Mobile Inter-networking with IPv6 : Concepts, Principles and Practices

22

Seamless Handovers

If your result needs a statistician, then you should design a better experiment.    –Ernest Rutherford

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22.1 INTRODUCTION

While bandwidth may be abundant at the Internet core, access networks are typically traffic bottlenecks requiring careful resource management. This is visible in dial-in, cable modem, DSL and wide-area wireless Internet access. The prevailing wisdom for Internet applications and services is a “simple core” and an “intelligent edge” network. As we discussed in Chapter 16, resource management at an intelligent edge network inevitably introduces state or context at the access network nodes in order to meet the needs of applications as well as those of the network itself. QoS and header compression are two good examples that require context management on the access networks due to application constraints and network constraints respectively. With node mobility, these contexts have to be carefully managed in order to support uninterrupted services to the user. In this chapter, we discuss the transfer of the header compression state synchronized with handovers. This is a reflection of experiments using the implementations of fast handover and context transfer, both of which we have discussed at length in previously.

The particular feature context of interest here is header compression [3,4], which is compelling for the following reasons. First, ...