What Are Small Cells?

By far the most confusing industry term that is widely used today is ‘small cell’. I see at least a couple of different articles every day talking about some aspect of small cell deployment. What becomes quickly clear after reading a few such articles is that the small cell terminology is being used to describe a number of different technologies.

A lot of the blame for this confusion comes from the CTIA, the industry group that representing the large cellular carriers. As part of lobbying the FCC last year to get the ruling that allows the carriers to deploy devices in the public rights-of-way the CTIA constantly characterized small cell devices to be about the size of pizza boxes. In reality, there are devices that range from the size of a pizza box up to devices the size of dorm refrigerators.

There are a number of different kinds of deployments all being referred to as small cells. The term small cell brings to mind the idea of devices hung on poles that perform the same functions as the big cellular towers. Fully functional pole-mounted cellular sites are not small devices. The FCC set a limit for a pole-mounted small cell to be no larger than 28 cubic feet, and a cell tower replacement device will use most of that allotted space. Additionally, a full cell tower replacement device generally requires a sizable box of electronics and power supply that sits on the ground – often in cabinets the size of the traditional corner mailbox.

These cell-tower replacements are the devices that nobody wants in front of their house. They are large and can be an eyesore. The cabinets on the ground can block the sidewalk – although lately the carriers have been getting smarter and are putting the electronics in an underground vault. These are the big ‘small cell’ devices that are causing safety concerns for line technicians from other utilities that have to worry about working around the devices to fix storm damage.

Then there are the devices that actually are the size of pizza boxes. While they are being called small cells just like to giant boxes, I would better classify these smaller devices as cellular repeaters. These smaller devices re-originate cellular signals to boost coverage in cellular dead spots. I happen to live in a hilly city and I would love to see more of these devices. Cellular coverage here varies widely block by block according to line-of-sight to the big cellular towers. Cellular carriers can boost coverage in a neighborhood by placing one of these devices within sight of a large tower and then beaming from there to cover the dead spots.

If you look at the industry vendor web sites they claim shipment of millions of small cell sites last year. It turns out that 95% of these ‘small cell’ devices are indoor cellular boosters. Landlords deploy these in office buildings, apartment buildings and other places where cellular coverage is poor. Perhaps the best terminology to describe these devices is a cellular offload device that relieves traffic on cell sites. The indoor units use cellular frequencies to communicate with cellphones but then dump cellular data and voice traffic onto the broadband connection of the landlord. It turns out in urban downtowns that 90% plus of cellular usage is done indoors, and these devices help to meet urban demand cellular without the hassle of trying to communicate through the walls of larger buildings.

The next use of the term small cell is for the devices that Verizon recently used to test wireless broadband in a few test markets. These devices have nothing to do with cellular traffic and would best be described as wireless broadband loops. Verizon is using millimeter wave spectrum to beam broadband connections for a thousand feet or so from the pole-mounted devices.

The general public doesn’t understand the wide array of different wireless devices that are being deployed. The truly cellular devices, for now, are all 4G devices that are being used by the cellular carriers to meet the rapidly-growing demand for cellular data. The industry term for this is densification and the carriers are deploying full cell-tower substitute devices or neighborhood repeaters to try to relieve the pressure on the big cellular towers. These purely-cellular devices will eventually handle 5G when it is rolled out over the next decade.

The real confusion I see is that most people now equate ‘small cell’ with fast data. I’ve talked to several cities recently who thought that requests for small cell attachments mean they are going to get gigabit broadband. Instead, almost every request for a small cell site today is for the purpose of beefing up the 4G networks. These extra devices aren’t going to increase 4G data speeds, aren’t bringing 5G and are definitely not intended to beam broadband into people’s homes. These small cells are being deployed to divvy up the cellular traffic to relieve overloaded cellular networks.

Charter’s Plans for 6G

It didn’t take long for somebody say they will have a 6G cellular product. Somebody has jumped the gun every time there has been migration to a new cellular standard, and I remember the big cellular companies making claims about having 4G LTE technology years before it was actually available.

But this time it’s not a cellular company talking about 6G – it’s Charter, the second largest US cable company. Charter is already in the process of implementing LTE cellular through the resale of wholesale minutes from Verizon – so they will soon be a cellular provider. If we look at the early success of Comcast they might do well since Charter has almost 24 million broadband customers.

Tom Rutledge, the Charter CEO made reference to 5G trials being done by the company, but also went on to tout a new Charter product as 6G. What Rutledge is really talking about is a new product that will put a cellular micro cell in a home that has Charter broadband. This hot spot would provide strong cellular coverage within the home and use the cable broadband network for backhaul for the calls.

Such a network would benefit Charter by collecting a lot of cellular minutes that Charter wouldn’t have to buy wholesale from Verizon. Outside of the home customers would roam on the Verizon network, but within the home all calls would route over the landline connection. Presumably, if the home cellular micro transmitters are powerful enough, neighbors might also be able to get cellular access if they are Charter cellular customers. This is reminiscent of the Comcast WiFi hotspots that broadcast from millions of their cable modems.

This is not a new idea. For years farmers have been buying cellular repeaters from AT&T and Verizon to boost their signal if they live near the edge of cellular coverage. These products also use the landline broadband connection as backhaul – but in those cases the calls route to one of the cellular carriers. But in this configuration Charter would intercept all cellular traffic and presumably route the calls themselves. There are also a number of cellular resellers who have been using landline backhaul to provide low-cost calling.

This would be the first time that somebody has ever contemplated this on a large scale. One can picture large volumes of Charter cellular micro sites in areas where they are the incumbent cable company. When enough homes have transmitters they might almost create a ubiquitous cellular network that is landline based – eliminating the need for cellular towers.

It’s an interesting concept. A cable company in some ways is already well positioned to implement a more traditional small cell cellular network. Once they have upgraded to DOCSIS 3.1 they can place a small cell site at any pole that is already connected to the cable network. For now the biggest hurdle to such a deployment is the small data upload speeds for the first generation of DOCSIS 3.1, but cable labs has already released a technology that will enable faster upload speeds, up to synchronous connections. Getting faster upload speeds means finding some more empty channel slots on the cable network and could be a challenge in some networks.

The most interesting thing about this idea is that anybody with a broadband network could offer cellular service in the same way if they can make a deal to buy wholesale minutes. But therein lies the rub. While there are now hundreds of ‘cellular’ companies, only a few of them own their own cellular networks and everybody else is reselling. Charter is large enough to probably feel secure about having access to long-term cellular minutes from the big cellular companies. But very few other landline ISPs are going to get that kind of locked arrangement.

I’ve always advised clients to be wary of any resell opportunity because the business can change on a dime when the underlying provider changes the rules of the game. Our industry is littered with examples of companies that went under when the large resale businesses they had built lost their wholesale product. The biggest such company that comes to mind was Talk America that had amassed over a million telephone customers on resold lines from the big telcos. But there are many other examples of paging resellers, long distance resellers and many other telco product reselling that only lasted as long as the underlying network providers agreed to supply the commodity. But this is such an intriguing idea that many landline ISPs are going to look at what Charter is doing and wonder why they can’t do the same.