HaLowLink 2 (EU Version): Support for India's 865–867 MHz Licence-Free Spectrum

General
1

Hello, We are evaluating the HaLowLink 2 (EU version) for an embedded application (image transfer from multiple ESP 32 P4 based cameras) and would appreciate some clarification regarding its configuration and networking capabilities.

We intend to operate in India, where we plan to use Wi-Fi HaLow in the 865–867 MHz band. We would like to know:

  1. Can the HaLowLink 2 (EU version) be configured to operate in the 865–867 MHz range, or is a different firmware or regional version required?
  2. Is it possible to configure the router to operate at a center frequency of 866 MHz using a 1 MHz channel bandwidth?
  3. If this is supported, could you please explain how the frequency and channel bandwidth are configured?

We also have a few questions regarding network operation:

  1. When a Wi-Fi HaLow device connects to the HaLowLink 2 in STA mode, does it obtain an IP address (e.g., via DHCP)?
  2. Once connected, can the HaLow device use standard TCP/UDP sockets and HTTP/HTTPS requests directly, similar to a conventional Wi-Fi network?
  3. Alternatively, can the HaLow device simply send data to the HaLowLink 2, with the gateway automatically forwarding the data to a preconfigured remote server or URL? If so, how is this configured, and which approach do you recommend?

Our intended application involves multiple Wi-Fi HaLow devices (ESP 32 P4) periodically uploading images to a remote server, so we would appreciate any recommendations on the most suitable architecture.

Thank you for your assistance. We look forward to your response.​

2

Hi @omumbare,

  1. HalowLink 2 EU will operate in 863-868 MHz, with a duty-cycle of 2.8% (STA)
  2. 866 centre is not a valid EU channel, so that won’t be able to be set. This is defined by the 802.11 wifi spec.
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From a cursory read, it seems like India will fall under the same channelisation scheme definitions as EU, based on the 802.11 Global and S1G operating classes definitions. You’ll need to confirm that the EU and IN follow the same power and emissions restrictions as the EU, and that you are conforming to your regions legislation.

Regarding the network operation questions:

  1. By default the HL2 will be running a DHCP server, so the devices can obtain an IP address through DHCP
  2. Once connected, it’s all just Wi-Fi! There’s no difference from a networking perspective between 2.4GHz WI-Fi, Wi-Fi HaLow or any other medium. Our stack will manage the HaLow bits, and from the application and network perspective it can do all the usual stuff.

For your architecture, you can treat it like any Wi-Fi connection, with the exception that there’s reduced bandwidth. Unless you deploy a significant number of stations you will likely be fine if it is image upload.

If your cameras upload at a reoccurring interval and you do find you have issues with devices sending traffic at the same time, you could try offsetting the timing slightly.

3

Thank you for your response.

The networking is a great news, however I still have a doubt about how can I use EU version in Indian license free frequency (865-867) range? Is there any setting when can be done so that Halowlink 2 can work/ can be restricted to this range?

Looking at the diagram posted in your reply does it mean there is a setting to set channels for example Looking at the diagram, the valid 1 MHz center frequencies are approximately:

863.5 MHz (Channel 1)

864.5 MHz (Channel 3)

865.5 MHz (Channel 5)

866.5 MHz (Channel 7)

867.5 MHz (Channel 9)

For example can I use 1Mhz band Channel with channel 5 or 7 which might set/ restrict it to work in the range of 865 - 867Mhz.

Currently i have MM6108 based FnLink 4108E-S chip and a quectel based FGH100M M.2 module. Which i am planning to interface with my ESP P4 (library to be used : morsemicro/halow from ESP component registry)

I know these module can connect to EU HalowLink2 but I still have question about how do I restrict or use frequency in range of license free band in india (865 - 867).

For multiple camera sending the data at the same time, how is that dealt with? There is no fixed timing, images are captured based on a trigger.

4

Through the UI it’s not currently possible to configure a specific channel. I know that we are looking at adding that functionality in an upcoming release.

I’m not sure if there is a way to restrict the channel from the terminal, I will get back to you on that.

As for the STA nodes, you will need to ensure they only scan the allowed channels. You can do this by setting the “IN” country code. This will select the IN channels. As they share the same op class as EU, the STA should associate to the AP without issue, if the AP is on one of these channels.

For multiple camera sending the data at the same time, how is that dealt with? There is no fixed timing, images are captured based on a trigger.

First off, I’ll just point out that you’re unlikely to have issues with scheduling because of the 2.8% duty cycle there will be plenty of air time for each device. You would need ~35 devices all using their full allocation of air time to saturate the medium.

When you say “trigger” do you mean one action causes all cameras to take a picture and send it? Or each camera may be triggered by an event (such as movement) and therefore are triggered independently?

If they are being triggered together, then adding a short random delay between capture and send would reduce collisions. If they are triggered independently, it won’t be an issue.

Hope that helps!

5

Thank you for your response it cleared few things,

As you said, currently in settings/configuration UI of HalowLink2 we cannot set a Channel exclusively, but what about setting the country code to “IN”? Is “IN” country code available as an option in HalowLink2?

Because if we are able to set country code to “IN” that solves my issue of operating it within 865 -867 band right? And then I dont have to worry about channels?

If this is available as a setting, can STA connect to Halowlink2 just by having same country code? And are channels are automatically set? So i dont need to worry about setting channels for STA and Halowlink2?

6

I don’t think the country code can be modified on the HL2. You’ll need a way to set a specific channel/restrict the operational channels.

Setting the STA to IN will ensure it only scans and associates on a valid channel.

If your HL2 is set to EU on one of the valid channels (5,7,9) and the STA is set to IN, they will associate fine.

7

Thank you for your response

So what i understand is, if I use HL2 EU as it is, and just set country code to IN for my STA nodes, the entire network will follow Indian restriction perfectly fine. And whole network (multiple STA + HL2) will work at 865-867.

Does this mean HL2 broadcasts on all EU channels and valid STA can read and then connect?

Please correct me if I am wrong.

8

No, you need to force the HL2 to only operate in the valid channels. Currently it will channel hop and would sometimes operate outside of the allowed range (channel 1,3).

If you restrict the HL2 to a single channel, or a subset of channels, in the valid range (5,7,9), then the STAs would discover and connect correctly.

9

Is there a way to do this? Any setting or anything for HL2?

Why cannot STA in IN country code not connect to HL2 halow?

10

As before, I’m not sure, I’ll let you know once Ive spoken to my colleagues (next week).

I don’t understand this question. I haven’t tested it, but in theory it should work, assuming the AP is on one of the valid channels.

11

Sure kindly let me know, I will be waiting for this information as we are looking forward to purchase HL2 in bulk if it works fine in Indian frequency range.

Also, As you said in theory it should work directly, but wont channel hoping disconnect the STA? Or is it once it connects to STA in Channel range 5 or 7, will HL2 stay connected by holding same channel for that specific STA or is there a chance for it to disconnect?

12

Hi @omumbare, It sounds like there is no way to restrict the channel on the current release of HL2, so you cannot guarantee the AP will only operate on the appropriate frequencies. This behaviour will be modified in a future release.

13

Thank you for your response.

So this means i cannot use HL2 in india with guarantee of operating within 865-867mhz restricted frequency only, for my network, for now, and only option is to wait till next release?

If so, I believe i can use halow chip in AP mode and then forward the data to wifi network using a microcontroller right?

So 1 halow esp 32 p4 will be STA and other will AP then I will be able to recieve data from STA and then forward to remote server using onboard wifi capability? But will this setup provide similar capabilities like providing IP from DHCP to the STA and will i be able to use http on the sta in this setup (chip used : fnlink 4108E-S or quectel fgh100m)