BBR-CWS: Improving the Inter-Protocol Fairness of BBR

TCP congestion control adjusts the sending rate in order to protect Internet from the continuous traffic and ensure fair coexistence among multiple flows. Especially, loss-based congestion control algorithms were mainly used, which worked relatively well for past Internet with low bandwidth and small bottleneck buffer size. However, the modern Internet uses considerably more sophisticated network equipment and advanced transmission technologies, and loss-based congestion control can cause performance degradation due to excessive queueing delay and packet loss. Therefore, Google introduced a new congestion control in 2016, Bottleneck Bandwidth Round-trip propagation time (BBR). In contrast with traditional congestion control, BBR tries to operate at the Kleinrock’s optimal operating point, where delivery rate is maximized and latency is minimized. However, when BBR and loss-based congestion control algorithms coexist on the same bottleneck link, most of bottleneck bandwidth is occupied by flows that use a particular algorithm, and excessive packet retransmission can occur. Therefore, this paper proposes a BBR congestion window scaling (BBR-CWS) scheme to improve BBR’s inter-protocol fairness with a loss-based congestion control algorithm. Through Mininet experiment results, we confirmed that fairness between BBR-CWS and CUBIC improved up to 73% and has the value of 0.9 or higher in most bottleneck buffer environments. Moreover, the number of packet retransmissions was reduced by up to 96%, compared to the original BBR.

An Analogy of a Network to an Electro Hydrodynamic Fluid Flow to Analyze the Energy Required for Transmitting a Packet in a Network Susceptible to Multiple Failures

Computer networks have become pervasive to human life and now, people are inseparable from connectivity. The world’s networking communities have been constantly raising the bar of standards to provide the best possible service to their users. Every packet drop is treated as a blunder and a game ender by the companies. Standards lead to organizations that govern the service rules and policies, penalize the companies heavily if packets are lost, connections are severed midconversation. This makes the companies spare no expense into developing smarter and faster rerouting methods, packet retransmission protocols. The observation of these systems leads to believe that the system is modeled after an electro hydro dynamic fluid flow through a charged medium. In this paper the analogy and the analysis of the energy spent for rerouting packets in case of node failure, is presented in its complete mathematical form.

A Throughput and Energy Efficiency Scheme for Unlicensed Massive Machine Type Communications †

In this paper, the throughput and energy efficiency of an unlicensed machine type communications network is studied. If an outage event happens in the network, there is a possibility for packet retransmission in order to obtain a lower error probability. The concept of spectrum sharing is used here for modeling the network, which allows the two types of licensed and unlicensed users to share the same uplink channel allocated to the licensed users. However, it is done in a way that no harm is done to the licensed nodes’ transmission for sharing the same channel with the unlicensed users, while licensed nodes’ transmission causes interference on the unlicensed network. Poisson point process is used here to model the location of the nodes and the effect of interference on the network. We study how different factors such as the number of retransmissions, SIR threshold and outage can affect the throughput and energy efficiency of the network. Throughput and energy efficiency are also both studied in constrained optimization problems where the constraints are the SIR threshold and the number of retransmission attempts. We also show why it is important to use limited transmissions and what are the benefits.

Performance Evaluation of Time Synchronized Multi Layer-MAC Protocol

Background & Objective: Patents suggest that time synchronization in Wireless Sensor Network (WSN) directs at imparting a common time scale for local clocks of nodes in the network. It has been observed that all hardware clocks are unsynchronized, local clocks of nodes may drift away from each other in time. Hence durations of time intervals may differ for each node in the network. This paper evaluates the performance by suggesting an algorithm for time synchronized MLMAC protocol. Methods: Packet retransmission drains the non-replaceable power source that degrades the network lifetime, one of the major concerns in WSN. Simulation results indicate that time synchronized MLMAC outperforms the existing ML-MAC scheme in terms of both energy efficiency and packets dropped at individual nodes. Results: After Analyzing the results of simulation, network for improved synchronization performs better w.r.t. network lifetime and packets dropped. Throughput and delay are matter of concern which needs to be explored further. Conclusion: Simulation results validate the proposed protocol under various network conditions and application requirements.