It’s a new year and a new decade which makes it a perfect time to look ahead to predict the important trends in wireless networks and their impact on wireless test systems and processes. Here we go:
Hindsight and 2020 vision
As expected, 5G stole the stage in the wireless world in 2019. Between the CES and MWC Barcelona, nearly every mobile and infrastructure player introduced a 5G product or service. While some of these products turned out to be more real than others, they mostly shared the same characteristic – they all suffered from being first-generation products.
If you were one of the early adopters who laid down $1,300 for a first-generation 5G mmWave phone, you had to find the right street in the right city and celebrate when the “5G UWB” logo popped up on your screen. However, if you got 5G signal, don’t move! And definitely don’t go inside!
You might have also noticed that if you were testing the gigabit download speeds, after a couple minutes the phone would jump back into 4G mode for a little bit to let the device cool down.
OK, so not surprisingly, 5G in 2019 was a bit of a technology demonstration. Mobile products delivered high data rates, but limited ability to take advantage of 5G won’t tempt a large number of consumers to ditch the phone they currently have. Also, 5G mobile hotspots haven’t exactly been flying off the shelves, carrying a relatively high price point, capped data plans and limited network availability.
Sales are expected to increase in 2020 as second- generation versions of 5G chips are making their way into products, and analysts are forecasting a big pop in unit sales. Expectations are for 175 million to 200 million 5G-enabled smartphones to ship in 2020, an estimate that seems to grow with each release of a new market report. This growth is largely driven by an aggressive 5G build-out in China using mid-band spectrum, and China-focused handset makers are preparing for this ramp. Additionally, we should expect Japan to highlight a wide variety of 5G use cases when they host the Tokyo Summer Olympic games this year.
The 5G era is still early, but it’s now here in both sub-6 GHz (FR1) and mmWave (FR2) deployments. Now that we’ve experienced the first round of 5G product launches, it’s time for vendors to get serious about high-volume manufacturing for the next round. For mmWave 5G products, there are still some unanswered questions in the supply chain regarding in which production phase to detect quality problems, but product companies are starting to get more comfortable with the technology.
Testing these products is becoming more affordable, with manufacturers applying multi-device parallel test techniques to improve manufacturing economics. On sub-6 GHz 5G products, the manufacturing challenges lie in the number of antennas in the product to support the new mid-band spectrum and MIMO.
Manufacturers are experimenting with the optimal mix of tests performed in different stations in the factory vs. yield and takt time on the line. Achieving the 5G market growth targets in 2020 requires not only a more consumer-friendly price point, but also delivering a great user experience with a high quality product.
Next up on the block: More spectrum
For the U.S. in 2020, there are a lot of wireless spectrum issues to get sorted to really enable the big 5G roll-out. There are three major spectrum areas in play this year: an additional round of mmWave spectrum auctions, opening up 6 GHz unlicensed spectrum, and making more mid-band spectrum available. In particular, from a North-American point of view, there is a big need to get to work on the mid-band 5G spectrum. While the sexy mmWave spectrum creates the headlines with multi-Gigabit download speeds, the mid-band spectrum is really the workhorse for 5G network coverage, and will be a key piece of the 5G infrastructure build-out.
As the timeline for mid-band 5G availability in the US gets sorted out, there is also a need to focus on the 6 GHz unlicensed spectrum (5.925 GHz – 7.125 GHz). I cannot overstate the importance of this event – it has been 20 years since the last significant chunk of unlicensed frequency was made available for use, and more than doubles the existing available spectrum.
Today, this spectrum is primarily discussed in the context of Wi-Fi, but the industry will eventually be deploying 5G here as well – expect an update on that next year. For Wi-Fi, one of the good news / bad news challenges with the evolution of the technology is backwards compatibility. As Wi-Fi has evolved, it has always carried forward the previous generations.
Today, particularly in densely populated areas, the 2.4 GHz and 5GHz bands are over-crowded with devices using legacy Wi-Fi technologies. The current roll-out of Wi-Fi 6 employs a significantly different wireless transmission method than was used in previous generations. The 6 GHz spectrum is vitally important to deliver a “clean” environment for Wi-Fi 6 to deliver the significant improvements that are designed into the standard.
In 2019, Wi-Fi product development that takes advantage of this new unlicensed spectrum was underway and should lead to 6 GHz-enabled Wi-Fi products hitting the market this year. As the industry looks at how to approach testing of devices that operate in the 6 GHz band, a unique challenge is raised. Until now, nearly all of the high-volume, consumer wireless technologies have been constrained to < 6 GHz. Because of this, 6 GHz has become somewhat of a threshold for RF components, where crossing the threshold bumps you into a different class (i.e., cost). As a test solution provider, LitePoint is delivering solutions that address the new spectrum without adding costly (and performance-degrading) bolt-ons, enabling compatibility with previous applications running in manufacturing.
Stock up on bullets and bottled water, it’s a zombie apocalypse!
Now for something totally different for 2020.
First, let me briefly take you back to the year 2002. The United States was riding high on a record 34 medals at the winter Olympic Games hosted in Salt Lake City, the average cost of a gallon of gas was $1.61, CBS had the top-rated TV show with CSI, and Limp Bizkit finally won an American Music Awards for Favorite Alternative Artist after its third nomination.
Coincidentally, this was also the year that the WiMedia Alliance was founded to commercialize a high-speed wireless standard based on ultra-wideband (UWB) technology. Despite some good marketing and the tantalizing promise that UWB could deliver “wireless USB” connectivity, we flash forward 7 years to 2009 and the combination of the Great Recession and the incessant march of the Wi-Fi performance evolution drove a stake through the heart of UWB.
But everyone knows that you can’t keep a zombie down with a stake to the heart, you need a double-tap to the head as well. UWB was left for dead, the WiMedia Alliance was disbanded, and the technology receded into obscurity to wait for the one day that the zombie could rise.
OK, back to present day, and when we visit the technology graveyard, we find that UWB is no longer there. In fact, it has gone back to its 1950s roots and has reemerged as an accurate positioning and ranging technology. The focus this time is not moving gigabits of data through the air, but rather it is determining the relative position of two devices within a few centimeters. Based on the IEEE 802.15.4z standard, UWB is an innovative companion technology, rather than a replacement technology, that enhances application use cases around authentication and indoor positioning.
Testing UWB is a bit different than other typical consumer wireless technologies. On one hand, some of the testing is simpler – there is no specific requirement for a modulation accuracy specification, such as error vector magnitude (EVM). On the other hand, UWB has a different challenging key spec to validate: Time-of-Flight (ToF).
Accurate positioning requires extremely precise timing measurements between packets – in free space, a signal travels 1 centimeter in roughly 30 picoseconds. Test equipment must be able to calibrate ToF factors in devices with a high level of precision. Additionally, there are some uniquely challenging specifications when compared to other mainstream connectivity standards: frequency and signal bandwidth. The frequency range covered in 802.15.4z is 6.5 GHz to 10 GHz, operating outside the “standard” <6 GHz frequency range that we see in most consumer wireless technologies, and the signal bandwidths are typically 500 MHz wide, and can go as high as a 1 GHz or more.
Location, location, location
There is a clear trend heading into 2020 that location detection, gesture sensing, and indoor positioning technologies are going to be hot! I have already spent some time talking about UWB, but there are also several other wireless technologies seeking to address different types of positioning applications. Some additional notable technologies are:
- Bluetooth 5.1: “Smart stylus” products are expected to roll out in 2021 with the Bluetooth 5.1 version of the standard that enables the user to control features with gestures of the pen, and can even help locate that pesky pen if it is accidentally lost in the couch cushions. Particularly useful for mobiles and accessories, Bluetooth 5.1 can provide better performance combined with beacons to enable something like “indoor GPS.”
- 802.11az: The Wi-Fi location technology, 802.11az, seeks to address a different problem by improving the efficiency of Wi-Fi networks and user experience. By taking advantage of knowing where different Wi-Fi clients are located, the access points can connect to mobile products faster and improve energy efficiency by going to sleep when the network is not in use.
- 60 GHz unlicensed radar: Google’s Project Soli, which was widely introduced to the world in 2019 in the Pixel 4 phone, is an example of the use of unlicensed 60 GHz radar technology for gesture sensing. While it’s too early to declare this a gimmick or a future ubiquitous feature, it’s clear that incorporating gesture sensing in a mobile device creates an entirely new way for a user to interact with devices.
These technologies all have subtly different test requirements. Fundamentally, sensing location requires the device to know distance and direction. Distance can either be measured in time (ToF for UWB and radar) or signal strength (received signal strength (RSSI) for Bluetooth & Wi-Fi), requiring either a ToF calibration or a RSSI calibration. Direction can be determined either by placing several sensors/beacons in different locations (triangulation) or by measuring the angle-of-arrival (AoA) and/or angle-of-departure (AoD).
The AoA and AoD methods are particularly desirable because they are independent of the surrounding infrastructure that would require an installation of beacons. AoA and AoD require the device to have multiple antennas. Much in the same way as your ears work together to tell your brain which direction a sound comes from, a transmitted signal is detected on each antenna, and the small differences in phase of the received signal can be interpreted to calculate the direction from which the signal originated.
The race is won in the turns
It’s the turning of a new decade, and 5G will be the platform on which we build for the next decade of innovation. The smartphone was king in 4G – long live the king. The 5G vision expands so much beyond this, and it must, but the networks will be built on the back of the smartphone. Emerging and evolving companion technologies seek to add new dimensions to existing products as well as inspire creative thinkers to capitalize on making their products indispensable by increasing higher engagement between user and “thing.” Technology transition creates opportunities for players to disrupt existing ecosystems or invent new ones.
