Custom Gateways and Routers: When, Why and How

Organizations are transforming their businesses with wireless technology and IoT deployments. They need fast, effective connectivity solutions that enable them to complete their projects quickly, get to market faster than their competition, and at the same time be assured of product longevity. There are several ways to achieve those goals.

An off-the-shelf router or gateway may be the perfect solution, if you have standard connectivity requirements. However, if you are developing a product for a niche market, or you need greater control over your product specifications, or have highly specialized requirements, you may need a custom solution. And you may need it quickly to meet achieve your go-to-market objective. 

Working with an experienced professional engineering team to architect and develop a custom product – such as a custom gateway or router – is an excellent way to achieve that goal. This means your team can stay focused, and you can meet your timelines.

In this blog post, we’ll talk about the considerations for when, why and how you should evaluate a custom gateway or router, including cost factors and other key considerations, and when you should consider bringing Digi Wireless Design Services (WDS) into your design and development process.

Looking for high-performance off-the-shelf solutions? See the full suite of Digi enterprise, industrial and transportation cellular routers, and Digi cellular gateways.
 

When and Why Do Custom Products Make Sense?

Companies look at developing a custom product when they have certain needs such as regulatory requirements, or a certain combination of features such as unique sensor interfaces, serial bus interfaces or edge computing needs not found in off-the-shelf gateways.

It gets really interesting really fast, because even when companies have the same requirements at a high level, the development of the required functionality can vary greatly.

For example, two companies that need to send critical data to the cloud most likely need to do so under very different circumstances. A medical company might need to send electrocardiogram signals to the cloud directly from a patient wearing an ECG system. By contrast, a water treatment company might want to send pressure data to the cloud from a water pump located in a basement of a building. These use cases have very different needs from a hardware, software, connectivity and regulatory perspective.  In the end, both send critical data to the cloud.

The following are the typical reasons organizations tell us they would like to evaluate a custom solution.
 

The Project Has Unique Requirements

For a range of reasons, the desired end product may have specific requirements, such as a specific box size, particular connectivity interfaces, or a combination of interfaces and protocols that are not available in an off-the-shelf solution.

For example, depending upon the environment or specific use cases for the product, the device may need a case that is hardened so it can perform on a boat where it will be subjected to salt air, such as for a military application. Or the application may require a CAN Bus or Modbus, and also the ability to run DigiMesh or Zigbee, as well as LoRA or Bluetooth. In many cases, the organization may not need all of these options right away, but may know they will need them down the road, so they want to build those capabilities into the product up front so it can scale to meet those needs.
 

The Product Must Meet Specific Regulatory Requirements

In highly regulated industries, such as medical applications, the regulatory requirements for the intended product may be such that an off-the-shelf product won’t suffice.

Medical devices are subject to the IEC 60601 standard. This is a series of standards to ensure safety and essential performance for medical devices.

For example, in an ECG system there are wired sensors attached to the patient’s chest, and it’s critical that the device does not cause patient harm, such as an electrical shock. Digi Wireless Design Services is highly familiar with these regulatory requirements, and can ensure the device will meet all the IEC 60601 standards while being able to communicate wirelessly to the cloud meeting all the certification standards for cellular devices.

The Device Must Have an Extended Lifecycle

This is also very common for medical devices. Unlike a commercial product that might have a life of 5 years, on average, medical devices need extra-long life due to the expense of developing and certifying those products. Custom routers or gateways can provide a way to sustain that product life for much longer.

Digi SOMs (System on Modules) are very popular for these applications because they are built for long product life spans. Custom medical devices designed with Digi SOMs typically have at least 10 years of life. Digi manages obsolescence, so changes to the components are documented, tested and recertified. This reduces engineering, testing, documentation and letter to file efforts for medical device manufactures.
 

The Organization Wants Full Control of the Product

For a variety of reasons, many organizations want complete control of their design and intellectual property (IP). Designing the custom gateway allows for the exact use cases and future needs to be implemented without unnecessary circuits, software or features that add to cost and complexity.  It may be to ensure product longevity, as we have discussed, or other business requirements. For example, the organization may want the ability to work with different contract manufacturers.  For all of these reasons the organization has a leg up on their competition.

Owning your design, and even patenting it to protect your design and company IP may make sense if you have a unique product.
 

The Organization Wants Competitive Advantage

This is an adjunct to the need for control over your IP, as we discussed above. For competitive advantage in the marketplace, you may want a custom niche product with unique properties that only your organization can offer such as: custom indicators, data speed, edge computing, wireless protocol flexibility, company branding, battery power, waterproofing – the list goes on. You may also want the ability to sell that custom solution as well.
 

Avoiding Excess Product Costs and “Gotchas”

It is important to understand the full spectrum of factors and considerations when making decisions about your product selection, design and development. The initial development costs are only a portion of the cost considerations in the lifecycle of the product. This means the decisions you make can have both short and long-term impact.

After many years of working with organizations and development teams, and seeing a number of unfortunate repeat scenarios, we have developed a “short list” of things every organization can do when developing and deploying a new custom gateway or router to be set up for success.

1. When you have specific product requirements or want to have full control over your product’s design and intellectual property, consider a custom product design. Ensure you document the use cases and requirements for the entire system that support the business plan. We have seen customers wallow back and forth without clear definition and architecture plans, causing large undue development costs.
2. When making choices about your product, think long-term. Consider the lifecycle of the product, and the associated costs of redesign and recertification if you select components or design features that have a limited life.
3. Remember the costs of deploying, provisioning, controlling, updating and keeping products secure. IoT devices are often deployed in large numbers, in out-of-reach or hazardous areas, or in remote locations. To mitigate the costs of ongoing maintenance, such as troubleshooting and security and firmware updates, you will need an integrated management system. Digi off-the-shelf devices integrate Digi Remote Manager®, and Digi WDS can integrate this valuable management tool into custom designs.
4. Avoid PCB “Revision G”.  If you work with an outsourced design team, make sure they have expertise in wireless and cellular technology. Designing systems using cellular modems is a very different design process than basic RF functionality. Today’s cellular protocols such as Cat-M and NB-IoT are designed for very high receive sensitivity to extend the range. This means managing noise on your board is a much tougher design challenge. At WDS, we understand these gotchas and can help you avoid them in your initial design, rather than learning them the hard way – on the third or fourth board spin!
5. Ensure you have the entire design history file.  You can then take that design to any contract manufacturer. We have seen scenarios where the relationship with a contract manufacturer goes sour, or where the CM facility experiences a catastrophic fire or weather event, any of which will impact the ability to get product when needed.
6. For any critical applications, keep safety stock. This means that you anticipate the possibility of needing more products or components from your supplier or ODM, and you ensure that you have these in stock. This is especially important if you buy mature off-the-shelf products that have been on the market for a few years, as it is more likely that components could become obsolete or the product could be replaced by a next-generation model with updated features.
7. Manage your supply chain. Know ordering and shipping times, and your manufacturing company’s end-of-life plans. Keep in contact about future deployment plans to ensure the product and its components have longevity.
8. Be aware of your contractual agreements.  If you take your design to an ODM without paying for non-recurring engineering (NRE) costs, that ODM might be able to take your design and create a product and sell it, making money on your IP.  Working with WDS you own your design.

Why Outsource Design and/or Development of Custom Designs?

The reasons to outsource design and engineering work typically fall into two categories:

1. Proactive: The organization recognizes the need for supplemental design and development work to augment their team, to ensure they have the resources with sufficient experience in the area for their specific application and for cellular and wireless device design, certification and production.
2. Reactive: The organization realizes they have taken too long and want to accelerate the development and reduce time to market. The product development or certification process has floundered and the development team needs course correction.

Let's look at these scenarios in more detail.
 

Augmenting Your Development Team – Proactive

Many organizations understand up front that a custom development project will be most successful with the help of an outsourced team. They may have evaluated their resources for managing development of a one-time project and realized any or all of the following:

• The organization does not have the right talent in their internal team required to develop the product, or the project will over-tap their existing resources.
• The organization understands their core competencies well and the detailed embedded engineering efforts are outside of their core.  Their team is focused on specific core business needs, and taking on a large one-off, non-core project will likely derail other important commitments.
• They lack the on-site tools and specialized equipment for successful development and testing of wireless products. For example, these can include:
  • Anechoic chamber
  • Call box (Wideband Radio Communication Tester)
  • Faraday cage in a screen room to isolate yourself from RF
  • Tools such as spectrum analyzers for doing near-field probing on a board to identify the source of noise
• They want to expedite the process with rapid development, testing and certification, with as few board spins as possible.

Organizations look at outsourcing custom design work when they realize, up front, that the cost of doing the project internally could actually be much greater than hiring a dedicated development that is equipped with the skills and knowledge to complete the project quickly.
 

Problem Scenarios and Design Rescues - Reactive

There are many problem scenarios when an engineering team such as Digi WDS, with deep experience and knowledge in solving design and certification problems, can quickly get a project back on track. The scenarios we see include the following:

• The architecture cannot scale to support the number of devices in the field. Improper architecture for the system can lead to server bottlenecks and loss of data or system crashes.  Designing for use with a system like Digi Remote Manager gets customers up and running fast without issue.
• Challenges with data processing at the gateway or sensor device. When architecting the system to support all of the use cases and requirements, we have seen both undersized processing platforms and greatly oversized, overpowered processing cores used. Both lead to unwanted costs such as:  launch delays, excessive product cost or missing features.
• Open source license concerns.  We have had customers both be unaware and overly cautious about using open source licenses of other software components.  WDS understands these concerns and helps companies tread the open source waters.  You can find deeper insights on this topic in our related article on open source operating systems.
• Issues getting a signal. If a device will not get a signal, this is often because the development team is trying to debug a cellular problem without equipment to isolate noise even though there’s a cell tower right down the street.
• Noise floor vs. receive sensitivity. If the “noise floor” is higher than the “receive sensitivity” floor, this effectively reduces signal range. The board is likely noisy due to avoidable design errors. For example, with cellular protocols such as NB-IoT and Cat-M, you have a much higher receive sensitivity, and that needs to be managed in the board design.
• Certification problems. Often a product will not pass certifications, and the team cannot pinpoint the reason. We often talk with teams that have been through the process three or four times, at a very high cost, and their design still does not pass certs.

In many of the problem scenarios, outsourcing to a professional engineering team from a proactive standpoint could have solved problems faster and at a lower cost. We are happy to support teams at any point in their planning, system architecture, design, development or certification process, but naturally we encourage you to reach out to us sooner, so we can help you avoid the pitfalls and get your product to market as quickly and painlessly as possible.


 

Working with Digi WDS

Digi Wireless Design Services can provide any level of support, at any point along the way in your design, prototyping, development and certification process. Naturally, sooner is better, as we have the dedicated resources, lab equipment, and deep experience to evaluate all of your requirements and drive toward a market-ready product, fast.

Additionally, we can recommend, develop and integrate the right components, antennas, ports, protocols, software and management tools to help manage costs and ensure your project is a success. Digi WDS has decades of experience developing and integrating custom software, custom edge computing and custom electronics. Contact us at www.digi.com/ContactWDS to start the conversation about putting that experience to work for you.