Cutting cables: Demand for wireless links is on the increase

Designers have two broad choices – to go with ISM based solutions or to take the GSM route. And if you are thinking about ISM, there is a further split between point to point and mesh networks. John Sharples, managing director of Low Power Radio Solutions (LPRS), said demand for wireless connectivity is booming. "We have passed the tipping point. Everyone now expects everything to be wireless; consumers don't want to plug things in and the same goes for the equipment market." One of the main drivers in this market is cost, but Sharples contends that other factors, such as device quality and reliability are more important. He also believes the availability of low cost wireless connectivity is leading to overcomplicated designs. "We've got to the point where designers are including functionality without considering whether there's a market for the product. We are always telling engineers to think carefully about their designs and to not design in unwanted functionality." Looking to broaden its wireless portfolio, LPRS has recently signed a deal with Czech company Microrisc to distribute the IQRF product range in the UK. This move complements LPRS' easyRadio line. The IQRF transceiver module is a small board said to feature all the circuitry needed to support rf communication. Operating in either the 868 or 916MHz ISM bands, the board includes a PIC microcontroller and operating system with 80 basic instructions. Low power consumption has been an important design parameter and Microrisc claims the device will draw no more than 1mA when running, 24mA when transmitting and 13mA when receiving, with many parameters software selectable. With a maximum bit rate of 115kbit/s, the device can transmit over distances of up to 700m using an rf output power of 3.5mW. A range of development tools is also available. Sharples noted: "The IQRF range supports mesh networking and is more competitive with ZigBee." And it is the contrast with ZigBee which Sharples is keen to highlight. "When we get asked for a networking product, the customer often asks whether we have ZigBee products. While ZigBee has a lot of good points, it's not always the right answer; you have to get 'under the skin' of the application in order to understand the requirements. But neither is the IQRF range right for everything." According to Sharples, LPRS has been aware of Microrisc's development of the IQRF portfolio for a couple of years. "Our first question was to ask whether we could do it ourselves. We could, but we didn't want to reinvent the wheel. Over the last two years, the IQRF product range has developed substantially and we decided at the beginning of 2011 that it had matured to the point where we could take it to market. We were confident that it was the right product for us to address markets we couldn't before." Sectors where Sharples has high expectations include smart metering, smart grids and street lighting. "IQRF is the right product at the right time," Sharples enthused. "It's not ZigBee, although it can work with it. It's a great product for someone who thinks they need ZigBee, but what they actually need is a mesh networking device." GSM for M2M What if the ISM band doesn't meet your needs? The other option is to take the GSM route, an approach advocated by cellular M2M specialist Cinterion. Starting life as part of Siemens Wireless, Cinterion launched the first GSM data module for M2M applications in 1995. Spun out of Siemens, the company was acquired by Gemalto and is now run, according to UK manager Mark Foster, as a 'company within a company'. "We have an industrially focused road map focused on telematics, smart metering, health, remote maintenance and security," he explained. "Our modules fit into open architectures and can support Java as an on board OS or work with an external microcontroller." The M2M market originally developed around GSM communications, but the network operators didn't really focus that closely on the opportunities. But, according to Cinterion's UK channel manager Neil Bosworth, that's changing. "Operators are tuning in more. They ignored M2M before because it was a small market compared with handset traffic. Now, they all have M2M activities because there are more machines than people." And he said the approach is suited to all kinds of data rate. "Most M2M applications transmit only around 100byte of data per day." While the 2G network would seem to be the obvious environment for M2M links, Foster said there was a drive to the use of 3G. "It's being driven by the need for connectivity, rather than data rate. Another reason is that, in some countries, the future of the 2G network is suspect, so developers want confidence and are turning to 3G." Bosworth added: "But there is still a lot of network available to 2G; for example, a lot of smart metering applications are using the 2G network." But why should a developer use GSM in this application, rather than ISM? Bosworth continued: "The trouble with ISM is the equipment operator has to use a ZigBee based approach and doesn't have control over the backhaul. A smart meter could use ISM to link to a wireless router, but that link would not be under the control of the utility company. By using GSM, the utility company is assured of a secure link." Cinterion's BGS2, part of the company's value range, is said to be the smallest 2G wireless module available in the lga format. The BGS2 is available in two options: quad band (850/900/1800/1900MHz) GPRS class 10; and dual band (900/1800MHz) GPRS class 8. All modules come with full type approval. Both options can download data at up to 85.6kbit/s, with the maximum uplink rate of 42.8kbit/s and 21.4kbit/s respectively. The module is suitable for use in remote health care. Cinterion believes devices ranging from blood pressure measurement and scales to glucose meters and spirometers will benefit from the ability to transmit data via the mobile network. It's easy LPRS continues to expand its point to point easyRadio portfolio, with the latest addition being the easyRadio Advanced range of transmitters and transceivers. These parts allow developers to change many of the parameters of the radio to suit specific requirements. Multiple channels and frequencies are supported, with a choice of FSK and ASK modulation. Available in 433 to 434MHz and 868 to 920MHz options, easyRadio Advanced allows users to program transmission frequency, output power, serial data rate and bandwidth.