Comparison Between Cellular and UNB Network
for Smart Street Lighting Application
As Cities are planning to implement smart street lighting projects, choosing the right communication network is an important decision.
This article offers a technical and commercial comparison of using Cellular IoT versus Ultra-Narrow Band (UNB) communication networks. It aims to provide municipalities and city corporations with the necessary information to make an informed decision about which communication network to choose for their upcoming smart street lighting projects.
How do Cellular based Smart Street Lights Work?
A smart street light controller based on Cellular IoT connects to the internet via local telecom network. Here the controller uses 2G/ 3G/ 4G/ 5G signal (technically termed as LTE CAT 1, LTE CAT M1, NB-IoT, GSM, EGPRS and/ or EDGE). This is similar to how a typical mobile phone, ATM, traffic light or smart-meter connects to the internet. There is no need for a local gateway.
How do UNB based Smart Street Lights Work?
UNB stands for ultra narrowband. UNB based street lamp controller uses unlicensed radio frequencies (863 – 870 MHz / 910 – 923.5 MHz) to communicate to a central UNB Gateway(s). The Gateways act as central hub to connect UNB based lamp controllers to the internet.
Cellular vs UNB
A detailed technical and commercial comparison
Network Type
UNB
- UNB is a private network that can exchange small packages of data between private UNB Gateways and the Devices. Gateway to Device range can be from 500m to 16 km depending on the antenna power.
- UNB Gateways can connect between 100 – 3000 devices.
- However, the UNB Gateways are often considered as a single point-of-failure. Entire network gets down, when a Gateway fails.
Cellular IoT
- Cellular communication network is often referred to as IoT (internet of things) communication when used by smart devices.
- Cellular IoT network can exchange medium-to-very high amounts of data on real-time basis between the local Cellphone towers and the Devices.
- Options include: LTE CAT M1, NB-IoT, LTE CAT 1 (4G) or GSM / EGPRS (2G/ 3G). Device selects the most suitable network based on the availability from the local telecom operators.
Market Applications
UNB
- UNB offers low-to-medium bandwidth, low-to-medium latency
- It is provided by some private companies for Smart Lighting and some proprietary solutions
- UNB network was not accepted by Global Telecom (3GPP) alliance and was dropped from cellular standard. And therefore limited number of devices operate on UNB network, mainly from limited private companies.
- UNB communication network uses free, unlicensed and unregulated frequency spectrum (863 – 870 MHz / 910 – 923.5 MHz). And therefore 868 MHz/ 910 MHz frequency is used by many low-cost equipment manufacturers from children toys to drones.
- However, UNB Gateways are considered a single point of failure. And security vulnerability is considered a major drawback for use in public critical infrastructure applications. Therefore the use of UNB network in public infrastructure such as traffic lights, CCTV and ATM are not existent.
Cellular IoT
- Cellular IoT offers medium/ very high bandwidth, low latency (fast two-way communication)
- This network topology can support all LoRA/ UNB type market applications, as well as applications that need real-time communication, such as ATM, Traffic lights, Security Cameras, Public Parking systems, Smart Lighting, and other Smart City applications.
- Several billion devices work on cellular network today.
- All mobile phones in the world use Cellular IoT.
Unlicensed versus Licensed (regulated) Spectrum
UNB
- UNB works on unlicensed spectrum (868 – 869.6 MHz or 910 – 923.5MHz). This is free and unregulated frequency bandwidth.
- Since 868 MHz/ 915 MHz are free, unlicensed and unregulated frequency spectrum, many low-cost equipment from children toys to drones operate on this frequency bands.
- The chances of interference and jamming on unlicensed spectrum (disturbance in the radio communication because of multiple applications using the spectrum) are significantly higher.
- There is no guarantee that this unlicensed spectrum will be allowed to operate after 2028.
- Due to it’s easy vulnerability to security breaches, many countries demand formal approval from National Telecom Regulatory Authority (TRA) to use UNB for any public infrastructure related projects.
Cellular IoT
- Local telecom operators purchase the licensed spectrum to operate local cellular networks (license are managed by 3GPP global alliance and granted by national government)
- All connections are checked, verified and only then allowed to join the network
- Local Telecom Operators actively manage the networks often with 24 x 7 service availability, thereby maintaining a high reliability
Quality of Service & SLA
UNB
- UNB is a proprietary network. Only a couple of private companies can supply a UNB gateway.
- In case a municipality wants to manage its UNB network, then its IT organization needs to take care of the SLA and the network availability.
- Municipality needs trained staff for network maintenance, emergency back-up, trained personnel for restoration of the network, network security, etc. This is mainly to manage failure scenarios – if UNB is used in public critical infrastructure
Cellular IoT
- Local Telecom Operator provide guaranteed resource allocation needed for managed Quality of Service (QoS), uptime is often as high as 99,99%
- Local Telecom Operators offer different Service Level Agreements (SLA), including availability guarantees for the different network topologies
- NB-IoT and LTE-CATM1 use 3G, 4G and 5G licensed spectrum of the Telecom Operators, and therefore all SLAs and availability guarantees are applicable for this network topology
- In other words, municipality does not have to worry about the network management (same as network for cellphone)
Standard
UNB
- UNB is offered by a private company. It has not been adopted by the large Telecom Operators. Telecom operator cannot support if there is any issue in such a private network
Security
UNB
- UNB is a private proprietary network. Any security breach in the network can be solved only by the private company who supplied the hardware equipment.
- 868 MHz/ 915 MHz frequency spectrums used by UNB are free, unlicensed and unregulated, and therefore public critical infrastructure such as traffic lights, security cameras, ATMs never consider using UNB.
- UNB Gateways, by design, are often considered a single point-of-failure. Such Gateways in public domain are vulnerable to security breach. If a Gateway is down, then 1000s of devices become unreachable.
Cellular IoT
- Strong network security based on 3GPP global standards
- It remains a global standard with highest security levels (with continuous updates) today in the industry
- Public critical infrastructure such as traffic lights, security cameras, ATMs depend on cellular IoT network for day-to-day operation
Remote Software & Security Updates
UNB
- UNB network can support OTA depending on the size of the network.
- However, such OTA can take time. This can range from several hours to several weeks – depending on the size and distance of the network.
- Both the UNB Gateway and the UNB Devices must be continuously online for such OTA update to work
Cellular IoT
- Due to availability of good bandwidth and speed, controllers based on cellular network (spread across the city or town) can be updated fully automatically in a matter of minutes
Complexity of Installation
UNB
- UNB network based streetlights need multiple Gateways
- This requires a detailed network design (for example, how many Gateways needed, where to install them, is there line of site, etc.). This also requires specific knowledge and expertise of the installation team
- Intervention process, in case of a Gateway failure, also needs to be well documented/ planned
Connectivity Costs
UNB
- Similar to LoRA, UNB network is often marketed as a “free” network. However, unfortunately this is not true
- If municipality installs UNB network in the city, then it is personally responsible to manage, monitor and maintain the network. Personnel and resources have to be recruited and trained to manage the Gateways
Cellular IoT
- The costs for cellular M2M / IoT connectivity was one of the major barriers to the adoption for smart street lighting application. However, this cost has come down significantly over the last five years.
- Today, several MVNOs and local telecom operators offer connectivity at US $15 to $20 for 10 years per controller device. In other words, there is no monthly subscription fees to be paid.
- This is an excellent new development in the industry. Therefore, increasing number of smart city applications, including smart street lighting projects, have started using cellular IoT network.
Conclusion
Both Cellular IoT and UNB have their own merits when considering the smart street lighting application.
UNB Pros & Cons for Smart Street Lights
UNB communication network uses unlicensed and unregulated frequency spectrum (863 – 870 MHz / 910 – 923.5 MHz). It is free to use. It offers wider coverage. Each Gateway can support from 100 – 3000 devices. And therefore 868 MHz/ 910 MHz frequency is used by many low-cost equipment manufacturers from children toys to drones.
However, UNB Gateways are considered a single point of failure. Also, the limited bandwidth and the security vulnerability are considered a major drawback for use in public critical infrastructure applications. Therefore the use of UNB network in public infrastructure such as traffic lights, CCTV and ATM are not existent. Cities can consider using UNB network for smart street lighting application due to it’s low-cost, however security aspects should be fully researched and documented.
Cellular IoT Pros & Cons for Smart Street Lights
Cellular IoT network is used by billions of devices today. Managed by global standardization and security alliances, Cellular IoT offer one of the highest known security standard available today. Cellular connectivity is used by consumers (smart watches, mobile phones), professionals (smart meters, industrial machines) as well as public critical infrastructure (energy grids, traffic lights, water pumps, ATMs, CCTV) applications.
In the past, one of the key barriers of using Cellular IoT was the cost of ownership, because it requires one sim card / esim required per controller. However, this cost has gone down significantly during the last 5 – 8 years. Today, several MVNOs and local telecom operators offer Cellular IoT connection at US $15 – $20 with an all-inclusive coverage for 10 years. That means, US $1.5 – $2 for all-inclusive connectivity for one year. Furthermore, municipality does not need to worry about network planning or maintaining the local Gateways over several years.
Therefore, we observed that increasing number of towns and cities across the globe are adopting Cellular IoT for their smart street lighting projects. Research shows that this trend will continue.
Questions?
Smart street lights clearly offer many advantages. It has become a de facto standard in many new LED streetlight installations across the globe. We hope that this article provided you with the technical and commercial insights when choosing between UNB and Cellular IoT for smart street lighting and smart cities applications.
Do you have any questions or feedback? Would you like to learn more? Please feel free to contact us at info@tvilight.com.