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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.
All testing was performed with the Speedtest.net app running on Google Chrome on a MacBook Air with no other internet-reliant applications running and no extensions installed. Tests were run three times in each location, and then averaged to find ping, download and upload averages for each device.
|Sydney CBD results||Ping||Download||Upload|
|Telstra Mobile Wi-Fi 4G||45.33||13.99||13.97|
|Telstra Pre-Paid Wi-Fi 4G||16.66||8.8||14.81|
|Telstra Pre-Paid 3G USB+Wi-Fi||76||7.17||1.18|
|Optus E3276 Premium 4G Modem||57.66||5.053||0.486|
|Optus E589 Mini WiFi Modem||56.66||2.48||0.57|
|Optus E5331 Mini WiFi Modem||120.6||2.26||0.58|
|Vodafone Pocket Wifi Extreme||122.33||1.5||0.06|
|Sydney Airport results||Ping||Download||Upload|
|Optus E3276 Premium 4G Modem||35||41.99||9.55|
|Optus E589 Mini WiFi Modem||35||13.51||9.91|
|Telstra Mobile Wi-Fi 4G||46.66||13.35||14.12|
|Telstra Pre-Paid Wi-Fi 4G||50.33||11.73||11.09|
|Optus E5331 Mini WiFi Modem||55.66||7.2||0.53|
|Telstra Pre-Paid 3G USB+Wi-Fi||71.66||6.88||1.19|
|Vodafone Pocket Wifi Extreme||70.33||2.27||0.2|
|Hornsby, NSW, results||Ping||Download||Upload|
|Optus E3276 Premium 4G Modem||57||11.55||1.16|
|Optus E589 Mini WiFi Modem||80||8.98||1.15|
|Vodafone Pocket WiFi Extreme||61||8.83||3.49|
|Telstra Pre-Paid Wi-Fi 4G||48||7.72||1.85|
|Telstra Mobile Wi-Fi 4G||49.33||7.68||2.31|
|Telstra Pre-Paid 3G USB+Wi-Fi||59.33||6.65||2.5|
|Optus E5331 Mini WiFi Modem||73.66||2.75||0.55|
|Adelaide CBD results||Ping||Download||Upload|
|Telstra Pre-Paid Wi-Fi 4G||10.33||24.46||6.51|
|Telstra Mobile Wi-Fi 4G||52.66||14.21||2.5|
|Telstra Pre-Paid 3G USB+Wi-Fi||72||11.12||1.17|
|Optus E5331 Mini WiFi Modem||98||7.16||1.11|
|Optus E589 Mini WiFi Modem||79||1.01||0.12|
|Optus E3276 Premium 4G Modem||90.33||0.803||0.106|
|Vodafone Pocket WiFi Extreme||201.33||0.313||0.04|
|Adelaide Airport results||Ping||Download||Upload|
|Optus E3276 Premium 4G Modem||85.33||12.47||1.13|
|Telstra Pre-Paid Wi-Fi 4G||41||10.02||7.42|
|Optus E589 Mini WiFi Modem||80||8.83||1.14|
|Telstra Mobile Wi-Fi 4G||33.66||8.34||7.2|
|Optus E5331 Mini WiFi Modem||89.33||6.25||1.103|
|Vodafone Pocket WiFi Extreme||95.66||3.33||1.31|
|Telstra Pre-Paid 3G USB+Wi-Fi||236.33||0.593||0.366|
|Glenelg, SA, results||Ping||Download||Upload|
|Optus E589 Mini WiFi Modem||71.66||20.44||1.15|
|Telstra Pre-Paid Wi-Fi 4G||52||13.55||0.82|
|Telstra Mobile Wi-Fi 4G||52||13.55||0.82|
|Vodafone Pocket WiFi Extreme||42.66||11.55||1.35|
|Telstra Pre-Paid 3G USB + Wi-Fi||76.33||8.49||1.1|
|Optus E3276 Premium 4G Modem||88||8.17||1.15|
|Optus E5331 Mini WiFi Modem||85.66||7.03||1.15|
There are a lot of 3G devices out there, and that means when you test any 3G device, you're fighting for scarce resources with every other user out there. As such, we weren't all that surprised with the E5331 Mini WiFi Modem's overall performance, which was always outmatched by 4G devices in the same tests, and sat at or near the bottom of the pack for each test. The exception to this was in the Adelaide CBD, where its 3G status appeared to be a boon compared to Optus' own 4G network, recording a much higher speed. Optus is still rolling out its 4G network in Adelaide, however, so that's a figure we'd expect to see change in due course.
In terms of battery life, the Optus E5331 Mini WiFi Modem lived up to its billing, managing around four hours in our tests, although the lower power drain of 3G HSPA+ undoubtedly played a part in that.
The Optus E5331 Mini WiFi Modem is a cheap and simple Wi-Fi hotspot option. You're not paying a premium for the device or the data, and in return you're getting a very basic service. If you do happen to live in a metropolitan area currently serviced by Optus' 4G network, we'd advise spending a little more on a 4G device, because the speed differences are generally quite remarkable, while the data costs are identical. But if you're after a solid but unremarkable mobile data device, the Optus E5331 Mini WiFi Modem is entirely satisfactory.