Discover a new article in this Hub about IoT Network !
As stated earlier in this document, IoT is not a single system and is not defined by a common standard. Specific applications, usages, needs, network range, network topology, power source and throughput drives organizations to publish their own IoT “implementation” of those standards.
Even though the IoT Network layer will be made of different technologies, we believe that:
- Wireless networks will be a key component of the IoT network layer
- Software in the IoT network layer will take more and more importance as it holds a lot of value in the overall IoT value chain across the layers. We would not be surprised to see pure software players being attracted by this layer and pure networking players facing commoditization of their hardware and software.
Analog manufactures often don’t consider the network when designing their products. Instead, they need to understand the importance of the network layer, not just as a source of bandwidth, but as an enabler of value by providing enhanced stickiness between their products and the associated network.
To illustrate the importance of this layer and the need to correctly address it when designing IoT devices and gateways is number of network topologies that can be leveraged. Use cases have a direct impact on which network topologies needs to be used. Some network topologies will be enablers for better connectivity, bandwidth, security in one use case while be a bottle neck on another use case.
Here are some network topologies :1-Network topologies
When designing IoT products or transforming an existing analog product portfolio, one must understand where the product or the range of products fits into this wireless network landscape. This is because connectivity will be one of the minimum requirements products will have to comply with and also because wireless networks enable far more flexibility than wired networks.
Unfortunately, the wireless landscape is made up of so many acronyms and protocols that it is necessary to clarify what are the most relevant and how to leverage those wireless protocols to transform and connect your current analog portfolio.
To begin classifying the most known technologies and protocols, we will use network range as a first filter. A network range is typically categorized into 5 classes:
- Proximity, body area networks – covers all wearable devices (including implants, surface mounted on the body, etc.)
- WPAN: Wireless Personal Area Network – covers a range of about 10 meters to 100 meters
- WLAN: Wireless Local Area Network – covers a range of about 100 meters to 1000 meters
- WNAN: Wireless Neighborhood Area Network – covers a range of about 1000 meters to 10 km
- WWAN: Wireless Wide Area Network – covers a range above 10km (as big as the entire globe of needed
Transforming an analog offer portfolio into an IoT offer portfolio requires choosing very carefully which protocols you want to leverage and which applications you want to serve. Applications such as automotive, asset tracking, industrial networks, connected homes, smart grids and so forth require very different geographic coverage, network topologies and functionalities.
There is still an important fragmentation of the industry which in turns sees increasingly more Alliance/consortium type of organizations pushing for their own open stack/framework, which are very often proprietary, to get standardized and build an ecosystem of companies as part of their activity.
Below are descriptions of the key wireless technologies that appear to be leading the pack when looking at them from an IoT perspective (we will be using the network range as a filter):
IoT Network : Proximity Network
NFC (Near Field Communication)
NFC allows two-way indications between electronic devices, especially smart phones, to transfer digital contact information with applications such as contactless payment transactions, opening doors with secured NFC door locks, and connection to computers.
NFC has a range of less than 4 cm.
RFID (radio frequency identification)
RFID allows memorization and recovery of the digital information thru tags (active and passive) and tag readers. The main application of RFID technologies is for identification and tracking purposes (objects, animals, persons). There are different set of standards specific per industry and set by separate organizations such as the International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC), the DASH7 Alliance and EPC global.
RFID passive tags have a typical range of about 1cm up to 5 meters; RFID active tags can reach up to 100 meters.
IoT Network : WPAN (Wireless Personal Area Network)
Bluetooth enables simple and low cost-efficient connections between mobile phones, smart things, and wearable products into small personal network, also called piconet. In the IoT space, Bluetooth technologies will typically be used to easily connect two devices that can deal with minimal configuration, and low speed such as thermostats, telephones, tablets, headsets, watches, and light switches.
The Bluetooth Special Interest Group (SIG) is the caretaker and creator of the core specification and service. There are mainly 2 types of Bluetooth: Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) for short-range continuous connection and Bluetooth with low energy (LE) for short bursts of long range connections. BLE uses IEEE 802.15.1. You will need different chips to leverage those implementations or chose dual-mode chipsets.
Bluetooth has a range between 1 cm up to 100 meters.
Thread is a recent royalty-free open standard protocol stack, introduced in 2014 by the “Thread Group” alliance (https://threadgroup.org/), and based on multiple standards which include IEEE802.15.4, IPv6 and 6LowPAN. It is reliable, cost-effective, low-power, wireless D2D (device-to-device) communication designed for Connected Home applications. The most interesting facts about Thread is that it supports mesh networks and can support up to two hundred and fifty nodes with authentication and encryption; also, it defines a portion of a typical IoT stack in a simple and quite elegant way. This will help IoT device manufacturers focus on their product rather than spending time on redefining IoT stacks.
Thread is becoming one of the most used stacks for the IoT for home automation in much the same way as the standard TCP/IP stack has been for the internet.
Thread Wireless range is about 120 feet or 40 meters. It can support up to 250 devices on a single meshed network.
ZigBee PRO (http://www.zigbee.org) from the ZigBee Alliance (consortium of manufacturers & developers) is a proprietary protocol stack using open standards. Its main objectives are to address low data-rates, low-power consumption meshed and star networks in particular commercial building automation and lighting control solutions. ZigBee PRO leverages the IEEE 802.15.4.
Zigbee has a wireless range up to 70m indoors and 400m outdoors. It can support over 65,000 devices on a single network.
Z-Wave is a wireless communications protocol for home automation and small commercial buildings mainly aimed for products which don’t require a lot of power such as sensors and LEDs. Z-Wave leverages the IEEE 802.15.4 standard. The Z-Wave Alliance was established in early 2005 and groups more than 450 companies.
Wireless range of Z-Wave is about 120 feet or 40 meters. The maximum range with 4 hops is roughly 600 feet or 200 meters. It can support 255 devices on a single network.
EnOcean technologies are intended to leverage energy harvesting such as slight vibrations, temperature difference, and light in order to obtain self-powered wireless networks. The technology is typically used for home automation and commercial buildings. The technology has been ratified in 2012 by The International Electrotechnical Commission (IEC).
EnOcean Wireless range is about 100 feet or 30 meters in buildings and can range up to 1000 feet or 300 meters outdoors.
IoT Network : WLAN (Wireless Local Area Network)
Wi-Fi & Low Power Wifi – 802.11ah
Wi-Fi® leverages the Institute of Electrical and Electronics Engineers‘ (IEEE) 802.11 standards and is widely used because of its interoperability and also the fact that it can handle fast data transfer and large quantities of information. Wi-Fi Alliance® drives the adoption and evolution of Wi-Fi globally. Wi-Fi® is a trademark of the Wi-Fi Alliance®.
There are currently multiple protocols version in use such as 802.11a, 802.11g, 802.11n, etc.
Wi-Fi® will be a key component of the IoT network infrastructure due to the need to have fast wireless data transfer but has, unfortunately, a major disadvantage: it requires high power consumption which makes battery life in IoT devices a concern.
The Wi-Fi Alliance® introduced in 2016 an extension of Wi-Fi®: 802.11ah, also called Wi-Fi HaLow™, intended to answer to the specific needs of the IoT in, for example, connected homes, connected cars, Smart Cities: low energy and extended range.
Wireless range of Wi-Fi HaLow™ is expected to reach 1600 feet or 500 meters.
DASH7 is based on the ISO 18000-7 Active RFID standard and is managed by the DASH7 Alliance similar to what the Wi-Fi Alliance® does for the Wi-Fi®. Dash7 is intended for building automation, connected homes, logistics, automotive, etc. It differentiates from Wi-Fi and Bluetooth by the fact that it provides longer range and has a very good behavior in indoors environments.
Dash7 is aiming at reaching between 300m and up to 1/5 km ranges. That range is much larger than the likes of ZigBee, but less than the maximum ranges quoted by Sigfox and LoRa.
IoT Network : WNAN (Wireless Neighborhood Area Network)
Wi-SUN has the same objectives as other industry alliances such as the Wi-Fi Alliance® (who own the Wi-Fi trademark and leverages the IEEE 802.11 standard) or the WiMAX forum (who own the WiMAX trademark and leverages the IEEE 802.16 standard): be a certifying authority for interoperability testing focused on IEEE 802.15.4g and ipv6. IEEE 802.15.4g is an enhancement of the 802.15.4 towards large scale process control applications typically used in smart utilities networks (SUN) and smart grid networks.
JupiterMesh, also called ZigBee-NAN, is the intent of the ZigBee Alliance to expand beyond their short-range market. It’s a mesh protocol using the 802.15.4g standard, as the Wi-SUN Alliance and was announced in June 2016.
It is difficult to list all existing IoT “compatible” protocols as we consider the IoT being an evolution of the M2M market. There are multiple other wireless networking technologies such as ISA100.11a and WirelessHART for industrial applications for example.
IoT Network : WWAN (Wireless Wide Area Network)
The WWAN is currently where the most important battle is taking place with very different strategic choices. We consider that, as we write this book, there are mainly 5 main technologies/approaches:
Sigfox is both a network and a privately-owned company. Its aim is to become a global Internet of Things service provider (93). SigFox uses the Ultra Narrow Band (UNB) – sub GHz ISM band, which is a free frequency band. A Sigfox gateway can handle 1.3 million messages per 24 hours maximum, thus if each object transmits 10 messages per day this would be 130K objects. The network redundancy is achieved by overlapping cells coverage of 3 gateways. As the spectrum usage is not optimized this mean any message use the spectrum available to 3 gateways and thus its cell capacity is approximatively 130K / 3 = 43K objects/cell. A cell’s range, in rural areas, is between 30 to 50 km and in urban areas between 3 to 10 km. The standby time for a 2.5 Ah battery with a SigFox access is about 20 years.
LoRaWAN ™ (Long Range Wide-area network) s an open global standard for wireless communication drive by the LPWAN industry through the LoRa Alliance™. The Alliance’s aim is to provide both a standardized framework as well as it’s associate technology hardware bricks that can be used by companies to guarantee interoperability (94); it has 500 members, covers over 50 nationwide deployments, 150 countries with smart city/enterprise networks and has over 100 LoRaWAN certified solutions. The LoRa Intellectual Property is owned by Semtech® who have invested around 300M$ in the technology and it is estimated some 100.000 developers are working on LoRa centric solutions. Semtech has licensed LoRa Intellectual Property to companies like Microchip and ST Microelectronics in order to ensure no single sourcing exists anywhere in the value chain. LoRa leverages the Ultra Narrow Band (UNB)-sub GHz ISM band which is free frequency bands. It’s cell capacity is around 40,000 objects/cell and has a throughput of between 300 bps to 50 000 bps. The cell’s range is, in rural areas, around 15 km and in urban areas, between 2 to 5 km. The stand by time for a 2.5Ah battery is about 20 years.
In an interview done by the author in November 2017 with Ir Jaap Groot, VP of Business Development at Semtech and Board Member of the LoRa Alliance, he stated that: “When you compare LoRA power consumption to cellular IoT technologies (LTE-M/NB IOT), LoRa is 5 to 10 times more power efficient in transmit and sleep, its peakpower (important for battery dimensioning and cost) is about 5 times lower than its cellular compagnons. One should position the cellular IoT and LoRa as complementary, hence many operators choose to deploy LoRa next to LTE-M. Important scalability for LoRa comes from the adaptive data rate, controlling the transmission speed (Kb/sec), which makes the networks infinitely scalable as the objects connect only to those gateways they need to (the higher the bitrate the lower the distance). A derived benefit is that LoRa can be deployed in very small gateways such as USB keys, set top boxes, routers and also Wifi hotspots. Other features include full bidirectional support, firmware or application updates over the air, geolocation without GPS and embedded security. On capacity the same argument as above, best measured by number of messages in uplink and downlink as objects differ in transmission frequency and the real limiting factor is time on air. However due to the adaptive data rate there is no limitation, when capacity is needed operators deploy new gateways, indoor, outdoor or even as USB keys in routers. Most important argument for cellular IoT versus LoRa is the fact one does not need licensed spectrum, hence the subscription can be a factor lower then cellular IOT and basically anyone can deploy a network.’”
Ingenu is a privately-owned company that provides an entire stack for wireless networks based on their proprietary RPMA® (Random Phase Multiple Access) technology as well as a public network The Machine Network™ that can be used to sign up RPMA® enabled devices.
Ingenu leverages the Ultra Narrow Band (UNB)-2.4 GHz b which is a free frequency band. RPMA® cell capacity is around 500,000 objects/cell and has a throughput of about 625 000 bps. The cell’s range is in urban areas around 15 km.
LTE-M, NB-Iot and EC-GSM-IoT
LTE-M, NB-Iot and EC-GSM-IoT are evolutions of existing mobile/cellular technologies for existing cellular network operators to leverage their existing geographic base stations’ footprint, private radio spectrum (which ensures no coexistence issue with other cellular networks) and market access. EC-GSM-IoT (Extended Coverage GSM for IoT) is an improvement of GSM technologies due to the fact that GSM is still a dominant mobile technology in numerous markets. It also enables operators to extend the usage of their important 2G legacy installed base. eMTC (enhanced Machine Type Communication, often referred to as LTE-M) and NB-IoT (Narrow Band Internet of Things) can be deployed together with legacy Long Term Evolution networks, or as stand-alone, in a reframed GSM carrier. They require a software upgrade of their existing network infrastructure.
Weightless technology is being driven by the Weightless Special Interest Group (SIG). The SIG’s objectives are to globalize the Weightless open standard as an alternative to short range IoT wireless technologies as well as 3GPP technologies (EC-GSM-IoT) and LTE based variants (LTE-M and NB-IoT).
There are different Weightless standards: Weightless-W, Weightless-N and Weightless-P.