Abhinav Sinha

Generalized proportional allocation mechanism design for multi-rate multicast service on the Internet

In multicast transmission on the Internet, agents are divided into multicast groups based on the content they demand. In addition, when multi-rate transmission is used, each user in the same multicast group may request different quality of service for the same content. With multi-rate multicast transmission, each link on the network carries only the highest quality content of each multicast group passing through this link, thus resulting in substantial resource savings compared to unicast transmission. In this paper a mechanism is constructed that fully implements social welfare maximising allocation in Nash equilibria for the case of multi-rate multicast service under the assumption of strategic agents for whom utilities are private information. The emphasis of this work is on full implementation, which means that all pure strategy Nash equilibria of the induced game result in the optimal allocations of the centralised allocation problem. The mechanism, which is constructed in a quasi-systematic way starting from the dual of the centralized problem, has a number of additional useful properties. Specifically, the proposed mechanism results in feasible allocation (in fact in Pareto optimal allocation) even off-equilibrium. Finally, in the extended version of this paper it is shown how strong budget balance at equilibrium can be added to the proposed mechanism in a straightforward manner.

Incentive Mechanisms for Fairness Among Strategic Agents

Mechanism design for incentivizing strategic agents to maximize their sum of utilities (SoU) is a well-studied problem in the context of resource allocation in networks. There are, however, a number of network resource allocation problems of interest where a designer may have a different objective than maximization of the SoU. The obvious reason for seeking a different objective is that this notion of efficiency does not account for fairness of allocation. A second, more subtle, reason for demanding fairer allocation is that it indirectly implies less variation in taxes paid by agents. This is desirable in a situation where implicit individual agent budgetary constraints make payment of large taxes unrealistic. In this paper, we study a family of social utilities that provide fair allocation (with SoU being subsumed as an extreme case) and derive conditions under which Bayesian and dominant strategy implementation is possible. Furthermore, it is shown how a modification of the above-mentioned mechanism by adding just one message per agent can guarantee full Bayesian implementation, i.e., no extraneous equilibria. We consider the problem of demand-side management in smart grids as a specific motivating application, and through numerical analysis, it is demonstrated that in this application, the proposed method can result in significant gains in fairness of allocation and a reduction in tax variation among agents.

Mechanism Design for Resource Allocation in Networks With Intergroup Competition and Intragroup Sharing

We consider a network where strategic agents, who are contesting for allocation of resources, are divided into fixed groups. The network control protocol is such that within each group agents get to share the resource and across groups they contest for it. A prototypical example is the allocation of data rate on a network with the multicast/multirate architecture. Compared to the unicast architecture (which is a special case), the multicast/multirate architecture can result in substantial bandwidth savings. However, design of a market mechanism in such a scenario requires dealing with both private and public good problems as opposed to just private goods in unicast. The mechanism proposed in this paper ensures that social welfare maximizing allocation on such a network is realized at all Nash equilibria (NE), i.e., full implementation in NE. In addition it is individually rational, i.e., agents have an incentive to participate in the mechanism. The mechanism, which is constructed in a quasi-systematic way starting from the dual of the centralized problem, has a number of useful properties. Specifically, due to a novel allocation scheme, namely “radial projection,” the proposed mechanism results in feasible allocation even off equilibrium. This is a practical necessity for any realistic mechanism since agents have to “learn” the NE through a dynamic process. Finally, it is shown how strong budget balance at equilibrium can be achieved with a minimal increase in message space as an add-on to a weakly budget balanced mechanism.