The medium-access control (MAC) protocols for wireless networks proposed or implemented to date based on collision-avoidance handshakes between sender and receiver either require carrier sensing or the assignment of unique codes to nodes to ensure that intended receivers hear data packets without interference from hidden sources. We present and analyze a new collision-avoidance MAC protocol that we call receiver-initiated channel-hopping with dual polling (RICH-DP). RICH-DP is the first MAC protocol based on a receiver-initiated collision-avoidance handshake that does not require carrier sensing or the assignment of unique codes to nodes in order to ensure collision-free reception of data at the intended receivers in the presence of hidden terminals. The throughput and delay characteristics of RICH-DP is studied analytically, and extensive simulations are presented to verify the analysis and to present a more accurate prediction of how RICH-DP would operate in realistic scenarios. RICH-DP is applicable to ad-hoc networks based on commercial off-the-shelf frequency hopping radios operating in unlicensed frequency bands.

The medium-access control (MAC) protocols for wireless networks proposed or implemented to date based on collision-avoidance handshakes between sender and receiver either require carrier sensing or the assignment of unique codes to nodes to ensure that intended receivers hear data packets without interference from hidden sources. We present and analyze a protocol that we call channel-hopping multiple access (CHMA) for multi-channel, ad-hoc networks which does not require carrier sensing or the assignment of unique codes to nodes to ensure collision-free reception of data at the intended receivers in the presence of hidden terminals. We compare CHMA against MACA-CT and show considerable improvement in the performance achieved. The correct avoidance of collisions in CHMA protocols is verified, and their throughput and delay characteristics is studied analytically. CHMA protocols are applicable to ad-hoc networks based on commercial off-the-shelf spread spectrum radios operating in unlicensed frequency bands.

The medium-access control (MAC) protocols for wireless networks proposed or implemented to date based on collision-avoidance handshakes between sender and receiver either require carrier sensing or the assignment of unique codes to nodes to ensure that intended receivers hear data packets without interference from hidden sources (i.e. IEEE 802.11). We present and analyze a receiver-initiated channelhopping (RICH) protocol, which is the first MAC protocol based on a receiverinitiated collision-avoidance handshake that does not require carrier sensing or the assignment of unique codes to nodes to ensure collision-free reception of data at the intended receivers in the presence of hidden terminals. The correct floor acquisition for RICH is verified, and the throughput and delay characteristics are calculated analytically. The RICH protocol presented here is applicable to ad-hoc networks based on commercial, off-the-shelf, spread spectrum frequency-hopping radios operating in unlicensed frequency bands. I.

viii Acknowledgements x Dedication xii Chapter 1

ix Dedication x Acknowledgements xi 1 Introduction 1 2 Receiver-Initiated Multiple-Access Protocols 10 2.1 Receiver-Initiated Collision Avoidance . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.2 Receiver-Initiated Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2.1 Protocols with Simple Polling . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2.2 Protocols with Dual-Use Polling . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.2.3 Protocols with Broadcast Polling . . . . . . . . . . . . . . . . . . . . . . . . . 23 2.3 Correct Collision Avoidance in RIMA protocols . . . . . . . . . . . . . . . . . . . . . 25 2.4 Performance Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2.4.1 Approximate Throughput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2.4.2 Average Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 2.5 Simulation Results . . . . . . . . . . . . ...