Despite the growing need for spectrum resources, spectrum licensed for commercial use remains largely underutilized due to lack of established market mechanisms for dynamic trading of the spectrum between cellular operators. Further, there are no protocols that implement such sharing and exchange on short time scales. Multi-operator spectrum sharing is therefore necessary not only to make best use of this critical resource (spectrum), but also to improve the profitability of spectrum service providers and reduce the cost to customers. Towards this goal, the project aims to develop new market mechanisms and protocol support for dynamic and automated spectrum sharing between cellular providers. Deriving motivation from electricity markets, the project analyzes a two-step design for spectrum markets, involving trading of both forward and spot spectrum contracts between cellular operators. Building upon the Open Radio Access Network (O-RAN) software framework, the project also analyzes designs that provide logical connectivity from different radio access networks (that might belong to different operators) to the cellular core networks of one or more of the chosen operators. This project explores a design of a two-timescale market involving a forward spectrum market (FSM) and a spot spectrum market (SSM) through which forward and spot spectrum contracts are traded between cellular providers, in addition to any bilateral settlements that may exist over longer timescales. This e