Connecting 3G Devices to Wi-Fi

Are we heading towards a wireless utopia? Will there come a point soon when you could use the same portable device to access your SOHO wireless? Could that same device connect to a WiFi hotspot in a cybercafé or airport? Allow you to check your email? Utilize global positioning system data?

Perhaps such a device could even allow you to make national and international phone calls, do messaging and VoIP calls from anywhere in the world without having to worry about which type of cellular network you’re on? Oh, and while we’re at it, could that very same device be used to enable high-speed broadband access to the Internet with another device, such as a laptop computer?

According to Nidal Nasser of the Department of Computing and Information Science, at the University of Guelph and Hossam Hassanein of the School of Computing, at Queen’s University, in Ontario, Canada, “future wireless networks will generally be characterized by heterogeneity in architecture, protocols and air interfaces.” In other words, they will do just what I asked for in the opening paragraphs.

However, the wireless networking scene is dominated by two distinct networking platforms: cellular networks, currently at the third-generation (3G) stage, and wireless local area networks, commonly known as WiFi and operating at various speeds under the IEEE standard known as 802.11. And, never the twain shall meet.

Actually, that’s not strictly true, Nasser and Hassanein explain in a special issue of the International Journal of Wireless and Mobile Computing. “Recent trends,” they say, “indicate that 3G networks and WLANs will coexist to offer public wireless broadband services to end users. The two platforms offer characteristics that complement each other perfectly.” So what can we expect from this complementarity?

3G cellular systems support real-time and non-real-time multimedia services with data rates from 144 kb/s to 2 Mb/s with wide coverage and almost universal roaming, the researchers explain. However, the radio frequencies, the spectrum, at which the 3G system operates and the equipment upgrades themselves, are expensive to the operators, which means 3G is expensive to you and me.

WLAN, on the other hand, is very cheap to run and much, much faster than 3G (wireless-g works at 54 Mb/s and wireless-n coming next year promises a maximum rate of 248 Mb/s). However, WLANs lack the vast coverage of cellular networks and have none of the roaming support jet setting 3G users have grown to love.

If only there were a way to combine the coverage and roaming of 3G with the low cost and speed of WiFi and avoid the disadvantages of each, then we would enter that utopian world of ubiquitous high-speed wire-free data. “Development and standardization efforts are currently underway for defining suitable architectures for integrating 3G and WLAN,” explain Nasser and Hassanein, “However, designing a network architecture that efficiently integrates 3G systems and WLAN is a challenge task that needs a lot of research effort.”

Much of which is described in the special issue covering topics such as 3G/WLAN architectural design, technical management and operation of such a hybrid system, resource management, end-to-end quality of service (QoS) to make sure the whole experience of using a 3G-WLAN device is seamless and transparent, video streaming, and inevitably charging and billing.