Case Study: Handover With WLAN, WiMAX and 3G

Abstract

In this chapter, the above reasoning is extended to include data-centric standards such as WLAN, WiMAX and 3G [1]. It is important to note the choice of standards for a topic like this. This choice should make sense from a usability perspective. WLAN, WiMAX and 3G fall into the categories of Local Area Network (LAN), Metropolitan Area Network (MAN), and Wide Area Network (WAN) respectively. No Personal Area Network (PAN) standard is included since the mode of usage of Bluetooth for example which is a PAN standard is typically in parallel with other standards. As a result, PAN standards will always have their dedicated transceivers and it does not make sense to include them here.

Additionally, each of WLAN, WiMAX and 3G has something unique to offer and thus they can be considered complementary. For example, the high connection speeds and the low-cost of connecting to, most of the time free, WLAN networks are unbeatable if the user is nomadic more than mobile. On the other extreme, the wide coverage that 3G (and GSM) have is unbeatable due to the excellent network deployments that providers have done over the years. WiMAX falls somewhere in between and it is expected that the market models and the benefits/disadvantages differ so much that all these standards will have their market share.

Our main focus is the implementation of the physical layer. However, as we delve more into this topic, it becomes also clear that one of the things to look for consists of the constraints and/or benefits that can be extracted by studying the upper layers. Some questions that we will be trying to answer are: given the Sniffer-based architecture, how simplified can the Sniffer be in terms of physical specifications? What are the minimum functions that the Sniffer should include while still being able to perform its functionality?

In order to answer these questions, we have chosen to put the initial focus on the link-establishment procedures as well as the idle mode procedures of these standards. After extracting these from the standards documents along with the minimum physical specifications that the Sniffer should have, we form simplified flowcharts that we combine afterwards in order to show the complete handover flow that takes place between the Sniffer and the main transceiver.