Adding 3G Radio to Embedded Devices: Five Steps to Success

Mike Cannon

October 20, 2009

Mike Cannon

A 3G radio is rapidly becoming standard equipment on embedded devices. 3G technology offers much faster download and upload speeds compared to older cellular technologies and, for the first time, allows for simultaneous data and voice transmission. With these and other benefits, more OEMs are finding 3G radios make their devices much more capable and powerful.

Just as there are infinite applications for 3G technology, there are infinite ways to deploy it. Having so many options seems like it would make deployment easier, but it actually raises complexity. This article will walk you through key decisions to help you best integrate 3G technology with your existing hardware and software.

What is 3G?
The term 3G simply refers to the third generation of wireless telecommunications standards, including mobile voice and video calls and data transfer. There are several standards; however the most common are the CDMA standards known as CDMA2000 which includes CDMA2000 1xRTT, 1xEV-DO, 1xEV-DO Rev. A, 1xEV-DO Rev B, and the GSM standards known as WCDMA which includes UMTS, HSDPA, HSUPA, and HSPA+.

The most noticeable advance in the third-generation technology is speed. (See Figure 1 below. Comparison of data upload speed by network type.) Data throughput speeds are much improved. Download speeds of up to 14.4 Mbit/s are possible and capable of upload speeds up to 8 Mbit/s.

Figure 1. Comparison of data upload speed by network type.

Of course, performance varies substantially from device to device and even network-to-network. Generally 3G has come to indicate speeds of between 384kbits/s and 10Mbits/s.

To get a better understanding of how wireless technology has improved, let's look at its growth through a consumer application. With 2G wireless technology, it could take as much as 40 minutes to download one three-minute MP3 file. With 2.5G technology, the download time for that file may drop to just nine minutes. With 3G technology, the download time drops to as little as 11 seconds.

That's a dramatic increase in speed, though one of the biggest advances in 3G is that, it's possible to send voice and data simultaneously over the same wireless connection. This advance opens the door for many new potential applications.

Potential 3G applications
The uses for 3G technology are limitless, but here are a few common applications helped by its capabilities and capacity.

Handheld terminals. Handheld data collection and inventory devices are commonly used by factory, warehouse and field workers. These employees often also have to carry a two-way radio or cell phone to contact dispatch or other staff.

3G technology, which allows for simultaneous voice communication and data transfer, allows you to combine both of those devices. Doing so could potentially increase worker productivity and lower device and communications costs.

Device requirements vary by application, but include an audio codec supporting approximately 12.2 K/bps for voice. You also need to consider how much data the workers will need to send. Simple inventory tracking devices may require relatively little data capacity. Other field workers may need to transmit or download photos. Plan to provide appropriate bandwidth to meet their needs.

Kiosks. Video kiosks provide dynamic information and services and are increasingly in use in more public places. For example, a Kiosk can help generate interest in activities at tourist attractions. Adding video conferencing capabilities could help even more. Tourists who need help could get one-on-one assistance without the need for individual staffing at each kiosk location.

Adding a 3G radio to the kiosk could enable this assistance. Video conferencing requires 30 fps QVA high-quality video stream for download and 15+ fps VGA high-quality video stream for upload (limited by upload speed).

Surveillance systems. Surveillance systems can also receive a major upgrade using 3G wireless technology. Real-time video improves performance of video surveillance by providing a continuous monitor of activity.

Using 3G connectivity, the camera system will have sufficient band width for video and yet be protected from being disabled by severing a network cable. This application requires live streaming real-time video up to 15+ fps with QVGA or better resolution.