JTP: An Energy-conscious Transport Protocol for Wireless Ad Hoc Networks

Within a recently developed low-power ad hoc network system, we present a transport protocol (JTP) whose goal is to reduce power consumption without trading off delivery requirements of applications. JTP has the following features: it is lightweight whereby end-nodes control in-network actions by encoding delivery requirements in packet headers; JTP enables applications to specify a range of reliability requirements, thus allocating the right energy budget to packets; JTP minimizes feedback control traffic from the destination by varying its frequency based on delivery requirements and stability of the network; JTP minimizes energy consumption by implementing in-network caching and increasing the chances that data retransmission requests from destinations "hit" these caches, thus avoiding costly source retransmissions; and JTP fairly allocates bandwidth among flows by backing off the sending rate of a source to account for in-network retransmissions on its behalf. Analysis and extensive simulations demonstrate the energy gains of JTP over one-size-fits-all transport protocols.Defense Advanced Research Projects Agency (AFRL FA8750-06-C-0199

NFV orchestration on intermittently available SUAV platforms: challenges and hurdles

Proceeding of: IEEE INFOCOM 2019 - IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS MiSARN 2019: Mission-Oriented Wireless Sensor, UAV and Robot Networking), 29 April-2 May 2019 Paris, FranceIn this paper, we analyze the main challenges and issues related with the orchestration of Virtualized Network Functions (VNFs) on Small Unmanned Aerial Vehicles (SUAVs). Our analysis considers a reference scenario where a number of SUAVs are deployed over a delimited geographic area and provide a mobile cloud environment that supports the deployment of functionalities using Network Functions Virtualization (NFV) technologies. The orchestration of services in this reference scenario presents different challenges, due to the constrained capacity and limited lifetime of battery-powered SUAVs, the intermittent availability of network communications, and the need to consider enhanced policies for the allocation of virtual functions to SUAVs. Finally, we perform a first exploratory evaluation of the identified challenges and issues, using a well-known and widely adopted virtualized infrastructure manager, i.e., OpenStack.This article has been partially supported by the European H2020 5GRANGE project (grant agreement 777137), and by the 5GCity project (TEC2016-76795- C6-3-R) funded by the Spanish Ministry of Economy and Competitiveness

An Energy-conscious Transport Protocol for Multi-hop Wireless Networks

We present a transport protocol whose goal is to reduce power consumption without compromising delivery requirements of applications. To meet its goal of energy efficiency, our transport protocol (1) contains mechanisms to balance end-to-end vs. local retransmissions; (2) minimizes acknowledgment traffic using receiver regulated rate-based flow control combined with selected acknowledgements and in-network caching of packets; and (3) aggressively seeks to avoid any congestion-based packet loss. Within a recently developed ultra low-power multi-hop wireless network system, extensive simulations and experimental results demonstrate that our transport protocol meets its goal of preserving the energy efficiency of the underlying network.Defense Advanced Research Projects Agency (NBCHC050053

Topology influence on TCP congestion control performance in multi-hop ad hoc wireless

Wireless ad hoc nodes are freely and dynamically self-organize in communicating with others.Each node can act as host or router.However it actually depends on the capability of nodes in terms of its current power level, signal strength, number of hops, routing protocol, interference and others.In this research, a study was conducted to observe the effect of hops count over different network topologies that contribute to TCP Congestion Control performance degradation.To achieve this objective, a simulation using NS-2 with different topologies have been evaluated.The comparative analysis has been discussed based on standard observation metrics: throughput, delay and packet loss ratio.As a result, there is a relationship between types of topology and hops counts towards the performance of ad hoc network.In future, the extension study will be carried out to investigate the effect of different error rate and background traffic over same topologies

A model for congestion control control of transmission control protocol in mobile wireless ad hoc networks

Transmission Control Protocol (TCP) is a fundamental protocol in the TCP/IP Protocol Suite.TCP was well designed and optimized to work over wired networks where most packet loss occurs due to network congestion.In theory, TCP should not care whether it is running over wired networks, WLANs, or Mobile Ad hoc Networks (MANETs).In practice, it does matter because most TCP deployments have been carefully designed based on the assumption that congestion is the main factor of network instability.However, MANETs have other dominating factors that cause network instability. Forgetting the impact of these factors violates some design principles of TCP congestion control and open questions for future research to address.This study aims to introduce a model that shows the impact of MANET factors on TCP congestion control.To achieve this aim, Design Research Methodology (DRM) proposed by BLESSING was used as a guide to present this model. The proposed model describes the existing situation of TCP congestion control.Furthermore, it points to the factors that are most suitable to be addressed by researchers in order to improve TCP performance.This research proposes a novel model to present the impact of MANET factors on TCP congestion control.The model is expected to serve as a benchmark for any intended improvement and enhancement of TCP congestion control over MANET

TCP Sintok: Transmission control protocol with delay-based loss detection and contention avoidance mechanisms for mobile ad hoc networks

Mobile Ad hoc Network (MANET) consists of mobile devices that are connected to each other using a wireless channel, forming a temporary network without the aid of fixed infrastructure; in which hosts are free to move randomly as well as free to join or leave. This decentralized nature of MANET comes with new challenges that violate the design concepts of Transmission Control Protocol (TCP); the current dominant protocol of the Internet. TCP always infers packet loss as an indicator of network congestion and causes it to perform a sharp reduction to its sending rate. MANET suffers from several types of packet losses due to its mobility feature and contention on wireless channel access and these would lead to poor TCP performance. This experimental study investigates mobility and contention issues by proposing a protocol named TCP Sintok. This protocol comprises two mechanisms: Delay-based Loss Detection Mechanism (LDM), and Contention Avoidance Mechanism (CAM). LDM was introduced to determine the cause of the packet loss by monitoring the trend of end-to-end delay samples. CAM was developed to adapt the sending rate (congestion window) according to the current network condition. A series of experimental studies were conducted to validate the effectiveness of TCP Sintok in identifying the cause of packet loss and adapting the sending rate appropriately. Two variants of TCP protocol known as TCP NewReno and ADTCP were chosen to evaluate the performance of TCP Sintok through simulation. The results demonstrate that TCP Sintok improves jitter, delay and throughput as compared to the two variants. The findings have significant implication in providing reliable data transfer within MANET and supporting its deployment on mobile device communication

TCP Performance in Mobile Ad hoc Networks

In this paper, we present a survey of TCP (Transmission Control Protocol) protocol for better performance in the MANET (Mobile Ad Hoc Network). After a short presentation of the main features of TCP, we give the most important problems from which TCP suffer in MANET. We present after that some approaches proposed in the literature in order to improve its performance. Our paper contains also a performance evaluation of TCP NewReno and TCP Vegas transport protocols under AODV and DSR routing protocols. The simulations are conducted under varying conditions of number of TCP connections, number of nodes and mobility.Hamrioui, S.; Lloret, J.; Lorenz, P.; Lalam, M. (2013). TCP Performance in Mobile Ad hoc Networks. Network Protocols and Algorithms. 5(4):117-142. doi:10.5296/npa.v5i4.4773S1171425