Section 14.1. The Mobile Web

14.1. The Mobile Web

With the World Wide Web now firmly entrenched as a part of normal modern life, it is only natural that users want to access web content wherever they may be, at any time. Responding to this demand, vendors now offer an incredible array of devices and access methods to meet that need. Although the types of devices number in the hundreds, the overall market can be examined as a few key product categories.

14.1.1. Devices

Most of today's mobile devicesmobile phones and personal digital assistants (PDAs)have digital displays, typically an LCD, and onboard processing. So why not a built-in browser?

14.1.1.1. Mobile phones

The browser software resides in the cell phone's core operating system and the end user cannot easily upgrade or extend it. And, as we discuss in more detail shortly, it has far fewer features than are normally associated with a typical desktop browser. Other features are available only to the persistent user willing to endure horrifically bad user interfaces to reach them.

The cell phone provider gives you access to the Internet by any one of several different technologies, and some restrict the available content, or make it difficult to access content outside of their proprietary web portal.

14.1.1.2. PDAs

PDAs arguably provide the best mobile web experience. The PDA marketplace is dominated by devices running the Palm OS operating system from PalmSource, Inc. (originally Palm Computing, Inc.) and those running the Windows Mobile operating system from Microsoft. Regardless of vendor, these devices provide a high-quality browser that may include many of the features you would normally find in a desktop browser. The end user can upgrade or extend the browser with relative ease. Other network applications, such as email and FTP, may be available as well.

PDAs typically rely on the Institute of Electrical and Electronics Engineers (IEEE) standard 802.11, commonly known as WiFi (pronounced "why fie"), for wireless Ethernet-based connectivity with a network and, ultimately, the Internet. Some PDAs use Bluetooth, an alternative wireless technology, to connect with another network device, such as a mobile phone, laptop computer, or Bluetooth network access point, in order to ultimately connect with the Web.

14.1.1.3. Convergence devices

Convergence devices attempt to marry the convenience of a mobile phone with the flexibility and power of a PDA. They use cellular network connectivity, but may also offer 802.11 networking, as well. They can run most applications available to PDA users and provide some integration between the PDA experience and conventional telephony features. Convergence products are currently offered by PalmSource (running Palm OS and Windows Mobile) and various cellular phone manufacturers (running Windows Mobile). Convergence devices offer distinct compromises between the PDA experience, with its larger screen and computing power, and mobile phones, with their small form factor and ease of use.

14.1.2. Cellular Access

In addition to the device type, users can choose from a number of access plans that allow their mobile device to connect with the Internet. As with mobile devices, hundreds of access plans are available, but they can generally be categorized into a few common groups.

14.1.2.1. Low speed

Often known as first- or second-generation data access, low-speed cellular access operates at rates similar to that of a 56-kilobaud dial-up modem. Providers typically charge by the byte (!), with packages offering blocks of bytes on a monthly basis. Because of its speed and relatively high cost, low-speed access is intended for intermittent, sparse use for specific small-volume tasks . Continuous access using these plans is not feasible , both from the cost perspective and from its arduously slow data rate. This kind of low-speed access is available exclusively on mobile phones and some convergence devices from many different vendors.

14.1.2.2. High-speed cellular access

Recent advances in cellular technology have enabled carriers to offer high-speed cellular access with speeds ranging up to 1.5 megabits per second. At these speeds, users can enjoy a high-quality web experience that includes video and audio content. Recognizing the market potential, most carriers offer high-speed access in a single-price, unlimited-usage plan. Marketed under a variety of monikers (such as EDGE and EVDO, among others), this kind of connectivity was originally deployed in mobile phones, but is fast showing up in PDAs, convergence devices, and some laptop computers.

14.1.2.3. WiFi

Many web-enabled PDAs and some convergence devices include 802.11 wireless networking and, consequently, can connect with compatible wireless LAN access points that have become ubiquitous in the last few years . Whole cities and campuses now provide pervasive wireless and consequent mobile access to the Internet. While most devices offer the "b" version of the technology (802.11b), which operates at a maximum of 11 megabits per second, some newer devices include the "g" version, which provides for rates up to 54 megabits per second. Access costs range from free (home networks, employer networks, and public access points) to tens of dollars per month for independent suppliers, such as Cingular and T-Mobile.

Based on this device and access taxonomy, the mobile web content designer has nine potential user environments to consider. Unfortunately, it gets much worse because each specific device and access plan may have its own restrictions and idiosyncrasies. As we'll see in the next section, dozens of variables can affect the overall mobile web user experience.