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IoT in the city: a street-light mesh and LoRaWAN. A district of street lights, each with a radio controller, and a LoRaWAN gateway on the tallest roof.

Layers

Scenario

A district of street lights, each with a radio controller, and a LoRaWAN gateway on the tallest roof.

01/04

500 MHz

1 GHz

2 GHz

5 GHz

10 GHz

20 GHz

40 GHz

EU868 LoRaWAN: 863–870 MHz · λ 35 cm · LPWAN, 1 % duty cycle · LoRa Alliance RP002-1.0.4

Network scenes

IoT in the city: a street-light mesh and LoRaWAN

Street-light controllers form a radio mesh that routes around a failed node to its border router, while meters and sensors report to a rooftop LoRaWAN gateway.

The place: City centre

In this scene

Border router on a street light
The mesh joins the city network here: one controller with a cellular or fibre uplink for a district of lights. (IEEE 802.15.4g, Wi-SUN FAN 1.1, IETF RFC 6550 (RPL))
Street-light controller
A controller in each lantern: dimming, metering and fault reports, relayed hop by hop through its neighbours. (IEEE 802.15.4g, Wi-SUN FAN 1.1)
Scene input: reliable hop range 125 m between poles 110 m apart
Rooftop LoRaWAN gateway
Hears water and heat meters, parking and air-quality sensors across the district. (LoRaWAN L2 1.0.4 (TS001-1.0.4), LoRa Alliance RP002-1.0.4)

Computed for this scenario

Gateways in service
1 of 1
End devices served
30 of 30
Mean spreading factor
SF7.0
Mean time on air, 20 B
57 ms
SF12 ring radius
6.1 km
Uplinks an hour at SF12 under 1 % duty cycle
27
Mesh nodes reaching the sink
63 of 63
Longest route
8 hops
Cut off
0

Scenarios

Normal
Every light reaches the border router in a few hops.
Three lights fail
Three controllers next to the border router fail; the mesh recomputes its routes around them.

Tour transcript

  1. A district of street lights, each with a radio controller, and a LoRaWAN gateway on the tallest roof.
  2. The mesh: grey lines are usable links, red lines are the routes each light uses to reach the border router.
  3. Three controllers next to the border router fail. The routes are recomputed around them.
  4. Meters and sensors report to the rooftop gateway; the whole district sits inside its SF7 ring.

How the numbers are computed

Mesh links join controllers closer than 125 m; routes minimise the sum of 1 + (d / range)² per hop, a proxy for the expected transmission count RPL objective functions favour, recomputed with Dijkstra when nodes fail. LoRaWAN rings use urban Okumura–Hata at 868 MHz from the rooftop gateway height.