Please share your experience with tethered cellular

[jbienz]

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!

[#2]

We've got the Telit FN980 (5G) running with hololens now.
FN980 supports RNDIS driver.

You have to configure the RNDIS Mode only initialy with AT Commands over any computer.

Enable RNDIS USB Mode:
- Check Current Mode: AT#USBCFG?
- Enable RNDIS Mode: AT#USBCFG=1

Here ist a List with possible Modes:
0: RNDIS + DIAG + ADB + NMEA + MODEM + MODEM + AUX
1: DIAG + ADB + RmNet + NMEA + MODEM + MODEM + AUX
2: DIAG + ADB + MBIM +| NMEA + MODEM + MODEM + AUX
3: DIAG + ADB + ECM + NMEA + MODEM + MODEM + AUX

Now attach FN980 to hololens and it should appear as Ethernet Adapter.

For auto connection to cellular networks the Autoconn feature of FN980 can be enabled after an APN was configured.

Enable Autoconn:
AT#ICMAUTOCONN=<apn-number>,<1: enable, 0:disable>

Example:
AT#ICMAUTOCONN=1,1

There is unhappily a problem with the power supply over usb. While transfering at high data rates (mainly upload), the power supply over Hololens USB-C Port is not enough. Transfering small data on low data rates is working without any additional power supply.

[#3]

Wow, very detailed response dan1-m. Thank you so much for sharing. Have you found a way to provide additional power if needed? I'm aware of USB pigtales that split power, but that's usually for charging the host device while using another.

[#4]

I can report that the HoloLens 2 works great tethered over USB-C to an AT&T Netgear Nighthawk mobile hotspot.

It does not work with an iPhone 11 Pro Max tethered over an apple certified USBC-Lightning cable. The iPhone draws power from the headset, and the headset doesn't show an ethernet indicator and a tethering prompt doesn't appear on the iPhone.

[#5]

@jbienz @JR_Celona 

Has anyone tried the Huawei E3372 (or E3372h) 4G LTE USB Modem over USB-C?  

The Windows 10 Desktop identifies it as RNDIS device but when connected to the HL2, it does not work out-of-the-box.

[#6]

Has anybody tried the 5G Dongle M210? Its documentation states that if the equipment with can act as RNDIS HOST, the 5G Dongle could be plugged in and used directly. Would it be compatible with the HL2 then?
https://www.hocell.com/productinfo/566002.html

[#7]

Hi,

May I ask, how did you connect your Nighthawk M2 to the Hololens 2? Was it through USB tethering? we would like to use the same setup to get high speed 5G on our Hololens 2.

Thanks!
Zaid

[#8]

We tested the Huawei E3372h-320 on HL2 and it did not work - even though a Win10 desktop recognizes it as RNDIS device and it works without driver installation.

Maybe it has to be configured somehow that it works on HL2?

[#9]

@retosan Unfortunately all RNDIS devices aren't created equal. Sometimes additional steps are necessary. We recommend using WiFi HotSpot as this works just fine for virtually all use cases. The only time when tethering really helps is in extreme low-latency scenarios like Azure Remote Rendierng.

If you can't use HotSpot, devices that appear to the HoloLens as a USB-C Ethernet adapter work best. If it's possible, please try one of those or try a different RNDIS device.

Lastly, if you need to use this exact RNDIS device, and if not being able to use this exact RNDIS device is blocking a large deployment of HoloLens 2, please let me know. I can't promise anything, but if we're talking about a large scale rollout we can investigate what might be needed to support that specific  RNDIS device.

[#10]

@jbienz Thanks for the feedback. Right, it would be for ARR scenarios and we are using hotspots already for other scenarios. We'll be able to switch to other USB-C adapters.  Right now, I do not know any working device that is available in Europe though. 

[#11]

@jbienz Hi, do you think the Nighthawk M5 router could be connected to the HL2 through USB tethering to provide a low-latency 5G connection? 

https://www.netgear.com/home/mobile-wifi/hotspots/mr5200/

Thanks,

Zaid

[#12]

@zaid_alsabbag yes we tested both USB-C tethering (cables should be no more than 1.8-2m in length and obviously support data transfer - we tested both Belkin and Targus cables for this) and also using the wi-fi hotspot.  The M2 isn't 5G though, only 4G/LTE

[#13]

Netgear Nighthawk M1 or M2 devices work fine over tethered USB-C and are available in Europe

[#14]

previous Nighthawk routers (M1 and M2) have worked just fine so i would expect it to yes, but I've not managed to obtain and test the M5! Let us know if you do first :)

[#15]

Thank you! Will update this once we get and test it with HL2.

[#16]

Does anyone have update about the supported devices? I mean some USB Routers or something like this, I need something small to get attached to the HL2. Thank you guys!

[#17]

I have looked closely at 2 options - one is not yet in production, the other is the FN980 @dan1-m mentioned earlier, but that one requires some work and more advanced knowledge.

No true 5G dongles are really available commercially yet in a USB form factor - your best bet is taking an M.2 and fitting it into an adapter. The SD X55 chipset is being widely in the US used so anything based off that has decent community support.

Power will likely be a big issue - I saw my HL drain about 17% in 10 minutes just keeping my dev kit for the FN980 powered. Haven't figured that out yet without building a custom PCB or adding on a splitter + battery pack.

[#18]

Dear Dan,

I found Telit FN980 only with M.2 port from factory.

Could you please tell more detail about which adaptor is used from M.2 to USB-C?

Would be great, you would share some documentations of the whole connection process?

Best Regards,

Guang

[#19]

I've had some good luck with the MU201 adapter from TechShip.

https://techship.com/products/techship-mu201-adapter-m-2-key-b-to-usb3-type-a-dual-sim/

[#20]

Thank you very much! I will try this one.