I'm curious how HSMM-MESH moves the operation of the router from part 15 rules to part 97 rules.  Is there anything in the firmware that makes the router operate under part 97 rules or do we only operate under part 97 rules if we change the antenna and/or increase the output power?  Can someone please educate me as to when the router stops operating under part 15 rules and begins operating under part 97 rules?

Thanks,

AC7BR

Hi Brad,

From what I have seen of the implementation, there is nothing inherent in the firmware changes that would re-class it from a part 15 to part 97. If you increase power, use antennas with sufficient gain, or go outside of the normal part 15 authorized spectrum, then you would want to consider it a part 97 device. If there are no overt changes that re-classify the device, then it appears you are free to simply assert that it is being operated as Part 97 if you so choose.

Some people claim that an HSMM-MESH node is classified as a repeater. I do not believe this to be the case since it does not meet the repeater definition of retransmitting on a different "channel". In my opinion, HSMM-MESH more closely fits the definition of a message forwarding system as described in Part 97.219. In fact, this is a preferable classification for HSMM-MESH purposes for the purposes of carrying third party traffic while in automatic control.

An important consideration is that the part 97 rules forbids an amateur station from retransmitting the signals from a non-amateur radio station [see 97.113(a)(5)(c)]. This could mean that if you are participating in a mesh with a station that is re-purposed to part 97, then the other ham NEEDS your node to be a part 97 device. This could also apply if your node is attached to your own Amateur Radio station in some way to retransmit signals message.

With all of that being said, it could be argued that these type of part 15 devices participating in a true part 97 network is not an issue since it is simply common, transparent infrastructure and they do not rise to the definition of a "radio station". Consider the case of an amateur using a Bluetooth, part 15 device, with his HT - I doubt the FCC would have any stomach for issuing a citation under part 97.113.

Also be aware that if you are operating as a Part 97 device and are retransmitting messages from other stations (as in an HSMM-MESH configuration) then you are required to authenticate the other station if you do not want to be held liable for the content of the messages you are forwarding [see 97.219(d)(1)]. The rules provide no guidance for the "authenticate" requirements but one could assume the presence of a valid call sign ID should reasonably suffice.

I am curious what others think. I hope you generate a lively thread.

- Glenn DJ0IQ and W0IQ

One thing different from the Part 15 device - The HSMM-MESH configuration requires that you put in an identifier which is your call sign, and broadcasts that are part of the regular sequence of operation - every 5 minutes  as I recall. We are also selecting a frequency within the ham bands to do our operation.

And as would happen in the other modes of communication - if a non-ham were to try to join our mesh we would find some way to exclude him/ report the illegal operation.

Not a whole lot different fro me retuning some old commercial gear for 2 Meters and 440.

Hi Pete,

The issue of sending a call sign really doesn't have any effect on Part 15 vs Part 97 operation in my opinion. A part 15 user can pick absolutely any SSID that they wish, including an amateur radio call sign to which they have no claim. There is nothing in any part of the FCC regulations that prohibits such use. The fact that this is used to facilitate our need to identify a Part 97 device is incidental to the discussion unless you could prove that the Part 15 person used it for a nefarious purpose to gain access to your station.

To the best of my knowledge. when using an access point that has been flashed with the HSMM-MESH firmware, the channel to frequency correlation is not changed from that of a standard consumer Part 15 device. While it is true that Amateur Radio operators have a primary allocation for channels 1-6, I don't think you will find any sympathy from the FCC for a complaint that a Part 15 device is associating with your Part 97 device. Consider the huge commercial pressure that would be brought on the FCC if they started making such rulings. There is plenty of prima facia evidence, in my opinion, that the FCC is heavily swayed by commercial influences in such cases.

We must also consider that the FCC could actually come back and site that under 97.3(a)(13) that you as the control operator are responsible for proper operation of your Part 97 station and that you have not taken the necessary steps to protect your station from Part 15 devices - particularly since you should reasonably be aware of the potential "interference". They could further point to 97.219(d)(1) and say that you are equally accountable for all messages passed since you didn't authenticate the other "station". A more precedent FCC response could be that in fact your are not operating a Part 97 device but instead it is a Part 15 device for the reasons sited in my earlier post.

The good news is that very few, if any, home users will have installed the OLSR software in their AP. This is the essential code that makes the HSMM_MESH work as a mesh AP instead of a normal AP. Without this installed in their AP, your HSMM_MESH AP won't even recognize their AP. So there is some protection built in through this level of obscurity. If OLSR were to become popular, then a better authentication scheme for HSMM-MESH would probably need to be deployed to meet the authentication requirement of 97.219(d)(1). I say this because simply having a call sign in the SSID of an OLSR enabled AP probably doesn't meet a reasonable test of authentication in that scenario.

- Glenn DJ0IQ and W9IQ

Hi Pete,

As I understand the HSMM-MESH firmware, it does not operate in a way that changes it from a part 15 device to a part 97 device. The device is using power output that is available to both part 15 and part 97 devices. Furthermore, the frequencies are also available to part 15 and part 97 devices. The operator of the device can choose to operate under part 97 rules by increasing the output power via an amplifier or using higher gain antennas.

If my understanding is correct, than an operator of a HSMM-MESH devices does not need to use a callsign for the SSID unless he/she chooses to operate under part 97 rules by increasing power and/or gain.

My supposed "understanding" is what prompted my original post. I want to make sure I really understand how the HSMM-MESH device operates and that I don't violate any FCC rules. With that in mind, please correct me if I am wrong.

Thanks,

AC7BR

Pete,

Don't get me wrong. I'm not saying I don't want to use my ham call sign. Actually I plan to run the mesh the same way most people are, which includes using my call sign. I'm on a learning expedition with this post. I'm really trying to figure out what in the firmware differentiates the device from part 15.

You also make a good point about our privileges and using them or losing them. I think that is a good reminder for everyone.

Thanks,

AC7BR

Hi K5DLQ,

I think your question is very relevant and have thought about it myself. Perhaps it is worth its own thread.

As KD5MFW pointed out, the software does not use WEP/WPA or any other sort of encryption. However, as you point out the users of the mesh could send SSL or other encrypted traffic over the mesh. Does this violate part 97? I have no idea. I am also not a lawyer (IANAL) so I couldn't even begin to give you an educated legal answer to this.

However, I can tell you what I am working on doing. I will not allow traffic that has the potential for encryption, such as port 443 (HTTPS). I will block it at some device. That way, I won't be in possible violation of part 97. To be honest, I am working towards a white list of ports that are allowed. It would be trivial to add another port to that list if needed.

Is this the right approach? I don't know, but that is the direction I am headed.

Thanks,

AC7BR

In case you're still wondering, I would recommend reading the following article: http://www.qsl.net/kb9mwr/projects/wireless/Data Encryption is Legal.pdf

We have found that the only people who want to discuss this subject are those that are in it for the sake of arguing.

Please drop the subject, or if needed (and I really hate doing this) Ill remove the entire topic from the server's MySQL database directly.

WE DONT ENCRYPT.

DONE.

NO MORE.

Now wheres the Bacardi.....