Fixing Optus Home Wireless Internet Low Signal issues

So you've got a Home Wireless internet connection, and it's been working great, but suddenly it's dropping out sometimes and it's not quite got the speed it used to. There's a few bars in the configuration menu and the lights are green, you have reception, so it makes sense that you should also have data.. and you do, sort of. What's going on? This article will tell you how to fix intermittent dropouts and low speed with your Optus Home Wireless internet connection, it also helps if you're getting low signal to noise ratios.

Usually what's going on is that the frequency you're connecting on has interference on it, and you have two options.

  • Figure out which frequencies exist in your area and make sure your modem is connecting to one with a stronger signal
  • Get an antenna for your modem

The modem we're talking about here is specifically the older style E5186, the older white one that looks like this. This information also applies to other brands of modems, but the tools don't, and you're going to need a different antenna type for other modems. This should apply to both the -22a models and the -61a. They're visually identical but you can tell which one you have by logging into your interface at and going to Settings > System (on the left side menu) > Device Info. It will be the "Device Name" value across the top. I'm confirming this with a -61a, the 22a should be effectively identical, but your mileage may vary.

What we're going to be doing is tracking down what the signal to noise ratio is on the modem (since it connects to the internet like a phone) and trying to figure out if there's a tower nearby that will give a better signal at a lower frequency. As I understand it most modems will try to connect to the highest frequency that they can find that has at least a given signal to noise (-100dB to -75dB) on the RSSI. Higher frequencies have better speed and can support more devices at once, but they have the drawback that they are much more susceptible to interference, so you have more maximum speed, but a much more fragile signal. Lower frequencies are slower, but are much more reliable if your signal is not quite as good as it could be. Ignore the signal bars on your device, they are useless. In the device info screen please take note of the RSSI value, lower is better, around -50 dB is solid, at -75dB you're getting a connection, but it's probably not great.

Please download the tool here. You'll want version 0.9, the E5186 toolbox lets you search for the towers in your area, as well as forcing a given modem to use a specific band, I've not been able to break anything with the main page, but your mileage may vary, I can't take any responsibility for any damage to your device, so please take this advice with that in mind. Note that telling the modem to use a band that doesn't exist will make it snap back to its default, when the Band field has something in it, you know that the change has taken effect, you will lose internet for a moment as well.

The version you want is 0.9. 

The first step is to hit connect on the top right of your screen when running the tool on the same network as your modem. Assuming you haven't changed your username and password you should see your device settings appear on the right side like in the example.

The second step is to hit "search" on the MCC row. This is your internet provider, and the search button will open up a browser window to which will prompt you for location access. Just hit "Allow" and it should take you to your suburb. This will show you which towers are around you and the frequencies they support. Remember that the E5186-61a modems only support the bands 3,7,28 and 40. Just so you know the most common frequencies in Australia are..

B1 - 2100Mhz

B3 - 1800Mhz

B7 - 2600Mhz

B8 - 900Mhz

B20 - 800Mhz

B28 - 700Mhz

B38 - 2600Mhz

B40 - 2300Mhz

In my case I realized that there was a Band 3 tower across the street, while I was connected to Band 7 from the nearest tower... in the next suburb over. However I only realized this by trying several bands from the bottom up and realizing that only Bands 7 and 3 appeared on the Device Information panel, as those are the only two in the default list that the E5186-61a can actually use. By the way, if you're curious about the -61a designation, there's also a E5186-22a modem that, in so far as I'm aware looks and works identically, but has a different antenna inside that works with a different set of bands, if you're doing this in Australia then you've almost certainly got the 61a version.

One additional thing to be aware of is that The E5186 supports the 700Mhz band 28 that's heavily used in rural Australia. This is the best band for getting signal strength over long distances, but doesn't show up in the Toolbox menu by default. You can add it by adding the following lines to the config.xml file in the toolbox directory while the software is off.

<name>700Mhz / B28</name>

Just add it after the </band> that has the B20 in it and before the LTE-A row's <band> and save the file, it will show up in the menu the next time the E5186 toolbox is started. If you need band 40, the entry for that is..

<name>2300Mhz / B40</name>

For reference, if you're with Optus, your default band out of the box for the modem is going to be the 1800 band, which is also where the antenna we've recommended is strongest. The modems will also use the 2300 band if available for additional speed.

The third step is to select your new network band from the dropdown on the left and select apply. Other guides have cautioned against using this screen instead of the API on the second tab but in my experience this works perfectly on the E5186 model device and the changes survive restarting the device. In my case I switched to Band 3 and clicked apply. The RSSI dropped from -76 to -55 and the line became far more stable. You'll want to try a few different bands to see which one gives you the highest SINR value as that's generally the best indicator.

The second option is to buy an antenna.  Apparently this model is known to work with the E5186 modem, they're hard to track down and my first order took a few weeks to arrive, however subsequent antenna orders arrived within two days. If you want to get the maximum possible performance, this is probably a better bet than changing the band settings.

The antenna should just plug into the two sockets in the back of the device, though you'll need to pop off the back panel to reveal them, there's a plastic clip about 1/5th of the way down the device that has the sticker with the default passwords on it, that panel pops off to reveal another sticker with the same password and the antenna slots. It's worth noting that while both antenna sockets receive, only one transmits, the first antenna you install absolutely has to be in the socket closest to the power cable. This should be the one on your left side with the sockets facing you. Make sure the modem is off when attaching or removing the antenna.

You'll know you've done everything right if the SINR value in the E5186 toolkit is much higher than it was previously. For example if it moved between -8 to -3 before, it will be positive 7 after, though they do have a tendency to jump.

I've also tried a few other different antennas but none of them showed better performance than the rabbit eared antenna. Given that the better antennas can be fairly expensive and a new Optus modem won't be over $200 you may be better off just requesting that Optus sends you a new modem if the rabbit ears don't work as the newer modems have different antenna configurations internally and are supposed to have much better noise cancelling.