Communication protocols for wireless ad-hoc and sensor networks
by Jin Ding, Ph.D.
Washington State University
Chair: Sirisha Medidi
Demand for decentralized wireless ad-hoc systems, where hosts are free to leave or join, to replace
wired communication systems has seen a phenomenal growth. The protocols developed for wired systems
cannot handle the new problems that come with wireless networks. This inability lays our entire
communications capability open to disruption, and requires entirely new protocols.
Traditional TCP (Transport Control Protocol), designed for wired networking, degrades significantly
over wireless links and provides abysmal throughput. This performance degradation occurs because the
TCP protocol is carefully tuned for wired networks, where most packet losses are primarily due to
congestion loss. However, in wireless ad-hoc networks, packet loss could be because of several reasons
such as link loss, node mobility and network misbehavior to name a few. Current techniques for improving
TCP do not consider the malicious packet drop attack.
Energy-efficient information dissemination is a critical operation in wireless sensor networks.
Conventional protocols like flooding or gossiping have problems such as data implosion, overlap, and
resource blindness. SPIN (Sensor Protocols for Information via Negotiation), proposed to handle these
issues uses negotiation with meta-data descriptors and resource-adaptation. However energy-efficiency was
not considered in this design.
This dissertation addresses these challenges by providing two communication protocols, one that
improves TCP performance over lossy links and another that provides energy-efficient data distribution.
First, TCP-Manet, a reliable transport protocol over wireless ad-hoc networks is introduced.
TCP-Manet determines the characteristics of the packet loss based on current connection status and reacts
effectively to the packet loss. Theoretical and simulation results show that TCP-Manet provides better
throughput performance than TCP-Reno.
Next, SPIN-G, an energy-efficient data dissemination protocol is developed. SPIN-G adapts to the
remaining battery power at any sensor node there by extending network lifetime. This protocol also uses
the negotiation, meta-data description, and resource adaptation features of SPIN and improves on the
negotiation by explicitly accounting for the battery capacity. Simulation experiments confirm that SPIN-G
dissipates less energy compared to SPIN and converges (all nodes in the network get all the data) slightly
slower than SPIN.
School:Washington State University
School Location:USA - Washington
Source Type:Master's Thesis
Keywords:wireless communication systems application protocol computer network
Date of Publication: