Today’s location-sensitive service relies on user’s mobile device to determine the current location. This allows malicioususers to access a restricted resource or provide bogus alibis by cheating on their locations. To address this issue, we propose A Privacy -Preserving Location proof Updating System (APPLAUS) in which colocated Bluetooth enabled mobile devices mutually generate location proofs […]
Towards Statistically Strong Source Anonymity for Sensor Networks
In certain applications, the locations of events reported by a sensor network need to remain anonymous. That is , unauthorized observers must be unable to detect the origin of such events by analyzing the network traffic. Known as the source anonymity problem, this problem has emerged as an important topic in the security of wireless […]
Optimal Geographical Forwarding using Relay Selection in Wireless Sensor Networks with Sleep-Wake Cycling Nodes
Our work is motivated by geographical forwarding of sporadic alarm packets to a base station in a wireless sensor network (WSN), where the nodes are sleep-wake cycling periodically and asynchronously. We seek to develop local forwarding algorithms that can be tuned so as to tradeoff the end-to-end delay against a total cost, such as the […]
A new Distributed Cooperation and Diversity Combining framework in hybrid wireless networks
Our focus is on heterogeneous networks with devices equipped with two types of radio frequency (RF) interfaces: short-range high-rate interface (e.g., IEEE802.11), and a long-range low-rate interface (e.g., cellular) communicating over urban Rayleigh fading channels. Within this framework, we propose and evaluate a set of distributed cooperation techniques operating at different hierarchical levels with resource […]
Improving Probabilistic Route Discovery in Mobile Ad Hoc Networks
Due to high mobility of nodes in mobile ad hoc networks (MANETs), there exist frequent link breakages which lead to nfrequent path failures and route discoveries. The overhead of a route discovery cannot be neglected. In a route discovery, broadcasting is a fundamental and effective data propagation mechanism, where a mobile node blindly rebroadcasts the […]
Resource allocation for multicast services in multicarrier wireless communications
Multicast/broadcast is regarded as an efficient technique for wireless cellular networks to transmit a large volume of common data to multiple mobile users simultaneously. To pledge the quality of service for each mobile user in such single-hop multicasting, the base-station transmitter usually adapts its data rate to the worst channel condition among all users in […]
Semi-random backoff: Towards resource reservation for channel access in 802.11e wireless LANs
This paper proposes a semi-random backoff (SRB) method that enables resource reservation in contention-based wireless LANs. The proposed SRB is fundamentally different from traditional random backoff methods because it provides an easy migration path from random backoffs to deterministic slot assignments. The central idea of the SRB is for the wireless station to set its […]
An asynchronous neighbor discovery algorithm for wireless sensor networks
Neighbor discovery is an important first step in the initialization of a wireless ad hoc network. In this paper, we design and analyze several algorithms for neighbor discovery in wireless networks. Starting with a single-hop wireless network of nodes, we propose a ALOHA-like neighbor discovery algorithm when nodes cannot detect collisions, and an order-optimal receiver […]
Bandwidth scheduling and path computation algorithms for connection-oriented Networks
An increasing number of high-performance networks provision dedicated channels through circuit switching or MPLS/GMPLS techniques to support large data transfer. The link bandwidths in such networks are typically shared by multiple users through advance reservation, resulting in varying bandwidth availability in future time. Developing efficient scheduling algorithms for advance bandwidth reservation has become a critical […]
Correlated flooding in low-duty-cycle wireless sensor networks
Although existing flooding protocols can provide efficient and reliable communication in wireless sensor networks on some level, further performance improvement has been hampered by the assumption of link independence, which requires costly acknowledgments (ACKs) from every receiver. Flooding is a network-layer protocol that delivers a message from one node to all the other nodes inside […]