Performance of Prefix Delegation-Based Route Optimization Schemes: Intra Mobile Network case

Among the route optimization schemes in NEtwork MObility (NEMO), the prefix delegation-based schemes perform better than other schemes. Since the prefix delegation-based schemes are designed for communication between a mobile network and a wired network, they lack evaluation for the case of intra mobile network communication involving MIPv6 incapable hosts in a mobile network. We evaluate prefix delegation-based schemes to reveal their inefficiencies for the case where both the communicating hosts are mobile and MIPv6 incapable, propose extensions, and compare them. Since both the communicating hosts are mobile, handoff latency in extended schemes are large resulting in significant performance loss when the speed of the mobile network is high. Results reveal that the effect of speed of the mobile network dominates the performance in such cases. We conclude that for slow moving mobile networks, extended schemes are preferable

Route Optimization in Network Mobility: Solutions, Classification, Comparison, and Future Research Directions

NEtwork MObility (NEMO) handles mobility of a set of mobile nodes in an aggregate way using one or more mobile routers. NEMO introduces several advantages, such as reduced signaling, increased manageability, reduced power consumption and conservation of bandwidth when compared to individual host mobility. NEMO Basic Support Protocol (BSP), the IETF standard for NEMO, suffers from a number of limitations, like inefficient route and increased handoff latency. Most of the recent research efforts on NEMO have concentrated on solving the problem of inefficient route resulting in several route optimization schemes to solve the problem. To choose a route optimization scheme, it is very important to have a quantitative comparison of the available route optimization schemes. The objective of this article is to survey, classify and compare the route optimization schemes proposed in the literature over the last five years. We classify the schemes based on the basic approach for route optimization, and compare the schemes based on protocol overhead, such as header overhead, amount of signalling, and memory requirements. We conclude that performance of the classes of schemes has to be evaluated under criteria such as available bandwidth, topology of the mobile network and mobility type

Gender differences in the repayment of microcredit: The mediating role of trustworthiness

Growing evidence suggests that women are more likely to repay collateral-free microloans than men. However, we know little about what explains such gender differences. We hypothesize that better repayment performance of women microcredit borrowers can largely be explained by gender differences in innate trustworthiness. We conduct a trust game and a microloan repayment game in rural Bangladesh. We find that women are more trustworthy than men and that they are more likely to repay their loans irrespective of any control mechanisms, such as joint liability or dynamic repayment incentives. The results of a mediation test suggest that the gender effect on loan repayment is significantly mediated by differences in innate trustworthiness. We conduct a sensitivity test to check the extent to which unobserved confounders might have influenced the mediation effect, and find no evidence of significant omitted variables bias

Delegated monitoring in crowdfunded microfinance: Evidence from Kiva

We study the role of delegated monitoring in crowdfunded microfinance. We use data from Kiva, a crowdfunding platform, where crowds lend to borrowers through microfinance institutions (MFIs) instead of lending directly. These MFIs monitor debt contracts on behalf of crowds. We find that borrowers who are more intensely monitored by MFIs are more likely to repay crowdfunded loans on time. Monitoring is particularly important in reducing repayment problems of individual loans rather than group-based loans. Monitoring has a stronger impact in less competitive lending markets. We also find that when lending to borrowers, crowds are attentive to the loan-administering MFI's ability to monitor loans

A Sender-based TFRC for Saratoga: A Rate Control Mechanism for a Space-Friendly Transfer Protocol

Abstract—Saratoga is a protocol for fast file transfers across dedicated links in private networks, using small amounts of feedback for loss recovery. It is in use to download large amounts of imaging data from remote-sensing satellites, where the link environment is highly asymmetric and uplinks are constrained. However, Saratoga lacks a rate-control mechanism to allow fair share with co-existing flows for simultaneous competing transfers, or for across the congested Internet where it must coexist fairly with TCP. TFRC, a selfand TCP-Friendly Rate Control mechanism, can be adopted for Saratoga and leverage its existing protocol information. Use of TFRC normally requires significant changes in protocol operation, including additional data in feedback. We design a sender-based TFRC for Saratoga, needing only simple modifications within the sender and using only existin