Future Wireless Information Networks (WINs) will provide integrated services (e.g., voice, video, data, images, and multimedia) each with its own bandwidth and Quality of Service (QoS) requirements. To meet this challenge, it is necessary to design systems that deal effectively with bandwidth management, mobility, multipath fading, shadowing, interference, abrupt changes in link (channel) quality and network topology, variability in QoS re-quirements, and increasing user demand. Designs that deal effectively with the above issues will have to jointly optimize the operation of subsystems that potentially cut across several network architecture and protocol layers. The proposed research aims at integrated designs of WINs that account for the interactions among layers and takes advantage of these interactions to discover algorithms that deal effectively with the above mentioned issues. We believe that the physical layer plays a crucial role in the performance of WINs because it is the least controllable and predictable layer in the network architecture. This is why we propose to: (i) understand primarily the impact of the physical layer on the performance of the data link control, Media Access Control (MAC), network, and transport layers; and (ii) exploit this impact to develop a systematic approach to the integrated design of WINs. To achieve this goal, we propose to investigate single-hop and multi-hop problems separately, with the understanding that, eventually, an overall design will integrate, in an iterative manner, the issues critical for single-hop problems with those that are critical for multi-hop problems. For single-hop problems, we will (i) investigate the interactions among components of the physical layer so that we can improve the layer's design; (ii) exploit the impact of the physical layer on the data link control, MAC, and transport layers in order to develop efficient Automatic Repeat request (ARQ) algorithms, and dynamic resource allocation algorithms, and to develop mechanisms to improve the performance of Transmission Control Protocol (TCP) over wireless links. For multi-hop problems, we will (i) exploit the impact of the physical, data link control, and MAC layers on the network layer to develop efficient multi-hop routing, alternate routing, power control (topology control), load-balancing, and congestion control algorithms; (ii) take advantage of the impact of the physical, data link control, and MAC layer on the transport layer to design simple, efficient, and robust mechanisms of TCP in multi-hop WINs; (iii) design and validate simple communication protocols incorporating the algorithms and mechanisms developed in (i) and (ii). The proposed activities in connection with other relevant research activities at the University of Michigan and Purdue University will provide an excellent vehicle for the training of future wireless information network engi-neers.
Keywords: Wireless networks, resource allocation, receiver architecture, fading channels, integrated services, routing and flow control. ***
