MESH NETWORK HAMNET

Discussion in 'Echolink/IRLP Tech Board' started by KD4YSH, Nov 22, 2014.

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  1. KD0WHU

    KD0WHU Ham Member QRZ Page


    Beg all you want, it's a fact of reality. If you use something like Asterisk as a central server, SIP and OpusVoice, between the protocols you already have a 6-10ms delay before it even hits the wire. If you now have to jump through 20 miles of mesh nodes where you're getting 5-7ms of latency PER HOP, yes, you'll have an audible echo by the time you get to the other end, god forbid it actually hit the internet.

    Like i've said, other than use it or lose it, there's virtually no point to a mesh network, emcomm or otherwise. (which is a piss poor excuse that people hide behind too much lately) You can do so much more with high gain directional antennas, sector/panel antennas and simple rooftop stuff versus hacked up linksys gear that was NEVER meant to be strapped to a light pole in a tupperware container. I've had better success using AP WDS repeater stuff than anything the hamnet stuff could ever provide. I have 300Mbit floating about 40 miles around town here, all i need is one antenna and 15 foot poles and i can get on the network from virtually anywhere in town. The entire network (tower space/climbers notwithstanding) was a whopping $1500. It's all outdoor rated, commercial carrier class equipment with certified parts and antennas. Anyone who wants a serious network would look this direction, leaving the hamnet stuff in the dust.

    Like someone else said, you're hamstrung (no pun intended) of what you can even schlep across the link.
     
  2. N1EN

    N1EN Premium Subscriber QRZ Page

    I won't disagree with that second statement. If you have the time and resources to properly plan a network, you can do better than mesh (regardless of whether that better solution is Part 15, Part 90, or Part 97).

    But from where I'm sitting, mesh has the advantage of requiring a lot less planning. A "lot less planning" isn't ideal...but those situations where "a lot less planning" is likely are precisely the situations where amateurs might be tasked with helping (along with "something to fill in until something better/more robust can be brought in").

    I'd be careful about how high you're setting the bar with the "virtually no point" bar. At the level you're suggesting, most of ham radio would fail the test.

    Sometimes "the point" is simply experimentation/learning by doing, etc.

    Why did Sir Edmund Hillary climb Everest? Because it was there.
    Why did the ham build a mesh network? Because he could.
     
  3. KB3VWG

    KB3VWG Ham Member QRZ Page

    As they say "it's all good."

    Well...as I mentioned...I provide services for those who mostly wouldn't be able to afford them, you have to improvise alot and think on your feet. It's not that I "advocate" the use of the equipment, it's that the cost-of-entry would be so high for Hams, and the consumer market for the equipment so low, that COTS (consumer-off-the-shelf) devices manfactured to spec for Part 97 use will never be built by any manfacturer.

    You mentioned removing the encryption...I wrote about that somewhere in anohter mesh forum (I have to find the link)...personally...I'm not of the opinion that WPA1/2 or WEP is "obscuring the meaning of the communication" per the Communications Act and Part 97 (but I don't plan to test those waters, except it be a REAL emergency)...plus, at any rate, you can get around that by "publishing" the key. I'm of the opinion that as long as you don't use a proprietary protocol (Layer 1), obscure the Wireless Ethernet Frame (Layer 2) nor the IP Packet (Layer 3), that you're good to go.

    The main value we find for Meshing in the MDC section is to be able to remote control stations, connect to a NON-COMMERCIAL Internet Service Provider (hint-hint) in emergencies and allow data to be transfered between our ARES/RACES served agencies (Hospitals, County Health Dept., EOCs, Red Cross facilities, etc.). During drills, are are hitting our 1200 baud bandwith threshold; were it were a real emergency, we're concerend that we would be of little pratical use if they need to pass data and had no other recourse. We'd either have to read verbatim and record the RX, or they'd have to get Public Safety to drive a message/thumbrive/external HDD across the county. We simply need another method to pass data for our served agencies becides 1200 baud TNCs on UHF. 802.11 is that solution for us.

    Fruther, I advocate the use of some carrier-grade devices with expansion ports. Some of those take 400MHz and 900MHz 802.11 cards. I never said we would be constrained to 2.4GHz COTS equipment. In fact, we're planning to do our point-to-points with either 400 or 900 MHz, to as I implied, make islands of Mesh nodes with a robust backbone.


    73,


    KB3VWG

    PS: I re-read that I said 'decimal or hex,' I meant 'binary or hex." LOL
     
    Last edited: Dec 13, 2014
  4. KC2UGV

    KC2UGV Ham Member QRZ Page

    Then, somehow, the Freifunk mesh group discovered a way around reality. They have a VoIP network spanning Berlin.
     
  5. KC2UGV

    KC2UGV Ham Member QRZ Page

    You do understand the "mesh" part is just the routing protocol, not much different than OSPF, it's using OLSR for it's routing which is self-healing, and self-discovering. It can grow up to 1000 nodes (Tested, in the wild), without much in the way of issues with route convergence and loops.

    You can design a mesh that is also partly star topography (Which we're planning out right now), where in the case of backbones going down, client devices can be used for routing. Again, in the wild testing has gotten us ~20mb/sec over 6 hops using part 15, off the shelf devices.
     
  6. KM4IFT

    KM4IFT Ham Member QRZ Page

    I have a couple of these routers with the firmware installed

    Now what??

    I'm interested in the subject, and found many many setup threads and videos etc etc.

    But I've found very little on the subject of actually using them.

    Many people have talked about data transfer and webcams, but I can't find a single tutorial on how to "use" HSMM HamNet.
     
  7. KC2UGV

    KC2UGV Ham Member QRZ Page

    You use it the same as you use any IP network, such as the internet.
     
  8. K1RFD

    K1RFD Ham Member QRZ Page

    Just a quick point about VoIP latency: Virtually all ham communications are half-duplex, not full-duplex. Echo is not an issue. The most commonly used VoIP systems for amateur radio work just fine with more than 100 ms of latency.
     
  9. KC2UGV

    KC2UGV Ham Member QRZ Page

    Over IP, it doesn't have to be half-duplex. That being said, one can enable half-duplex to solve the latency problems you described :)
     
  10. G6GIF

    G6GIF Ham Member QRZ Page

    Yet another example of nay saying flame wars on QRZ, I agree with George Thomas W5JDX you do need asbestos underwear to post anything on here.
    As for BBHN its another branch of ham radio that lots of folks interested in microwave working are enjoying and despite what some people think it does work surprisingly well.

    BBHN is attracting interest from the younger generations who have grown up with computers and wireless networking all around them, if we don't get their interest there is no Ham Radio (look around you at any club meeting or Hamfest 25 years from now we will be lucky if we enjoy the same number of interested people we now have and no interest = no ham bands ! ).

    Much of ham radio could be called "mostly useless" ( thousands of stations filling the HF bands with "CQ contest" in one mode or another comes to mind ). Personally I'm glad we have this diversity of frequencies and modes to use and learn about its what makes Ham Radio what it is today.

    73 de Mick G6GIF/KD5PEX
     

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