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RAVENET MTE 481 · Fall 2026
Capstone Design Project

Comms that
survive the crowd.

A low-cost mesh network device that keeps text messages and location sharing alive when 50,000 phones on one cell tower means none of them work.

<$10–20BOM cost / unit
<10smessage latency
1,000users per mesh
The need

Cell networks buckle exactly when you need them most

In areas of extremely high device density, cellular reception can't handle every phone trying to access the network at once. Even the simplest functions stop going through: calls, texts, location services. The exact things you'd reach for in an emergency.

Case in point: during the 2019 Raptors championship parade, cell service across downtown Toronto collapsed. Finding friends or family in the crowd meant guessing, not messaging.
Large events Music festivals Marathons & parades
Objective

Move critical messages off the saturated band

Build a mesh network system that keeps high-priority cellular services functioning in large crowds. It routes over a separate frequency band (LoRa or Wi‑Fi HaLow) that never touches standard cell frequencies, so it can't add to the congestion it's working around.

Constraints

What the solution can't do

  • Whether it's a protocol or a device, it must never obstruct any other function of the phone or cellular network.
  • As a device: it must also be lightweight, low-cost to the consumer, and durable enough to survive weather and being worn on a person all day.
  • Low power enough to run for a full day on a battery, transmitting only when required, not continuously.
Success criteria

What has to work, in order

Core

Text messages and location updates transmit reliably over the mesh network.

Milestone 2

Voice calls transmit over the network.

Stretch

Direct contact to medical services from the device.

Differentiator

Better form factor and lower cost than existing competitors, achieved by using the phone as the interface instead of building a new one from scratch.

Requirements

Spec targets

Water resistantSurvives rain, sweat, spills
DurableDrops, crowd contact, all-day wear
Battery poweredNo mains dependency
$10–20Bill of materials, per unit
<10 secText message latency
<10 secLocation update frequency
Mesh network 3–5 hops Up to 1,000 users
Prior art

Competitors

TotemCompass and CrowdCompass both ship hardware for this exact problem. Both build a full custom interface onto the device itself rather than leaning on the phone people already carry, which drives up cost and bulk.

  Totem Compass Crowd Compass Ravenet (target)
Max group size8 peopleN/A1,000 people
Cost$113 CAD$177$10–20 BOM
MessagingNoYesYes
ProtocolCustom 2.4 GHzLoRaLoRa / Wi‑Fi HaLow
Map (see friends)NoYesYes
InterfaceOn-deviceOn-deviceYour phone
Alternatives considered

Why not satellite phones?

  • Prohibitively expensive for the average attendee.
  • Not everyone owns one, or would think to bring one to an event.
  • Shared satellite bandwidth would likely hit the same network-flooding problem at high density.
Open risk

Drawbacks we're designing around

Phones die over a long event

A dead phone can't run our app, no matter how good the mesh is.

Mitigation: airplane mode drops the phone's own cellular radio search, so pairing with our device may net-save battery compared to a phone hunting for signal all day.

Adoption depends on density

A mesh network needs enough devices nearby to actually form hops.

Mitigation: target group and event distribution (not solo retail) so density arrives with the crowd.