Duplexing methods for PON systems using multimode fiber with multicarrier transmission

Deploying a PON using multimode fiber in the access network is viewed as a costeffective solution. However, a multimode fiber link exhibits a time-dispersive nature. To cope with this problem, an OFDM transmission method is used. In this work, a comparison study on several duplexing methods for this system was performed to decide upon the recommended method for the system. The choices that were examined are: TDD, FDD, WDD and SDD (time-, frequency-, wavelength- and space- division duplexing). Based on the following criteria: channel characterization, flexible bandwidth proportion, crosstalk & beat noise impairment, components-saving and system capacity, it was concluded that SDD is the most feasible one among other choices, immediately followed by WDD

Anglo-Dutch premium auctions in eighteenth-century Amsterdam

An Anglo-Dutch premium auction consists of an English auction followed by a Dutch auction, with a cash premium paid to the winner of the first round. We study such auctions used in the secondary debt market in eighteenth-century Amsterdam. This was among the first uses of auctions, or any structured market-clearing mechanism, in a financial market. We find that this market presented two distinct challenges - generating competition and aggregating information. We argue that the Anglo-Dutch premium auction is particularly well-suited to do both. Modeling equilibrium play theoretically, we predict a positive relationship between the uncertainty in a security's value and the likelihood of a second-round bid. Analyzing data on 16,854 securities sold in the late 1700s, we find empirical support for this prediction. This suggests that bidding behavior may have been consistent with (non-cooperative) equilibrium play, and therefore that these auctions were successful at generating competition. We also find evidence suggesting that these auctions succeeded at aggregating information. Thus, the Anglo-Dutch premium auction appears to have been an effective solution to a complex early market design problem