Is this supposedly magical wireless technology really going to supersede the NBN?
Over the recent weeks, a company branded as “Lightning Broadband” has been making waves in Australia. It’s claiming that for $120 per month, it can deliver an unlimited 100 Mbps connection to residents using its wireless network. But exactly how does the company plan to build its wireless network?
If you read the “technical explanation” on its website, you’ll realise that it doesn’t make sense.
The company is claiming that it uses fibre to connect to their DC. It then says DC, in that case, means a DC-HSDPA (effectively 3G technology). In the following paragraphs, it then goes on to explain that it doesn’t use HSDPA — but rather 24GHz microwave backhaul links followed by 802.11ac over the 5.8GHz band for the final hop to the customer.
However, if you read between the lines and interpret DC as its usual meaning of a data centre, it makes more sense. The company is effectively using the fixed 5.8 GHz band to transmit a Wi-Fi signal to the end user. This removes the need for hefty mobile spectrum licences that typical carriers like Telstra, Optus and Vodafone pay to secure their spectrum slice.
How much bandwidth does that give?
In Australia, the majority of the 5 GHz band can either only be used indoors or is subject DFS (Dynamic Frequency Selection) as this band has potential to interfere with radar signals. The 5.8 GHz slice (5745-5825 MHz) is the only band that doesn’t have these limitations and is what Lightning Broadband is claiming to use. This effectively gives a single 80 MHz continuous band for the last mile transmission.
The leading data rates and speeds of the 802.11ac standard (256-QAM, MCS 9, Guard Interval of 800ms) gives a maximum theoretical throughput of 390 Mbps.
As for real world performance? One of the leading “point-to-point” Wi-Fi hardware providers, Ubiquiti, claims its NanoStation M5 (5.8GHz) Wireless Bridge & WiFi AP can deliver 150 Mbps. With a beamwidth of anywhere between 42 and 60 degrees, you’ll have to share the same 150 Mbps bandwidth with everyone on the same sector as you.
Not exactly lightning speed as soon as you have a dozen or so people on the network during peak times — especially when you’re selling an “unlimited” plan.
Lightning Broadband has nothing to worry for now. It’s not intended to be a mass-market product, with large number of customers. The spectrum bandwidth simply won’t support it (because, physics). But kudos to them for the concept and to help consumers get connected while the NBN is still rolling out.
At the end of the day, it can only exist in very specific areas — outer metro areas with a tall building with a willing management who will let you install your equipment on the roof. But as soon as you have some other company else do exactly the same thing in your area, you’re screwed.
This type of technology has been used for years by regional and rural folks to relay mobile broadband from a shed to get a decent mobile signal.
So no, this is not going to make the NBN redundant. But it’s a good interim solution to help a small number of users get connected while it’s still being rolled out.