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SIGMETRICS 2001 / Performance 2001Capacity Evaluation of Frequency Hopping Based Ad-hoc Systems |
| Authors |
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Apurva Kumar <kapurva@in.ibm.com> Rajeev Gupta <grajeev@in.ibm.com>
IBM India Research Lab, New Delhi, India
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| Abstract |
| The IEEE 802.15 Wireless Personal Area Networks (WPAN) study group has been working on evolving a standard for short-range wireless connectivity between low complexity and low power devices operating within the personal operating space (POS). The scenarios envisioned for WPANs are likely to involve a large number of POSs operating in an indoor environment. Among short-range wireless technologies, BluetoothTM 1 based ad-hoc connectivity comes closest to satisfying the WPAN requirements. Bluetooth provides a gross rate of 1 Mbps per network and allows several such networks to overlap using frequency hopping. The 'aggregate throughput' thus achieved is much higher than 1 Mbps. In the absence of external interfering sources, aggregate throughput is limited by self interference which depends upon, (i) physical layer parameters like hopping rate, hopping sequences, transmitted power, receiver sensitivity, modulation, forward error correction (ii) channel characteristics like coherence bandwidth and coherence time (iii) spatial characteristics. In this work we consider the problem of finding the capacity of Bluetooth based ad-hoc systems by accurately modeling the Bluetooth physical layer and the indoor wireless channel. We predict the throughput in Bluetooth based ad-hoc systems as a function of a generalized set of parameters using realistic scenarios and assumptions. |