Browsing by Author "Jiang, JR"

Now showing 1 - 2 of 2

Quorum-based asynchronous power-saving protocols for IEEE 802.11 ad hoc networks
(2005-02-01)
Jiang, JR
;
Tseng, YC
;
Hsu, CS
;
Lai, TH
;
資訊工程學系
This paper investigates the power mode management problem for an IEEE 802.11- based mobile ad hoc network (MANET) that allows mobile hosts to tune to the power-saving ( PS) mode. There are two major issues that need to be addressed in this problem: ( a) wakeup prediction and (b) neighbor discovery. The former is to deliver buffered packets to a PS host at the right time when its radio is turned on. The latter is to monitor the environment change under a mobile environment. One costly, and not scalable, solution is to time-synchronize all hosts. Another possibility is to design asynchronous protocols as proposed by Tseng et al. in [ 25]. In this paper, we adopt the latter approach and correlate this problem to the quorum system concept. We identify a rotation closure property for quorum systems. It is shown that any quorum system that satisfies this property can be translated to an asynchronous power-saving protocol for MANETs. Thus, the result bridges the classical quorum system design problem in the area of distributed systems to the power mode management problem in the area of mobile ad hoc networks. We derive a lower bound for quorum sizes for any quorum system that satisfies the rotation closure property. We identify a group of quorum systems that are optimal or near optimal in terms of quorum sizes, which can be translated to efficient asynchronous power-saving protocols. We also propose a new e-torus quorum system, which can be translated to an adaptive protocol that allows designers to trade hosts' neighbor sensibility for power efficiency. Simulation experiments are conducted to evaluate and compare the proposed protocols.
Secure bootstrapping and routing in an IPv6-based ad hoc network
(2003)
Tseng, YC
;
Jiang, JR
;
Lee, JH
;
資訊工程學系
;
Department of Computer Science
The mobile ad hoc network (MANET), which is characterized by an infrastructureless architecture and multi-hop communication, has attracted a lot of attention recently. In the evolution of IP networks to version 6, adopting the same protocol would guarantee the success and portability of MANETs. In this paper we propose a secure bootstrapping and routing protocol for MANETs. Mobile hosts can autoconfigure and even change their IP addresses based on the concept of CGA (cryptographically generated address), but they can not hide their identities easily. The protocol is modified from DSR (dynamic source routing) to support secure routing. The neighbor discovery and domain name registration in IPv6 are incorporated and enhanced with security functions. The protocol is characterized by the following features: (i) it is designed based on IPv6, (ii) relying on a DNS server it allows bootstrapping a MANET with little pre-configuration overhead, so network formation is light-weight, and (iii) it is able to resist a variety of security attacks.