Projects

In this project, we aim at understanding and addressing buffering and packet scheduling requirements when data from multiple VLC links needs to be aggregated across an acoustic network. The lower capacity of acoustic link forms a network bottleneck, requiring us to research, explore, and devise mechanisms for buffer sizing to limit queuing delays. Further, packet scheduling techniques will also be explored to provide Quality of Service (QoS) guarantees to data packets.

In this project, we tackled the dense deployment and energy efficient operation of sensor systems in underwater and terrestrial environments. We proposed an optimal node placement strategy that builds an initial underwater wireless sensor network infrastructure for implementing further research. We formulated the problem as a nonlinear programming with objectives of minimizing the total transmission loss, minimizing the number of nodes, and maximizing the covered volume.

Wireless mesh networks (WMNs) are a type of ad hoc wireless network that uses multi-hop wireless communications to provide or improve connectivity between wireless devices. The objective of this project is to maintain high network utilization while providing low queuing delays. This is a complex problem due to the time-varying capacity of the wireless channel as well as random access mechanism of 802.11 MAC protocol. While arbitrarily large buffers can maintain high network utilization, this comes at the cost of large queuing delays.

Delay Tolerant Networks (DTNs) are characterized as sparsely connected, highly partitioned, and intermittently connected networks. In such networks, the end-to-end path between a given pair may never exist. In this project, we developed a suit of solutions to problems of resource allocation, packet scheduling, and buffering in DTNs. Particularly, we developed and evaluated a novel routing protocol called self adaptive routing protocol (SARP). The protocol is characterized by employing an efficient updating strategy for the stochastic information at each node.

In this project, we considered the optimization of transmission power and delay in a wireless mesh networks. Our target is to dynamically determine a set of transmission rates for all the nodes in the network according to the nodes's data queue length and channel states, in order to initiate an optimal tradeoff between the power consumption and queuing time of transmitted data. We formulated this problem via a suite of modeling approaches, including the Jackson network model for data transmission and a Markov model for formulating the channel states transition.