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Abstract : |
Monitoring the location of customer equipment is an important problem in the direct broadcasting satellite industry. This is because the service providers would like to prevent unauthorized movement of a customer's set top terminal (STT) from a home to a public venue, or across an international border, due to various financial, copyright and political issues. In this paper we study four schemes for detecting the movement of the an STT using the existing (or emerging) communication infrastructure. We start with the currently used scheme which is based on the telephone network's ANI or CND (caller-ID) features, and show how it can be undermined. Then we suggest three new schemes which are more robust than the caller ID scheme: one that that uses the Global Positioning System (GPS), one that uses the cellular phone's enhanced 911 (E911) service, and one that measures the time-difference-of-arrival of the satellite's broadcast. We discuss the accuracy, features and vulnerabilities of each scheme. We also present possible attacks that allow pirates to conceal their movement when these schemes are employed., |
