Smart Street Lighting is among the biggest segment in smart cities and smart roadways. Naturally, the street lighting controller market is enormous with the global market easily running into a hundreds of millions of units. Having said that, no two projects or deployments are exactly the same. In fact, we at Inaluz today offer more than a dozen different variants of our smart street lighting controllers, with varying feature set and technology combinations.
In choosing the right lighting controllers there are many factors involved. Firstly, there are the features in the lighting controllers like (Energy metering, GNSS, Fault detection and sensor integrations etc). These are self-explanatory and based on the requirements these can be either included or removed almost on à la carte basis. Based on the project budgets and business models, our product variants allow our customers to pick and choose any permutation and combination of these features.
Then there is a choice of connectivity technologies and the overall solution architecture. The solution architecture is dependent on the connectivity technology and hence the real decision factor is the choice of connectivity technology. With connectivity technology there are three broad categories
- Cellular IoT – NB-IoT, LTE CAT M1, GPRS, LWM2M
- LPWAN – LoRaWAN, Sigfox
- RF Mesh – Sub GHz, 2.4Ghz (Zigbee, BLE Mesh, Proprietary Mesh Technologies)
Each of these options has its own advantages and tradeoffs, that one must understand before the right decision can be made. The choice of one of these also depends on lot of deployment factors and hence it is not a binary decision. The pros and cons must be weighed in the context of the deployment scenario.
We are using cellular IoT as a blanket term for all cellular network-based communication technologies starting from GPRS to the newer NB-IoT and LTE Cat M1 networks. Following are the relative pros and cons of the cellular IoT technologies-based connectivity for smart street lighting.
- Ubiquitous cellular networks for plug and play connectivity
- Robust, reliable and scalable cellular networks enabling any size of deployments
- Much higher bandwidth per device allowing near real time controls and telemetry
- Huge dependency on mobile network operator for connectivity
- Mobile network operator charges and costs
- SIM cards and device provisioning challenges especially if migration from one network to another is needed for any reason.
- Higher standby power consumption
Though some of the cellular IoT technologies also come under LPWAN technologies, we are considering only non-cellular LPWAN technologies like LoRaWAN and Sigfox for this category. Following are the pros and cons of such Non-cellular LPWAN technologies.
- Choice of own network or using existing network operators
- Lower operational cost than Cellular Networks
- Lower standby power consumption
- Highly constrained bandwidth and communication
- Requires carefully planned communication and fail safes
- Real time controls and telemetry not possible requires scheduled activities
RF Mesh here can be any mesh technology in any unlicensed frequency band in the respective country of deployment. For example, smart street lighting in India this could mean a standardized Mesh communication technology like Zigbee in the 2.4GHz ISM band, or even a proprietary mesh communication technology in the Sub GHz 865Mhz to 867Mhz band.
- Lowest cost of ownership and operations
- Higher bandwidth per device than LPWAN technologies, however lower than Cellular Technologies.
- Near real time controls and telemetry possible.
- Complex architecture to deploy and manage for large deployments.
- Requires careful planning of deployments to avoid blind spots in the network.
- Failure of a few devices can isolate many devices from the network