Please share your experience with tethered cellular

Microsoft

We've recently added a new docs page to include more information on connecting HoloLens to cellular networks. You can find it at https://aka.ms/HL5G. While hotspot / WiFi is sufficient for most use cases, there are still times when tethering provides some benefit (for example ultra low latency or Azure Remote Rendering).

 

Though we're unable to provide a curated list of cellular devices that are compatible with HoloLens 2, we're hoping folks in our community can share your own experience with the devices that have worked for you.

 

Thanks in advance for sharing, and thank you for being part of the community!

38 Replies
hey Jared, we've tested successfully with the Samsung Galaxy Note 10 mobile phone, plus collaborated with Netgear to test with their Nighthawk M1 (up to 1Gbps) and M2 (up to 2Gbps) mobile internet routers. We suggest the Netgear devices, as opposed to mobile phones, to our clients for a few reasons:
- avoid any risk of damage/drain of battery of a mobile phone, which may be needed for more important reasons later, e.g. emergency calling or location tracking
- not all users may have a suitable mobile phone (including appropriate data SIM) issued to them or that they're willing to use, whereas a dedicated mobile internet router and SIM is purposely there for its need then and can be shared between other users, especially if the HL2 is shared
- they're cheaper than most mobile phones

KEY THING TO NOTE: due to the USB-C standard, the HoloLens 2 will always try and charge the tethered device, which obviously has an impact on the battery life. We reported this to engineering a while back and unfortunately there's no way to get around it. For this reason, we also advise customers to consider something like the Belkin 'BOOSTCHARGE' 20K power bank (we collaborated with Belkin to find a suitable product for HL2) to enable remote workers to have easy access to mobile charging (even whilst using the HL2 if they're not using the USB-C port for anything else). I've also got a Galaxy S20+ and Microsoft Surface Duo phone here currently that i can test if that's any use?
Hey Jared, Just reporting that we have successfully tested with a Samsung Galaxy Z Fold2 mobile phone with a USB-C tethering To HoloLens 2.

@wez_p 

 

I have an unlocked Samsung S10 I am attempting to connect to HL2 via USB-C. It has not showed up as a connection as yet, can you share your specific Note 10 settings?

 

I am also currently testing the following devices with a goal of connecting HL2 to CBRS LTE networks;

 

Inseego Mifi 8000 - Can select USB Tether mode when HL2 connects but it does not show as available interface.
AMIT IDG120 - Not detected, tried both Windows Moe and Chromebook Mode
Sercomm Wingle - Not detected even though it is an RNDIS compatible device.


I'll share any progress as I work with the various vendors to develop a working solution.

Thanks all!

JR

I have confirmed the Sercomm USB Wingle uses RNDIS driver on two Win10 devices, a desktop and a Zebra Tablet. I saw Ethernet appear for a fraction of a second but then immediately went to 'No Internet' status. No Ethernet interfaces showed up in settings.

I usually use my Samsung Galaxy S20+ 5G with mobile hotspot for off-site meetings where the HoloLens 2 is connected over Wi-Fi to the phone's hotspot. I just tried it with USB tethering and it seems to be working as well. USB Tethering can be great to avoid more Wi-Fi inference in certain environments with lots of signals around but keep in mind that the phone will be charged using the HoloLens 2 battery if you connect it with USB. Would be good if this can be turned off.

Interesting, I am seeing similar behaviour across a range of devices. I have new USB dongles arriving this week and a few more handsets to try including the latest Motorola Evolve.

Thank you wez_p, JR_Celona and Rene Schulte. Really appreciate the details shared. Feedback heard on the charging part. I've asked if there's anything we can do but haven't heard back yet. Not sure if that's even something that can be addressed in the firmware. It looks like there are some USB-C hubs that claim to do pass-through power delivery. I wonder if you could use one of those to charge and do data at the same time. Understand of course that would be a bit bulky.

@JR_Celona,

 

I saw in your post that you were receiving some dongles and handsets to test. By any chance are these 5G dongles or are they still 4G? If you have received them, by any chance have you had a chance to test them? 

Is there any possibility to connect network adapters without RNDIS ?

I've tested Telit 4G (LM 940) Modem and 5G (FN980) without any success.

 

You can control Cellular Modems with AT-Commands over serial connection.

Is this possible with hololens 2 ? 

 

 

@dcanepa

The devices mentioned above are all 4G LTE (on CBRS).

I received a new 4G/5G dongle late last week, great form factor and confirmed working on the HL2. Due to NDA I cannot share details of the dongle as yet but I have written up some of the details here; https://docs.celona.io/en/articles/5132236-microsoft-hololens-2-headset-on-celona
Currently WiFi hotspot, RNDIS and Ethernet are the only options supported. If your network adapter appears to Windows 10 as a regular Ethernet adapter, it should work. As far as I know, AT commands and serial connections are not currently supported for network connectivity.
so is this 5G and with a double screen with full AR capabilities in the Remote Assist app? This is what i was aiming for with the Surface Duo but then there was no 5G and no ARCore support :)
sure, it's basically the 'USB tethering' option on the USB settings. When i connect the cable, an item appears in the notifications list for the USB connection and it may default to something else such as 'Charging phone only'. If i select USB tethering then the HL2 will immediately detect the phone as an Ethernet connection and i'm good to go. I do also have the 'USB controlled by' setting set as 'This phone' instead of 'Connected device', in case that helps.
can confirm Surface Duo working fine too as a USB tethered internet connection (4G), but no ARCore support so basic functionality in Remote Assist mobile app only

Hello All,

 

By any chance has anybody managed to connect a device to a Stand Alone (SA) private 5G network and then used that device so the HoloLens could connect to? A customer got in touch that they want to do a PoC with HL and 5G but that the network is a private SA 5G network and not a public one. So far they haven't been able to find a device that connects to one of these networks. The 5G enabled mobile phones can't connect to it, thus they haven't been able to use that as a hotspot/tethering option.

@JR_Celona,

Is there a place that I could contact you to ask you about the dongle/solution you mentioned here:
https://docs.celona.io/en/articles/5132236-microsoft-hololens-2-headset-on-celona

I'm wondering if this could help the customer that was asking about private 5G networks
Sure thing, PM sent .

I finally got a response back about HoloLens charging the phone when tethered.

 

In short, this is by design. We provide power because we wanted to support external storage. While there are some methods for devices to negotiate who charges who (for example TRY.SNK), those were still being ratified at the time HL2 design was finalized. Unfortunately it doesn’t appear support can be added now.

 

They did offer two possible workarounds, but neither are tested or supported by Microsoft:

 

  1. A USB-C splitter like this one might work. You would plug the phone into the “headphone” side of the splitter. I don’t have a compatible phone to test with so you’d have to test this on your own. If you do, please share your results.
  2. This option is not warrantied, supported or recommended by Microsoft. Proceed at your own risk. It may be possible to create a custom USB-C to USB-C cable that limits the power over VBUS rather than disabling it. You would need to read up on how Automatic Input Current Limit (AICL) works to determine how to make such a cable. Depending on how your USB device responds to AICL, it may still enumerate but draw little power.

 

I know that's not the answer some were hoping for, but I do still hope it helps.

I can confirm that ZTE MF833V does NOT work with Hololens2 (via usb-c to usb-a adapter).
The HL2 powers up the ZTE and sees it plugged in, but does not get internet.
Will keep searching for "RNDIS" compatible 4G/5G dongle and post if I find any.