We’ve all heard about the digital divide. About how disadvantaged New Zealanders don’t have the same access to broadband as their better off neighbours.
We also know about the rural-urban digital divide. People who live outside the UFB fibre areas often make do with second class broadband.
There’s another digital divide that you don’t often hear about. That’s the performance gulf between two classes of Rural Broadband Initiative (RBI) customers.
Fixed wireless broadband
Fixed wireless broadband is used to deliver connectivity to RBI customers. It may be second class when compared with fibre, but on a good day the service isn’t bad. When it works well, RBI customers can see speeds that are more than adequate for most applications, including streaming high resolution video.
The problem is that some people, the people on the wrong side of New Zealand’s third digital divide don’t ever have good broadband days.
It’s a complex topic, so while engineering types may disagree with my explanation, here’s the problem described for non-experts.
Vodafone and Spark mainly use 4G mobile technology for the first generation RBI towers. This is often called RBI1.
Carriers have two sets of spectrum. The 700 MHz band is used to connect people who live further away from towers. The 700 MHz signals reach further, in some cases over 20km from a tower and do a better job of dealing with obstacles. You don’t need line of sight.
Urban standard, but in the bush
RBI towers often also include antennae using, for the want of a better term, ‘urban 4G spectrum’. This tends to work only where the customer can actually see the tower. Or as they say in wireless communications circles, where there is “line of sight”.
In effect the urban spectrum delivers much the same fixed wireless broadband performance that customers will get if they live in a city or town. It tends to be faster and is more reliable, which means fewer drop outs.
There are nuances. Wireless performance depends on a number of factors; distance, the nature of obstacles and, in some cases, atmospheric conditions, can all play a part. Some more remote RBI1 customers are lucky. Others are not.
Customers connected to the same tower can see a huge difference in performance. While some may be able to enjoy Netflix, others may struggle to get their email out.
A second, related problem, is that carriers engineered and managed their RBI towers to cope with the levels of demand they saw before the Covid-19 lockdown. This includes limiting the number of connections on a tower so that users get a reasonable experience.
Fixed wireless bandwidth is shared. When too many customers connect at the same time there isn’t enough to go around. It requires a careful balancing act. The calculations used to manage numbers date from before the lockdown. Since the lockdown all broadband demand has increased dramatically. Which means towers that were coping before are now under pressure.
We don’t hear much discussion about the gulf between different classes of RBI1 users connected to the same tower, but the problems are real. Fixing it won’t be easy.