New-Tech Magazine - Europe | January Digital edition

Wireless coexistence Some systems require wireless technologies to be operating concurrently. There is potential signal interference in these circumstances, resulting in higher latency because of the need to use packet traffic arbitration to avoid simultaneous data transmission and reception, or even data loss due from receiver input saturation. These potential side effects are clearly unacceptable in mission-critical industrial and medical applications so it’s important to optimize coexistence of the various wireless technologies to ensure interference-free operation. Using multiple single-technology radios means that longer development time is needed todeal withwith the coexistence issue, adding to cost and extending time-to-market for the end product. In a stand-alone multiradio device, coexistence is handled within the multiradio chip, eliminating these challenges. Minimizing type-approval effort Implementing several single-radio solutions in a product requires extra regulatory testing. Even if a single wireless module has obtained modular regulatory approval, additional testing and reporting will be required when integrating additional radio modules into the device. This once again extends time-to-market, adds development cost, adds test facility cost, and increases technical risks. With a stand-alone multiradio module these problems are avoided. Multiradio solutions - ideal for gateways A wireless gateway is a networking device that routes packets from

interface so fewer components are required, for example those for antenna matching. Some even have an integrated antenna, either as primary radiator or as a backup if an external antenna is damaged or becomes disconnected. The more components that a printed circuit board has to carry, the more complex and expensive it becomes. Using a multiradio solution contributes to simplicity and will not only enable smaller boards to be used but may facilitate using boards with fewer layers, which can result in considerable cost savings. One implementation - several radio options for the user The overall cost savings from using multiradio solutions make it economical to implement this design strategy across a product range, even when different products will eventually use only one of the available wireless protocols. For example, you may want to offer Bluetooth or Wi-Fi versions of a product, rather than one that’s designed for both. The approach is particularly useful with a range of products that use a common architecture, and perhaps a common main printed circuit board for all the variants. Even if one of the products in the range only uses one of the wireless technologies, the implementation and maintenance is minimized for the entire product range. External technology discovery and proximity detection There is often a requirement for two wireless-enabled devices to connect automatically when they come within range of each other. Sometimes one radio technology is used for device service discovery and another for data exchange. One of the wireless technologies frequently implemented in multiradio solutions is Bluetooth low energy. With its unique radio service discovery, Bluetooth low energy becomes particularly useful in multiradio implementations. The protocol can be used to detect a user or device when the signal close to another device, effectively acting as a proximity beacon. Once detected, a second radio technology can be used for the data exchange if higher bandwidth is required. For example, in a retail point-of-sale environment, Bluetooth low energy signals may advertise the presence of the nearest receipt printer to a hand-held payment terminal. The connection set up and data transfer could then take place over Classic Bluetooth or Wi-Fi.

In this use case only one of the radio technologies is being used at a time.

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