How-To: A Non-Bluetooth Wireless Headset for a Mobile Phone

Nexus 5 & Logitech H820eA few days back someone over at the DSL Reports VoIP Forum posed a question. Along with expressing some frustration with Bluetooth headsets, they asked how they might use a wireless headset that was not based upon Bluetooth with a mobile phone?

That is a curious question. I certainly understand that people can be frustrated with Bluetooth headsets. It’s something that I have suffered now and then.

Class 2 Bluetooth, which is limited to 2.5 mW radiated power, is the most common variety. It’s supposed to deliver a 10 foot range. That’s fine when a mobile phone is in your pocket, but inadequate when it’s on your desk and you need to refill your coffee.

Class 1 Bluetooth kicks the RF power up to 100mW, aiming to allow you to wander up to 100 feet from the host device. Unfortunately, to achieve this freedom to roam, both the host and the headset must be class 1 devices. AFAIK, no mobile phone has ever had a class 1 Bluetooth radio.

Practically, this means that Class 1 headsets, like the Plantronics Savi Go that I reviewed way back in ’09, are usually paired with USB dongles for use with computers.

If all forms of Bluetooth are inappropriate why not DECT? DECT-based cordless phones and headsets are awesome! Good voice quality, freedom to roam some 300 feet from the base, under ideal conditions. Massive battery life.

You just don’t see DECT headsets offered for mobile use. They’re all for office applications, connecting to desk phones or computers. That means RJ type connections or USB. My trusty beloved Sennheiser DW Pro2 is fine and somewhat typical example of such gear.

This got me thinking. Current Android phones have supported USB audio devices for some time. In the past I have used a Blue Yeti USB microphone with a Nexus 7 tablet by way of a USB on-the-go cable. In that case I was using the microphone as an input to Audio Tool, an audio test and measurement application.

That combination worked well enough. There was no reason to expect that the same sort of arrangement would not work with a DECT headset.

Conjecture be damned, this was worth a quick test to be certain. I found my USB OTG cable and used it connect my Nexus 5 mobile phone to a Logitech H820e DECT headset that I had lying around.

On the Nexus 5 I went into the system developer controls and set the USB port to be an “Audio Source.” There are a variety of options (pictured below, left) but since there is one specifically for audio I thought that’d be a good place to start.

Nexus 5 - USB Settings & Bria in-call

The combination seemed to work, although the OTG cable wasn’t a very secure fit into the micro USB connector on the base of the phone. If I were to use this routinely I’d probably acquire a charging dock for the phone. I once owned a similar dock for the Galaxy Nexus.

Incidentally, the dock for the Nexus 7 (2013) has both USB and micro-HDMI connections, making it very useful indeed. I know folks who use it to watch movies on their HDTVs.

Since I didn’t have anyone to help me test this setup I launched Bria on the Nexus 5, which was registered with ZipDX. So armed, I called the ZipDX test and demo service, which is, or just 3366 if the client is register with ZipDX direct. The call was answered (pictured above, right) and I heard the prompts playing on the headset. So far, so good.

Pressing #, I toggled the service into wideband mode. Then pressing 9, I selected an echo test.

Once the echo test began I could hear myself echo’d back with a short delay. Taping on the headset microphone, I heard a resounding thump echo’d back, confirming that it was being used to make the call.

So there you have it, on an Android phone running Marshmallow, you CAN use a USB-attached DECT headset. If the headset is suitably capable it will even deliver HDVoice.

While the idea of using a USB-attached DECT headset on a mobile phone may seem a little obtuse, it works nicely.

8 thoughts on “How-To: A Non-Bluetooth Wireless Headset for a Mobile Phone”

  1. Some have asked if hook state control worked via the OTG connection. I tried both the Logitech H820e and my Sennheiser DW Pro2. Neither had workable call state control when connected via USB OTG.

    1. No. The Savi Go I had came with a Plantronics USB adapter. In fact, I still have it, even though I no longer have the headset.

      The high-gain adapter you reference may be a problem. It’s not enough to have higher RF performance at the host interface. The headset must support it as well, or you’ll get dropped links. Their claim of 300 m seems optimistic. That must be between two of their devices with high-gain antennas.

      1. I suspect the Savi Go is not truly Bluetooth standards-compliant, it is the only device to repeatedly drop the connection and forget pairing. I use several other bluetooth devices with the Sena Class 1 adapters without issue. Standard is the whole point, having to use their special dongle fails to impress, nor does it work with how I implemented BT.

  2. Hi Michael,
    I just stumbled across this, looking for a similar solution and I found it very interesting, especially the on-hook/off-hook state issue. Thank you for sharing!

    Most, if not all, cell phones have a Mini Jack for sound (both media and phone calls). Have you ever tested your DECT headsets via the Mini Jack plug? (Both Jabra and Sennheiser offer converter cables)?

    1. Nope. Such a connection would be analog. I’d don’t see much advantage to it. Most especially considering the potential for over driving the mic level input of the phone. That was the appeal of the USB connection. It’s digital, and has zero potential for level mismatch issues.

      1. Analog, yes. Advantage? On-hook/off-hook feature should work flawlessly, like with an analog wired headset. I did not think of the mic level as an issue, though…

        I need a wireless headset for my application (work) and I am trying to avoid Bluetooth, due to it’s range limitations and some times stability issues. A DECT headset that works like a B.T. headset would be the optimal solution, IMHO.

        When I am at work, I need to charge my phone, so the USB-port is already taken…

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