Machine-to-machine communications will drive cellular network spectrum expansion

Mobile data networks will serve an ever-widening range of applications going forward. Why does that matter if you are working in an embedded space? Well, you might find the need to integrate a cellular radio either directly into the end product or perhaps in an intermediate device such as a local base station to serve embedded devices or a wired or wireless local network of some type. Indeed, machine-to-machine connections over cellular networks are already prevalent and perhaps will become the largest consumer of wireless bandwidth in the long run.

Research firm IDC has gained considerable fame from its projection that by 2015 there will be 15 billion intelligent connected devices on the Internet. Most of those devices will fall into the category of machine-to-machine connections, and surely, wireless is the only way to broadly link that many clients.

Already applications such as point-of-sale transactions are traversing the cellular network. Medical applications such as heart monitors relay data over cellular networks. There are already cellular-equipped utility meters for gas and electricity. At some point, the cellular modem becomes sufficiently cheap so that it can be used for convenience in low-end products. There is really no limit to the range of applications that might eventually use the cellular system.

You might worry that cellular bandwidth will be quickly saturated based on this optimistic outlook of the machine-to-machine future. Fortunately, the cellular service providers are doing everything possible to secure additional spectrum for applications such as video that may or may not approach the demands of machine-to-machine applications in the long term. The recent CTIA Wireless show was almost purely focused on more spectrum and therefore more bandwidth. See my recent article, “Viewpoint: Understanding the mobile carrier spectrum plea.”

So, where do designers turn when contemplating a design that embeds a cellular modem? If your application is very high in volume or very high priced, then you may need to approach the design as if it were a mobile handset. Applications such as small heart monitors may require a design at the chip level and therefore, require that the design team engage with a chipmaker such as Qualcomm.

Most embedded applications, however, can proceed at the modular or board level. Embedded designers can proceed in much the same way they do in selecting CPU boards and peripheral boards from off-the-shelf supplies.

Multi-Tech offers one such example of a modular product. The company’s SocketModem HSDPA is compatible with the GSM side of the divided cellular world. The GSM family of standards is supported by AT&T and T-Mobile in the U.S. and is the predominant standard used throughout Europe.

The SocketModem HSDPA includes support for a range of GSM technologies and a number of frequency bands. Indeed, the modem supports the 3G HSDPA networks that are broadly used by owners of mobile devices such as the iPhone for Internet connectivity.

The modular modem supports download speeds of more than 1 Mbit/s. But the product should still connect in remote areas where HSDPA is not available. The product is compatible with the older EDGE and GRPS technologies that are part of the GSM family of prior generation standards.

The modem also supports three HSDPA frequency bands and four bands used with earlier GSM standards. Embedded design teams should be able to deploy the SocketModem HSDPA anywhere in the world where GSM services are available and leverage the fastest transmission speeds supported by any given cellular base station.

Multi-Tech also offers SocketModem family members for use with CDMA family cellular networks, Wi-Fi networks, and even wired Ethernet and dial-up networks. Design teams can work with what Multi-Tech calls the Universal Socket and develop a system that works with any of the SocketModem family members.

You can get started with machine-to-machine wireless design using one of several kits. For example, Multi-Tech offers a Universal Socket developer’s kit that includes a development board, an array of antennas, and a software-development CD. The kit works with all of the SocketModem products. Multi-Tech also offers a range of wireless modules packaged in ruggedized enclosures for embedded wireless networks.

Rabbit Semiconductor also offers a Machine-to-Machine application kit that can jumpstart wireless projects. The kit works with modems from Multi-Tech and Wavecom and includes antennas, a prototyping board, and software tools. Meanwhile, Rabbit’s parent, Digi, has a variety of ruggedized wireless products designed for embedded applications.

Embedded design teams should consider cellular links as another tool in their bags when contemplating connected-device designs. Certainly Ethernet or Wi-Fi or even good old serial ports will be better choices in come cases to link smart devices. But cellular technology is no longer only for the domain of the consumer product design team.