Bandwidth Estimation for Admission Control in MANET: Review and Conceptual MANET Admission Control Framework

The widespread of wireless mobile network have increased the demand for its applications. Providing a reliable QoS in wireless medium, especially mobile ad-hoc network (MANET), is quite challenging and remains an ongoing research trend. One of the key issues of MANET is its inability to accurately predict the needed and available resources to avoid interference with already transmitting traffic flow. In this work, we propose a resource allocation and admission control (RAAC) solution. RAAC is an admission control scheme that estimates the available bandwidth needed within a network, using a robust and accurate resource estimation technique. Simulation results obtained show that our proposed scheme for MANET can efficiently estimate the available bandwidth and outperforms other existing approaches for admission control with bandwidth estimation

TCP-BFA: Buffer Fill Avoidance

The main goal of a congestion avoidance algorithm is to maximize throughput and minimize delay (Jain & Ramakrishnan 1988). While TCP Reno achieves high throughput, it tends to consume all of the buffer space at the bottleneck router, causing large delays. In this paper we propose a simple scheme that modifies TCP Reno's congestion avoidance algorithm by throttling back the opening of the congestion window once an increase in round-trip time is perceived. We call the scheme TCP-BFA and have implemented it in the ns network simulator and in BSD 4.4. We show through simulations and measurements of real traffic on the Internet that TCP-BFA results in lower router buffer occupancies and lower delays while maintaining a throughput similar to that of TCP Reno. The advantages of TCP-BFA are (1) smaller router buffer size requirements, (2) an order of magnitude improvement in network power (the ratio of throughput to delay), (3) fewer packet losses, (4) faster detection of multiple losses due to lower retransmission timeout estimates, and (5) smoother traffic patterns

RTT-Based Congestion Control for the Internet of Things

Part 1: IoT and Sensor NetworksInternational audienceThe design of scalable and reliable transport protocols for IoT environments is still an unsolved issue. A simple stop-and-wait congestion control method and a lightweight reliability mechanism are only implemented in CoAP, an application protocol that provides standardised RESTful services for IoT devices. Inspired by delay-based congestion control algorithms that have been proposed for the TCP, in this work we propose a rate control technique that leverages measurements of round-trip times (RTTs) to infer network state and to determine the flow rate that would prevent network congestion. Our key idea is that the growth of RTT variance, coupled with thresholds on CoAP message losses, is an effective way to detect the onset of network congestion. To validate our approach, we conduct a comparative performance analysis with the two loss-based congestion control methods of standard CoAP under different application scenarios. Results show that our solution outperforms the alternative methods, with a significant improvement of fairness and robustness against unacknowledged traffic

A BBR-based Congestion Control for Delay-sensitive Real-time Applications

The current User Datagram Protocol (UDP) causes unfairness and bufferbloats to delay sensitive applications due to the uncontrolled congestion and monopolization of available bandwidth.This causes call drops and frequent communication/connection loss in delay sensitive applications such as VoIP. We present a Responsive Control Protocol using Bottleneck Bandwidth and Round trip propagation time (RCP-BBR) as an alternate solution to UDP. RCP-BBR achieves low latency, high throughput, and low call drops ratio by efficiently customizing Transmission Control Protocol (TCP) Bottleneck Bandwidth and Round-trip propagation time (TCP-BBR) congestion control. We conducted comprehensive experiments, and the results show that proposed protocol achieves better throughput over UDP in stable networks. Moreover, in unstable and long-distanced networks, RCP-BBR achieved smaller queues in deep buffers and lower delays as compared to UDP, which performed poorly by keeping delays above the call drop threshold

Improving the performance of TCP on guaranteed bandwidth connections

This paper discusses the performance of the Transmission Control Protocol under two aspects: First, the future Internet will provide some kind of service di#erentiation and bandwidth guarantees. Nevertheless, TCP connections often cannot fully exploit the reserved bandwidth over time. The congestion control mechanisms like slow start and congestion avoidance have to be revised in the context of guaranteed services, where no congestions occur for special flows

Enhanced bandwidth estimation algorithms in the TCP congestion control scheme

Abstract The use of enhanced bandwidth estimation procedures within the congestion control scheme of TCP has been recently proposed as a way to improve the performance over links affected by random losses. In this paper we propose TIBET (Time Intervals based Bandwidth Estimation Technique), a new bandwidth estimation scheme that can be implemented within the TCP congestion control procedure by modifying only the sender-side of a connection. TIBET allows TCP sources to achieve higher performance over wireless links, while guaranteeing a good fairness level with TCP Reno over wired networks. We analyze and compare the performance of the new algorithm with that of previously proposed schemes