Detecting Spectrum Opportunities in Poisson Primary Networks
Abstract
Opportunistic spectrum access (OSA), also referred to as spectrum overlay, is one of several approaches envisioned for dynamic spectrum management. The basic idea of OSA is to allow secondary users to exploit temporarily and locally unused channels without causing unacceptable interference to primary users. One of the central issues in OSA is spectrum opportunity detection through sensing. Before transmitting over a particular channel, a secondary user needs to decide whether this channel is an opportunity. This is the so-called "Listen-before-Talk" (LBT) process. In this report, to quantitatively characterize the performance of LBT, we consider a slotted network setup in which primary users are distributed according to a spatial Poisson process. We first analyze the performance of LBT at both physical and MAC layers, and then we investigate the translation from physical layer opportunity detection performance to MAC layer performance, which is crucial in the design of the opportunity detector. In particular, we demonstrate the complex dependency of the relationship between PHY and MAC on the application type (guaranteed delivery vs. best-effort delivery) and the use of handshaking signaling such as RTS/CTS at the MAC layer. Throughout the report, we use capital letters for parameters of primary users and lower-cased letters for secondary users.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2007
- Accession Number
- ADA575938
Entities
People
- Qing Zhao
- Wei Ren
Organizations
- University of California