Abstract: A method and apparatus are provided for decelerating an inverter-controlled machine reel in a paper machine. The method includes detecting a break in a paper web from a machine reel, determining the inertia of the machine reel, determining continuously the angular speed of the machine reel, and determining continuously the torque required to decelerate the machine reel, on the basis of the determined inertia and angular speed, for the purpose of stopping the machine reel in a predefined time. The method also includes decelerating the machine reel electrically to stop the machine reel, in accordance with the determined torque, and using a mechanical brake when the rotation speed of the machine reel is lower than a predefined rotation speed and when the torque obtained by electrical deceleration is too small to stop the machine reel in a predefined time.

Abstract: The invention discloses a method for controlling an electric drive that drives reels of a slitter in the paper machine. In the method at least speed and acceleration/deceleration of a slitter is controlled. According to the invention a limit value of the electric drive is defined in the method, values of at least two or more parameters effecting to the electric drive is monitored, a reference value of the acceleration/deceleration is defined on the basis of at least two parameters, and the electric drive is controlled so that the acceleration/deceleration corresponds to the highest possible reference value, by which the reference value of the acceleration/deceleration defined on the basis of any parameter is not exceeded, and that the limit value of the electric drive is not exceeded.

Abstract: A method and apparatus are provided for decelerating an inverter-controlled machine reel in a paper machine. The method includes detecting a break in a paper web from a machine reel, determining the inertia of the machine reel, determining continuously the angular speed of the machine reel, and determining continuously the torque required to decelerate the machine reel, on the basis of the determined inertia and angular speed, for the purpose of stopping the machine reel in a predefined time. The method also includes decelerating the machine reel electrically to stop the machine reel, in accordance with the determined torque, and using a mechanical brake when the rotation speed of the machine reel is lower than a predefined rotation speed and when the torque obtained by electrical deceleration is too small to stop the machine reel in a predefined time.

Abstract: The invention discloses a method for controlling an electric drive that drives reels of a slitter in the paper machine. In the method at least speed and acceleration/deceleration of a slitter is controlled. According to the invention a limit value of the electric drive is defined in the method, values of at least two or more parameters effecting to the electric drive is monitored, a reference value of the acceleration/deceleration is defined on the basis of at least two parameters, and the electric drive is controlled so that the acceleration/deceleration corresponds to the highest possible reference value, by which the reference value of the acceleration/deceleration defined on the basis of any parameter is not exceeded, and that the limit value of the electric drive is not exceeded.

Abstract: A communications system comprising: a first network comprising a plurality of first network subscriber units and a first network sink node unit capable of wireless communication with the first network subscriber units; and a second network geographically at least partly overlapping the first network and comprising a plurality of second network subscriber units and a second network sink node unit capable of wireless communication with the second network subscriber units; and a dedicated connection between the first network sink node unit and a second network unit capable of communication in the second network, whereby a first network subscriber unit may be provided with a communication path to another second network unit.

Abstract: A wireless access network, and an associated method, is formed of multiple tiers to provide for communications between individual nodes. Each tier of the network operates at different frequency ranges and provides for connectivity between selected nodes of the different tiers.

Abstract: The invention is related to a base station for a cellular network, the base station being connected via the radio path to the mobile stations (MS) in the area of a cell formed by the base station and via a transmission network to the means controlling the base station (MSC). The base station comprises (a) a first group of units forming a physical interface for the transmission network and a radio interface for the mobile stations (MS), and (b) an internal bus system, which comprises several buses into which the units are connected and by means of which the units are connected to each other. In order to efficiently provide other telecommunications services, the base station has a second group of units, which forms at least one interface for other external devices, and the base station is equipped with an internal cross-connection for switching traffic at least between the external devices and the transmission network.

Abstract: The invention is related to a base station for a cellular network, the base station being connected via the radio path to the mobile stations (MS) in the area of a cell formed by the base station and via a transmission network to the means controlling the base station (MSC). The base station comprises (a) a first group of units forming a physical interface for the transmission network and a radio interface for the mobile stations (MS), and (b) an internal bus system, which comprises several buses into which the units are connected and by means of which the units are connected to each other. In order to efficiently provide other telecommunications services, the base station has a second group of units, which forms at least one interface for other external devices, and the base station is equipped with an internal cross-connection for switching traffic at least between the external devices and the transmission network.

Abstract: A wireless access network, and an associated method, is formed of multiple tiers to provide for communications between individual nodes. Each tier of the network operates at different frequency ranges and provides for connectivity between selected nodes of the different tiers.