Changing Face of Cities through Smart Poles & Edge Computing
In the previous article, the data awareness circles and its correlation with IoT and X-computing are introduced, and it is emphasized why the local data processing is much more efficient to analyze the surrounding environment or to interact with it. Many examples presented in this article necessitates the near data processing for many reasons. In another article, where the use cases from the merge of digital twin and metaverse are detailed, it is a tough task to realize these use-cases without near computation power. For many areas, especially in closed environments, a powerful edge device can be replaced with the traditional router, so that the required power can be met, however, our life is not closed into single environment, rather we use the public places extensively. Personally, I believe this usage will be enriched through AR technologies. For these scenarios, we need a solid computation power, and it should be distributed across the city, since apart from the humans there will be also lots of other devices such as autonomous vehicles, drones, etc. that require the computation power. The fundamental question is how and where to put distributively the edge computers in cities? To address this issue, we analyze the streetlights as a potential edge computing places. In those days, the streetlights are called as smart poles if they are equipped with some sensors, communication technologies and edge computation power. In this article, we focus on the smart poles, their features, available products on the market, analyze how they can contribute to the edge computing by giving the edge-computing related use cases, and finally discuss where and how smart pole should be deployed.
Importance of Smart Poles
From the first candle usage on the ancient streets for bringing the brightness on the way to the invention of bulbs and their first usage for lighting the street is an evolving process. Apart from 2014 the first concept of the smart pole in the humble lamppost project, the traditional streetlight is equipped with various sensors and actuators to observe the environment and to interact with the users. This type of streetlights are called as smart poles and inherits all features of streetlights.
The most important advantage of smart poles is to be distributed and be everywhere in a city. This increases the closeness of smart poles to users and objects, thus having the opportunity to extract the regular patterns from the street, meeting the user daily requirements such as information sharing, etc. through the data processing in an anonymous fashion. All these use cases necessitates the computation power and smart pole can embed an edge computer. Their distributed structure across the city keeps the network traffic local and can reduce the network traffic towards the cloud. When considering all these features, smart poles are one of the best candidates as a host for realizing the edge computing scenarios.
Characteristics of Smart Poles
As aforementioned, smart poles is an enriched version of streetlights, which is mainly evolved in four categories. These categories are sensor and actuators, connectivity, computation power and energy. The sensors and actuators enable to sense the environment, and interact with the surrounding things if needed. For example, monitoring the streets, vehicles, and humans can be counted as a sensor feature, whereas establishing the communication with a human using a chatbot or a person can be seen as an actuator feature. Sensors and actuators are crucial in such components, since they help in recognizing the characteristics of the environment, culture, thus creating a blueprint of its environment.
The usage of the electric energy grows every year, especially the technology transition at vehicles. Smart grid projects directly focus on the distribution of the generated energy across the city, and this can be visualized as a grid where you retrieve the energy at the provided price, and then sell to the grid if you have more. Smart homes and buildings are also corner stones of the smart grid. The role of smart poles at that point is rather to distribute the energy to the technological devices such as vehicles, scooters, electrical bikes, smartphones, etc. The variety of these devices would increase over time, however, the key is here to supply the required energy to them. Even if smart poles can generate energy through the solar panels and wind tribunes, these can meet only the energy required for its operation for the time being. In case the current situation of the streets are thought and the existing number of vehicles, smart poles can be seen one of the best candidates for charging them.
Figure 1: Smart Pole Characteristics
The connectivity is another important feature of smart poles, since the generated data can be transmitted to the cloud through LTE, 5G, so that not only the current status of a smart poles, but also the environment status can be monitored. If the generated data is not too much, then other communication protocols can be selected, such as 6lowpan, Lora, etc. Even the communication among smart poles can also be established with these protocols. The significant point is here exactly to identify the requirements for the use case that will be applied. For this reason, a communication protocol matrix that shows its range, date rate, consumed power for a single package, its reliability such as consideration of QoS levels.
The vision of IoT and the massive data generation requires capacity-rich computers to process them. Even a single vehicle is composed of more than 30 sensors and generates nearly every 10 ms data to observe the status of the vehicle, etc. Considering the augmentation of the sensors at the vehicle, the transmission of these data to the cloud necessitates first a stable connection and then the enough bandwidth to transmit them. The current legacy architecture cannot meet this requirement for the vehicles. If the AR tech are added on top of this use case, then the locally generated data cannot be transmitted, and a bottleneck in the core network is unavoidable. In this article, I explained the importance of the data generation level and data interpretation level, and how the layered data processing level should be handled. Smart poles can address this issue by helping vehicles in processing the data, in other words, they will behave as edge computing devices, so that all data can be processed at the local level, and only the cloud relevant data would be transferred to the cloud. By doing that, the latency for data processing and the bandwidth usage towards the cloud can be minimized.
Available Smart Poles on the Market & their Features
Smart poles is one of the smart city component, and the humble lamppost conceptualized in 2014. From that point to today, there are dozens of companies that concentrates on the smart poles. Some of them are quite matured and have many enriched use cases. Below, you can find a list of existing smart poles.
- TviLight, WeLight, Schredder Shuffle, The Humble Lamppost
- Omniflow, SEAK Smart city, Luxturium 5G, Elko
- Sansi, Intellistreet, Signify, gridComm
- Lumenova, Devtech, Zgsmlightings, Advantech
- Soonlite, Aaeon, Dfdled, We-gov, Ericsson and Phuilips
- Huawei, Nct, Onion
List 1: Available Smart Poles
From the sensor point of view, nearly all products have the same equipments. Only few of them supports edge computing, however, this feature can be also added to them easily if needed. The control mechanism of the smart poles are in general connected to a smart city platform, especially, TviLight, WeLight, Humble Lamppost, Luxturium 5G and SEAK Smart City along with Omniflow are the most elaborated systems in comparison to other products. These products provide a quite rich use cases represented by applications. Probably, Schredder Shuffle and Elko differ from all products due to their modular structure. Especially, Shredder Shuffle allow customer to equip the smart pole according to their requirements. In case the novelty is taken into account, the Omniflow and Luxturium 5G integrates the 5G, and the both platform offer drones a landing&charging place. In addition, Omniflow has an integrated wind tribune to produce energy, which is the unique feature in comparison to all other products. Below, six different smart poles are pictorially added.
Figure 2: Intellistreets, Signify, Sansi Smart Poles
Figure 3: Elko, Omniflow, LuxTurium 5G Smart Poles
The following table indicates a cumulative feature list for all products listed above.
Table 1: Available Features of Smart Poles
Edge-Computing Related Use Cases for Smart Poles
The quality of the weather measurements can be increased through the deployed number of the sensor, and smart poles can deliver the exact value of the weather information about their environment. A cumulative view of all environment sensors integrated in smart poles can give us a representative weather information for a specific region. The following visualization is cited from  the communication of a bunch of sensors, called as mesh network. The environmental data coming from various sensors such as humidity, temperature, volatile organic compounds, formaldehyde, particulate, matter, and Co2 can be analyzed at the edge without transmitting to the cloud environment. Based on the predefined rules or updated rules by the cloud, in case of an abnormal situation, the reaction time can be close to the real time.
Figure 3: Environmental Sensors on Smart Poles Connected to Cloud
Drones Use Cases
The usage of drones emerges in the world from private usage to the military purposes, and there is an increasing interest in utilizing this technology. Thanks to its mobility and computation capacity in comparison to IoT devices, it is an affordable and flexible flying computer. The unique limitation for a drone is its battery capacity, therefore drones should be regularly charged to continue an operation. Some use cases where drones can be used:
- Environment monitoring via Cameras for a number of use cases, i.e.crowd detection, accident monitoring
- Package transporter (the first tests are performed by Amazon, a couple of years ago)
- Turning into a Wi-Fi provider (it is connected to Internet with a cellular tech.)
- Flying Taxis or human transporter
- And many other use cases
Smart poles can improve the operation of drones in the following cases:
- Charging place for drones: In case multivendor is thought, a dynamically changing reservation system for the drones would be required, since there will not a single drone, rather many drones from many vendors, like today delivery services. Omniflow does already offer a charging place for drones, however, there is any resource reservation system behind the scene.
Figure 4: Smart poles as charging places for drones
- Position for observing the environment for a period of time: Smart poles can integrate cameras or not, it depends on the decision, however, drone be placed on a smart pole to observe the environment in more detail.
Drones can also add non-existing functionalities to smart poles, i.e.
- Providing extra computation capacity (Integrable Computation Power)
- Providing a sensor or actuator (Integrable Sensor and Actuators)
- Expanding network capacity through the additional network interfaces (Integrable or Non-Integrable Wi-Fi, LTE, etc.)
Augmented Reality (AR) Use Cases
AR enriches the surrounding environment via the additional information, that can inform or guide us or even enable us to interact with it. Based on its applicability field, the AR use cases and the type of interaction can vary. As in many other cases, one of the essential challenge in the future is the data transmission between AR app and Cloud in case the content is composed of rich items. In addition, the latency is also another major concern for keeping the customer experience at the acceptable level. For this reason, the edge computing has a key role to provide the required computation power, decrease the latency, and establish the connection to the cloud. For example, a vehicle fully connected and equipped with sensors as shown in the figure can see the critical information on the routes and additional information that describes the route, the status of vehicles, etc.
Figure 4: Augmented Reality for Vehicles
Another application field of AR is the games and AR can revolutionize our traditional game understanding and bringing the games into the street. The first example, Pokémon, is already introduced and most of us was a player, even it was the first multiplayer AR game that attracts millions. Considering the interest of peoples for the games, the required network performance would be quite demanding, and it will be challenging to answer all service/game performance requirements.
Figure 5: Augmented Reality for Street Gaming
AR touristic apps can also attract the attention of the tourists, which would guide them across the city, provide each time additional rich information about the visited location and even make the tourists time travel that shows how the objects have been evolved over time. These details can also be interesting for the residents, since this provides totally another experience level and all information are condensed and context-dependent. The two following figures help us in visualization how these apps can look like.
Figure 6: Augmented Reality for Touristic Apps
All aforementioned application coincide at a single point, which is the necessity of a near computation power, edge computing, that would provide the required resources. Smart poles can meet this requirement through its closeness to the end users and its edge computing capability.
Design Criteria for Smart Poles in Smart Cities
City streets have different characteristics that reflects its culture, therefore a single design of smart poles may not match these characteristics on each street. Furthermore, the required equipment may also differ from street to street or from the population age, or the environment. Considering these points, the following questions should be answered before designing a smart pole and deploying it.
- Modularity: The variety of the streets can necessitate smart poles equipped with different features. A modular structure, i.e. Schredder Shuffle smart poles, can enable the integration of only required features or modules into the smart pole. Furthermore, these smart poles can be later extended in case new features are required due to the varying environment conditions.
- Sensor & Actuator Variety: Sensor requirements can be different at each street due to the street characteristics. For this reason, the most adequate sensors and actuators should be selected. For example, the necessity of a camera or a wireless digital traffic sign or many other sensors for a street can only be identified based on the prepared use cases for the related street.
- Connectivity: A smart pole can communicate with either another smart pole or another edge computing powered computer or directly to the cloud in order to transmit its data. As the variety of sensors generates different amount of data, the communication protocol that would be selected does also play a crucial role. The figure below indicates the communication protocols and applications and their suitability for the applications.
Figure 7: Connectivity Options, Suitability and Comparison of Communication Protocols
The main criteria that should be considered for the IoT communication protocols: data rate, consumed power, range, and security levels for the protocols that are close to the physical layer in OSI, i.e. Lora, BLE, Zigbee, NB-IoT. Most of these protocols consumes less energy and some of them such as Lora and 6lowpan has long range, however, the transmitted data rate is quite low. The second group can be classified as the application layer protocols, they have also various differences, such as the underlying transmission protocol(TCP, UDP), support for pub/sub or request/response, support for different QoS level (as in MQTT), available security protocol (mostly TLS/SSL), etc. The key performance indicator for this group of protocols as follows: Latency, bandwidth usage, energy consumption and throughput and reliability (QoS level).
- Services & Applications: The variety of the services depends on the use cases defined for the environment. For example, the following figure shows the functional features of the Humble Smart Pole w.r.t the layers. These services consume the sensor resources in order to represent them in applications or process them to figure out the hidden patterns on the street.
Figure 8: The Humble Lamppost functions
- IoT Platform: The connection of all these devices and services can be established in an IoT platform. The Humble Lamppost architecture is depicted in Figure 9, which was designed in 2014, therefore it may not consider rich applications, however, its design includes all aspects of a smart pole. In Figure 10, the FIWARE reference architecture for the smart cities is depicted, which is a broader platform that involves not only smart poles but also many other smart city components. Apart from the technological performance, the biggest advantage of FIWARE relies on the context data from multi resources, not only smart poles. Therefore, the contextual rich applications and their quality in the sense of the data accuracy can be more performant.
Figure 9: The Humble Lamppost Architecture
Figure 10: FIWARE Reference Architecture for Smart Cities
- Citizen Characteristics: A street is composed of the residents, and it is structured through their demographic forms, since the street is by surrounding peoples and constructed on their requirements. Considering them, the population diversity, the ratio of the old and young people, the visitors (tourists) to the street would change the requirements of the smart poles on this street.
- Animal and Plants Variety: Animal and plants are also part of the street and their requirements should be also taken into account. For instance, which animals or plants are available, what kind of protection mechanisms can be applied and how smart poles contribute to them. In addition, the plant ecosystem can be closely observed through the smart poles, thus extracting a blueprint of the street ecosystem for the plants and animals.
- Street Characteristics: As listed in the previous sections, there are lots of smart poles available on the market. Even they are quite close to each other from the functionality perspectives, one missing point is to have a suitable design for streets. Some streets are composed of ancient buildings, others can reflect the modern buildings. Therefore, during the deployment of smart poles or their generation, street oriented smart poles should play a crucial role to not disturb the street structure.