Abstract: The present invention relates to a method for measuring link cost metrics and evaluating their accuracy with respect to reference measure of link quality in a communication network, said method comprising the steps of: during a given time interval, simultaneously transmitting several types of probe packets and data traffic, and estimating a plurality of link cost metrics (metricA, metricB, . . . , metricN) and a reference measure of link quality for a set of communication links; evaluating the accuracy of the estimated link cost metrics (metricA, metricB, . . . , metricN) by computing their correlation with the reference measure of link quality; and collecting cross-layer information for each probe packet.

Abstract: The invention concerns a method of configuring the topology of a communication network comprising a plurality of nodes (i,j, . . . , N), the communication network being organized as a forest structure comprising trees and subtrees, wherein at least one node i maintains a periodic timer and an expiration of the timer of the node i triggers the steps of: searching, by the node i, a parent node; selecting, by the node i, a parent node using at least throughput and subtree size as selection criteria; and migrating the node i to the selected size as selection criteria; and migrating the node i to the selected parent node along with its subtree size. Preferably, the step of selecting a parent node by the node i comprises a sub-step of executing a function having as parameters respective subtree sizes of a node j before and after the migration of the node i to another node k.

Abstract: The present invention concerns a method for characterizing a communication link in a communication network comprising at least two communication nodes and operating using a network protocol comprising a MAC layer and a network layer, said method comprising the steps of: sending unicast packets from a communication node comprising a driver, to another communication node through a link; collecting, by said node at the level of said driver, information concerning transmission characteristics at the level of both MAC layer and network layer; deriving, from said collected information, the following values: delivery ratio of unicast packets; and average time to transmit a unicast packet; and estimating, in said node, the quality of said link at the level of both MAC layer and network layer, by computing the following quantity: mean ? ( P ? ? T ? ? T ) du .

Abstract: The invention concerns a method for synchronizing clocks of a set of nodes in a TDMA (“Time Division Multiple Access”) communication network comprising a plurality of nodes, among which some called time reference (TR) nodes are synchronized to a common time reference through a predetermined out-of-band synchronization mechanism, other nodes being called non-TR nodes, each node comprising an internal clock, characterized in that it comprises the steps of: transmitting, at the level of at least one of said TR nodes, a broadcast beacon packet during a given time slot of sub-frames, each sub-frame comprising a plurality of time slots; propagating among the remaining nodes said beacon packet using the slotted structure of the TDMA protocol, each node being pre-assigned a conflict-free time slot in a sub-frame to broadcast said beacon packet received from another node in a previous slot of said sub-frame; and updating in at least two of said non-TR nodes the internal clock based on an updated offset estimate, up

Abstract: The invention concerns a method of configuring the topology of a communication network comprising a plurality of nodes (i, j, . . . , N), said communication network being organized as a forest structure comprising trees and subtrees, wherein at least one node i maintains a periodic timer and an expiration of said timer of said node i triggers the steps of: searching, by said node i, a parent node; selecting, by said node i, a parent node using at least throughput and subtree size as selection criteria ; and migrating said node i to the selected parent node along with its subtree size. Preferably, said step of selecting a parent node by said node i comprises a sub-step of executing a function having as parameters respective subtree sizes of a node j before and after the migration of said node i to another node k.

Abstract: For directory services for telecommunication, a data network, a terminal connected to the data network, at least one database in the data network, and a device for interactive communication between the terminal and the network regarding the database are provided. The database includes catalogue data regarding subject information about persons/families/companies, so that catalogue searches using different search criteria can be done. The desired information and adequate search criteria may be asked for from the terminal. The search is performed, and the desired catalogue data is presented visually on a display of the terminal asking for the subject information. The device also includes a reliable database outside the network, accessible and changeable only by admitted operating staff devices, and a transmitter for transmitting information from the reliable database to at least a reliable part of the database inside the network.