02 May 2016
Multiradio Modules will enable the IoT
Nick Robins, Technical Director at Alpha Micro Components looks at the way the variety of wireless technologies will provide the main enabler for the Internet of Things, IoT.
The extent to which applications — both present and future — will be defined or re-categorised as being part of the Internet of Things, IoT is for all practical purposes limitless.
Today those applications could be succinctly described as revolving around monitoring and measuring ‘activities’, such as the movement of goods, public and private transport, data communications and production. In the future, the activities that suppliers and consumers will want monitored are set to increase because, if nothing else, it will offer the opportunity to charge for those activities on a per use basis.
This is just one of the scenarios where the IoT promises significant gains and it will largely be enabled through the process of connectivity; for the majority of IoT nodes that connectivity will be enabled through wireless technologies. A question remains, however, about which one.
Figure 1 – Wireless Protocols
The Simple Answer
Two of the most widely adopted wireless protocols for connectivity in general and, arguably, the IoT in particular are Wi-Fi and Bluetooth (both Classic and Low Energy, or ‘Smart’). Both protocols offer the necessary features for ad hoc networking on a wide and personal area basis respectively. For this reason, many manufacturers are keen to adopt both in their applications, because it allows a single device to address a wider range of applications.
While widely accessible and available for use without a license within the ISM bands, the use of any wireless technology in an end-application still requires that device to be certified, and if two or more protocols are used it requires twice the amount of effort to get that certification. This presents an unnecessary barrier to many manufacturers unfamiliar with the certification process, or reluctant to integrate two wireless technologies due to the potential problems this may introduce with respect to certification.
This potential problem may be best addressed through the use of pre-certified modules, which are easily integrated into an end-product and reduce or completely remove the uncertainty involved with gaining type approval from the respective radio regulatory authorities. These so-called multi-radio modules offer two or more wireless technologies in a single physical package, and their general availability and adoption is growing in step with the development of the IoT.
The Benefits of Integration
While power and performance are important factors, size is also a major consideration for manufacturers, particularly in mobile devices. It’s common for these devices to integrate several complementary forms of wireless connectivity, such as Wi-Fi, Bluetooth, GPS and NFC, often covering two bandwidths — in addition to cellular.
If integrated as separate solutions this can easily represent a significant proportion of the overall space available in a space-constrained device, but with a multi-radio module these concerns can be easily avoided. Modules also require much fewer supplementary components to support them than discrete single-radio implementations, and modules can also include essential features such as Low Noise Amplifiers (LNAs), antenna matching components, oscillators and crystals, significantly lowering the PCB requirements. Some modules can also integrate a primary or secondary antenna, further saving essential board space.
This level of integration also has the benefit of increasing reliability at the PCB level; fewer components mounted on the board can lower manufacturing costs, as well as test time and reduce the risk of point-failure. With fewer interconnects, the adoption of multi-radio modules can also result in using PCBs with fewer routing layers to be used, further lowering the BoM and production costs.
While cost savings are, of course, important, the inherent benefit of a lower BoM means it can become cost-effective to adopt a single design based on a multi-radio module across an entire family of products, even in variants where only one radio interface is required. It means, for example, that three product variants; one offering only Bluetooth, one offering only Wi-Fi and one offering both, could be designed using the same PCB and Wi-Fi/Bluetooth multi-radio module. It also presents the option to unlock an additional wireless interface after the initial sale.
The proliferation of different wireless protocols can often be seen as presenting a choice when looking to achieve the same result, but increasingly the technologies are being seen as complementary. For example, one technology may be used for data exchange, while another is dedicated to network management. Bluetooth Low Energy (BLE) is a case in point; the protocol implements a radio service discovery mode that allows it to ‘seek out’ other BLE-enabled devices in its proximity — the so-called Beacon use-case. This can be used to exchange a token (essentially a URL) which may direct a device or a user to an online resource, a process that is much better achieved using Wi-Fi connectivity.
In this scenario, coexistence of the two technologies is best achieved through the use of a multi-radio module that has been designed as a single solution. This will result in coordinated operation, instead of concurrent transmission which could result in signal interference, introducing the need for packet traffic arbitration and, ultimately, higher latency. There is an increasing number of use-cases that would benefit from this optimised radio coexistence, particularly in emerging applications such as medical devices.
Looking further afield, the general trend known as the Internet of Things will make extensive use of multiple radio standards and this is expected to create demand for ‘gateways’ able to communicate with any number of nodes employing various protocols. A multi-radio module would be an ideal basis for an IoT gateway design, which would need to combine wireless connectivity with the features of a router and the ability to implement some level of security in the form of a firewall.
Figure 2 – ODIN-W262
The ODIN-W262 from u-blox is an example of a multi-radio module targeting these use-cases. Measuring just 14.8 x 22.3 x 4.5mm, the module supports multiple concurrent Wi-Fi (2.4GHz and 5GHz), Classic Bluetooth and Bluetooth Low Energy, controlled through simple AT commands. Already type-approved in countries across the world, it also offers a built-in antenna making its use even simpler.
The deployment of wireless technology is on the increase, particularly in portable devices and peripherals. However, the introduction of true IPv6 support in to the Bluetooth protocol has set the stage for even wider use, while the benefits of Wi-Fi means it will remain a predominant solution for internet connectivity.
The development of pre certified, type-approved multi-radio modules will accelerate the adoption of wireless technologies in an ever increasing range of application areas, while the promise of the Internet of Things is that it will introduce greater control and with it greater efficiency. Seamless integration of multi-radio modules will enable any number of devices in all vertical markets to benefits from the advantages of wireless connectivity and, with that, IoT.
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About the author
Nick Robins is one of the founders / directors of Alpha Micro Components. He has over 35 years of experience in embedded design and product support and has an extensive knowledge of using the products Alpha Micro stock and sell. Nick’s pre-Alpha Micro experience includes designing cordless telephones, electronic musical instruments (including master keyboards), drum machines and samplers, dial-up modems, 2G and 3G radio modem products and GPS asset tracking devices.
Founded in 1995, Alpha Micro Components is a successful independent franchised distributor of components for telematics, M2M and IoT. The company supplies wireless communication components from franchised product lines including u-blox, Laird, FTDI, Lantronix, GainSpan, AXSEM, and its own 'AMC' range. A team of in-house design engineers integrate components into board-level designs, adding real value to the solutions on offer and providing customers with products that exactly meet their varied and demanding requirements. The company has helped customers to network-enable more than 2 million devices using various technologies ranging from simple dial-up modems and serial connections to sophisticated wireless solutions. Privately funded, with a strong balance sheet, we're investing heavily in our people and our franchise product lines to strengthen our position in the M2M and telematics markets.
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