The Battle for IoT

There is an interesting battle going on to be the technology that monetizes the control of Internet of Things devices. Like a lot of tech hype, IoT has developed a lot slower than originally predicted – but it’s now finally becoming a big business. I think back to a decade ago when tech prognosticators said we’d soon be living in a virtual cloud of small monitors that would monitor everything in our life. According to those early predictions, our farm fields should already be fully automated, and we should all be living in the smart home envisioned by the Jetsons. Those predictions probably say more about the tech press that hypes new technologies than about IoT.

I’ve been noticing increasing press releases and articles talking about different approaches to monetizing IoT traffic. The one that we’ve all heard the most about is 5G. The cellular companies told Wall Street five years ago that the monitoring of IoT devices was going to fuel the 5G business plan. The wireless companies envisioned households all buying a second cellular subscription to monitor devices.

Except in a few minor examples, this business plan never materialized. I was reminded of it this week when I saw AT&T partnering with Smart Meter to provide patient monitoring for chronic conditions like diabetes and high blood pressure. The monitoring devices worn by patients include a SIM card, and patients can be monitored anywhere within range of a cellular signal. It’s a great way for AT&T to monetize IoT subscriptions – in this case, with monthly fees likely covered by health insurance. It sounds like an awesome product.

Another player in the IoT world is LEO satellites. In August of last year, Starlink made a rare acquisition by buying Swarm. This company envisions using satellites to be able to monitor outdoor IOT devices anywhere in the world. The Swarm satellites are less than a pound each, and the Swarm website says the goal is to have three of these small satellites in range of every point on earth by the end of 2022. That timeline slowed due to the purchase by Starlink, but this could be a huge additional revenue stream for the company. Swarm envisions putting small receivers in places like fields. Like with Starlink, customers must buy the receivers, and there is an IoT data monitoring plan that will allow the collection of 750 data packets per month for a price of $60 per year.

Also still active in pursuing the market are a number of companies promoting LoRaWAN technology. This technology uses tall towers or blimps and CBRS or some other low-power spectrum to communicate with IoT monitors over a large geographic area. The companies developing this technology can be found at the LoRa Alliance.

Of course, the current king of IoT is WiFi. Charter recently said it is connected to 5 billion devices on its WiFi network. WiFi has the advantage of a free IoT connection for the price of buying a broadband connection.

Each of these technologies has a natural market niche. The AT&T health monitoring system only makes sense on a cellular network since patients need to be monitored everywhere they go during the day. Cellular should be the go-to technology for mobile monitoring. The battle between LoRaWAN and satellites will be interesting and will likely eventually come down to price. Both technologies can be used to reach farm fields where cellular coverage is likely to never be ubiquitous. WiFi is likely to carry the signals from the devices in our homes – the AT&T vision of everybody buying an IoT cellular data plan sounds extremely unlikely since we all can have the same thing for the cost of a WiFi router.

Courts Uphold 6 GHz WiFi Order

The right to use spectrum is turning into one of the most valuable pieces of real estate in the country. Cellular carriers have been paying huge sums in FCC auctions to get the rights to use spectrum. Perhaps the biggest sign of the value of spectrum is that there is seemingly a lawsuit every time the FCC makes a spectrum decision by those who want to see the spectrum used in other ways.

The United States Court of Appeals for the District of Columbia recently upheld the FCC’s April 2020 order that assigned 1,200 MHz of the 6 GHz spectrum band for public use. That order was challenged by a coalition of Apple and cellular carriers like AT&T. The challengers wanted some of the 6 GHz spectrum to be auctioned to those willing to pay the most for it – presumably the cellular carriers. Not surprisingly, the intervenors supporting the FCC decision were the big cable companies who take the most advantage of WiFi.

The original FCC order clearly supports the idea that the public needs better WiFi. The 6 GHz spectrum band will revolutionize the way we use WiFi in homes and businesses. WiFi performance is already slated to improve due to the new WiFi 6 technology. But adding the 6 GHz spectrum will drive performance to yet another level by adding seven 160 MHz channels to the WiFi environment.

The legal challenge followed the lines of other recent spectrum challenges that question the FCC’s technical assumptions used in making the order. Since this new spectrum band is open to everybody, including the cellular carriers – the challengers argued, among other technical points, that there will be too much interference to make the spectrum useful for cellular data.

The Court came down clearly on the side of the FCC. The court said that the courts owe ‘significant deference’ to the FCC and its technical staff in deciding complicated technical issues. Intervenors had raised the same interference issues at the FCC during the deliberation of the issue – and the courts were not having any rehashing of issues that the FCC had already considered.

The court did remand one minor issue related to interference back to the FCC raised by the National Association of Broadcasters about interference in the 2.4 GHz WiFi band. The FCC will revisit that issue.

The court decision finally frees up the 6 GHz spectrum for WiFi use. Vendors have assumed this would be ordered and have been building the capability to use the spectrum into devices over the last few years.

I think we’re going to look back at the FCC’s decision to expand WiFi and the Court’s backing of that order as the most important spectrum decision of our time. The current WiFi spectrum is overtaxed and growing busier by the day. This new spectrum will revitalize the WiFi distribution of bandwidth around the home and the office that we’ve all been wanting.

Industry vendors haven’t been sitting still and have already started to develop the next generation of WiFi that will create another big leap in performance.

LAA and WiFi

University of Chicago students conducted a study on and near the campus, looking at how LAA (Licensed Assisted Access) affects WiFi. Cellular carriers began using LAA technology in 2017. This technology allows a cellular carrier to snag unlicensed spectrum to create bigger data pipes than can be achieved with the traditional cellular spectrum. When cellular companies combine frequencies using LAA, they can theoretically create a data pipe as large as a gigabit while only using 20 MHz of licensed frequency. The extra bandwidth for this application comes mostly from the unlicensed 5 GHz band and can match the fastest speeds that can be delivered with home routers using 802.11AC.

There has always been an assumption that the cellular use of LAA technology would interfere to some extent with WiFi networks. But the students found a few examples where using LAA killed as much as 97% of local WiFi network signal strength. They found that when LAA kicked in that the performance on nearby WiFi networks always dropped.

This wasn’t supposed to happen. Back when the FCC approved the use of LAA, the cellular carriers all said that interference would be at a minimum because WiFi is mostly used indoors and LAA is used outdoors. But the study showed there can also be a big data drop for indoor WiFi routers if cellular users are in the vicinity. That means people on the street can interfere with the WiFi strength in a Starbucks (or your home).

The use of WiFi has also changed a lot since 2017, and during the pandemic, we have installed huge numbers of outdoor hotspots for students and the public. This new finding says that LAA usage could be killing outdoor broadband established for students to do homework. Students didn’t just use WiFi hotspots when they couldn’t attend school, but many relied on WiFi broadband in the evenings and weekends to do homework. Millions of people without home broadband also use public WiFi hotspots.

LAA usage kills WiFi usage for several reasons. WiFi is a listen-before-talk technology. This means that when a WiFi device wants to grab a connection to the router that the device gets in line with other WiFi devices and is not automatically connected immediately. LAA acts like all cellular traffic and immediately grabs bandwidth if it is available, This difference in the way of using spectrum gives LAA a priority to grab frequency first.

LAA connections also last longer. You may not realize it, but devices using WiFi devices don’t connect permanently. WiFi routers connect to devices in 4-millisecond bursts. In a home where there aren’t many devices trying to use a router, these bursts may seem continuous, but in a crowded place with a lot of WiFi users, devices have to pause between connections. LAA bursts are 10-milliseconds instead of 4-ms for WiFi. This means that LAA devices both connect immediately to unlicensed spectrum and also keep the connection longer than a WiFi device. It’s not hard for multiple LAA connections to completely swamp a WiFi network.

This is a perfect example of how hard it is to set wireless policy. The FCC solicited a lot of input when the idea of sharing unlicensed spectrum with cellular carriers was first raised. At the time, the technology being discussed was LTE-U, a precursor to LAA. The FCC heard from everybody in the industry, with the WiFi industry saying that cellular use could overwhelm WiFi networks and the cellular industry saying that concerns were overblown. The FCC always finds itself refereeing between competing concerns and has to pick winners in such arguments. The decision by the FCC to allow cellular carriers to use free public spectrum highlights another trend – the cellular companies, by and large, get what they want.

It will be interesting to see if the FCC does anything as a result of this study and other evidence that cellular companies have gone a lot further with LAA than promised. I won’t hold my breath. AT&T also announced this week that it is starting to test LAA using the unlicensed portion of the 6 GHz spectrum.

Broadband Interference

Jon Brodkin of ArsTechnica published an amusing story about how the DSL went out of service in a 400-resident village in Wales each morning at 7:00 am. It turns out that one of the residents turned on an ancient television that interfered with the DSL signal to the extent that the network collapsed. The ISP finally figured this out by looking around the village in the morning with a spectrum analyzer until they found the source of the interference.

It’s easy to think that the story points out another weakness of old DSL technology, but interference can be a problem for a lot of other technologies.

This same problem is common on cable company hybrid-fiber coaxial networks. The easiest way to understand this is to think back to the old days when we all watched analog TV. Anybody who watched programming on channels 2 through 5 remembers times when the channels got fuzzy or even became unwatchable. It turns out that there are a lot of different devices that interfere with the frequencies used for these channels including things like microwave ovens, certain motors like power tools and lawnmowers, and other devices like blenders. It was a common household occurrence for one of these channels to go fuzzy when somebody in the house, or even in a neighboring home used one of these devices.

This same interference carries forward into cable TV networks. Cable companies originally used the same frequencies for TV channels inside the coaxial wires that were used over the air and the low TV channels sat between the 5 MHz and 42 MHz frequency. It turns out that long stretches of coaxial wires on poles act as a great antenna, so cable systems pick up the same kinds of interference that happens in homes. It was pretty routine for channels 2 and 3, in particular, to be fuzzy in an analog cable network.

You’d think that this interference might have gone away when cable companies converted TV signals to digital. The TV transmissions for channels 2 through 5 got crystal clear because cable companies relocated the digital version of these channels to better frequency. When broadband was added to cable systems the cable companies continue to use the low frequencies. CableLabs elected to use these frequencies for the upload portion of broadband. There is still plenty of interference in cable networks today – probably even more than years ago as coaxial networks have aged and have more points for interference to seep into the wires. Until the pandemic, we didn’t care much about upload bandwidth, but it turns out that one of the major reasons that cable companies struggle to deliver reliable upload speeds is that they are using the noisiest spectrum for the upload function.

The DSL in the village suffered from the same issue since the telephone copper wires also act as a big outdoor antenna. In this village, the frequency emanating from the old TV exactly matched the frequencies used for DSL.

Another common kind of interference is seen in fixed wireless networks in a situation where there are multiple ISPs using the same frequencies in a given rural footprint. I know of counties where there are as many as five or six different wireless ISPs, and most use the same frequencies since most WISPs rely on a handful of channels in the traditional WiFi bandwidth at 2.4 MHz and 5 MHz. I’ve heard of situations where WiFi is so crowded that the performance of all WISPs suffer.

WiFi also suffers from local interference in the home. The WiFi standard says that all devices have an equal chance of using the frequencies. This means that a home WiFi router will cycle through all the signals from all devices trying to make a WiFi connection. When a WiFi router connects with an authorized device inside the home it allows for a burst of data, but then the router disconnects that signal and tries the next signal – cycling through all of the possible sources of WiFi.

This is the same issue that is seen by people using WiFi in a high-rise apartment building or a hotel where many users are trying to connect to WiFi at the same time. Luckily this problem ought to improve. The FCC has authorized the use of 6 GHz spectrum for home broadband which opens up numerous new channels. Interference will only occur between devices trying to share a channel, but that will be far fewer cases of interference than today.

The technology that has no such interference is fiber. Nothing interferes with the light signal between a fiber hub and a customer. However, once customers connect the broadband signal to their home WiFi network, the same interference issues arise. I looked recently and can see over twenty other home WiFi networks from my office – a setup ripe for interference. Before making too much fun of the folks in the Welsh village, there is a good chance that you are subject to significant interference in your home broadband today.

Finding a Business Case for 5G

We are now more than a year into what the carriers are labeling as 5G. If you read this blog regularly you know by now that I don’t think we’ve seen any 5G yet – what has been introduced so far is new spectrum. A new band of spectrum can improve broadband performance in crowded markets, and so the carriers are getting some praise for this development. But these new spectrum bands are operating as 4G LTE and are not yet 5G.

However, we’re getting closer to 5G. Within another few years we will start to see some of the innovations contained in the 5G standards hit the market. This won’t be spectacular at first. Remember that the carrier’s primary short-term goal for 5G is to improve the capacity of cellular networks to get ahead of the exploding demand curve. Cellular data traffic is growing at an astronomical 36% annually and that is stressing cellular networks to keep up with demand. 5G is part of a 3-prong approach to increase capacity – introducing small cells, introducing new spectrum, and finally introducing 5G features. These three changes ought to brace cellular networks for another decade, although eventually, the networks will hit a wall again if growth stays on the current growth curve.

Over the last two and three years, the cellular carriers and the press were full of stories of the wonderful ways that 5G would transform our world. AT&T, Verizon, and T-Mobile spun stories about having gigabit cellular, having fleets of self-driving cars, and having big broadband with us wherever we go. You may not have noticed, but those stories have disappeared. The carriers are not talking much about 5G capabilities other than faster speeds. They are no longer trying to soothe investors with stories of huge future 5G revenue streams.

I think the reason for this is that cellular carriers don’t have any grand visions of future 5G revenues. They still have not built a business case for 5G that justifies the cost of deploying dense networks of small cells.  Consider some of the ideas that were highly touted just a year or two ago.

Millimeter wave spectrum that can deliver gigabit broadband speeds is likely to remain a novelty. The carriers have introduced this in downtown urban neighborhoods to produce a marketing wow factors with TV commercials showing broadband speeds faster than a gigabit. But millimeter wave networks only work outdoors., and even that is funky since everything including a customer’s body can block the signal. There is no business case for spending the money for dense fiber-fed networks since cellphones are not designed for big bandwidth applications. Urban 4G is already pretty good, and there is no benefit other than bragging rights for a customer to shell out extra money for a millimeter wave phone and data plan.

There was talk for a while that 5G would displace WiFi inside homes and businesses. The idea was that 5G could do a better job of keeping data private while also bringing blazing speeds. However, the FCC has approved new WiFi spectrum that when coupled with WiFi 6 technology promises a magnitude improvement in WiFi performance. Once people start using the new WiFi there is going to be little interest in paying a monthly subscription for something that can be done well with off-the-shelf routers.

There still is talk about using 5G in medicine, touting things like the ability of surgeons to perform remote surgery. But is that ever really going to be a thing? It’s taken fifteen years and the COVID-19 crisis to get doctors to finally try telemedicine. There can’t be many doctors ready to tackle performing surgery in another city using robots. It’s also hard to think that insurance companies are going to support surgery that could go off the rails due to a fiber cut or electronics failure. 5G has also been touted as making it easier to monitor patients away from hospitals. But that’s a small bandwidth application that can be handled fine with the ever-improving 4G LTE.

There has been the hope of using 5G technology to help automate factories, and that sounds like a legitimate use of 5G. Factories that need high-precision and low latency are perfect for 5G. This will avoid any interference issues that might come with WiFi. But are there going to be enough new factories using this technology to move the financial bottom line of AT&T or Verizon?

For several years there was a story spun about how self-driving vehicles would communicate with the cloud using 5G. This never made any sense because for this to work there would have to be a dense cellular network built along every road. If the fleets of self-driving cars are developed before the 5G network, they’ll find a solution other than 5G. There also came the ugly realization that networks crash and the image of all the cars coming to a halt in a city because of a broadband outage means this may never become a reality.

Finally, there was talk of how 5G would free people from the monopoly power of the cable companies for broadband. People could have their entertainment with them at all times everywhere. However, most people are smart enough to know that the big cellular companies are also ugly monopolies. They have been engaging in bad behavior such as selling customer location data, even after being told by the FTC to stop the practice. The cellular companies are not going to win an argument that they have the moral high ground.

I have been trying to figure out the 5G revenue stream for several years and I’m no closer to it today than I was three years ago. Some people are willing to pay extra money to get faster cellular broadband speeds, but most customers think they are already paying for this in their cellular subscription. If Dish is successful in launching a new 5G network, the price pressure for 5G will likely be downward rather than increasing. The cellular carriers are going to introduce 5G even without new revenue streams because it’s the only way to keep their networks from crashing in a few years. But what they do after that is still a mystery to me.

 

Just a quick personal note. I’ve now published 1,800 blogs since I started in March 2013. That’s about 1,600 more than I thought I would be able to do. I tell myself once in a while that I’ll stop writing this blog when I run out of topics – but that doesn’t seem like it will be happening any time soon. I thank those of you who have been reading my musings. Onward to 1,800 more!

Introducing 6 GHz into WiFi

WiFi is already the most successful deployment of spectrum ever. In the recent Annual Internet Report, Cisco predicted that by 2022 that WiFi will cross the threshold and will carry more than 50% of global IP traffic. Cisco predicts by 2023 that there will be 628 million WiFi hotspots – most used for home broadband.

These are amazing statistics when you consider that WiFi has been limited to using 70 MHz of spectrum in the 2.4 GHz spectrum band and 500 MHz in the 5 GHz spectrum band. That’s all about to change as two major upgrades are being made to WiFi – the upgrade to WiFi 6 and the integration 6 GHz spectrum into WiFi.

The Impact of WiFi 6. WiFi 6 is the new consumer-friendly name given to the next generation of WiFi technology (replaces the term 802.11ax). Even without the introduction of new spectrum WiFi 6 will significantly improve performance over WiFi 5 (802.11ac).

The problem with current WiFi is congestion. Congestion comes in two ways – from multiple devices trying to use the same router, and from multiple routers trying to use the same channels. My house is probably typical, and we have a few dozen devices that can use the WiFi router. My wife’s Subaru even connects to our network to check for updates every time she pulls into the driveway. With only two of us in the house, we don’t overtax our router – but we can when my daughter is home from college.

Channel congestion is the real culprit in our neighborhood. We live in a moderately dense neighborhood of single-family homes and we can all see multiple WiFi networks. I just looked at my computer and I see 24 other WiFi networks, including the delightfully named ‘More Cowbell’ and ‘Very Secret CIA Network’. All of these networks are using the same small number of channels, and WiFi pauses whenever it sees a demand for bandwidth from any of these networks.

Both kinds of congestion slow down throughput due to the nature of the WiFi specification. The demands for routers and for channels are queued and each device has to wait its turn to transmit or receive data. Theoretically, a WiFi network can transmit data quickly by grabbing a full channel – but that rarely happens. The existing 5 GHz band has six 80-MHz and two 160-MHz channels available. A download of a big file could go quickly if a full channel could be used for the purpose. However, if there are overlapping demands for even a portion of a channel then the whole channel is not assigned for a specific task.

Wi-Fi 6 introduces a few major upgrades in the way that WiFi works to decrease congestion. The first is the introduction of orthogonal frequency-division multiple access (OFDMA). This technology allows devices to transmit simultaneously rather than wait for a turn in the queue. OFDMA divides channels into smaller sub-channels called resource units. The analogy used in the industry is that this will open WiFi from a single-lane technology to a multi-lane freeway. WiFi 6 also uses other techniques like improved beamforming to make a focused connection to a specific device, which lowers the chances of interference from other devices.

The Impact of 6 GHz. WiFi performance was already getting a lot better due to WiFi 6 technology. Adding the 6 GHz spectrum will drive performance to yet another level. The 6GHz spectrum adds seven 160 MHz channels to the WiFi environment (or alternately adds fifty-nine 20 MHz channels. For the typical WiFi environment, such as a home in an urban setting, this is enough new channels that a big bandwidth demand ought to be able to grab a full 160 MHz channel. This is going to increase the perceived speeds of WiFi routers significantly.

When the extra bandwidth is paired with OFDMA technology, interference ought to be a thing of the past, except perhaps in super-busy environments like a business hotel or a stadium. Undoubtedly, we’ll find ways over the next decade to fill up WiFi 6 routers and we’ll eventually be begging the FCC for even more WiFi spectrum. But for now, this should solve WiFi interference in all but the toughest WiFi environments.

It’s worth a word of caution that this improvement isn’t going to happen overnight. You need both a WiFi 6 router and WiFi-capable devices to take advantage of the new WiFi 6 technology. You’ll also need devices capable of using the 6 GHz spectrum. Unless you’re willing to throw away every WiFi device in your home and start over, it’s going to take most homes years to migrate into the combined benefits of WiFi 6 and 6 GHz spectrum.

Can 5G Replace WiFi?

Verizon recently posted a webcast with investors where Ronan Dunne, EVP and CEO of the Verizon Consumer Group said that he believed that 5G hotspots using millimeter wave spectrum will eventually displace WiFi in homes.

He cites major benefits of 5G over WiFi. He believes that a 5G network will be more reliable and more secure. He thinks that people will value the safety that comes from having traffic inside their home being encrypted as it rides Verizon’s 5G network compared to the more public nature of WiFi where every neighbor can see a home’s WiFi network.

He also cites the convenience of being able to transfer 5G traffic between networks. He paints a picture where a customer making a call or watching a video using a home 5G hotspot will be able to walk out the door and seamlessly continue the session outside on their cellphone. That’s pretty slick stuff should that ever come to pass.

The picture he’s painting for Verizon investors is a future where homes buy a Verizon 5G subscription to use in place of WiFi. This is part of Verizon’s ongoing effort to find a business case for 5G. His vision of the future is possible, but there are a lot of hurdles for Verizon to overcome to achieve that vision.

It’s going to get harder to compete with WiFi since the technology is getting a lot better with two major upgrades. First, the industry has introduced WiFi 6, which brings higher quality performance, lower latency, and faster data rates. WiFi 6 will use techniques like improved beamforming to greatly reduce interference between WiFi uses within the home.

Even more importantly, WiFi will be incorporating the new 6 GHz spectrum band that will increase bandwidth capabilities by adding seven 160 MHz bands and fourteen 80 MHz bands. It will be much easier to put home devices on separate channels when these new channels are added to the existing channels available on 2.4 and 5 GHz. This means that 5G will be competing against a much improved WiFi compared to the technology we all use today.

Another big hurdle for Verizon to overcome is that WiFi is ubiquitous today. WiFi is built into a huge number of devices, and a homeowner might already own a dozen or more devices capable of using WiFi. Verizon will have to somehow convince homeowners that 5G is so superior that it’s worth replacing the panoply of WiFi devices.

Another hurdle is that there is going to be WiFi vendors painting almost the same picture as Verizon. The makers of WiFi routers are already envisioning future devices that will introduce millimeter-wave spectrum including 5G into the home. There are vendors already working on devices that will provide both WiFi 6 and 5G using millimeter-wave connections simultaneously, using the publicly available 60 GHz V band. These solutions envision offering everything that Verizon can do, except the ability to roam seamlessly in and out of a home – and it will be done by selling a box instead of a new monthly subscription.

Another interesting hurdle to switching home networks to 5G is that there might be separate 5G solutions for each cellular carrier that uses different bands of spectrum. It’s relatively easy for device makers today to build a cellphone or other device that can use different cellular carriers because the carriers all use similar spectrum. But as each cellular company picks a different mix of frequencies moving forward, there is likely going to be cellphones and other devices that are specific to one carrier. It’s impossible to build a cellphone with today’s battery technology that can receive a huge range of spectrums – the multiple antenna systems would drain a cellphone dry in no time.

The largest hurdle of all is that WiFi is free to use after buying a WiFi router or meshed WiFi devices for the home. There is no monthly subscription fee to use the wireless WiFi connections within the home. Verizon clearly foresees a world where every home has a new monthly subscription to use its in-home 5G network.

Mr. Dunne makes one good point. It’s becoming increasingly clear that public WiFi networks are susceptible to hacking. A 5G network controlled by a carrier should be a lot safer than a WiFi hotspot managed by a coffee shop. The big question is if this enough incentive for people to buy 5G-capable devices or for coffee shops to switch to 5G networks. Even should coffee shops go with a 5G solution, will homes follow suit?

Mr. Dunne vision has an underlying assumption that people will value data security enough to be willing to pay more for it. He envisions people choosing a managed network when they have a choice. He could be right, and perhaps there will be enough data breaches in coming years with WiFi that the paradigm will change from WiFi to 5G. But it’s going to be incredibly hard to dislodge WiFi, particularly when it’s evolving and improving along with 5G.

Even if Mr. Dunne is right, this shift is not coming soon, probably not within this decade. For now, WiFi has won the device war and any shift to 5G would drag out over many years. It’s going to be incredibly difficult for the cellular carriers to convince everybody to switch to 5G.

I sympathize with Mr. Dunne’s dilemma. Investors want to understand where the revenues will come from to fund the expensive upgrades to 5G. Verizon and the other cellular carriers have tossed out a lot of ideas, but so far none of them have stuck to the wall.  Investors are getting rightfully nervous since there doesn’t appear to be any significant 5G revenues coming in the next few years. The carriers keep painting pictures of an amazing 5G future as a way to not have to talk about lack of 5G revenues today.

We Need Public 5G Spectrum

Last October the FCC issued a Notice for Proposed Rulemaking that proposed expanding WiFi into the 6 GHz band of spectrum (5.925 to 7.125 GHz). WiFi has been a huge economic boon to the country and the FCC recognizes that providing more free public spectrum is a vital piece of the spectrum puzzle. Entrepreneurs have found a myriad of inventive ways to use WiFi that go far beyond what carriers have provided with licensed spectrum.

In much of the country the 6 GHz spectrum is likely to be limited to indoor usage due to possible outdoor interference with Broadcast Auxiliary Service, where remote crews transmit news feeds to radio and TV stations, and Cable Television Relay Service, which cable companies used to transmit data within a cable company. The biggest future needs for WiFi are going to be indoors, so restricting this spectrum to indoor use doesn’t feel like an unreasonable limitation.

However, WiFi has some inherent limitations. The biggest problem with the WiFi standard is that a WiFi network will pause to allow any user to use the bandwidth. In a crowded environment with a lot of devices the constant pausing adds latency and delay in the system, and in heavy-use environments like a business hotel the constant pauses can nearly shut down a WiFi network. Most of us don’t feel that interference today inside our homes, but as we add more and more devices over time, we will recognize the inherent WiFi interference into our network. The place where WiFi interference is already a big concern is in heavy wireless environments like hospitals, factories, airports, business hotels, and convention centers.

Many of our future computing needs are going to require low latency. For instance, creating home holograms from multiple transmitters is going to require timely delivery of packets to each transmitter. Using augmented reality to assist in surgery will require deliver of images in real time. WiFi promises to get better with the introduction of WiFi 6 using the 802.11ax standard, but that new standard does not eliminate the innate limitations of WiFi.

The good news is that we already have a new wireless standard that can create a low-latency dedicated signal paths to users. Fully implemented 5G with frequency slicing can be used to satisfy those situations where WiFi doesn’t meet the need. It’s not hard to picture a future indoor network where a single router can satisfy some user needs using the WiFi standard with other uses satisfied using 5G – the router will choose the best standard to use for a given need.

To some degrees the cellular carriers have this same vision. They talk of 5G being used to take over IoT needs instead of WiFi. They talk about using 5G for low latency uses like augmented reality. But when comparing the history of the cellular networks and WiFi it’s clear that WiFi has been used far more creatively. There are thousands of vendors working in today’s limited WiFi spectrum that have developed a wide array of wireless services. Comparatively, the cellular carriers have been quite vanilla in their use of cellular networks to deliver voice and data.

I have no doubt that AT&T and Verizon have plans to offer million-dollar 5G solutions for smart factories, hospitals, airports and other busy wireless environments. But in doing so they will tap only a tiny fraction of the capability of 5G. If we want 5G to actually meet the high expectations that the industry has established, we ought to create a public swath of spectrum that can use 5G. The FCC could easily empower the use of the 6 GHz spectrum for both WiFi and 5G, and in doing so would unleash wireless entrepreneurs to come up with technologies that haven’t even been imagined.

The current vision of the cellular carriers is to somehow charge everybody a monthly subscription to use 5G – and there will be enough devices using the spectrum that most people will eventually give in and buy the subscription. However, the big carriers are not going to be particularly creative, and instead are likely to be very restrictive on how we use 5G.

The alternate vision is to set aside a decent slice of public spectrum for indoor use of 5G. The public will gain use of the spectrum by buying a 5G router, with no monthly subscription fee – because it’s using public spectrum. After all, 5G is a just standard, developed worldwide and is not the proprietary property of the big cellular companies. Entrepreneurs will jump on the opportunity to develop great uses for the spectrum and the 5G standard. Rather than being held captive by the limited vision of AT&T and Verizon we’d see huge number of devices using 5G creatively. This could truly unleash things like augmented reality and virtual presence. Specialty vendors would develop applications that make great strides in hospital health care. We’d finally see smart shopping holograms in stores.

The public probably doesn’t understand that the FCC has complete authority over how each swath of spectrum is used. Only the FCC can determine which spectrum can or cannot be used for WiFi, 5G and other standards. The choice ought to be an easy one. The FCC can let a handful of cellular companies decide how society will use 5G or they can unleash the creativity of thousands of developers to come up with a myriad of 5G applications. We know that creating public spectrum creates immense societal and economic good. If the FCC hadn’t set aside public spectrum for WiFi we’d all still have wires to all our home broadband devices and many of the things we now take for granted would never have come to pass.

The Resurgence of Wireless Mesh?

I’ve had several calls recently from clients asking about wireless mesh networks. Those that have been in the industry for a while probably remember the mesh network craze in the late 1990s. At that time large cities all over the country considered building WiFi mesh networks to try to bring broadband to everybody in their cities. Many cities deployed pilot systems, but in the end, the technology never panned out. The technology had the squirrely problems often associated with wireless technology and never delivered the bandwidth that the manufacturers promised.

Apparently, the technology is back. I went to the web for a quick investigation, and sure enough there are carrier-class outdoor mesh radios available from a number of different manufacturers. In case you aren’t familiar with the concept of a mesh network, it’s a network comprised of multiple radios, each of which connects to multiple other radios. Most mesh networks are dynamically linked, meaning that the radios work autonomously to find the most efficient routing path for traffic within the mesh. The easiest way to understand this is with this diagram from Cisco, which has been manufacturing mesh network gear for many years. In this diagram each radio interconnects with neighboring radios.

The biggest flaw in the technology two decades ago was that the mesh networks didn’t scale well. This was for two reasons. First, by definition, a wireless link loses half of its bandwidth with every hop to another radio. Mesh networks with too many hops don’t deliver very much bandwidth to the most remote nodes in the network.

Large mesh network also developed an unexpected problem. One of the characteristics of a mesh network is that the radios constantly coordinate with each other. If a given node is temporarily overloaded with a big bandwidth demand from an end user, the network dynamically routes other traffic around the bottleneck. Unfortunately, it turned out that in large networks the radios spent a majority of the bandwidth communicating with each other at the expense of the bandwidth left for end users. As mesh network grew in size the amount of bandwidth throughput decreased significantly. Technicians determined that this excess internode chatter could be reduced by limiting the number of nodes that any radio could communicate with, but in doing so the network was no longer a real mesh.

The other big problem in the 1990s is that the networks were deployed as outdoor radios, meaning that very little bandwidth actually made it into homes. I remember working one day at a client where I could see a nearby mesh radio through a window. As long as I sat where I had a direct line of sight to the radio I could use the WiFi, but if I moved to another part of the room the signal completely died. Broadcasting WiFi with outside radios is an inefficient way to provide bandwidth indoors.

Those inherent problems are still an issue today. There is no way to eliminate the issue of the bandwidth decreasing with each hop. However, the difference from today and the 19990s is that we can feed a mesh network with gigabits of broadband instead of with a few T1s. To some degree, that means that we can overpower the system so that at least some bandwidth makes it to the furthest nodes in the network.

One of the other weaknesses of a mesh network is that most networks use WiFi spectrum. Practically every wired home uses WiFi today to move bandwidth around the house. Superimposing a mesh WiFi network in a neighborhood means a lot more high-power WiFi sources to cause interference with every other WiFi device. Anybody who has ever tried to maintain a WiFi signal in a crowded business hotel understands the issues with WiFi interference.

Even with those limitations, I can see some great uses for a mesh network. The vendors are pushing the technology as a way to bring bandwidth more easily to outdoor spaces like parks. There is a brand of outdoor mesh devices being marketed as a way to spread WiFi around a farmhouse to the outdoor buildings. While nobody seems to be marketing the idea yet, a mesh network might be a good way to spread WiFi signals to fields and pastures to track the small bandwidth sensors being used to collect data from fields and herds.

What my clients really wanted to know is if a mesh network could be used to provide residential broadband. There might be situations where this makes sense. Rather than trying to beam the bandwidth from outside hotspots, each radio could feed a wire into a home. But mesh networks still have the same inherent problems as in the past and in most cases other solutions can probably produce faster and more consistent bandwidth. As a consultant I always have an open mind, but having seen the technology crash and burn once before I’d want to see this in practice before buying the resurgence of the technology again.

5G and Home IoT

I’ve been asked a lot recently about the potential future of 5G – everybody in the industry wants to understand the potential threat from 5G. One of the biggest proposed uses for 5G is to connect IoT devices to the cloud. Today I’m going to look at what that might mean.

It’s clear that 5G cellular will be the choice for connecting to outdoor IoT sensors. Sensors for farm equipment in rural areas or for outdoor weather and traffic sensors in urban areas are going to most easily handled by 5G cellular since the technology will eventually be everywhere. 5G is particularly suited for serving IoT devices due to frequency slicing where just the right amount of bandwidth, large or small, can be allocated to each small outdoor sensor. 5G has another interesting feature that will allow it to poll sensors on a pre-set schedule rather than have the sensor constantly trying to constantly connect – which will reduce power consumption at the sensor.

It’s clear that the cellular carriers also have their eye on indoor IoT devices. It’s harder to say that 5G will win this battle because today almost all indoor devices are connected using WiFi.

There are a couple of different 5G applications that might work in the indoor environment. The cellular carriers are going to make a pitch to be the technology of choice to connect small inside devices. In my home I can get a good cellular signal everywhere except in the old underground basement. There is no question that cellular signal from outside the home could be used to connect to many of the smaller bandwidth applications within the home. I can’t see any technical reason that devices like my Amazon Echo or smart appliances couldn’t connect to 5G instead of WiFi.

But 5G cellular has a number of hurdles issues to overcome to break into this market. I’m always going to have a wired broadband connection to my home, and as long as that connection comes from somebody other than one of the big cellular carriers I’m not going to want to use 5G if that means paying for another monthly subscription to a cellular provider. I’d much rather have my inside devices connected to the current broadband connection. I also want all of my devices on the same network for easy management. I want to use one hub to control smart light switches or other devices and want everything on the same wireless network. That means I don’t want some devices on WiFi and others on cellular.

One of the sales pitches for 5G is that it will be able to easily accommodate large numbers of IoT connections. Looking into the future there might come a time when there are a hundred or more smart devices in the house. It’s not that hard to picture the Jetson’s house where window shades change automatically to collect or block sunlight, where music plays automatically when I enter a room, where my coffee is automatically ready for me when I get out of bed in the morning. These things can be done today with a lot of effort, but with enough smart devices in a home these functions will probably eventually become mainstream.

One of the limitations of WiFi today is that it degrades in a busy environment. A WiFi network pauses each time it gets a new request for a connection, which is the primary reason it’s so hard to keep a good connection in a busy hotel or convention center.

However, the next generation with WiFi 6 is already anticipating these needs in the home. WiFi can adopt the same frequency slicing used by 5G so that only a small portion of a channel can be used to connect to a given device. Events can be scheduled on WiFi so that the network only polls certain sensors only periodically. The WiFi network might only interact with the smart coffee pot or the smart window shades when something needs to be done, rather than maintaining a constantly open channel. It’s likely that the next iterations of WiFi will become nearly as good as 5G for these functions within a closed home environment.

There is an even better solution that is also being discussed. There’s no reason that indoor routers can’t be built that use both WiFi and 5G frequencies. While the cellular companies are gobbling up millimeter wave spectrum, as long as there is an unlicensed slice of spectrum set aside for public use it will be possible to deploy both WiFi on mid-range frequencies and 5G on millimeter wave frequencies at the same time. This would blend the benefits of both technologies. It might mean using WiFi to control the smart coffee pot and indoor 5G to connect to the smart TV.

Unfortunately for the cellular carriers, these duel-function routers won’t need them. The same companies that make WiFi routers today can make combination 5G / WiFi routers that work with the full range of unlicensed spectrum – meaning no revenue opportunity for the cellular carriers. When I look at all of the issues I have a hard time seeing 5G cellular becoming a preferred technology within the home.