Technical Working Of LoRaWAN Technology

Technical Working Of LoRaWAN Technology
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    Technical Working Of LoRaWAN Technology

    Are you considering using LoRaWAN to deploy your IoT solution? LoRaWAN Technology is one of a number of industries that have recently adopted momentum-building protocols deployed on public networks. If you are choosing a private network solution for an industrial or enterprise use case, you can take a thorough look at this protocol first. In this article, we explain the differences between LoRa Technology and LoRaWAN technology and give an in-depth introduction to how LoRaWAN technology works, its pros and cons, application cases, and other basics you should know. It also helps you make better decisions.

    What is LoRa and how does LoRa technology work?

    LoRa is an effective remote low-power wireless communication system developed by Semtech. LoRa’s simple layout and huge investment potential have made it widely used in manufacturing, transportation, agriculture, retail, and home appliances. LoRa is also a wireless modulation technology based on CSS (Chirp Spread Spectrum) technology, which uses Chirp pulses to encode information in radio waves. In addition, because of its strong modulation and anti-interference, it can receive data transmission over a long distance.

    With its star topology and cleverly implemented signal transmission technology, LoRaWAN technology is specifically designed for the energy efficiency and secure networking of devices in the Internet of Things. We can explain how the technology works.

    The Internet of things imposes many requirements on the network technologies used. What is needed is an architecture that is designed for thousands of nodes that can be far from populated areas and in hard-to-reach places. The architecture must also safely support battery-powered sensor nodes while simplifying installation and maintenance. That speaks for radio operation. Network technology must take into account the strict power consumption requirements for end nodes, many of which are to be operated with a single battery for decades. High security is essential to prevent eavesdropping and to ward off hackers.

    The design of such a network technology begins on the physical level. Similar to a number of other radio protocols that are used for IoT applications, LoRaWAN technology uses spread spectrum modulation. An essential difference between the LoRaWAN protocol and other protocols is the use of an adaptive technique based on chirp signals – and not on conventional DSSS (direct sequence spread spectrum signaling). This approach offers a compromise between reception sensitivity and maximum data rate, which supports this adaptation node by node thanks to the modulation configuration.

    what is lora technology

    What is LoRaWAN and how does LoRaWAN Technology works

    The LoRaWAN specification at the software level is a wide area and low power network standard based on LoRa, developed and maintained by the LoRa Consortium. It wirelessly connects battery-operated devices to regional, national and global networks. It determines when the device transmits data and in what format.

    There are 5 main groups of components that make up LoRaWAN: End node, gateway, network server, application server and join the server.

    End-nodes– Devices located at the End of the network are used to periodically collect and monitor data in real-time. They typically come in the form of low-power microcontrollers and are equipped with low-power LoRa transmitters to send packets to the gateway, with batteries that can run for decades without any maintenance.

    Gateway – The LoRaWAN Gateway acts as a bridge between the node and the network and is considered as a packet forwarder. It uses a LoRa concentrator to obtain information from the end-node and then transfers the data to the network server through the private network infrastructure.

    Network Server -The Cloud LoRa server consoles all the data it obtained from the gateway and uploads it to the application server. Things Network (TTN) is one example of a Web server.

    Application Server – The Application server renders visual data for you so that you can integrate data points into a platform and take action accordingly. You can even set up a notification service to notify engineers when an accident is likely to occur.

    Join Serve – The connection server is responsible for processing the uplink request frame and generating the information needed for the downlink to receive the frame. It sends signals to the network server which the application server is required to connect to the end device and performs application and network session encryption key derivation. It communicates the device’s network session key with the network server and applies the session key to the corresponding application server.

    Classes of LoRaWAN end nodes

    LoRaWAN contains three different types of end devices to meet the different needs that arise in a wide range of applications:

    Class A-Lowest power, and bidirectional end device

    Class A communication is the default class that all LoRaWAN end devices must support, is initiated by the end device, and is not synchronous. Each uplink transmission is allowed to be sent at any time, followed by two short downlink Windows, providing the possibility for network control commands or two-way communication. When uplink communication is allowed at any time, the terminal device can still enter the low-power sleep mode, which makes class A the lowest power mode. In addition, downlink traffic should be buffered on the network server until the next uplink event as downlink traffic is required to keep following a schedule defined by the end-device application for uplink traffic.

    Class B-A bidirectional terminal device with deterministic downlink delay

    Class B devices use periodic beacons to synchronize to the network and open downlink “ping slots” at times that are scheduled. This enables the network to send downlink communications with a definite delay, although results in some additional power consumption on the end devices. To accommodate different usages, the latency is programmable for more than 128 seconds. In addition. Because the additional power consumption is low enough, it is also suitable for battery-powered applications.

    Class C-Minimum delay, bidirectional terminal equipment

    Besides the Class A structure of the uplink and two downlink Windows, Class C further decreases latency on the downlink by maintaining the receiver of the end device open all the time when the device is not transmitting. The network server is able to initiate a downlink transmission under the assumption that the end device receiver is open, so there is no delay. It is determined that the power loss of the receiver can even be as high as ~50mW, so the C level is more suitable for applications with a continuous power supply. Temporary mode switching between class C and class A is possible for battery-powered devices.

    The accurate reference clock is important for LoRaWAN technology

    To ensure that the receiver can process the incoming code chips and convert the stream back into data, DSSS relies on an exact reference clock on the circuit board. Such clock sources are rather expensive and the increasing accuracy of the clocking also increases power consumption. The CSS technology used by LoRaWAN technology (chirp spread spectrum) can be implemented more cost-effectively because it does not rely on a precise clock source. A chirp signal is a signal whose frequency varies over time.

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    In the case of the LoRaWAN technology network, the frequency of the signal increases over the length of the code chips of the respective data bit group. To improve reliability, LoRaWAN adds error correction information to the data stream. In addition to the immunity of systems with a spread spectrum, CSS offers a high level of immunity to multipath distortion and fading, which is problematic in urban environments – just like Doppler shifts: overlays change the frequency. The CSS technique is more robust because Doppler shifts cause only a small change in the time axis of the baseband signal.

    More range or higher data rate 

    Like DSSS, LoRa can vary the number of code chips per bit. The standard defines six different scattering factors (SF). With a higher SF, the range of a network can be increased – but with more performance per bit and a lower overall data rate. With SF7, the maximum data rate is approximately 5.4 kbit / s and the signal can be considered strong enough at a distance of 2 km – although this distance depends on the terrain. With SF10, the estimated range increases to 8 km with a data rate of slightly less than 1 kbit / s. This is the highest SF in an uplink: a transmission from the node to the base station. A downlink can use two even larger SF. The SFs are orthogonal. This allows different nodes to use different channel configurations without influencing each other. In addition to the physical level that prepares data for CSS modulation and transmission, LoRaWAN defines two logical layers that correspond to levels 2 and 3 of the layered OSI network model (Open Systems Interconnection).

    • Level 2 is the LoRa data connection level. It offers fundamental protection of message integrity based on cyclical redundancy checks. LoRaWAN establishes basic point-to-point communication.
    • Level 3 adds the network protocol feature. The LoRaWAN protocol offers nodes the opportunity to signal each other or to send data to the cloud via the Internet – using a concentrator or a gateway.

    LoRaWAN technology uses a star topology: All leaf nodes communicate via the most suitable gateway. The gateways take over the routing and, if more than one gateway is within range of a leaf node and the local network is overloaded, can redirect the communication to an alternative. Some IoT protocols use mesh networks to increase the maximum distance of a leaf node from a gateway. The consequence is a higher energy requirement of the nodes for the forwarding of messages to and from the gateways, as well as for an unpredictable shortening of the battery life.

    The LoRaWAN architecture ensures that the battery of each IoT node can be dimensioned appropriately and predictably for the application. The gateway acts as a bridge between simpler protocols, which are better suited for resource-restricted leaf nodes, and the Internet Protocol (IP), which is used to provide IoT services. LoRaWAN technology also takes into account the different functions and energy profiles of the end devices by supporting three different access classes. All devices must be able to support class A. This is the easiest mode that helps maximize battery life. This class uses the widely used Aloha protocol.

    Automatic collision avoidance integrated

    A device can send an uplink message to the gateway at any time: The protocol has built-in collision avoidance when two or more devices try to send at the same time. Once a transmission is complete, the end node waits for a downlink message that must arrive within one of two available time slots. Once the response is received, the end node can go to sleep, which maximizes battery life.

    A LoRaWAN gateway cannot activate a class A end node if it is in an idle state. He has to wake up by himself. This is due to local timers or an event-controlled activation, which is triggered by an event at a local sensor input. Actuators such as valves in a fluid control system must be able to receive commands sent by a network application – even if they have no local data for processing and communication. These devices use Class B or C modes.

    With class B, each device is assigned a time window within which it must activate its recipient in order to search for downlink messages. The node can remain in sleep mode between these time windows. Uplink messages can be sent if the device is not waiting for a downlink message. Class B is used when the latency of up to several minutes can be tolerated. Class C supports significantly lower latency times for downlink messages since the receiver front end remains almost constantly active. A class C device is not in receive mode only if it sends its own uplink messages. This class is used by network-powered end nodes.

    LoRaWAN versus other technologies in the LPWAN ecosystem

    LoRaWAN versus other technologies in the LPWAN ecosystem

    If you know anything about the acellular space, you will know it’s not a new market. It is a diverse and fast growing technology as a limited part of the whole IoT connectivity market. Many operators prefer to continue to use a mix of cellular and non-cellular options. Orange, for example, sees LoRaWAN and LTE-M as a perfect match. In addition, the LoRa Alliance believes that LoRa technology and cellular LPWA, especially LTE-M, are complementary, with an increasing number of carriers offering both LoRa(WAN) and LTE-M.

    SigFox, LoRaWAN, NB-IoT, LTE-M, Link Labs, and Weightless are some of the LPWAN technologies and standards that are under active development. Other protocols, such as LTE-CAT M, IEEE P802.11AH, and Dash7 consortium protocols, are also important parts of the LPWAN ecosystem, but in this section, we will mainly dive into the previous technologies mentioned.

    • LoRaWAN

    The LoRa Alliance is a non-profit and open association with approximately four hundred member companies in Europe, North America, Asia, and Africa.

    However, LoRaWAN, as an open standard network layer managed by the LoRa Consortium, is not truly open because the underlying chips that implement the full LoRaWAN stack are only provided by Semtech. LoRa is the physical layer( chip) while LoRaWAN is the MAC layer(software) that is installed on the chip for networking.

    It functions similarly to SigFox in that it is primarily used for uplink only applications — data from devices/sensors to gateways – with many endpoints. But, it utilizes coded packets to distribute information over different data rates and frequency channels instead of using the narrowband transmission. These messages are less likely to collide and interfere with each other, increasing the gateway capacity.

    • Sigfox

    SigFox, a French company founded in 2009, has significant appeal in the LPWAN space. SigFox achieves a wider range by using an example of a slow modulation rate. Because of this design choice, SigFox is a good choice for applications where the system only is required to send infrequent and small bursts of data. Smart trash cans, parking sensors, and water meters are possible applications. However, it also has some disadvantages. It is severely limited to send data back to the sensor/device (downlink capability)and there is also signal interference.

    • NB-IoT and LTE-M

    NB-IoT and LTE-m are up-and-coming additions to the LPWAN space. The solution uses standard LTE connectivity while preserving resources. Nb-IoT is another 3GPP build that challenges the disruption caused by the LoRa alliance and Sigfox while NB-IoT operates outside of the LTE build.

    One of the advantages of NB-IoT is that it consumes minimal energy and reduces the overall component cost due to simple construction. Finally, NB-IoT has potential advantages in smart city applications. The building penetration of NB-IoT is better than that of LTE-M. On the other hand, LTE-M-enabled chips are also typically very expensive.

    Lte-m also has its advantages. First, it has a higher data rate, and its front end is pretty simple. However, beyond the fact that LTE is a largely American technology, there are other limitations and issues to consider.

    So, options should be made between the two based on your particular application. Nb-IoT may be best suited for smart meters, while LTE-M has advantages in drones or vehicles.

    • Link Labs

    Link Labs uses the LoRa chip. Instead of using LoRaWAN, however, Link Labs built a private MAC layer (software) called Symphony Link on Semtech’s chip. Symphony Link adds some important connectivity features over LoRaWAN, including guaranteed wireless firmware upgrades, message reception, repeater capabilities, and the removal of dynamic range and duty cycle limits.

    • Weightless

    Weightless SIG’s mission is to standardize LPWAN technology. As the only truly open standard, Weightless is operating on an unlicensed spectrum at sub-1ghz. There’re 3 versions of Weightless that can be used for different purposes:

    Weightless-w: Leverage whitespace (unused local spectrum in the licensed television band)

    Weightless-n: An unlicensed spectrum narrowband protocol derived from NWave technology

    Weightless-p: Two-way protocol derived from M2COMM’s Platanus technology

    Weightless N and P are more popular choices because the battery life of Weightless W is shorter.

    Why choose LoRaWAN technology

    • Ultra-low power: The LoRaWANterminal device can operate in low-power mode and its battery can last up to 10 years without requiring additional maintenance.
    • Remote: LoRaWANgateway is able to transmit and receive signals over ten km in rural areas, and more than three km in densely populated urban areas.
    • Indoor Deep penetration: LoRaWANnetworks is able to offer indoor deep coverage, and easily cover multi-story buildings.
    • Free Spectrum licensing: LoRaWANTechnology operates on free (unlicensed) frequencies, so deploying LoRaWAN networks doesn’t require paying expensive spectrum licensing fees.
    • Geolocation: LoRaWANnetworks is able to use triangulation to determine the location of end devices, without the need for GPS. The LoRa device is able to be located if at least 3 gateways obtained signals from the LoRa
    • High capacity: There is no limit to the maximum number of daily messages, and the LoRaWANweb server processes millions of messages from thousands of gateways.
    • Public and Private deployment: It’s easy to deploy both private and public LoRaWAN networks with the same software and hardware (end devices, gateways, antennas).
    • End-to-end security: LoRaWANutilizes AES-128 encryption technology to make sure secure communication between the application server and end device.
    • Firmware air update: You can remotely update the application and LoRaWANstack for a single or a group of end devices.
    • Roaming: LoRaWANterminal devices are able to seamlessly switch from one network to another.
    • Low cost: Due to its simple architecture, LoRaWANNetwork is considered low-cost end-node and open-source software.
    • Certification Program: The LoRaConsortium certification program authenticates end devices and offers end users confidence that the devices are compliant and reliable with the LoRaWAN
    • Ecosystem: LoRaWANhas a very large ecosystem of gateway manufacturers, device manufacturers, antenna manufacturers, application developers and network service providers.
    • Open: An open federation, an open standard, unlike Sigfox, which is a proprietary networking standard.

    Some disadvantages of LoRaWAN that you might need to consider

    • LoRaWAN Technology is not used for large data payloads, which have a payload limit of 100 bytes.
    • With the exception of Class C devices, LoRaWAN technology is not intended for continuous monitoring.
    • Not a good fit for real-time applications that require limited jitter requirements and low latency.
    • As gateways are deployed in large numbers in urban areas, the proliferation of LoRaWAN presents coexistence challenges.
    • The disadvantage of the open frequency is that it can be interfered with and the data rate can be very low.

    LoRa and LoRaWAN across the globe

    LoRa network is a cheaper option for cellular connectivity and is seen as an add-on on top of cellular, Bluetooth, and WiFi(each with its own typical use cases). LoRaWAN technology has been promoted worldwide, and many countries have even adopted this technology in various industries on a national scale. The following data is from several years ago, and as you can imagine, LoRaWAN’s prospects are very optimistic given this trend.

    • The Netherlands announced the previously mentioned national LoRanetwork at the end of June.
    • Belgium introduced LoRaWANnationwide at the end of 2016.
    • France began deploying LoRaWANnetworks in 18 urban areas in the first quarter of 2016 and will extend LoRa coverage nationwide by the end of 2016.
    • Italy fully covered the LoRaWANnetwork in 2017.
    • Germany rolled out LoRaWANnationwide in 2018.
    • The United States has used LoRa(WAN) in North America since June 2016, covering more than 100 cities in the United States and doubling the population in 2017.
    • LoRaWAN’s network in New Zealand already covers half the population.
    • Japan has also followed the trend of deploying LPWAN networks using the LoRaWAN
    • India had announced in late 2015 that LoRaWANnetwork will be deployed.
    • The LoRaWANIoT network deployed nationwide in South Korea covers 99% of the population.

    Continuous encryption of the transmitted user data

    In contrast to other protocols proposed for the IoT, LoRaWAN offers end-to-end encryption of the application data – right down to the cloud servers that are used to manage and provide the services. In addition to end-to-end encryption, LoRaWAN technology ensures that every device connected to the network has the required credentials and lets IoT nodes check whether they are not connecting to a gateway with a false identity. To ensure the required level of authentication, each LoRaWAN device is programmed during production with a unique key, which is referred to in the protocol as an AppKey.

    The device also has a unique identifier worldwide. To make it easier for devices to identify their gateway connections, each network has its own identifier in a list managed by the LoRa Alliance. Computers that are identified as join servers are used to authenticate the AppKey of any device that wants to join the network. Once the join server has authenticated the AppKey, it creates a pair of session keys that are used for subsequent transactions. The NwkSKey is used to encrypt messages that are used to control changes at the network level, e.g. to set up a device on a specific gateway. The second key (AppSKey) encrypts all data at the application level. This separation ensures that the user’s messages cannot be intercepted and decrypted by a third network operator.

    Another level of security is achieved through the use of secure counters that are integrated into the message protocol. This feature prevents packet playback attacks in which a hacker intercepts packets and manipulates them before feeding them back into the data stream. All security mechanisms are implemented via AES encryption, which has been proven to guarantee a high level of security. Due to its nationwide supply, energy efficiency and security, LoRaWAN technology is suitable for many applications as a protocol for setting up IoT networks.

    12 use cases of LoRaWAN technology

    The following LoRaWAN use cases may give you some idea of how to use LoRaWAN:

    1. Vaccine cold chain monitoring – LoRaWAN sensors are utilized to make sure that vaccines are maintained at a specific temperature during transport.
    2. Animal and asset tracking – LoRaWAN-based tracking sensors manage endangered species and valuable antiquities collections.
    3. Protection for the elder living alone– Wristband sensors can provide fall detection and medication tracking.
    4. Smart farms – Real-time insight into crop soil moisture and optimized irrigation schedules can not only reduce water consumption by up to 30% but also produce better crops.
    5. Water-saving– LoRaWAN-based water sensors can identify and repair leaks in urban water supply networks faster.
    6. Food safety – Temperature and humidity sensors ensure food quality by monitoring temperature changes in real-time.
    7. Smart bins– Bins level alerts are sent to employees regularly to optimize recycling schedules.
    8. Smart bike– LoRaWAN-based bike tracker tracks the location of bikes in dense buildings and remote areas.
    9. Airport tracking– GPS-free LoRaWANsensor monitors vehicles, people and luggage.
    10. Effective workspaces– Room occupancy, temperature and humidity, parking availability and energy use and monitoring.
    11. Animal health– LoRa sensors monitor animal health, detect disease and predict calf delivery time.
    12. LoRa in Space – A satellite providing global coverage based on LoRaWAN.

    MOKOSmart’s LoRaWAN solution includes LoRaWAN end-node devices, LoRaWAN gateway, and LoRaWAN module. Our common applications are for COVID-19 support, smart agriculture, smart city, smart building, smart home, smart retail, smart metering, smart healthcare, smart industrial control, smart logistics, and smart parking. Our End-node devices include LoRaWAN Motion Sensor, LoRaWAN GPS Tracker, LoRaWAN T&H Sensor, LoRaWAN Bluetooth Gateway, LoRaWAN Panic Button, and LoRaWAN contact tracker. Contact us now and let us see which solution suits best for you!

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