The present invention provides a system for operating a power line communications system that is comprised of a plurality of network elements, which may take the form of repeaters, bypass devices, backhaul devices, wireless backhaul devices, enhanced bypass device, communication interface devices and others. In one embodiment, two groups of network elements in the same electrical distribution system are isolated except selected communication link.

Power line communication system and method of operating the same

Various techniques including simple TCP/IP protocol modifications are presented for immediate ready implementations of virtually congestion free guaranteed service capable network, without requiring use of existing QoS/MPLS techniques nor requiring any of the switches/routers softwares within the network to be modified or contribute to achieving the end-to-end performance results nor requiring provision of unlimited bandwidths at each and every inter-node links within the network.

Immediate ready implementation of virtually congestion free guaranteed service capable network

A power line communications system (PLCS) that provides communications to one or more user devices by repeating data packets on the power distribution network is provided. The PLCS may employ any or all of the MV power line conductors and/or the neutral conductor and be dynamically and remotely transitioned to one of a plurality of potential configurations.

Power line communications system and method

A power line communications device that may provide rate limiting and quality of service control is provided. The device may include a first modem in communication with one or more user devices via a low voltage power line subnet and a second modem communicatively coupled to a second communications medium. The device also may include a controller in communication with the first and second modems and a computer readable medium encoded with instructions to control the operation of the controller. The controller may rate limit data to and/or from a destination and/or source based one or more parameters such as the destination address, the source address, the type of data, temporal parameters, and other criteria. In addition, the controller may implement QoS for data and transmit QoS parameters to power line modems to allow the power line modems to perform QoS.

Power line communication rate limiting system and method

Methods, apparatuses and systems directed to improving the efficiency of bandwidth allocation schemes by adapting to slow-start mechanisms associated with network communications protocols, such as the TCP/IP protocol suite. In one implementation, the present invention scales down the initial target rate assigned to a data flow to a fraction of an initial estimate of the effective rate capacity of the communications path between two hosts. As packets are received, the target rate is gradually increased, eventually up to the detected rate capacity of the communications path. Implementations of the present invention improve the efficiency of bandwidth allocation by reducing the over-allocation of bandwidth to data flows during the slow-start phase, leaving more bandwidth available to other data flows.

Slow-start adaptive mechanisms to improve efficiency of bandwidth allocation

A new Fast Recovery Plus (FR+) mechanism, and associated method, for wireless and/or mobile network applications to avoid network congestion in a TCP/IP packet-switched network. A method of flow control and congestion avoidance congestion in a network determining, at the source node, if packet loss is due to transmission error; and if the packet loss is due to the transmission error, setting, at the source node, the slow start threshold Ssthresh to Max (CWND, (Ssthresh + CWND)/2), wherein CWND and Ssthresh exhibit values recorded, when the packet lost was detected.

Performance enhancement of transmission control protocol (tcp) for wireless network applications

A new and improved Explicit Congestion Notification (ECN) mechanism, and associated method, for wireless and/or mobile network applications to avoid network congestion in a TCP/IP packet-switched network. A method of avoiding congestion in such a network comprises the steps of: transmitting, at a source node, data packets to a destination node, via at least an intermediate mode; determining, at the intermediate node, if an incipient congestion is encountered, and if the incipient congestion is encountered, setting a Congestion Experienced (CE) flag in each data packet which indicates the incipient congestion to notify the congestion to the destination node; receiving, at the destination node, a CE data packet, setting an Explicit Congestion Notification-Echo (ECN-Echo) flag in an acknowledgement (ACK) packet subsequent to the CE data packet received, and sending an ECH-Echo ACK packet back to the source node to inform that the congestion was encountered in the network on the path from the source node to the destination node; upon receipt of the ECN-Echo ACK packet, reducing, at the source node, a congestion window and a transmission rate to avoid the congestion, and determining if a packet loss is due to congestion or due to a transmission error, when the incipient congestion is still encountered in the network; if the packet loss is due to congestion, retransmitting, at the source node, only a lost packet to the destination node, via the intermediate node; and if the packet loss is due to the transmission error, re-transmitting, at the source node, the lost packet to the destination node, via the intermediate node, while increasing a round-trip timeout (RTO) but maintaining the same congestion window in order to improve the throughput of connection.

Enhancement of explicit congestion notification (ecn) for wireless network applications

L'invention concerne un nouveau mecanisme a recuperation rapide amelioree (FR+), et un procede associe, pour des applications de reseau sans fil et/ou mobile afin d'eviter la congestion de reseau dans un reseau a commutation de paquets TCP/IP. Un procede de controle de flux et d'evitement de congestion dans un reseau comporte les etapes de : transmission a un noeud source, de paquets de donnees a un noeud destinataire, via au moins un noeud intermediaire; reception a un noeud destinataire, de paquets de donnees emis par un noeud source, via le noeud intermediaire, et de production d'un accuse de reception ACK duplique envoye vers le noeud source afin d'informer le noeud source qu'un paquet de donnees a ete recu defectueux dans le reseau et sert a indique qu'un paquet de donnees a ete perdu; sur reception d'un nombre specifique de ACK duplique, au noeud source, determiner qu'un paquet de donnees a ete perdu; initialiser un compteur, au noeud source et enregistrer une fenetre de congestion CWND, un seuil de demarrage lent Ssthresh, et un nombre de sequence maximal SN qui a ete envoye dans le reseau; sur reception d'un nouveau ACK duplique, au noeud source, enregistrer son nombre de sequence accuse de reception ACK SN; determiner, au noeud source, si le nombre de sequence accuse de reception ACK SN n'est pas superieur au nombre de sequence enregistre SN; sinon, augmenter le compteur, au noeud source et retransmettre un paquet perdu; si le nombre de sequence accuse de reception ACK SN n'est pas superieur au nombre de sequence enregistre SN, determiner, au noeud source, si la perte du paquet est due a une erreur de transmission; et si cette perte du paquet est due a l'erreur de transmission, fixer au noeud source, le seuil de demarrage lent Ssthresh au maximum (CWND, (Ssthresh + CWND)/2), dans lequel CWND et Ssthresh presentent des valeurs enregistrees.

Xiang Li

Papers

Performance enhancement of transmission control protocol (tcp) for wireless network applications

Enhancement of explicit congestion notification (ecn) for wireless network applications

Amelioration de la performance du protocole de controle de transmission (tcp) pour des applications de reseau sans fil