Secure Roaming in 802.11 Networks

Chapter 2

with automatic intersystem handoff, call delivery, validation, and authentication [17]. How-

ever, these features did not appear in the cellular networks until the early 1990s, nearly

concurrent with the arrival of digital systems [19].

In the previous paragraph, we noted that IS-41 provides seamless roaming and “automatic

handoff.” This point is worth elaborating on, so that later, the reader may compare and contrast

handoffs and roaming in the cellular world to those in the 802.11 framework. Although there

are many different scenarios which cause roaming in the cellular world, we will focus on the

one depicted in Figure 2.3. In the figure, ...