5G DAS (Distributed Antenna Systems)

5G DAS (Distributed Antenna Systems)

5G DAS Solutions are really the elephant in the room right now. The exact strategy of how 5G will be delivered over DAS continues to become clearer and evolve each day. Realistically it will be a combination of 5G DAS and small cells where appropriate to provide the end-to-end experience. Don’t be fooled by the spruikers, this is not a 5G revolution require new everything, its just a repeat of the cellular evolution that happens time and time again from 3G to 4G, and now 4G to 5G

Like any significant technology shift, there is a lot of media attention and hysteria that comes with it. Some people will tell you that the DAS solutions of today will not support 5G and require a completely new system, and while elements of that are true, most of them are not. Likewise, we are seeing a lot of specifications demanding all DAS solutions be fibre fed active solutions to improve their 5G upgrade path, and while well-intentioned, this is often doing more harm than good. In reality, these buildings do not warrant an active system due to the size of the GLA and would be better served with a Passive system and actually significantly improving their 5G upgrade paths as it would provide complete wideband support. When FOMO kicks in people, start making decisions grounded in assumptions and fear, unfortunately, to make educated decisions right now its critical to get into the weeds and build up a basic knowledge of how DAS works and how a transition to 5G will take place.

5G includes a range of technologies across various bands, some of which will never be deployed over a conventional Distributed Antenna System, and there would be little reason to. Any spectrum above 6GHz will always be delivered over small cell infrastructure, and it will come at great expense consequently, it will not be widespread, it offers huge capacity for areas that really need it.

Wireless Coverage Solutions have an entire 5G technology-focused article that breaks down 5G into its various technologies and offerings. An understanding that there are a variety of flavours of 5G is pivotal in understanding DAS’s role in the delivery of 5G. Below is a summary of the various 5G technologies and their direct relevance to DAS Systems.

You may have heard of these >6GHz 5G deployments as mmWave 5G, which includes features such as Massive MIMO and Beamforming. These are some seriously exciting technologies that can only be delivered when every antenna in a system is ‘intelligent’. This is typically the architecture of a small cell system (which doesn’t currently support true multi-operator implementations). There will be times and use cases in buildings for high-density locations where there may be a viable solution (food courts, airport lounges, stadiums) however, it would be rare (and expensive) to deploy such a system throughout the building. This is where DAS differs as more often than not its a building-wide solution, so we want to discuss building-wide 5G, and targetted hotspots are a separate conversation.

It has become apparent 5G deployments are primarily happening in the sub 6GHz bands with the 3600-3800MHz bands, being a popular choice globally (and in Australia). This is important because the 3600MHz 5G band can be supported by DAS components to varying degrees. In addition to the deployment of 5G on this new band, operators are rolling out low band 5G and refarming their existing spectrum. This involves the carriers re-farming their existing spectrum, something which we have seen previously in the migration from 2G, 3G, 4G and now 5G. Telstra has recently announced its plans to reuse the current 3G 850MHz spectrum to 5G by 2024. Likewise, Optus is looking to refarm their existing 2300MHz spectrum from 4G over to 5G enabling increased compatibility of New and Old Distributed Antenna Systems

5G DAS, 5G DAS (Distributed Antenna Systems)
Spectrum map comparing FR1 and FR2

This is all great news for 5G Distributed Antenna Systems as it means that modern DAS will have an onramp into 5G, while you won’t be able to get 5G on a DAS system built-in 1999 (there are plenty still out there), there should be opportunities for a well-designed MCF2018 DAS system to see some form of 5G services in the future. Don’t be fooled by the spruikers, we have built systems that are now 4 years old which are actively having 5G deployed on them today (and often they are the boring, not so sexy passive DAS), with no upgrades to the DAS required. This is the beauty of refarming bands

There is lots of misinformation in the industry around 5G having to exclusively be delivered by Small Cells or Active DAS. Small cells will have their place, but will more likely complement an existing DAS and provide hotspots of capacity where the use case suits it, consider food courts or airport lounges. The use of fibre-fed systems should primarily be driven out of necessity, given that the majority of 5G sub 6GHz will be reused 4G spectrum and the new 3800MHz bands the best upgrade path actually comes from having complete wideband support from 700-3800MHz. Active DAS will require the complete swap out or at least the addition of new active hardware with significant associated costs and complexity. If someone is insisting that you need an Active DAS to deploy 5G, there is a good chance they are not fully across the intricacies of the 5G transition and Distributed Antenna Systems (or are just motivated to sell you the solution that makes them the best commission)

The important piece to note is that 5G DAS is an operator-driven rollout program right now and like all technology changes, the initial priority is the outdoor network. There are still plenty of buildings today without dedicated 4G DAS coverage (or even 3G Coverage) where tenants can’t even make phone calls. It’s incredible the amount of throughput that can be delivered on a 4G DAS today, which begs the question, what will we need 5G DAS for in the short-term future.

DAS is no different from shopping for a Big Screen TV, there will always be something new that comes out tomorrow. But if tenants don’t have coverage today, with typical DAS projects in the 6-9 month range, there is an immediate issue to solve. As with all technology, there will always be something new on the horizon, but at any point in time, we can provide a variety of steps to future-proof a DAS system for 5G based on the current technologies available. 

Wireless Coverage Solutions DAS Designs have a variety of considerations to allow for future upgradability, including 5G. Contact us today to discuss your project’s needs