ABSTRACT
Contents 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 6.2 MultiBand OFDM vs. Conventional Pulse-Based
Ultra-Wide-band PHY Layer/System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 6.3 Overview of the WiMedia Physical Layer . . . . . . . . . . . . . . . . . . . . . . . . . . 188
6.3.1 PLCP Frame Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 6.3.1.1 Generation of TD and FD Preamble Symbols . . . . . 191
6.3.2 Channelization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 6.4 WiMedia PHY Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 6.5 Media Access Control Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
6.5.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 6.5.2 Beacon Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
6.5.2.1 Beacon Collision Resolution Protocol . . . . . . . . . . . . . 198 6.5.2.2 Beacon Period Extension and Contraction . . . . . . . . 200 6.5.2.3 Merging of Multiple Beacon Periods . . . . . . . . . . . . . . 201
6.5.3 Data Transfer Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 6.5.3.1 Distributed Reservation Protocol (DRP) . . . . . . . . . . . 203 6.5.3.2 Prioritized Contention Access . . . . . . . . . . . . . . . . . . . . . . 207 6.5.3.3 Fragmentation, Reassembly,
Aggregation, and Acknowledgment Policies . . . . . . 209
6.5.4 Power Management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 6.5.5 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
6.6 WiMedia MAC Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
6.1 Introduction The WiMedia Alliance is a nonprofit association of more than 200 industry corporations and research institutions for the specification, promotion, and multivendor interoperability of ultrawideband (UWB) communication solutions. The six largest consumer electronics companies of the world and nine of the ten largest semiconductor companies are members of WiMedia. The first UWB standard of WiMedia enables data rates of up to 480 Mb/s and can therefore be used for the wireless transmission of USB2.0 frames between a personal computer and its peripheral devices. Another strength of UWB is its low power consumption, which makes it suitable for mobile devices, such as cameras, MP3 players, and so forth.
