Smart Street Lighting

Do you want to control your entire city’s street lights via a complete sub-GHz mesh network which is entirely embedded in an RF module? Then Radiocrafts’ Industrial IP Mesh (RIIM) Network is the solution for you!

hide node count

Large network with a single border router - 1000 nodes

long range

Cover a large area - up to 28 mesh hops, 700 meters between each node

ota

Future proof with over-the-air updates

low cost

No license or subscription fees

Two-way communication

2-way symmetrical communication

self-forming

Multicast - Create dynamic groups of street lights

Explore the results of our large 1000-node network street lighting simulation below.

Introduction To Smart Street Lighting

Legacy street lighting networks have some major drawbacks which makes their upgrade a must. Firstly, street lighting accounts for around a fifth of global electricity usage where each city in average spends a little less than half of its energy bill on street lighting. This, besides being very expensive, is also very environmentally unfriendly. Second, legacy street lighting networks are often used on an on/off scheme, which is not always optimum as sometimes different degrees of illumination is needed.

However, recent huge leaps in lighting technologies have given rise to some possible solutions. The most widely used light bulbs in the past were the HID (high intensity discharge) mercury vapor and the sodium halide bulbs. The switch to LED bulbs offers a 52% reduction in energy usage over HID and a 26% reduction over sodium halide bulbs. In addition to providing some new features such as reduced glare and better color rendering. Although LED lamps have a higher initial cost, the above-mentioned features added to the fact that LED lamps have much longer lifetimes makes them a very feasible solution for large scale street lighting systems.

Networked street lighting is gaining significant traction in Smart Cities and is a great way for cities and utilities to improve safety and cut costs for their customers. A networked street lighting system incorporates a cluster of streetlamps that can communicate with each other and provide lighting data to a local concentrator. The concentrator manages and transmits the relevant data, via a wireless RF module, to a secure server that captures the data and presents it in a dashboard interface.

A smart street lighting system also allows facility managers to remotely control streetlights while keeping track of electrical power consumption in the lamps. The lamp status is constantly monitored meaning scheduling maintenance becomes more efficient and cost-effective. Additionally, in case a lamp falls, the problematic lamp can be pin pointed remotely and fixed.

Radiocrafts' Solution for Smart Street Lighting - RIIM

The requirements on the network for a successful smart street lighting deployment include:

  • Support for large networks
  • 2-way symmetrical communication
  • Very simple network installation and node replacement (no touch commissioning)
  • Fast control of the light
  • Reliable Network
  • Support long pearl-of-strings networks
  • Alarms if a node is lost
  • Broadcast message of new schedules
  • Support multiple sensors (GPS, daylight, motion, tampering etc.)
  • Support long range
  • Easy upgrades/bug fixes

Radiocrafts’ Industrial IP Mesh, RIIM, provides a highly efficient solution to these Smart Street Lighting requirements.

RIIM by Radiocrafts is an Industrial IoT wireless IP mesh network completely embedded in a module. It includes all the critical components for a complete wireless IP mesh and has no license free or subscription costs. It is ready to go when you buy the module. Additionally, since RIIM is a mesh network, it is self-forming, self-healing, and self-optimizing. This is simplifies the deployment of your street lighting network greatly.

RIIM includes the ICI framework. An ICI application is always running on the module to tailor the modules behavior to the customers unique requirements. In its simplest form, the ICI application is just configuring the radio network, the modules hardware interfaces, and defines when to read and write to those interfaces. ICI makes it possible for the user to directly interface to virtually any sensor and/or actuator, such as a motion sensors, GPS, dim control sensors and more, removing the need for external circuitry. It supports mist computing to reduce bandwidth requirements and for fast responses to local events such as updating the brightness of light bulbs in a specific area of the city and more.

RIIM also supports multicast. In a street lighting application, remote configuration management is essential because it enables software upgrades over the air or other mass distribution messages to reduce the on-air communication time. In addition, in a large network of many hundreds or thousands of nodes, Multicast makes it possible for you to create virtual dynamic groups of streetlights, allowing you to update a certain parameter for those specific node groups all at the same time, for example, turning on/off lights in a specific area of the city, adjusting the colour of the lights, adjusting the dimness, broadcast message of new schedules, and more. This makes maintenance and management of the network much simpler.

RIIM also supports faulty node detection where the Border Router sends a message to every node asking if they are still connected to the network. If the Border Router does not receive a reply from one of the nodes, this means that this node is lost.

There are many existing street lighting deployments which use Zigbee. The competitive advantage of RIIM versus Zigbee is that RIIM can support longer range  (700 meters between each node in urban environments) with each mesh hop (28 mesh hops), and up to 1000 nodes for a single border router, reducing the cost of the installation as less gateways are needed to support a large scale deployment.

There are also many existing street lighting deployments which use LoRa. The competitive advantage of RIIM over LoRa is that a RIIM network supports 2-way symmetrical communication which essential for Over-The-Air Updates. This means that the user can update the user defined ICI firmware when the network is deployed and in full operation, so new sensors/controllers can be added when the need arises and the user can broadcast messages of new schedules efficiently. One major advantage is that RIIM is significantly more reliable than LoRa. RIIM supports Time Synchronized Channel Hopping (TSCH) which was designed to make a mesh with less packet collision and higher reliability. A TSCH network has proven to have a reliability of up to 99.99%. RIIM is also protected by encryption using a pre-shared key and supports DTLS end to end security.

Large Network Street Lighting Simulations Using RIIM

Our large network street lighting simulations using RIIM are simulations that fulfill various street lighting scenarios requested by some of Radiocrafts’ customers.

One simulation entailed:

  • 1000 nodes (1 Border Router and 999 Mesh Routers)
  • City-like layout
  • 40m in average between each light pole
  • Broadcast messages every 4 hours
  • Assumed maximum range between a node can communicate at is 210 m (With a good antenna design and LoS between light poles this is expected to be longer than this)
  • Sensor reading from each light pole every 2 hours
  • Run over a 24-hour period.

One major issue with large networks is how to prevent packet collisions. RIIM has various features which allow it to form large 1000-node networks quickly and reliably.

The best way to go about forming a large network using RIIM is “Synchronized Joining”, which is a measure by which the joining process is altered to allow enough time for nodes to join the network and avoid creating a bottleneck effect at the Border Router. This is done by using the “Random Function” feature which is already available in the RIIM API. This function can be used to set a random offset in the joining command for the nodes. This one-shot timer will create a random delay in each of the nodes’ joining procedure, limiting the number of nodes communicating with the Border Router at any instant.

Another feature in RIIM which can be used to avoid common problems seen in large networks is setting the “Network Type” to “Large Network” through RIIM’s APIs. Radiocrafts has created a set of parameters custom-made for large networks, which can be activated through ICI just by setting the network type to “Large Network”.

Simulation Results

Network Formation

The network was allowed to form with a joining delay offset of 10 minutes. This means that the 999 mesh router nodes started communicating with the Border Router at random times in a 10 minute window. The simulation results show the success of our measures as a large network of 1000 nodes took 9 minutes to form after the last node joined the network.

Multicast Latency

Multicast is a feature in RIIM which allows the Border Router to broadcast messages, and the child nodes repeat this message to ensure that even the most remote node still gets it.

Multicast messages are of utmost importance in street lighting applications as they are the means by which the core management system will send “turn lights on/off messages”.

The average time observed for the 5 multicast messages was 27,899 seconds.

Unicast Latency

Unicast messaging refers to messages sent from a child node to the Border Router. Such messages can be very important as it might be a lamp trying to inform the core management system of a certain failure it has. Therefore, unicast latency is a crucial parameter to consider in street lighting networks.

Since the network has 1000 nodes, sending a unicast message every 4 hours, it can be concluded that a total of 6000 messages were sent. Out of these 6000 messages, only 3 messages were lost.

We also measured the time it took for unicast messages to be sent from each node and the highest average value was around 900ms. This means that in a network with 1000 nodes, the Border Router will receive messages from the furthest node with an average delay of just under one second.