SIGLINK
SIGLINK
WATCH THE VIDEO REQUEST FIELD PILOT

MESH MESSAGING FOR iPHONE & MAC · NO INFRASTRUCTURE

When the network is the first casualty, the team still talks.

SIGLINK turns every iPhone and Mac around you into a relay. Messages hop device to device over peer-to-peer WiFi — through teammates, Macs, Sitrep Field Units and WiFi routers — up to 64 hops, end-to-end encrypted, with no tower, no internet and no server. Where a connection does exist, an optional relay and encrypted mailbox carry them further.

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MESH ACTIVE 64 HOPS · 255 EXTENDED END-TO-END ENCRYPTED

● DIRECT LINK · TALON-3 · 47 M

0
TOWERS · SIMS · SERVERS NEEDED
64
HOPS ON EVERY MESSAGE
255
HOPS WITH EXTENDED REACH
E2E
ENCRYPTED ACROSS EVERY HOP

WATCH · 57 SECONDS

See it in under a minute.

What happens when the network goes down, how the mesh carries a message phone to phone, and why none of the devices in between can read it.

Open the video full screen ↗

01 — THE PROBLEM

Comms plans assume a network. Contact doesn't.

Jammed, saturated, destroyed or simply absent — in DDIL environments (denied, disrupted, intermittent, limited) towers and backhaul fail first, and the radio plan never covers every runner, driver and attached specialist. SIGLINK turns the phones and laptops a unit already carries into a self-forming mesh: open the app and everyone in reach links up. No pairing, no codes, no RF plan.

A

Direct link

Device to device over peer-to-peer WiFi — no router, access point or SIM in the loop. Discovery is automatic. Works in airplane mode with WiFi switched back on.

● PRIMARY · NO INFRASTRUCTURE
B

Mesh

Out of reach? Every device in between passes the message on — teammates' iPhones, a Mac left running, or a WiFi network that turns its whole coverage into a single hop. 64 hops by default, 255 with Extended Reach.

● MULTI-HOP · CIPHERTEXT ONLY
C

Relay & mailbox

Where any internet path exists, the relay carries traffic beyond the mesh, and messages for closed apps wait encrypted in a mailbox with a push to wake the phone. One switch turns it off.

OPTIONAL · OFF = LOCAL ONLY

02 — GRID DOWN

When it all goes off, every device becomes the network.

A district at 21:00, then a blackout. The towers and backhaul go dark, every phone shows No Service — and the SIGLINK devices still in the streets, offices and flats link up and carry the message across, hop by hop.

iPHONE RUNNING SIGLINK MAC NODE WiFi NETWORK = ONE HOP SITREP FIELD UNIT CELL TOWER HOPS — / 64PATH —

RAVEN-2 · iPHONE

03 — THE APP

Built like a field tool. Feels like the messenger they already use.

Conversations, groups and a radar of who's in reach — with delivery ticks that tell the truth about where every message is.

3.1 · CHATS

Callsigns, not phone numbers

Everyone gets a callsign. The bar at the top says who is in reach right now; one-to-one chats and group nets sit side by side.

3.2 · CONVERSATION

Encrypted, verified, honest

Every message is end-to-end encrypted. Scan each other's code in person and the lock becomes a green shield. Ticks say exactly where a message is: on this phone, in the mesh, on the server, delivered, read.

3.3 · RADAR

Who's around, and where they last were

Position sharing is off until you turn it on, runs only while the app is open, and goes only to people you're linked to. When a teammate drops out, their last position holds, dimmed, with the time since contact.

3.4 · ALERTS

Locked. Muted. It still reaches you.

A new message lights up your locked iPhone and taps your Apple Watch, so you feel it even with the phone in a pocket on silent. Silent mode turns off the sound, not the alert. There's nothing extra to install on the watch: it follows your iPhone's notifications.

iPHONE · LOCKED · SILENT
● APPLE WATCH · ON YOUR WRIST

04 — CAPABILITIES

Everything a field net needs. Nothing it doesn't.

4.1

Zero-step netting

Open the app; everyone in reach appears in seconds. No pairing ceremony, no admin, no RF plan.

4.2

Mesh to 255 hops

Every device passes traffic on: 64 hops by default, 255 with Extended Reach. Duplicate suppression stops loops; a WiFi network counts as one hop.

4.3

End-to-end encryption

Sealed on the sender's device for each recipient. Phones carrying it, the relay and the mailbox hold only ciphertext. Verify in person by QR; key changes are flagged.

4.4

Delivery truth

Clock, one tick, two ticks, green ticks — and a plain caption when a message is waiting or retrying. It tells you when a held message finally lands.

4.5

Group nets

Squad-sized group chats that sync across the mesh, with invite links and live typing indicators.

4.6

Mac as a node

The same app runs on a Mac, linked to your identity by QR. Leave one running by a window and it's an always-on relay.

4.7

No phone number

Sign in once with an email; after that it works with no connection at all. No SIM, no phone number, no trackers.

4.8

Data stays on device

History lives on the handset and is excluded from iCloud backups. Optional backup is encrypted with a key only you hold.

05 — SIGLINK CONSOLE

One console for the whole team.

The web dashboard for team admins. Deploy SIGLINK to your people, see who's active and where, and put the vehicles and shipments you answer for on the same map. Sign in by scanning a code with your phone. The net itself works with or without it.

Set up your team Open the Console

Their location stays their call.

Everyone decides for themselves. Sharing with the organisation is off until they turn it on, no admin can turn it on for them, and they can mask themselves again at any moment. Masking deletes the position we held. Messages never appear in the Console at all.

5.1

Deploy to your team

We set up your organisation with the seats you need. Your people install SIGLINK and sign in, then you add them by email as members or admins.

5.2

Monitor location and usage

Shared positions on the team map, refreshed about once a minute, and every seat at a glance: active in the last 15 minutes, seen today, or silent for over a day, with how many devices each person runs.

5.3

Add or remove people

Control who is in your private network from one list. Removing someone takes them off your roster and map straight away; their own account and chats stay theirs.

5.4

Beacons on what moves

Scan the label on a Sitrep beacon to put a vehicle, shipment or piece of equipment on the map, with its position and, where the beacon reports them, battery, speed, temperature and humidity.

06 — OPERATING ENVELOPE

The honest spec sheet.

Claims you can test in a car park with a few phones. Limits stated up front, because discovering them in the field is how tools get thrown away.

DIRECT LINKPeer-to-peer WiFi (Apple AWDL) between devices — no router, access point or SIM. Typically 30–100 m per hop in the open; walls and crowds reduce it. Devices on the same WiFi network also link through it.
MESHEvery device running SIGLINK passes messages, receipts and group updates on. Standard: 64 hops — about 4.8 km of path with phones ~75 m apart. Extended Reach: 255 hops — about 19 km of path, a one-time upgrade. Macs and WiFi networks cover far more ground per hop, and Sitrep Field Units add fixed, battery-powered relays.
ENCRYPTIONEnd-to-end: each message is sealed on the sender's device for each recipient (X25519 key agreement, per-message content key). Relaying devices, the relay and the mailbox see who a message is for, when and how big — never what it says. Contacts verified by scanning codes in person; key changes flagged. Not FIPS-validated; no certification claimed.
RELAY & MAILBOXOptional. Where any internet path exists, carries traffic beyond the mesh; messages for closed apps wait encrypted for up to 30 days, with a push that shows the callsign only. Switched off, nothing leaves the local mesh.
IDENTITYEmail sign-in once; afterwards the app works with no connection. Callsign identities; one identity across iPhone and Mac, linked by QR. No phone number or SIM.
ALERTSMessages and incoming calls alert on the lock screen. With an Apple Watch on your wrist, message alerts reach it as a tap whenever your iPhone is locked. Silent mode removes the sound, not the alert. A Focus or Do Not Disturb holds alerts unless you allow SIGLINK in it. Off-grid, an alert needs the message to reach your phone over the mesh, as set out under Current Limits.
CONSOLEWeb dashboard at console.sitrep.us for organisation admins, part of SIGLINK Teams. It needs internet, and so do the positions it shows: members appear only after turning on sharing with the organisation, and only while SIGLINK is open. Beacons report over their own cellular connection. Beacons and member positions are visible to that organisation's admins only.
PLATFORMiPhone (iOS 17 or later) and Mac. Unmodified commercial devices already in pockets and on desks.
CURRENT LIMITSSTATED PLAINLY — On iPhone, off-grid messaging and relaying work fully while SIGLINK is open; in the background, short messages can still pass over Bluetooth. Macs and Sitrep Field Units relay continuously. Whenever any internet path exists, the encrypted mailbox and push notifications reach devices where the app is closed. SIGLINK runs on iPhone and Mac today.

SIGLINK is a commercial off-the-shelf communication tool. It is not a replacement for issued tactical radios or accredited secure communications, and should be evaluated under your own organisation's security policy.

07 — WHERE IT EARNS ITS PLACE

Anywhere the signal dies before the task does.

7.1

Urban blackout

Towers down, power patchy: the devices still in streets and buildings carry the net block by block.

7.2

Dismounted teams

Keep a patrol, stack or working party netted beyond radio issue or coverage.

7.3

Training & exercises

Instant comms for OPFOR, range staff and umpires without touching the exercise RF plan.

7.4

Disaster response

First 72 hours: coordinate search sectors and musters with what's already in people's pockets.

08 — EVALUATION

A few iPhones and ten minutes outdoors is a complete first evaluation.

We supply evaluation builds via TestFlight, a test protocol, and direct access to the engineering team. Mention SIGLINK in your enquiry.

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