Certify or not?

First ever LoRa product passed LoRaWAN protocol compliance certification tests in Espotel laboratory earlier this week. The LoRa Alliance will ratify certifications and publish them, thus I post no names here yet.

LoRaWAN introduction video in Youtube by LoRa Alliance.

Device manufacturer may wonder whether it is mandatory to certify every LoRa product? Yes and no. The cleverness of the LoRa technology is that it enables both public and private network use. Public network is like cellular network, there is an operator in place which provides commercial connectivity service. Private network is more like setting up your own WiFi access point - You do not need to ask permission to do so and you don't pay anything for the use of the wireless connectivity.

Why to certify? Public network operators want to ensure compatibility in between end-nodes and gateways, as well as guarantee quality of service. The end-device must meet certain minimum specifications, otherwise operator can not guarantee any performance level. If connectivity is bad, customer thinks it's operator's fault, not due to the device itself. These are the reasons why most public network operators require that every connected device must be LoRaWAN certified.

In case of private network use, there is no law that requires you to certify any product. It's your gateway and your device, you can do whatever you wish as long as regulatory requirements are met. Regulatory requirements means that product is CE labeled in the EU or FCC approved in the US. Regulatory requirements typically define things like maximum transmit power, maximum bandwidth and maximum duty-cycle.

The dual nature of the LoRa technology - managed for public use and license free for private use enables also new types of operations, crowdsourced Internet of Things like The Things Network which is a new type of establishing connectivity. The Things Network is based on voluntary network sharing. You may set up a gateway to get IoT connectivity for your devices, and simultaneously provide it for your neighbors. There is no central control, it's an anarchistic model - you do not need to set up a gateway of your own to benefit from connectivity provided by others. This is fundamentally different to many of the similar WiFi network sharing services introduced in the past.

In order to use crowdsourced network like The Things Network, the end-device must be LoRaWAN compatible - otherwise it just simply doesn't work. However, as it open to everybody without centralized control, there is nobody who could require and verify LoRaWAN certification for end-devices. In private networks even LoRaWAN compliance is not mandatory. Connectivity can be established directly a top of LoRa MAC, assuming your gateway supports that.

Professional customers who prefer to have certain SLA for the network service and wish not to trust on good will of people in the neighborhood, must use public service provided by commercial operators. For that the device manufacturer must get LoRaWAN certification to the product. And that means it's good time now to be a LoRa certification laboratory... :-)

PS. Frequently asked questions on LoRaWAN certification at Espotel site:
http://www.espotel.com/-/lorawan-certification-frequently-asked-questions

LoRaWAN certification

Lora Alliance All Member Meeting & Open house took place in Rotterdam this week. The board of alliance acknowledged Espotel and IMST as the first official certification test houses.

 Press release:

The LoRa Alliance Launches the LoRaWAN™ Certification Program End Device Interoperability to Enable Global Scalability for the IoT

SAN RAMON, Calif. - November 10th, 2015 - The LoRa Alliance is one of the fastest growing Internet of Things (IoT) alliances. It has drawn over 130 members since March 2015 and today announced the launch of the LoRaWAN™ Certification Program. The launch announcement was made at the 3rd European Open House Meeting in Rotterdam, Netherlands, and will ensure interoperability between end devices and LoRaWAN™ networks.

The LoRa® Alliance has a mission to ensure that the open LoRaWAN™ specification for secure, carrier grade, low power wide area networks (LPWAN) will enable all end devices to behave in a predetermined way when connected to a LoRaWAN™ network and interoperate with all gateway products. The Certification Program will provide assurance to end customers that their application-specific end devices will operate on any LoRaWAN™ network, which is a crucial requirement for the global deployment of the IoT using LPWANs.

The scope of the Certification Program will be to confirm that the end device meets the functional requirements of the LoRaWAN™ protocol specification, and will include a suite of tests that are specified in the LoRa® Alliance End Device Certification Requirements document. A device manufacturer must be a member the LoRa® Alliance to be LoRa® Certified and must use one of the accredited LoRa® Certification test houses to do the functional protocol testing. On completion of the tests the results will be listed on the LoRa® Alliance website, and upon compliance a LoRa® Certification certificate will be issued by the LoRa® Alliance. All LoRaWAN™ Certified devices will be listed on the Alliance website and there will not be a fee for the listing. The LoRa® Certified end devices are listed in a product catalogue and a portal on the website to enable visibility will be available by year end.

"This is a major milestone for the LoRa® Alliance in the adoption of LoRa® technology as a mature standard and will enable end device manufactures to have fully compliant LoRaWAN™ Certified products. The certified device will also ensure quick and easy integration into any LoRaWAN™ network," said Derek Hunt, System Solutions Director at Semtech and Certification Committee Chair for the LoRa® Alliance.

Two LoRa® Alliance members, IMST and Espotel, both respected test houses, have already implemented test suites to perform the testing and are accredited by the LoRa® Alliance. Both companies also offer RF or regulatory compliance testing and additional services for the end devices if required. "LoRa® is one of the most promising radio technologies for IoT solutions and we see plenty of great opportunities for this technology in Industry, utilities and logistics. Espotel provides engineering services, laboratory services and entire IoT systems, including cloud services, for customers willing to create LoRa® based services and solutions," said Espotel CEO Kari Liuska. "The LoRa® technology provides ultra-long range spread spectrum communication and high interference immunity whilst minimizing current consumption. Nevertheless, the individual device needs to be tested to ensure compliance to the LoRaWAN™ specification, enabling a smooth integration into bigger networks. IMST is working with LoRa® for more than three years and provides first-class LoRa® solutions for customers all over the world," said IMST Head of Test Centre Markus Ridder.

About LoRa Alliance
LoRa® Alliance is an open, non-profit association of members who believe the Internet of Things era is now. Our mission is to standardize Low Power Wide Area Networks (LPWAN) to enable the Internet of Things (IoT). The Alliance members collaborate to drive the global success of the LoRaWAN ™ secure, carrier grade protocol by sharing knowledge and experience to guarantee interoperability between operators in one open global standard. Now having gained over 130 members since March 2015, with nine announced operator networks and 56 operator networks in trials, it is the most widely deployed LPWAN technology.

About LoRaWAN™
The technology utilized in a LoRaWAN™ network is designed to connect low-cost, battery-operated sensors over long distances in harsh environments that were previously too challenging or cost prohibitive to connect. With its unique penetration capability, a LoRa® gateway deployed on a building or tower can connect to sensors more than 10 miles away or to water meters deployed underground or in basements. The LoRaWAN™ protocol offers unique and unequaled benefits in terms of bi-directionality, security, mobility and accurate localization that are not addressed by other LPWAN technologies. These benefits will enable the diverse use cases and business models that will enable deployments of LPWAN IoT networks globally.

About Espotel
Espotel is a leading provider of R&D services for embedded systems, industrial internet applications and test systems for industrial, telecom, medical and defense technology sectors. Positioned at the edge of new technology with such leading technology partners as IBM, ARM and National Instruments, and with strong roots in the development of electronic devices and systems, Espotel has created a wide international customer base. Espotel has offices in Finland, Poland and Sweden. Today Espotel employs about 300 professionals in the field of electronics, embedded systems and industrial internet development. With a turnover of 25 million euros in 2014, the company is showing continuous growth and profitability, enabling the development of technological expertise and excellence at customer service. www.espotel.com

About IMST
IMST GmbH is a leading design house and development center for wireless modules, communication systems, chip design, antennas, EDA software, and regulatory certification using an in-house accredited/certified regulatory test center. IMST offers both standard products such as radio modules with hardware/software as well as complete system and product design. Individualized support during every phase of product development including wireless technologies, from initial consulting to series production is one of the unique selling propositions of IMST. For more information, visit http://www.imst.com

Espotel LoRa platform now released

I'm most proud to announce that the ARM mbed enabled LoRa prototyping platform from Espotel is now officially published and live at ARM mbed platforms site. The purpose of the platform is to enable rapid prototyping and small scale piloting, and serve as reference design for development of full custom products.

Espotel LoRa platform at ARM mbed.

ARM mbed is software platform for embedded devices. It provides drivers and hardware abstraction layer (HAL), and development environment in cloud hosted by ARM. For professional development it is possible to install the compiler and software version control system on your own server and still benefit from the software provided by ARM.

At the moment there are 9 silicon vendors, 23 hardware platform vendors, and 71 boards listed in the public mbed catalog, and the number is increasing. mbed is similar to the popular Arduino in the sense that it enables easy start of embedded software development for prototyping, evaluation, hobby and eductional purposes. Unlike Arduino, mbed is also good for professional use and mass-production. And it provides support for much wider selection of silicons and boards.

Arduino form-factor is sort of de-facto standard among many prototyping boards, including ST Nucleo, Freescale FRDM, NXP LPCxpresso and many more. This makes it possible to use any Arduino-compatible extension shields from 3rd party vendors, including sensors and interface boards.

Special feature in Espotel platform is double Arduino headers for both master and slave use. It can be used either as LoRa interface shield for external MCU board, having application software and protocol stack running in separate MCUs, or as master with both application and protocol stack integrated and running in the same MCU. In both cases other extension shields can be used as well.

LoRaWAN compliant software stack with example applications is available as open source via the mbed web site. The LoRaWAN implementation is based on IBM LMIC distributed by Semtech. The board is confirmed to inter-operate with Multitech and Kerlink LoRa gateways, and it can be also used in point-to-point mode with LoRaMAC layer.

Key Benefits

• ARM® mbed™ IoT Device Platform
• Powerful ARM® 32-bit Cortex®-M4 CPU with FPU
• Semtech SX1272 Low Power RF Transceiver for 860-1020MHz with LoRa™ modem
• On-board detachable PCB antenna for 868 MHz
• Break-out module design for easy integration into existing applications
• High Sensitivity: down to -137 dBm
• LoRa™ bitrates of 0.24 – 37.5 kbps depending on bandwidth and spreading factor
• 127dB Dynamic Range RSSI
• FSK, GFSK, MSK, FMSK, LoRa™ DSSS and OOK modulation
• Multiple available interfaces (digital I/O, ADC, SPI, I2C and USART)
• Wide Supply Voltage Range: 1.8V-5.5V

Features

• ARM® mbed™ platform
• Modulation: FSK, GFSK, MSK, FMSK, OOK and LoRa digital spread spectrum
• Frequency: 860 - 1020 MHz
• XBee and module versions for development and deployment
• Low power mode extends battery life
• digital I/O
• analog
• SPI
• I2C
• UART

LoRa under cover

This time we put LoRa underground, reading water meter 2 meters below the surface. Other technologies including cellular data and 2.4GHz had already proven to fail with this task. Let LoRa proof its capabilities.

Well located at parking lot.

It this test, a water meter is located in an infrastructure well located at parking lot. The well has heavy cast iron lid and also all-metal collar for depth of 25 cm. Walls of the well are made with concrete rings. The water meter is at the bottom of the well, approx. 2 meters in depth. 

Water meter at the bottom of the well.

We build a demo setup with Multitech Conduit LoRa gateway, and mDot integrated with Raspberry Pi and M-BUS master interface, all put in an IP-classified plastic box. The box is well over-sized, but there is good space for battery. The LoRa transmitter in the "shoe-box" is interfaced with the meter over wired M-BUS. RF transmit power is 14dBm and spreading factor 12.

LoRa transmitter and gateway.

The transmitter was located next to the meter at the bottom of the well. The LoRa gateway was located in a meeting room inside a nearby building. The line of sight between meeting room and the well was blocked by a storage wing covered by metal plates.

Building where the gateway was located.

Distance of the well and the building is approx 25 meters. For realistic condition, the lid was closed tightly and a van was parked above the well. In the direct line between transmitter and receiver, there is several meters of soil, metal cage, brick wall and concrete floor.

Diagram of the test setup

And the results? Excellent!

Received signal strength is approx. -105dBm, which gives wide margin left. The gateway could be located much further away. We also tested signal coverate inside the office building and got it all covered from the same gateway location, 100 meters through several steel reinforced concrete floors and brick walls.

What's the meaning of all this? In an automated meter reading application, whether water, electricity or other types of meters or sensors, even a large complex with outdoor environment and difficult locations like basements and underground locations, it all can be covered with a single gateway located pretty freely in most convenient location. Outdoor wall installation or other difficult to reach position is not necessary.

This time we didn't tested the maximum distance from the well where the signal can be detected, as the results were good enough for the purpose of the trial.

New challengers entering IoT connectivity market

IoT connectivity market is far from mature. New challengers are popping up every now and then. The latest was announced Today, when Intel, Nokia and Ericsson released their co-op in a new mobile radio technology called Narrow-Band (NB) LTE-M for Low Power Wide Area IoT communication.

Like the name says, NB LTE-M is narrow-band version of the LTE-M. NB uses 200 kHz band where as the normal LTE-M consumes 1.4MHz. Both versions can co-exists without interfering each others. The purpose of the narrower band is to reduce end-device power consumption and cost. Intel says it will launch low-cost and low-power chips for IoT market using the new technology. What does that mean in numbers remains to be seen.

LPWA IoT Connectivity Overview
Nokia White Paper - LTE-M – Optimizing LTE for the Internet of Things

Technologies listed in the comparison above are all intended for public networks. LoRa is the only one which is available for private network applications also. That means you can set up a LoRa gateway of your own just like using WiFi. Sigfox is closed and propriterary technology, and use of licensed frequency bands means you got to be an operator to get the license in hand.

The greatest weakness of LoRa technology is the use of unlicensed frequency band. In Europe, the duty-cycle limitation is only 1%. That's regulatory not technology limitation. It does not affect much the downlink or uplink of many IoT applications, but over-the-air firmware updates are very difficult, next to impossible. It would take awfully long time to transfer any reasonable sized firmware. Perhaps some clever delta (diff) technology for patching the device firmware image could work.

 The above comparison is missing energy consumption. It seems to be difficult to find comparable numbers for real energy (J) consumption per delivered payload with different technologies. Mobile data suffers from significant overhead in terms of channel opening, handshaking, etc. Most of the energy is consumed by other functions than transmitting/receiving the actual payload data. As an opposite, LoRa introduces very low overhead. Any technology can provide battery life of over 10 years, it's only question of how much batteries you need.

LoRa is available as of Today. For LTE-M, first device and network manufacturers must introduce new products, then operators must upgrade their base stations. I don't believe LTE-M is really in place next year. Once it's there, the deployment of the technology will be fast for sure.

No convergence of IoT connectivity technologies is visible within the foreseeable future. There are different use cases for different types of radios. Main categories are short range radios (Bluetooth, Wifi, etc), Low Power Wide Area (LoRa, UNB), and cellular data. They have all different nature and no single technology will rule them all.

Conduit LoRa gateway and Espotel LoRa device supporting ThingPark

Multitech MultiConnect Conduit is latest LoRa gateway supporting Actility's ThingPark LoRa Network Server. I just got one of the very first setups.

Conduit gateway connected to ThingPark.

Recently Actility and Multitech created a custom firmware for Conduit to provide connectivity to ThingPark backend. Thanks to that, now there exists cost-efficient alternative gateway available for LoRa networks operated with ThingPark network management solution. Conduit may improve indoor coverage of public LoRa networks, or it can be used in private network installations. Later this year Multitech will introduce outdoor installation kit with IP-classified chassis and optional solar power pack.

Multitech and Kerlink gateways listed in my ThingPark account.

Espotel recently joined Actility's ThingPark certification program. The aim is to provide end-devices compliant with the ThinkPark network management solution. Espotel is now finalizing it's own LoRa reference design, nickname "ELMO" (Espotel LoRa Modem), which is Arduino form-factor compatible prototyping device.

Espotel LoRa Modem "ELMO"

ELMO will be LoRaWAN certified and tested against Actility's requirements. Right at the moment our engineers are working to introduce ELMO as public platform in ARM mbed development environment.

ELMO has dual Arduino-pinheaders. This enables function as a master or slave. ELMO can be used as LoRa-shield for external MCU boards, like STM32-Nucleo, Freescale FRDM, or Arduino. ELMO also supports integration of application software and protocol stack into one and running them both directly in ELMO's own MCU without external MCU needed. In both scenarios, 3rd party shields can be used to provide additional interfaces and sensors.

LoRa Network Server

When asking what is LoRa, you may get several different answer. One thinks it's  essentially the LoRa modulation, giving the extraordinary radio performance. Other one says it's the LoRaWAN protocol, as that is the only well specified part of the system. Third one may consider it's all about the Network Server where all the network management functionality is implemented.

LoRa network architecture. Source: Semtech 

.

In LoRa networks, especially when considering public network approach, the Network Server plays central role. Gateway is intended to be a simple packet forwarder and thus being inexpensive part of the system. At the moment there are three network server providers:

• Actility ThingPark  
• IBM LRSC
• Orbiwise UbiQ

Actility is perhaps the leading supplier with most commercial deployments in place at the moment. Espotel recently joined Actility's certification program in order to ensure end-devices are compatible with the ThinkPark back-end.

LoRaWAN certification acknowledged by the LoRa Alliance guarantees interoperability of end-devices with any gateway manufacturer. However, LoRa Alliance  does not specify the interface towards Network Server, thus it is implementation specific. That's why different back-end providers may have their own certification programs, like Actility does.

Kerlink outdoor gateway and LoRaMote test device with IMST LoRa module
as part of ThinkPark certification program content.

The test network is very easy to set up. The supplied gateway is pre-configured to ThingPark and requires no user configuration at deployment, just blug & play. Power-over-Ethernet with provided power injector makes cable installation easy. Only internet connectivity is required. There also exists variant with cellular data modem instead of Ethernet.

Screenshot of ThingPark DeviceManager web interface.

Edit 2015-8-26:
According to the feedback I have received, there are several other Network service providers emerged, including Lace, Loriot, Senetco, and The Things Network. I consider that as positive sign, meaning there are many parties who believe in LoRa technology. The ecosystem is stronger all the time.

Lora Network Coverage

Espotel LoRa network covers most of Espoo populated area with cell diameter of 20 km. Tested performance exceeds initial estimation.

Once the gateway passed solar powered test period, it was erected to it's final position at the highest point at roof-top of Espotel HQ, some 6 meters higher than previously in a more difficult to reach location some 15-20 meters above the ground.

Now more comprehensive network coverage test was performed. The testing focused on uplink performance. Results with distances from the gateway:

• 10 km - Stationary nodes in good position with proper antenna
• 7.5 km - Vehicle mount with external antenna
• 5 km - Indoor coverage with dipole antenna
• 2.5 km - Indoor coverage with integrated antenna

Espotel LoRa network coverage.

The network covers majority of the city of Espoo with more than 90% of it's population. Communication is possibly also in western parts of Helsinki downtown and from tall buildings further away. The map indicates circles with radius of 10km, 7.5km, 5km and 2.5km. 

868 MHz half-wave dipole antenna with magnetic mount at car roof-top.

Testing was performed using standard type 868 MHz half-wave dipole antenna mounted at vehicle roof-top with magnetic mount. Multitech mDot Lora-module was used with default parameter configuration.

Within distance from 7,5 to 10 km it was possible to communicate from car to the gateway every now and then, but in practice the reasonable maximum distance is about 7,5 km due to increased packet-loss ratio while distance increases.

Espotel engineer installing the gateway in it's new location.

First LoRa network now open

Espotel has released first open LoRa network in Finland for developers' and hackers' use.

The first gateway is located at the roof of Espotel HQ in southern Espoo.The network is intended for promoting LoRa RF technology and is open and free of charge for all development and test purposes. The gateway will be open for limited period of time and closed down when commercial public networks are available or winter blocks the energy source of the gateway, which ever comes first.

Solar powered LoRa gateway at the roof of Espotel HQ.

The gateway is solar powered in order to emphasis the low power nature of LoRa RF technology. The gateway has solar cell with 50W nominal power and 75 Ah battery that provides run time of one week without sun. That's necessary as the weather in Finland is often cloudy and there may be number of rainy days in a row.

At the moment the gateway is not at the highest possible location but in easy to access location, due to test run period ongoing to see whether the solar cell capacity is high enough. Even if the sun may shine in Finland up to 24h per day at Summer time, it's most of the time shining from wrong direction to the panel. Motorized panel with 360 degree rotation capability would be needed to utilize the full potential of mid-night sun.

I performed the first signal strength test Today while driving home from the office. With LoRa node in my car, I got signal transmitted some 6 km away from the gateway. The node had +14dBm TX power and quarter-wave dipole antenna. Once the gateway antenna will be erected some 5 more meters after solar cell test run, the initially expected 7 km range is most likely. More detailed network coverage map will be published later.

Location of gateway and most distant location from where signal was detected. 7km radius is marked with blue circle.

The gateway is connected to the internet with 3G/4G cellular data modem, and delivers all received data to IBM IoT Foundation and further to Bluemix. From there the data is available either with WebSocket, HTTP or MQTT interface. Tell me your device details and I'll give you access to your data. Currently only upstream data is supported for simplicity sake.

The gateway conforms with LoRaWAN 1.0 specification and LoRa devices are required to do so. Network key, application key and encryption are not defined, all devices and connections are accepted. If you have a cool project in mind, we may even sponsor you some LoRa hardware. Just contact me by email.

Happy hacking!

Driving global success of the LoRaWAN protocol

LoRaWAN 1.0 draft specification has passed the review period within LoRa Alliance, making it one step closer to ratification. As a LoRa Alliance member and in order to increase public awareness of LoRa RF technology, Espotel will launch an IoT campaign for the rest of the year.

Weatherproof LoRa gateway with Multitech Conduit
in a box and improved 868 MHz antenna.

An open and free of charge LoRa gateway located at the roof of  Espotel HQ in Espoo Finland will play central role within the campaign. The gateway is implemented with Multitech MultiConnect Conduit IoT Gateway with LoRa extension, located inside an IP65 classified plastic chassis for weather resistance and connected to Taoglas Omni-directional Outdoor 868 MHz ISM-band dipole antenna. Multitech Conduit gateway and mDot LoRa module conform with the LoRaWAN 1.0 protocol specification.

Expected network coverage spans over the southern part of the city of Espoo, including Aalto University campus in Otaniemi.

Expected coverage of the Espotel open LoRa network.

Espotel will organize and sponsor events like hackathons and other developer-oriented activities in order to provide hands-on experiences with capabilities of the radio technology. ARM mbed development environment makes it easy to start implementing custom applications. As the official ARM mbed Ecosystem partner, Espotel is committed to leverage mbed technology and bring platform support to the environment.

Example device RaspberryPi2 retrofitted with Multitech mDot LoRa module.

Together with technology partners like IBM, Multitech and Semtech, Espotel will organize business events to increase awareness of benefits of LoRa technology among decision makers and influencers within different industries.

Within the LoRa Alliance, Espotel is actively driving LoRaWAN conformance certification process, and intents to be become an Alliance acknowledged LoRaWAN conformance certification house. This is natural extension to the test and certification services provided by Espotel's accredited laboratory facilities in Finland.

This short video (2:33) gives a nice overview of our laboratory facilities. Our reference customer design, Enevo smart waste sensor is acting as a case example of testing service:
https://www.youtube.com/watch?v=JaU-J7Im144

LoRa Gateway with ARM mbed and IBM cloud support

Early review of the new IOT Gateway from Multitech, making IOT implementations yet another step faster and easier.

MultiConnect Conduit is soon to be available new IOT gateway from Multitech Systems inc. The gateway has high performance 7-band cellular data modem for internet connectivity in global operation.

Multitech Conduit IOT gateway and LoRa mDot module from Multitech.

Due to my deep interest to LoRa RF technology, I just got an early engineering sample with 868 MHz LoRa extension module for evaluation use. This is one of the very first Conduit units in Europe. Multitech also provides mDot modules for end device implementation. Espotel already uses LoRa mDots in a customer pilot project. The reason why Espotel has selected Multitech as it's LoRa gateway supplier is that both companies are in close co-operation with ARM and IBM, and members of LoRa Alliance.

Conduit runs developer-friendly Linux operating system with support for many different programming languages, including C/C++, Python, Ruby, Pearl, C#, Java, Node.js and Node-RED.
Node-RED is a cool graphical tool to define data paths and integrations. Database, web server and other services on-board makes it possible to implement stand-alone applications without mandatory need for other back-end or cloud at all.

Conduit has compact form factor with dimensions of 13 x 10 x 4,5cm. Two expansion slots together with integrated cellular data modem, GPS, Ethernet, and USB host makes it versatile for many different kind of IOT applications. Initial set of mCard expansion cards include RS-232/485, GPIO and LoRa RF. The USB host port enables use of Wifi, Bluetooth, BLE and other dongles as well as external storage and extended connectivity.

Multitech provides readily available integration with IBM Bluemix via IOT Foundation using MQTT protocol with secure connectivity and safe data storage. Bluemix is handy environment for rapid prototyping and integrations, spanning up to production use as well. Node-RED is one of the programming options in Bluemix as well.

mDot is a new intelligent RF module from Multitech. It is available in two versions; Xbee compatible form factor with pin headers, or surface mount PCB. LoRa variant of mDot contains LoRa RF chip from Semtech and STM32 microcontroller from ST for application software. The controller is freely programmable by user and there is no need for additional MCU. This makes it cost efficient alternative, as a comparison; Microchip's LoRa module has a network controller inside, but requires an external application controller outside, which affects the overall BOM cost structure of a device.

In ARM mbed Ecosystem, Multitech has provided mDot platform support for mbed environment. Free and open source software stack is available via mbed developer site. Free mbed IDE, compiler and repository in cloud makes it easy and straightforward to start development. For more demanding development there is option to deploy the build environment in Eclipse IDE.

With free mDot library and LoRaMAC implementation, plug & play connectivity with Conduit is provided. Multitech provides number of readily available example implementations in mbed team repository which makes it easy to start development. LoRaMAC and mbed can be used with other processors as well, not limited to Multitech modules, like I did with Freescale FRDM-LK25Z board reported in my previous blog posting.

Conlusions
With readily available mbed and Bluemix integration, developer can set up the full chain from device to cloud in matter of hours, not days or weeks or months. This is definitely a significant productivity improvement over the traditional approach.

From now on, I'd feel it silly to start implementing device side code from scratch, manually installing back-end services a top of virtual server, and so on.  When teams can focus on what brings the true value to the customer or user, they are able to fail fast - not after months of development - to get immediate feedback whether the idea works or not. As an investor I'd love this approach.

That's the great value prop of the new IOT era - make me able to fail faster than ever before.

Real-life performance of the LoRa radio

Numbers put in datasheet is one thing, but experimenting the performance in real environment gives you the confidence. According to our experiments, LoRa really does outperform other competing RF technologies.

Today I performed some RF link length and performance testing in customers premises in production facilities. The purpose was to detect the limits of different frequencies and radio technologies commonly used in Wireless Sensor Networks, which means low power and low cost. Testing was limited to license-free IMS bands with transmit power within legal limits. Protocol issues were not covered in this experiment since the purpose was to set theoretical limits of any radio.

National Instruments Finland kindly supported us by supplying necessary wireless measurement instruments: NI PXI FlexRIO SDR (Software Defined Radio) which acted as a base station, and NI USRP (Universal Software Radio Peripheral) which was used as mobile station together with laptop running LabVIEW.

RF testing ongoing: measurement man at the left,
USRP in the middle, and PXI FlexRIO on the right.

The test environment consist of 160m long warehouse with interconnected manufacturing and office spaces. All in all rather complex building with many concrete walls, number of metal plated walls, metal fire doors, and plenty of metal structures inside. Mobile phones didn't work in many spots and Wifi had very limited coverage. Definitely difficult environment for any radio, just like real industrial deployment sites tends to be.

Typical narrowband tranceiver have receiving sensitivity of -110dBm, thus we decided to map the border where typical radio can not detect signal from noise. Test results of 434MHz, 868MHz and 2.4 GHz didn't surprised much. 2.4 GHz achieved 80m link length with direct line of sights. It couldn't penetrate through the first concrete wall.

434 and 868 MHz had very similar performance to each other. Almost the whole building complex was covered with recognizable signal. Only at the other end of the building in a completely metal covered hall with tiny windows in doors the signal was completely lost.  434 MHz benefits from open doors, even if they are not within the direct line in between transmitter and receivers. This indicates the lower frequency reflects from structures better and can bounce within the labyrinth, whereas the higher frequency tends to travel more straightforward though obstacles. When fire doors were closed, there was no significant difference in performance.

Then we compared the results of narrowband RF with spread spectrum LoRa radio. We changed from NI equipment to actual LoRa hardware, as generating the spread spectrum signal with software radio would be way too complex and effort consuming exercise for the purpose of this test. ARM mbed-enabled SX1276 LoRa development board from Semtech and FRDM-KL25Z MCU development board from Freescale was used instead.

LoRa RF test equipment for 434 and 868 MHz with battery pack.

In this experiment, we did not only measured carrier signal strength, but two-way packet communication over LoRaMac was used. Other radio unit was located in the same spot with the original base station. With this setup, we couldn't identify the limits of the connectivity, as we got packets through in all over the building, even in most difficult locations.

We went event to a bomb shelter in the basement of the office wing, with heavy steel-reinforced concrete walls and blast doors. There was no problems with signal when doors were closed. We event put the radio into a all-metal locker in the bomb shelter and locked the door. Still the signal passed happily, obviously through the small ventilation holes of the locker, and through all the concrete walls up to ground and into next wing of the building.

Really incredible result!

At last we moved the base station into most distant location within the building at the end of the warehouse hall. Now we managed to create challenging enough conditions for the radio. To block the signal, several concrete walls, metal fire doors and dozen or so metallic warehouse shelves were needed. Performance of 434MHz and 868MHz Lora was similar to each other, just like recognized in narrowband Sub-GHz tests.

The conclusion: We did not quite reach the promised 150-160 dB link budget advertised by LoRa datasheets and marketing material. However, we did got 145 dB link budget in a real and challenging environment. It really does outperform any competing technologies, not only in paper but in practice as well, with actual two-way data link established.

The test was performed with two LoRa end-nodes. I'm really waiting for a possibility to repeat the experiment with real LoRa-gateway having a LoRa concentrator chip in place. LoRa Alliance was publish at the beginning of January 2015, thus it is still pretty new technology.

Internet of Testing

Internet of Testing is all about productivity improvement. Market leading test and measurement technology from NI integrated with leading Cloud technology from IBM makes at all possible.

"LabVIEW - Improving the Productivity of Engineers and Scientists". is the main value proposition of National Instruments, as stated on their web site. LabVIEW is great tool for test and measurement of all kinds of physical phenomena. Robustness of the technology makes it good for most demanding live monitoring and automation control applications.

The real value comes from the high productivity of software development with graphical LabVIEW programming language. Graphical presentation makes LabVIEW program easy and intuitive to understand, but the value lies in the great amount of readily available mathematical algorithms, instrument drivers, communication interfaces, and user interface elements.

LabVIEW program can run in a PC (Win, Mac, Linux) or in a measurement instrument (RT-Target) like myRIO, CompactRIO,SingleBoard RIO, System-on-Module RIO, etc.  However, so far LabVIEW has provided limited support for remote operations and distributed architecture. But now the situation has changed.

Internet of Things Foundation is a IBM cloud-hosted service for collecting, storing, and integrating data of Things. IoT Foundation provides ready and direct integration to Bluemix, it's like one of the Bluemix APIs. When talking of Bluemix, we're yet again talking about productivity improvement, which is the main value proposition of PaaS (Platform as a Service).

When combining these two technologies, we get productivity square two. And that's the big thing!

LabVIEW recipe for IOT Foundation

Espotel has contributed my work to the open source community. It's a recipe how to connect any LabVIEW program, running either in a PC or in a measurement instrument, to IOT Foundation cloud fast and easily. It's a simple LabVIEW library which can be included in any LabVIEW project.

Example usage of the LabVIEW library for IOT Foundation

IOT Foundation uses MQTT for data transfer. It's fast, reliable, lightweight and secure messaging protocol intended for M2M and IoT applications. The LabVIEW library consists of three main elements:

• Open MQTT connection to IOT Foundation
• Publish (transfer) data over MQTT to IOT Foundation
• Close MQTT connection to IOT Foundation

The library contains one more element for reading device credentials from a file. IOT Foundation provides secure device registration, authentication and data transfer mechanism, based on credentials. Storing credentials is a file makes it possible to use the library in any stand-alone instruments without local user interface.


Applications:

• Remote real-time LabVIEW or HTML user interfaces
• Remote measurement and distributed testing
• Condition monitoring