How will 5G small cells be deployed? How will 5G small cells be installed? How will the 5G small cell planning go? These are all good questions. Let’s touch the surface to understand what the starting points are. Let’s also cover how you can play a part in the 5G expansion.
Basically I am not sure what the 5G format will look like in the mmwave spectrum but we all know that LTE will be the foundation in existing spectrums. It could be LTE-Advanced or eLTE, evolved LTE. It looks like LTE will be here for a long time, in tech time anyway.
With the coming of 5G we will see more and more HetNets. This is obvious if you are in the industry, but the great thing is that the networks will be able to talk to each other. Much like the internet now, where you just plug-in, the wireless networks will start to connect to other wireless networks. The carriers will be able to connect to an independent network and hand off data. They are doing it now with Wi-Fi. However, Wi-Fi is not as friendly with LTE as we would all like to think. That is why LTE-U will make things easier to interconnect wirelessly. How exciting is that? This will make the carrier independent small cell a multi-carrier small cell. How cool is that? Looking at the unlicensed band as part of 5G is essential, because many small cells in the unlicensed band will be used to offload the constrained licensed spectrum.
Interested in DAS, Amazon has a good ebook by Soyola Baasan .
That is why you could build your own network then reach out to the carriers to see if you could connect to them. The carriers made it clear that they don’t want to pay for small cells or DAS unless they see a clear payback. However, I think they would entertain a partnership with a business or company that could help them serve their customers.
Just to note all the carrier say they are testing 5G, but it looks like Verizon and AT&T have really made public progress here in the states. Verizon went so far as to set a standard, look for it here.
I don’t’ want to take anything away from T-Mobile though, they have tested 5G with Nokia just last month. You can read about it here.
First off, what is a 5G small cell? That is the question! If you follow me at all you know I say that 5G is the system, not necessarily the format Well, it is, but when you hear about the carriers talking about testing 5G, what does that mean? Let me explain.
First off, 5G will be a combination of LTE and new formats. When I talk about 5G small cells I really am talking about the 28GHz spectrum and up. Considering that licensed and unlicensed will be included. LTE-U and Wi-Fi will play a part. We need all the spectrum we can get. So keep that in mind when focusing on the 5G small cell.
Now, the carriers are all testing 5G in small cells in the 28GHz spectrum and up. They are currently testing, in the USA, 28GHz because there is a lot of spectrum available there. The FCC approved it so let it be done! That is where most of the carriers have been testing equipment. Nokia and Ericsson are testing equipment in this range as well. So that is where we will focus on today’s discussion.
So the small cell will have to have the basics, a type of BBU and a radio head. Only this time, at 28GHz the cable loss would be super-duper high! Sorry for the technical terms, you need special cable to handle spectrum that high. So they will definitely have the radio head connected to the antenna. That is done today but most carriers, except T-Mobile, seem to like them separated so that can replace them if necessary. Usually they wind up replacing both, but I am getting off topic.
The radio head and the antenna one unit, just like microwave where they attach the radio head directly to the antenna. So think about the extra weight to the antenna will increase. This could have an effect on antenna placement and the way you mount the antenna. If it’s outdoors, then you may need to worry about the weight or the size of the unit. Most times it may not matter. Indoors it may not make a difference but you may not have the stealth unit you hoped for.
The BBU may all be in one unit for indoors or outdoors they could have it all-inclusive or could be a separate unit with a fiber connection between it and the radio head. The expectation is that the radio head will have more intelligence in it so that the fiber runs can be longer for someone like Verizon who loves to deploy the CRAN system. This will make the core and BBU more virtual The radio head will be able to do more but won’t have the full macro capability, but in theory it should not need it. It should be able to see the BBU which may be nearby or in the cloud. How cool is that? Virtual radio heads are not far away and the cloud will lower latency, but once again, I am getting off subject, let’s focus on the small cell.
So what has changed? It really doesn’t sound like much as far as the small cell is concerned. It sounds more like the same device, integrated into a different band that is smarter than the old device. So what?
Well, if you’re in this business you should already know the answer! It’s the antenna! That’s right, the antenna and the connection between the radio head and the antenna! That is going to help us get maximum spectrum from the radio head to the antenna and from the antenna to the UE device! How? I am glad you asked!
MIMO, (Multiple In Multiple Out) which allows more spectrum to pass between devices. First off, the radio head will have 4 to 16, (maybe more) connections to the antenna allowing many bands to talk to the end device. Fun MIMO PDF to read here. This gets highly technical, so bear with me. They cram a whole bunch of antenna panels into on antenna and then split signals to and from each little antenna. But wait, there is more! Now the little antennas can focus in a specific user giving them a priority and allowing it to pass more and more traffic. OK, maybe my explanation wasn’t so technical, but NI does a good job explaining massive MIMO here. My point is that the antennas are way smarter and they will be the game changer here.
MIMO can be used on macro or small cell, but for small cell the additional spectrum will really help because we have huge bands at 28GHz and up. In fact, Sprint has a ton of spectrum at 2.5GHz and up but they seem to be very slow to deploy. Maybe they would sell it, I have to think that they would because the CFO recently said how the spectrum would be perfect for 5G. Antennas got smart so it will really help you
Massive MIMO is going to make wireless connectivity better and better. Who knows what we will see next. I want to see this technology rolled out. It can be used in almost every band to improve throughput and coverage to the device. Think about what the cell will have to do, but also the devices will need to add more antennas to really utilize it. If the antenna can really have one smaller antenna talk to a specific device whilst talking to other devices simultaneously using common spectrum, it will be a game changer. I know there is more to it than that, but it sounds pretty cool.
The antenna technology will may take more RF engineering, I believe, because planning will take more time on smaller networks. On the other hand they will be in a higher band, 28GHz and up with more spectrum. This may allow installer to install based on line of site and then they can use the spectrum planning to keep the channels from stepping on each other, just a thought. That is somewhat like Wi-Fi now. Not sure how it will be handled or now neutral host will be handled. These are all thoughts that I am sure someone is working on.
There is a nice PDF found here, http://telecoms.com/wp-content/blogs.dir/1/files/2016/06/5G-architecture-options.pdf that covers architecture of the 5G radio. Please note that they clearly state that 2 technologies are discussed, but the reality is that it will include both LTE (which they will call ELTE) and the NR, (New Radio developed by Qualcomm I believe). We can talk about that in a future blog if you’re interested.
FYI – 28GHz will be licensed, but I am not sure how. I say it like that because the coverage area must be very small. So I would like to see it as lightly licensed. I really see it used more like the 3.65GHz band, only smaller coverage area or as a backhaul. With all of that spectrum you could have backhaul depending on the usage. More info here.