Over-the-air (OTA) updates are a critical component of any successful IoT product strategy. They allow you to remotely update firmware, fix bugs, and add new features to your connected devices, ensuring that your products remain secure, up-to-date, and competitive in the market. In this post, the first of our three-part series "Evolving OTA from Concept to Production," we'll explore the key considerations and best practices for implementing an OTA strategy in the early stages of IoT development.

Building Blocks of an Early-Stage OTA Strategy

When you're just starting out with a proof-of-concept (POC) or minimum viable product (MVP), your OTA strategy should focus on establishing a solid foundation for future growth. Here are the essential components to consider:

1. Firmware Version Control
   Implementing a robust firmware version control system is crucial for keeping track of changes, managing collaborators, and ensuring a smooth update process. Leverage a version control system such as Git, and ensure that you are tagging each release that you intend to deploy to the field.
   
   
2. Device Provisioning
   To enable OTA updates, you'll need a way to securely provision your devices with unique identities and authentication credentials. This typically involves flashing each device with a unique device ID and a public/private key pair during manufacturing.
   
   
3. Update Server You'll need a server-side component to store firmware binaries, manage update campaigns, and handle device authentication and authorization. For early-stage projects, a simple file server or cloud storage solution could suffice, however, this component needs to be adaptable/malleable to future change. Consider using something that can eventually serve dynamic updates based on the device, Amazon Lambda is a great choice.
   
   
4. Update Mechanism
   Define how your devices will check for, download, and install updates. This may involve periodic polling, push notifications, or a combination of both. Ensure that your update mechanism is reliable, secure, and able to handle interrupted or failed updates gracefully.
   A pull-based strategy is typically a safe place to start.
   
   
5. Rollout Strategies
   Consider how you'll deploy updates to your devices in the field. Will you push updates to all devices simultaneously, or use a staged rollout approach to minimize risk? Define your rollout strategies early on to ensure a smooth and controlled update process.

Best Practices for Early-Stage OTA Development

In addition to the key components outlined above, there are several best practices to keep in mind when implementing OTA in the early stages of IoT development:

1. Start Simple
   Don't try to build a fully-featured OTA solution right out of the gate. Start with a basic implementation that meets your current needs, and iterate as your product and user base grow.
   
   
2. Prioritize Security
   Security should be a top priority from day one. Devices should be provisioned with unique certificates and all communication to/from a device should leverage mTLS. Additionally, it is best practice to encrypt and sign all firmware delivered to the field.
   
   
3. Plan for Scalability
   While your initial OTA implementation may be simple, it's important to plan for future scalability. Be careful not to choose tools that leave you locked into a certain strategy or approach. Remember, you most likely won’t be able to control when a device first wakes up and requests its first update.
   
   
4. Test
   The majority of time spent developing your update mechanism should be in the validation of the update application itself. This is a key area of risk and common failure in connected products and you do not want to have unserviceable devices left in the field (i.e., bricked)

Conclusion

Laying a solid foundation for your OTA strategy in the early stages of IoT development is critical for the long-term success of your connected product. By focusing on the key components and best practices outlined in this post, you can set yourself up for success as your product and user base grow.

In the next post of this series, we'll explore the challenges that arise as your IoT product matures, and discuss strategies for adapting your OTA approach to meet the evolving needs of your business.