How to build a fully managed and scalable long-range network with low-power nodes


Connecting low power nodes to the Internet is possible today with a variety of different wireless technologies. 

Among all of them, the communication in the Sub-1 GHz band has the ability to reach the longest range and is better suited for indoor environments (office, building, home), at an overall lower system cost and complexity (no relay nodes) and with the lowest power consumption.

But when it comes to realizing the full potential of the Internet of Things (IoT), the requirements go far beyond "creating a link to connect a node to the Internet".

Cloud-based management systems for diagnostics and automation need the ability to control a large number of sensors in a coordinated way. Centralized servers for factory, building and retail must manage and automate procedures on a large scale to reduce maintenance costs.

Consumers at home require that the data communication flow of multiple low-power sensors and nodes are coordinated and funneled through a central hub (like an alarm panel of a security system), and available all the time via the Internet.

Wireless connectivity as a solution for the IoT responds to the challenge of deploying a system where a large set (from tens to hundreds) of nodes 'live and breathe'. This also means defining techniques aimed at identifying what type of data they can transfer depending on their role and adapting to the different use cases.

So, how can we leverage the great advantages of Sub-1 GHz as a wireless communication link and realize this potential, morphing it into a connectivity "system" solution?

  • We need to provide a networking infrastructure, where we make sure that a large set of nodes can be easily set up and maintained, and communication is secure. Nodes must discover the network they can attach to and commission to it. Their roles and services must be explored and the link maintained over time.
  • We must guarantee the reliability of the communication when nodes transfer or receive data and that the air medium is efficiently utilized to avoid traffic stall and network inefficiencies. These ultimately translate into poor user experiences and impact battery life of the nodes themselves.
  • We need to be able to service different types of traffic profiles for various scenarios. In generic sensor networks for instance (let’s take the case of a diagnostic system), data is reported to a central hub. On the other hand, in retail networks for example, the data is mostly dispatched to the peripheral devices (like in the case of a retail server sending updated pricing information to the end points).
  • All the above must be done while maintaining low power operations, with nodes staying asleep if they are not involved in the data communication. But striving for the best power consumption means also minimize the 'on' time in transmission and reception and using the least amount of power when in active mode.
  • And last but not least, we must be able to bridge the data local in the Sub-1 GHz network over an IP-Internet connection.

The design challenges people face when trying to address all the above requirements are now solved with the new TI 15.4-Stack software solution from TI. TI developed this software to bring true application-oriented Sub-1 GHz connectivity solutions to the IoT.

 Figure 1: New TI 15.4-Stack is a standard base Sub-1 GHz wireless networking solution

 The TI 15.4-Stack is a software development kit (SDK) running on the SimpleLink™ Sub-1 GHz CC1310 wireless microcontroller (MCU). Based on the proven IEEE 802.15.4 standard, it implements the 'g' amendment of the specification for operations in North America and Europe in the Sub-1 GHz band (regulated respectively by FCC and ETSI).

The IEEE 802.15.4 standard is used as a data-link layer of many popular networking standards deployed in the market (6LoWPAN, Wi-SUN, ZigBee®, Thread and WHART). It guarantees a solid wireless foundation thanks to features like air arbitration (through CSMA-CA), acknowledgments and retransmissions and built-in AES security. 

To improve link robustness and reliability, TI developed a frequency hopping scheme for the U.S. FCC band. The scheme relies on the Wi-Sun FAN standard, and TI optimized it for low power operations. Applications can directly benefit from the increased link robustness, as this translates into smaller latency for data and low power savings (as re-transmissions can be avoided).

TI 15.4-Stack software can be configured to operate in asynchronous mode (ideal for battery-powered sensor operations) and synchronous mode (suited for coordinated downlink traffic operations with low-power node reception), thus serving different types of application needs.

Additionally, the TI 15.4-Stack software is delivered on top of TI-RTOS foundation and comes with a complete set of application examples for sensor and collector devices. Both applications feature a logical link controller module (running on top of the 802.15.4 standard), that encompasses network and device management procedures.

This gives the user of the software a full reference solution which answers the design challenge of building a fully managed low-power network. TI 15.4-Stack software can support deployment from 10s to 100s of devices, depending on the configuration selected.

TI 15.4-Stack software also includes a Linux-based gateway software, which implements a local network controller and collector application. Through the gateway software, data coming from the Sub-1 GHz peripheral node can be monitored and actuated from a web browser interface.

This new software is built on TI’s low-cost development platforms: SimpleLink CC1310 LaunchPad™ development kit and Sitara™ AM335x processor BeagleBone Black development board. Through the development kit ecosystem of BoosterPack™ and cape plug-in modules, and relying on the TI-RTOS framework, applications can be easily extended.

Using narrowband modulation which gives the best performance of sensitivity and resistance to interference at a given external crystal cost, TI 15.4-Stack software unleashes the advantages of Sub-1 GHz wireless into the IoT.

By providing a full reference system solution for low-power managed networks, users can easily integrate the Sub-1 GHz wireless functionality into their existing networks.

Now creating applications with a network of low power nodes covering a whole building, an entire house or a parking lot area is not just a task for wireless technology experts.

And yet more is to come....

Additional resources:

  • TheDarkSide,

    I'm a newbie here, so, sorry for the stupid question(s) :)

    Thanks for the post - found what I was searching for.

    Just can't find how I'd connect to the Internet ONLY having a CC1310.

    Say we have a sub-1GHz-network with a number of sensors, etc. managed by CC1310 and powered by the TI 15.4-Stack.

    AFAIK, the CC1310 doesn't have a way to connect to the Internet (or I missed something?)...

    So, how would you monitor CC1310 through the Internet?

    Use an extra CC31xx/32xx as a Wi-Fi bridge for the CC1310?

    Thanks.

    Igor.

  • Hi Igor,

    you need to use a CC1310 in combination with an IP interface (like Wi-Fi or Ethernet).

    The TI 15.4-Stack SDK includes a Linux based collector and web server application on a BeagleBone Black, to be used in conjunction with the CC1310LP running as a MAC-CoProcessor implementing the Stack. This de-facto bridges from Sub-1 to the IP world.

    You can pull the web interface from a device running in the local sub-net as the BeagleBone Black, where you can exploit the native Ethernet interface on board.

    Please refer to the following document for a quick starting guide: www.ti.com/.../swru491

    Hope you enjoy the SDK and looking forward to see products out there based on it.

    TheDarkSide

  • Hi there!

    I'm working on a mesh network project using your CC1350 chip. On a typical start configuration works great but I need to use a mesh network to achieve long distances. I was in Electronica in Munchen last week and some of your team there told me it was possibe to do it.

    Can this TI 15.4 Stack do this job? Battery life is very important as well.... I'm doing my test on sensor tag dev kits....

    Thanks for all!

    Ramon

  • Hi,

    if you want to develop mesh networks on CC13xx platform please take a look at this link: processors.wiki.ti.com/.../Contiki-6LOWPAN

    CC13xx is supported on the open source Contiki tree. As you probably know, Contiki is an open source project which implements a 6LoWPAN-based stack.

    TI 15.4-Stack is instead a TI SW product that implements a star-based topology system.  It currently supports 2-GFSK 50 kbit/s PHYs in the 915 and 863 MHz bands (PHY-1 and PHY-3 in 802.15.4g specification).

    One thing i would like to clarify: there are different ways to extend the range, other than meshing the network out. I am saying this because from your comment it looks like you want to have mesh as a way to extend the range.

    Long-range capability can also be achieved 'natively' in star-topology system, by employing a different PHY with better long range performance for a point-to-point communication.

    Thanks,

    TheDarkSide  

  • Hello ThedarkSide,

    On the previous post you mentioned there are different ways to extend the range other than meshing the network out whitout using mesh as a way to extend the range.

    So, I am asking because I am developing a wsn for agriculture were the distance between nodes are 2000 feet or more (if possible). Indeed, farther is better.  

    My question is, how the TI Sub-1 GHz network help to improve the coverage without compromising nodes battery lifetime? I mean, does TI has a very long range radio solution?

    Regards,

  • Hi Thiago,

    have you looked at this e2e thread?

    e2e.ti.com/.../1685221

    It features a range estimator calculator so you can simulate your scenario.

    TI 15.4-Stack 2.0.1 (www.ti.com/.../simplelink-cc13x0-sdk) supports 2-GFSK 50 kbit/s PHYs, so in perfect radio conduions with direct LOS, this can reach out to ~ 1Km at 14 dBm.

    While the 15.4-Stack supports only 50 kbit/sec 2-GFSK for the moment, this seems like a good fit for your smart agriculture project where the sensors are presumably all visible to the central data collector.

    CC1310/CC1350 Wireless MCU support as well other type of modulation formats, that can extend that range by choosing a smaller bit rate. The above SDK includes SW examples that show how to use the RF core in those mode.

    I would encourage you to get a couple of Launchpads, download the SDK and try the impressive ultra long range performance of the CC13xx platform.

    Thanks,

    TheDarkSide

  • Hi TheDarkSide,

    Thank you for the range estimator calculator, I am learning how to use it.

    Do you have any tool to calculate the power consumption of the nodes?

    Thanks!