An IIoT Alternative to Point-to-Point (PtP) and Point-to-Multipoint (PtMP) Radios

Industrial automation professionals frequently use Point-to-Point (PtP) and Point-to-Multipoint (PtMP) radios to connect remote PLC’s, RTU’s, flow computers, and other field equipment to host SCADA systems. Over the past few years, a number of technological advances have made cellular edge of network gateways a viable alternative to traditional point-to-point systems. In the same way cloud computing transformed IT infrastructure from a large capital expenditure (CapEx) to a scalable operational expenditure (OpEx), a convergence of technologies is transforming remote industrial communications from a CapEx heavy endeavor into an agile OpEx implementation.

redigate cellular mqtt edge gateway point to point architecture

In this article, we explore the emerging technologies that are accelerating the adoption of cellular edge gateways as substitutes for traditional radio systems.

Reliable, accessible, and affordable cellular connectivity

US-based cellular providers continue to make significant infrastructure investments, greatly increasing the reliability and accessibility of their networks. Not only are these networks more available, companies like AT&T now offer IoT data plans that provide transparent, affordable,  and scalable pricing for connected devices. To see AT&T’s current IoT data pricing, visit:

Infrastructure as a Service (IaaS) providers

IaaS providers such as IBM Watson IoT, AWS IoT, and Azure IoT Hub have made deploying MQTT brokers in the cloud secure, scalable, and affordable. By combining the security of TLS encryption, certificates, and software-based firewalls, users can now securely connect their remote field devices to infrastructure without rolling out expensive private networks and servers. These IaaS companies provide transparent, scalable pricing which makes it easy to estimate continuing OpEx costs.

DNP, Modbus, EtherNet/IP to IBM Watson IoT, Azure IoT, & AWS IoT

Bandwidth efficient protocols, such as MQTT

Some of the world’s best run pipelines found a way around the inefficient bandwidth usage and slow response times associated with the poll/response architecture of traditional SCADA systems. MQTT’s lightweight publish/subscribe architecture offered the pipelines a simple, cost-effective way to receive data as it changed, which drastically reduced latency and bandwidth compared to the traditional poll/response methods. Forward thinking SCADA providers such as Inductive Automation Ignition, Wonderware, and B-SCADA are integrating MQTT clients directly into their platforms, empowering users to leverage MQTT and realize the bandwidth and latency improvements it affords. All of the major cloud IaaS providers also support the MQTT protocol, and we have a number of examples on our RediGate product support website outlining how to configure the RediGate to talk to those platforms. Check out our Bandwidth Savings Calculator to estimate the bandwidth you could save by using an MQTT report-by-exception architecture.

Screenshot of bandwidth savings calculator

Ruggedized, Smart, Edge of Network Gateways

Defining the “Edge” of industrial networks is more of an art than a science, but the ARC Advisory Group recently published a couple of articles that do a good job of defining the hardware and software components of the “Edge”. The Elecsys RediGate MQTT Edge Gateway combines a number of “edge infrastructure products” and “end devices” (as defined by ARC) into a single ruggedized, field-tested, edge of network gateway. Customers drastically reduce the total cost of ownership of their edge infrastructure by using RediGates as serial terminal servers, industrial network routers, Linux firewalls, protocol convertors, I/O concentrators, and cellular modems. By utilizing MQTT as the primary data transport protocol, the RediGate remains SCADA/IIoT platform agnostic, providing customers with the flexibility to choose the best platform for their application. Edge of network gateways provide the glue required to integrate existing infrastructure with IIoT and SCADA platforms.

RediGate mqtt edge gateways 4 devices in one

The convergence of cellular, IaaS, MQTT, and gateway technologies provides a lower cost alternative to CapEx heavy radio solutions for remote field device connectivity. The RediGate is a rugged, field-proven edge of network gateway perfectly positioned to leverage these technologies to provide an end-to-end hardware solution for connecting remote field devices into existing infrastructure. Our online documentation and example configurations provide all of the tools needed to implement your IIoT alternative to traditional radio systems. Visit for more information on how to order your RediGate today.