Device-to-Device and Relay-Enhanced Cellular Architecture
Creators: name: University Of California Office Of The President
Publisher: name: University of California Office of the President
publisherIdentifier: https://ror.org/00dmfq477
publisherIdentifierScheme: ROR
Year: 2024

description: In cellular communications today, a mobile user communicates with another user by sending signals through a base station. Device-to-device (D2D) communications would enhance this model: when two people who want to communicate are close to each other, their devices can transmit directly to each other. This might save on power and on bandwidth usage, because the same frequency which they use to communicate might be re-used by another D2D connection elsewhere in the same cell. We will also study the use of relays an additional augmentation of the architecture. These structures can be useful in areas with dense communications, such as airports, shopping malls, amusement parks, and university campuses, where resources may be strained by the large number of people trying to connect, and where many of the users are in fact communicating to other users nearby, where a D2D link would be feasible. We will develop and evaluate algorithms for determining when users should communicate in regular mode (via the base station) and in D2D mode, for allocating the number and specific choices of frequency bands and relays for the different users, and for monitoring the amount of interference users on the same frequency bands are causing to each other. We will quantify how much savings in terms of power and bandwidth result, and how much increase in the number of users the D2D and relay-enhanced underlay structure allows. We will also develop our theoretical understanding of the D2D and relay environment by analyzing the best coding methods and the system capacity. In addition to advances in algorithm development and theory, we will implement a reconfigurable wireless networking hardware testbed to make practical measurements and evaluations. A main application will be transmission of layered video over these D2D and relay links, for which we will evaluate the system performance in terms of received video quality. In particular, we will study the case where relays may be dedicated to a video base layer or an enhancement layer to optimize received quality. The proposed research is important because data traffic, especially video, over wireless networks is expected to grow exponentially, and it will be challenging for future networks to meet the growth. Direct D2D communications can allow more users, especially bandwidth-hogging video users, to share limited network resources, without huge infrastructure costs. This research will benefit California because many telecommunications electronics manufacturers, information providers, and cellular providers are large employers in the state. Successful completion of the proposed testbed research will enhance UCSD's infrastructure for experimental communication research, and the various theoretical, algorithm, and experimental components of the project will provide valuable training to both graduate and undergraduate students to provide a skilled workforce for the state of California.