Local alerts on MeshCore, and a mesh you can see

Mesh Dispatch started with a simple question: if the phones and the internet go down, how would people around Boston hear that a storm warning is out, a highway is closed, or the trains have stopped? MeshCore radios keep talking without either. Dispatch puts short, useful alerts onto the mesh, and keeps a public record of what the mesh is saying, so more people find it, trust it and join in.

What we have built so far

• A searchable archive. Every message on the public MeshCore channels our receiver hears, from greater Boston and across New England and New York, is saved and searchable, by channel at addresses like /channel/dispatch-boston. Posts the abuse checks flag are left out.
• Dispatch alerts. A bot posts short alerts to its own channels: National Weather Service warnings, MassDOT and Waze traffic incidents, Boston weather every hour from 7 am to 10 pm, and, as each one proves itself, MBTA disruptions on #mbta, power outages by town, Boston Harbor flood levels, Logan Airport ground stops, air quality and clusters of urgent 311 reports. Each source has a threshold, so routine noise stays off the air.
• Good manners on the air. Every post is scoped to the Boston region, so it does not flood the whole Northeast; there are quiet hours, a cap of a few posts per channel per hour, and duplicate checks. Links are short (/t/ plus four characters) so the message itself has room.
• A mesh you can see. The Repeaters page shows the repeaters we hear on a radar, by distance or by hops; Mesh links shows which repeaters hear each other and which already carry region traffic; every node has its own page.
• Tools for the community. Check a name before you pick one, a directory of bots, health checks, a list of local groups and maps on Community, and search across channels, nodes and hashtags.

How it works

1. A repeater on a rooftop north of Boston forwards traffic like any other repeater, and passes what it hears to a small computer at home.
2. That computer decodes the public hashtag channels (only those) and saves them. Private messages stay private.
3. It checks public sources every few minutes: the National Weather Service, MassDOT, the MBTA, NOAA, the FAA and others. Anything past its threshold becomes a short post.
4. A second radio, used only for sending, puts those posts on the air, scoped to the Boston region and within the limits above. An admin can hold any source for review before it goes out.
5. This website shows it all, and counts nothing about you beyond page views and clicks on our short links.

What we learned this week

We built a page that asks the New England analyzer, a network of about a hundred listening stations, how far each of our posts travelled. The answer was humbling: most of our posts stop at our own rooftop. The repeater is set up correctly, but it has one neighbour, on a link right at the edge of what the radios can decode. A post from the region usually reaches about nine listening stations; ours reached one.

So the next step is not more software. It is a better path out: a mobile test node to drive to hilltops and parks and measure where a message gets through, then a second repeater where it helps most. If you run a repeater around Woburn, Burlington, Stoneham, Winchester or Arlington and would not mind a new neighbour, we would love to hear from you.

The community we want to build

Mesh Dispatch is meant to be copied. The plan is to publish the code so anyone running a node can start Dispatch for their own town or region: their own channels, their own region scope, their own sources, on a small computer at home. A dispatch for Lowell, the North Shore, the South Shore, Worcester or Providence, each local, each scoped, each useful to the people around it.

The more people do this, the better the mesh gets for everyone. Alerts give people a reason to keep a radio on. A record of what the mesh is saying shows newcomers it is alive. And every new repeater placed to carry those alerts fills in a gap.

How you can help

• Add the channels. #dispatch-boston, #dispatches and #mbta, scoped to bos. The home page shows how.
• Tell us what you hear. Reply on the channel, or email [email protected], when an alert reaches you, or when it should have and did not.
• Run a node or a repeater where coverage is thin. The Devices page lists radios people use.
• Run Dispatch for your area when the code is out. Ask to be first in line.
• Join the conversation in the Greater Boston Mesh community.

Alerts can be late or missing. In an emergency, call 911.