheral sharing from mobile devices. Wilocity's Wireless PCI Express fits in that category today. The other application is in consumer electronics for wirelessly connecting stereo equipment, HD televisions, and gaming systems.
Conclusion
Products based on 802.11ad are still a few years away, but it is clearly taking Wi-Fi in a new direction. In terms of range, 802.11ad has more in common with Bluetooth than traditional Wi-Fi, though with way more than the three Mbps transmission rates we get on Bluetooth version 2 interface today. The development of 802.11ad is yet another indication that Wi-Fi is not going away any time soon, but even if this new variant fails to catch on, there will still be billions of traditional Wi-Fi devices out there.
The CEO of the Wi-Fi Alliance, Edgar Figueroa moderated a panel "Wi-Fi: Gigabit Performance (and a whole lot more!)" The Director for Standards and Business Development at Realtek, Sean Coffey talked about 802.11ac and the Marketing VP at Wilocity, Mark Grodzinksy outlined developments with 802.11ad. We're going to talk about the latter of those two standards in this TechNote.
So Where Does IEEE 802.11ad Fit?
Most of the talk has been about 802.11ac, which fits into the current model of Wi-Fi and will be the successor to the current 802.11n. By combining wider channels (up to 160 MHz versus 20- or 40 MHz in 802.11n), more efficient coding (256QAM versus 64QAM in 802.11n), and additional multiple input-multiple output (MIMO) streams (eight streams versus four in 802.11n) 802.11ac will push the maximum Wi-Fi data rate from 600 Mbps to a potential 6.934 Gbps. That's a 10x increase in capacity.
The 802.11ad is a second gigabit Wi-Fi standard, but it takes Wi-Fi in a different direction and will serve a new and different set of applications. Wilocity's Grodzinksy acknowledged this standard is in a much earlier stage of development and that it's still unclear when the first products will appear.
The big difference is that 802.11ad will operate in the 60 GHz band. There are few applications in the 60 GHz band primarily because the signal loss is so high relative to 2.4 GHz and 5 GHz. Higher loss translates into a much shorter transmission range. As a result, 802.11ad will not be capable of supporting transmissions between access points and devices dozens of meters apart. Rather, 802.11ad will be used for in-room wireless connections.
One major advantage of moving to 60 GHz is that there's a lot of spectrum to work with in that band. Mr. Grodzinksy says there is roughly 7 to 9 GHz available throughout most of the world, versus about 0.5 GHz in the 5 GHz band and 0.0835 GHz in the 2.4 GHz band. His company, Wilocity currently makes the Wireless PCI Express (wPCIeTM) cable replacement solution that also runs in the 60 GHz band.
Potential for 802.11ad
The current plans for 802.11ad will have it operating on a 2 GHz channel, meaning a single 802.11ad channel will have more bandwidth than what's available in the entire 2.4 GHz and 5 GHz bands combined. While it will operate in a very wide channel, the initial implementations will use a relatively simple modulation scheme and no MIMO capability. The result is that 802.11ad will deliver data rates up to around 7 Gbps at the outset. Mr. Grodzinksy pointed out that you can do uncompressed 1080P HD video in around 3 Gbps.
Longer term they expect to increase the efficiency of the modulation scheme much as we saw with the progression from 802.11b, to g, then a, and n. As those more efficient techniques are brought to bear, the data rate could potentially go to 25 Gbps.
To compensate for the high signal loss, 802.11ad will use directional antennas that can focus the radio beam into a six-degree angle. Even with that narrow beam, 802.11ad still can only be used for in-room applications. A six-degree beam means that you may have to aim the devices at one another, though there is an option to incorporate beamforming so the two devices could "find each other" and aim the beam automatically.
Two applications are leading the way in discussions centering on 802.11ad.The first is wireless connections for computer peripherals that would not only clean up the mess of cables we find behind our desks, but also allow more flexible peripheral sharing from mobile devices. Wilocity's Wireless PCI Express fits in that category today. The other application is in consumer electronics for wirelessly connecting stereo equipment, HD televisions, and gaming systems.
Conclusion
Products based on 802.11ad are still a few years away, but it is clearly taking Wi-Fi in a new direction. In terms of range, 802.11ad has more in common with Bluetooth than traditional Wi-Fi, though with way more than the three Mbps transmission rates we get on Bluetooth version 2 interface today. The development of 802.11ad is yet another indication that Wi-Fi is not going away any time soon, but even if this new variant fails to catch on, there will still be billions of traditional Wi-Fi devices out there.
It looks like 802.11ad is focused on both the computer and consumer entertainment markets. Am I reading that right?