MACAW

TLDR

The proliferation of mobile computing devices such as portables, palmtops, and PDAs has driven the need for new wireless LAN technologies, building on earlier protocols like MACA. The study investigates media access protocols for a single‑channel wireless LAN developed at Xerox PARC. Using packet‑level simulations, the authors evaluate performance and design issues of these protocols. The analysis results in MACAW, a protocol featuring an RTS‑CTS‑DS‑DATA‑ACK exchange and a distinct backoff algorithm.

Abstract

In recent years, a wide variety of mobile computing devices has emerged, including portables, palmtops, and personal digital assistants. Providing adequate network connectivity for these devices will require a new generation of wireless LAN technology. In this paper we study media access protocols for a single channel wireless LAN being developed at Xerox Corporation's Palo Alto Research Center. We start with the MACA media access protocol first proposed by Karn [9] and later refined by Biba [3] which uses an RTS-CTS-DATA packet exchange and binary exponential back-off. Using packet-level simulations, we examine various performance and design issues in such protocols. Our analysis leads to a new protocol, MACAW, which uses an RTS-CTS-DS-DATA-ACK message exchange and includes a significantly different backoff algorithm.