Australian telcos don't develop their own hardware, instead re-badging designs from external networking providers such as Sierra Wireless, ZTE and Huawei. The E5331 Mini WiFi Modem is a Huawei model, and it's easy to see where Optus got the Mini prefix from. At 92.8x6013.8mm and 82g, the E5331 Mini WiFi Modem really is quite mini.
It's also not exactly blessed with a lot of on-screen information, with very simple lights to denote power, battery, SMS, signal and Wi-Fi status. That makes it easy to read at a glance, but the flipside is that compared to the LCD displays on other Wi-Fi hotspots, including Optus' own E589 Mini WiFi Modem, it doesn't really tell you much.
The E5331 Mini WiFi Modem is a very basic Wi-Fi hotspot. It'll support up to eight connected devices at once, and uses a regular SIM card to connect to Optus' HSPA+ network. That's a much larger network than Optus' current 4G deployment, but it's also a much slower network, as it's shared with just about every other Optus mobile broadband and mobile phone device, save for the 4G devices. The E5331 Mini WiFi Modem doesn't have a whole lot of battery space. The supplied unit only comes with a 1500mAh battery, which Optus reckons is good for up to five hours of operation.
There are a few key metrics for any mobile broadband network, but testing them is perilous, simply because there are so many variables that can affect one test in one location. So we hit the road and tested seven different mobile devices across six sites to try to get a more complete picture of mobile broadband performance in two capital cities. Why capital cities and not regional zones? Partly, that's a factor of time, but also so that we could get a picture of 4G zones — and right now, Optus is concentrating mostly on capitals for its 4G — as well as the issues that congestion can introduce into a network.
We've tried to mix up our locations as much as possible, with our six sites covering a family home in Hornsby in Sydney's north (outside any 4G zone), Darling Harbour in the Sydney CBD (for an outdoors 4G test, because the 1800Mhz frequency used by 4G LTE has some in-building issues), in Glenelg Library in Adelaide (because it has thick walls and is a busy public space), in a coffee shop in Adelaide's Rundle Mall (because again the walls are an issue, as well as public congestion) and finally in departure lounges at Sydney and Adelaide airports, as they're awash with travellers checking mobile devices prior to boarding their planes.