Alcatel-Lucent

About: Alcatel-Lucent is a based out in Stuttgart, Germany. It is known for research contribution in the topics: Signal & Network packet. The organization has 37003 authors who have published 53332 publications receiving 1430547 citations. The organization is also known as: Alcatel-Lucent S.A. & Alcatel.

A proper model for the partitioning of electrical circuits

Abstract: Partitioning algorithms for electrical circuits are often based on the heuristic manipulation of a simple element-to-element interconnection matrix. However, the element-to-element interconnection matrix does not properly represent an electrical interconnection, or “net”, among more than two elements. This paper expands on several aspects of the discrepancy: 1) its source, 2) the circumstances under which it is likely to be significant, and its magnitude for typical circuits, and 3) the comparative difficulty and expense of using a more appropriate representation.A physically correct “net-cut” model is presented. This model is computationally straightforward and is easily adapted to the typical heuristic solution strategies. The “net-cut” model is coupled with the Kernighan-Lin partitioning algorithm [3]; using the same algorithm, comparisons with the “edge-cut” model demonstrate that the correct model reduces net-cuts by 19 to 50% for four digital logic circuits.

Local versus global torque optimization of redundant manipulators

Abstract: This paper compares local and global optimization methods for minimizing torque loading at the joints of a redundant manipulator in a least squares sense. Simulations show that the local methods show an unexpected instability for relatively long trajectories. The global method, however, was able to find a stable solution which outperformed the local algorithms at all times.

Radio propagation measurements and prediction using three-dimensional ray tracing in urban environments at 908 MHz and 1.9 GHz

Abstract: There is an explosive growth in the market of wireless communications services in urban areas. New regulatory environments as well as competition in the communications industry require that these systems be deployed quickly and at low cost. Computer-based radio propagation prediction tools are strong candidates for this goal. We introduce an outdoor radio propagation prediction tool using a ray tracing technique in two dimensions (2-D) and three dimensions (3-D). We have compared the predicted and measured results in various propagation environments. Comparisons indicate that 2-D is adequate for a low transmitter while 3-D is recommended for a high transmitter whose height is comparable with or higher than surrounding buildings. In most locations, the computer tool predicts the correct propagation loss with a mean error of less than 7 dB and a standard deviation of less than 8 dB.

Method for bandwidth sharing in a multiple access system for communications networks

Abstract: A method for data transmission in a wireless communication network utilizes an on-demand multiple access method with a fair queuing service discipline for efficient utilization of the limited bandwidth available in the network by sharing bandwidth among the remote hosts. In one embodiment, the base station broadcasts the system virtual time and the assigned shares of service classes to each of the wireless remotes. Each remote host computes its own service tag and reports it to the base station, which assigns transmit permits based on the service tag values and the available data slots. If a packet is lost or in error, the sending remote recomputes the service tag values of all its queued packets, including the packet whose transmission failed. Alternatively, the remote informs the base station of its queue size and the base station computes service tags for each remote based on the service shares of the remote and the available data slots. If a packet is lost or in error, the base station recomputes the service tag values for that remote host based on the current system virtual time. In an alternate embodiment, the AP or wireless node maintains a packet queue and a head-of-line tag. If a packet is lost, only the head-of-line tag needs to be changed. Once the head-of-line packet has been transmitted successfully, the rest of the queued packets will automatically receive the correct tag, the recomputed head-of-line tag plus appropriate increments. For half-duplex, both the uplink and downlink queues at the access points are managed as if there is only one system virtual time. For full-duplex, separate system virtual times for the uplink and the downlink traffic may be used. Remotes may also be divided into one or more separate groups, with each group having a different priority and receiving a different system virtual time. Service tags of all other remotes remain unaffected by the retransmission of a packet from any particular remote, meaning that the QoS experienced by the other remotes does not suffer.

Methods and systems for controlling handovers in a co-channel network

Abstract: At least one example embodiment discloses a method of controlling a handover of a user equipment (UE) from a serving base station to a target, base station in a heterogeneous network. The method includes determining, by a serving base station, a speed of the UE and a type of the handover, the type of the handover being one of macro cell to macro cell, macro cell to small cell, small cell to macro cell and small cell to small cell, and controlling, by the serving base station, the handover from the serving base station to the target base station based on the speed of the UE and the type of handover.