The future of Web services lies not just in traditional computer-to-computer communications. Instead, it will include the prevalent use of mobile devices, in particular cell phones.
As cell phones become increasingly powerful, with computer-like processors, memory and resident applications, they are becoming a more important part of the enterprise. And that means that they are increasingly targeted for Web services development.
In this second part of a two-part column, we'll look at the roadblocks holding back the use of Web services on mobile devices -- and see how those problems are likely to be solved, and what the future of mobile Web services may look like.
The problems with cell phones
Despite the potential for putting applications onto cell phones, to date that hasn't happened. Why haven't developers targeted cell phones?
Ron Schmelzer, senior analyst with ZapThink, says that a primary reason is that a cell phone "is a bad interface to the Web. It's not an intuitive form factor, the screen is small, you can't read graphics well, and there's no real keyboard."
Timo Skytta, director of Web services at Nokia, a company that has recently built Web service support into its phones, concurs with Schmelzer.
"The biggest problem is usability," he says. "There's a limited display and a limited keyboard."
Because of this, putting a full-blown application onto a cell phone, both Schmelzer and Skytta say, simply isn't practical. But this needn't hold back putting Web services onto phones.
"The answer is to put enough of a client on a phone to serve as a user interface, but to put the functionality on a server," Schmelzer says. That way, the phone can have a fully featured application, which in essence resides on a server.
That architecture, he notes, mirrors the Web services architecture. One can have a small application on the phone itself, and the server can populate it with data, and handle communications.
That's easier said than done, of course. Developing a client rich enough to be useful, but thin enough to reside on a phone is no easy task. But the solution may be close at hand. Schmelzer points out that Macromedia has developed a Flash client for phones, and he believes that it will be used as a front-end for many Web service deployments.
But no matter how widely a Flash client is used, browsing via the Web will be an important part of Web services deployments. The small screen of a cell phone simply isn't designed for that task.
Nokia's Skytta believes that in the long run, that problem will be solved. He points out that the W3C currently has a mobile Web initiative underway, which is targeted at how to better serve browsing for mobile devices. Most likely, he says, cascading style sheets and other technologies will solve the problem.
There are other issues as well, and bandwidth is a significant one. Cell phone networks, even 3G networks, are slow compared to wired networks, and XML traffic is "heavy and inefficient," according to Schmelzer.
Again, a solution is on the horizon. There is a movement toward binary XML, which is optimized by network traffic and processing. The use of binary XML would be ideal for a low-bandwidth network like a cell phone network. Additionally, the Flash player is extremely bandwidth-efficient, so will help as well.
Yet one more problem is security. Securing and authenticating Web services is a difficult enough problem, but when you add wireless communications to the mix, it gets even more problematic. But the federated identity movement, and authentication mechanisms such as biometrics or voicemail authentication may solve those problems as well.
What the future holds
Assuming all those problems are solved, what can we expect from mobile Web services?
Schmelzer points to a whole range of applications. The most obvious are sales and productivity applications for mobile sales forces, but he also says that they'll be well-suited for communications and collaboration as well. And the small size and portability of cell phones makes them a natural fit for bar code scanning and logistics applications.
But expect a whole host of consumer applications as well that let you buy movie ticket, find maps, or use GPS location services.
Skytta believes that within five to eight years, virtually everyone with a cell phone will be using Web services.
"Accessing Internet-based services with this technology will be an everyday thing," he believes. "Just look at the penetration of phones versus PCs, and you can see why that will happen."
Mobile network operators are especially keen on the idea, because their growth opportunity is in data services rather than voice, and so they'll be pushing the technology hard.
Beyond that, though, Skytta believes that large portions of the world will ultimately access the Internet via cell phones using Web services, rather than via traditional means of Internet access.
He points to Africa, in particular, as being ripe for this. The Internet infrastructure in Africa is barely developed, and mobile infrastructure is much easier to deploy. So a sizable portion of the world may view the Web through the small lens of a cell screen, thanks to Web services.