IoT networks can be characterized by three pillars of performance.
The varying needs of IoT systems have resulted in a bevy of protocol standards.
These standards continue to grow and change to meet new IoT design paradigms.
Connectivity in IoT is driven by balancing network performance for the system in question.
The internet has made the world a smaller place; local stories have become international and news cycles have expanded to around-the-globe coverage. Instantaneous communication has propelled an information age that would have been difficult to imagine even 40 years ago. Furthermore, the miniaturization of electronics has brought these implements to every corner of the world to study and showcase events from moment to moment.
Technological advancements and economies of scale have driven high connectivity in IoT and continue to push for network improvements for greater autonomy in professional and private spaces. With IoT continuing to grow in device number and functionality, designers need to be confident in their understanding of the forces shaping these networks as well as the form of current and evolving protocols in the space.
Qualifying Connectivity in IoT With Three Benchmarks
The central thrust of IoT, conceptually speaking, is enabling autonomous communication between devices for improved response to stimuli. Algorithms in-use to define a flowchart or decision tree for actions have grown to massive proportions to reflect the total interconnectivity of the network. While this increase in scope has enabled entirely new methods of computational models, it arrives alongside a marked uptick in system complexity.
To be sure, IoT is not one-size-fits-all; implementations must account for the physical arrangement of the network, communication speed, bottlenecking, design protocols, and more. There are several ways to analyze a network, but the most straightforward is evaluating three basic performance characteristics:
- Range - The range of a network is categorized as either short or long, even though there may be a wide discrepancy in area coverage between protocols within the same range designation. Short-range occupies an immediate proximity of approximately 100 meters or less, while long-range can span several kilometers.
- Data rate - The amount of data that needs to be sent per transmission (or unit time) differs wildly depending on the amount of information being conveyed in a system. More technical devices with large packets are likely to consume more power, and vice versa. Even the transmission model will have an impact on overall performance, as continuous communication operations will require greater bandwidth than a standby/acknowledge, receive, and send mode.
- Latency - Latency is positively correlated with data rate, though exceptions do arise. This should follow from the data size: exchanging large file sizes would become unbearable with high latency speeds, whereas smaller packets may not require exceptionally fast transfers. Though low latency is generally preferable, systems that do not require a high rate of sensor polling/actualizing or cloud processing may be able to reduce system demand by using slower speeds.
Identifying Strengths and Use Cases
Common IoT protocols weigh the importance of these characteristics and ensuing systems are built to take advantage of their particular strengths. Protocols are devised to maximize the performance of one or two of the aforementioned criteria, but achieving a trifecta of range, rate, and latency is an impossibility due to the conflicting nature of these three aspects (a reminder that there is no such thing as a free lunch in engineering). However, simply performing “well enough” in a category for a certain protocol, which is defined by the scope of each protocol’s design, ensures the system is meeting the IoT connectivity goals set forth by the designers. Some of the most common IoT protocols include:
- ZigBee - A short-range technology for wireless personal area networks, ZigBee uses three classifications for its network devices: coordinator, router, and end device. The coordinators keep actions running smoothly across the network (and other interlinked networks), while the routers handle packet exchanges. The end devices speak with a coordinator or router, but never directly. The protocol lends itself well to star and mesh topologies that provide either a level of centralization for the coordinators or dense communication webs for the routers.
- Bluetooth/BLE - Vanilla Bluetooth scales poorly for IoT, as its continuous data streaming is highly power-intensive. Fortunately, Bluetooth Low Energy (BLE) switches to a more source-efficient transmission style while still enjoying many of the benefits of Bluetooth such as network scalability (device counts in the 10,000s) and speed. BLE can utilize a large number of devices in a mesh topology with methods like flood routing, that send messages to every connected node where the message was received, excluding the node where the signal was received from. Additional network support features like message caching help to further assist with routing and preventing circular logic loops.
- WiFi - If BLE and ZigBee reflect the structure of networks at the sensor end, WiFi is what bridges these device networks to the internet. It is fast, with high data rates to prevent bottlenecking, but suffers from power consumption issues relative to the other protocols. Standards have been introduced for WiFi geared towards IoT that feature significantly reduced data rates and speeds, but with commensurate reductions in power draw.
- OWC - By using a different section of the electromagnetic band (specifically, infrared through ultraviolet) than the radio band, OWC can realize high-speed transfer rates with a low power consumption over short distances. Very much an emergent technology, OWC looks to provide networking solutions for remote or challenging locations that preclude the use of WiFi and other protocols.
- LTE - An industry standard in mobile communication networks, although 5G is rolling out as its replacement.
- 5G - Relative to LTE, 5G aims to improve data rate, latency, and larger network sizes. Certain applications are hoping to improve the reliability of the protocol as well, but balancing reliability with a decrease in latency are traditionally two goals at odds with each other.
- Low-power wide-area network (LPWAN) - LPWAN is a standard built out with IoT demands in mind: it combines a wide area, many devices, and low power consumption. There exist both unlicensed and licensed variant spinoffs, with the former lacking some of the associated testing costs, and the latter able to enjoy the infrastructure of LTE mobile networking.
Pushing IoT Design Requires an Exceptional Product Suite
Connectivity in IoT has a bevy of forms and styles to promote one or more critical features of network design. With the heavy optimization in today’s products and systems, all levels of IoT – whether that’s device or network, hardware or software – need to work in unison for the high level of performance demanded by end users.
Support for IoT hardware design starts with robust PCB design and analysis software that is both powerful and efficient for the many disciplines encompassed within networking. Designers can rely on the lightning-fast OrCAD PCB designer to smoothly integrate with all elements of a product development workflow.
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