Cable Labs Analysis of 5G

Cable Labs and Arris just released an interesting paper that is the best independent look at the potential for 5G that I’ve seen. Titled ”Can a Fixed Wireless Last 100m Connection Really Compete with a Wired Connection and Will 5G Really Enable this Opportunity?”, the paper was written to inform cable companies about the potential for 5G as a direct competitor to cable network broadband. The paper was released at the recent SCTE-ISBE forum in Denver. The paper is heavily technical and is aimed at engineers who want to understand wireless performance.

As is typical with everything I’ve seen out of Cable Labs over the years the paper is not biased and takes a fair look at the issues. It’s basically an examination of how spectrum works in the real world. This is refreshing since the vast majority of materials available about 5G are sponsored by wireless vendors or the big wireless providers that have a vested interest in that market succeeding. I’ve found many of the claims about 5G to be over-exaggerated and optimistic in terms of the speeds that can be delivered and about when 5G will be commercially deployed.

The paper explores a number of different issues. It looks at wireless performance in a number of different frequency bands from 3.5 GHz through the millimeter save spectrum. It takes a fair look at interference issues, such as how foliage from different kinds of trees affects wireless performance. It considers line-of-sight versus near line-of-sight capabilities of radios.

The conclusions from the report are nearly the same ones I have been blogging about for a while:

  • Speeds on 5G can be significant, particularly with millimeter wave radios. The radios already in use today are capable of gigabit speeds.
  • The spectrums being used suffer significant interference issues. The spectrums will be hampered when being used in wooded areas or with the trees on many residential streets.
  • Coverage is also an issue since the effective delivery distance for much of the spectrum being used is relatively short. The means that transmitters need to be relatively close to customers.
  • Backhaul is a problem. Fast speeds require fiber connectivity to transmitters or else robust wireless backhaul – which suffers from the same coverage and interference issues as the connections to homes.

The paper also takes a look at the relative cost today of deploying 5G technology at today’s costs:

  • The CAPEX for a 3.5 GHz system used for wireless drops (800-meter coverage distance) costs $3,000 for the transmitter and $300 per home. These radios would be making home connections of perhaps 100 Mbps.
  • A millimeter wave transmitter costs about $22,500 with home receivers at about $650. This would only cover about a 200-meter distance.
  • In both cases the transmitter costs would be spread over the number of customers within the relatively short coverage area.
  • These numbers don’t include backhaul costs or the cost of somehow mounting the radios on poles in neighborhoods.
  • These numbers don’t add up to compelling case for 5G wireless as strong cable competitor, particularly considering the interference and other impediments.

The conclusion of the paper is that 5G will be most successful for now in niche applications. It is likely to be used most heavily in serving multi-tenant buildings in densely populated urban areas. It can be justified as a temporary solution for a broadband customer until a carrier can bring them fiber. And of course, we already know that point-to-multipoint wireless already has a big application in rural areas where there are no broadband alternatives – but that application is not 5G.

But for now, Cable Labs is telling its cable company owners that there doesn’t seem to be a viable business case for 5G as a solution for widespread deployment to residential homes in cities and suburbs where the cable companies operate.