초록 ▼

A highly bandwidth-efficient communications method is disclosed that enables remote stations to synchronize in time and frequency to their serving base station. The invention enables a base station and its remote stations in a cell to synchronize in a noisy environment where signals interfere from o

A highly bandwidth-efficient communications method is disclosed that enables remote stations to synchronize in time and frequency to their serving base station. The invention enables a base station and its remote stations in a cell to synchronize in a noisy environment where signals interfere from other base stations and remote stations in other cells. The base station forms a forward synchronization burst that includes a plurality of tone frequencies arranged in a distinctive orthogonal frequency division multiplexed pattern unique to the base station. The unique pattern enables a remote station to distinguish the base station's bursts from other signals present in a crowded area. The distinctive orthogonal frequency division multiplexed pattern can be a Hadamard code pattern, for example. When the a base station has received a signal on a reverse link from a remote station, having significant interference, the base station selectively forms a request signal requesting the remote station to respond with a reverse synchronization burst that includes a plurality of tone frequencies arranged in the same distinctive orthogonal frequency division multiplexed pattern. The base station then transmits the forward synchronization burst and the request signal at a base station reference instant of time to the remote station. The reverse synchronization signals selectively occupy time slots in the transmission frame from the remote station to the base station, that would otherwise be occupied by channel control or traffic signals. Only when the base station requests the remote station to respond with a reverse synchronization burst, does this burst preempt the time slot from its other uses.

대표청구항 ▼

A highly bandwidth-efficient communications method is disclosed that enables remote stations to synchronize in time and frequency to their serving base station. The invention enables a base station and its remote stations in a cell to synchronize in a noisy environment where signals interfere from o

A highly bandwidth-efficient communications method is disclosed that enables remote stations to synchronize in time and frequency to their serving base station. The invention enables a base station and its remote stations in a cell to synchronize in a noisy environment where signals interfere from other base stations and remote stations in other cells. The base station forms a forward synchronization burst that includes a plurality of tone frequencies arranged in a distinctive orthogonal frequency division multiplexed pattern unique to the base station. The unique pattern enables a remote station to distinguish the base station's bursts from other signals present in a crowded area. The distinctive orthogonal frequency division multiplexed pattern can be a Hadamard code pattern, for example. When the a base station has received a signal on a reverse link from a remote station, having significant interference, the base station selectively forms a request signal requesting the remote station to respond with a reverse synchronization burst that includes a plurality of tone frequencies arranged in the same distinctive orthogonal frequency division multiplexed pattern. The base station then transmits the forward synchronization burst and the request signal at a base station reference instant of time to the remote station. The reverse synchronization signals selectively occupy time slots in the transmission frame from the remote station to the base station, that would otherwise be occupied by channel control or traffic signals. Only when the base station requests the remote station to respond with a reverse synchronization burst, does this burst preempt the time slot from its other uses. ermanent virtual channel (PVC) route through a predetermined communication network, each network element including an element data collecting means and a fault notifying means, and the system comprising: an ATM network resource managing means for managing resources included in the ATM network; a PVC route connection managing means connected to the element data collecting means through the communication network for managing situation of connection of the PVC route; a PVC route searching means for searching a plurality of PVC routes; a fault event analyzing means for receiving a fault from the fault notifying means through the communication network when the fault occurs at any one of the network elements, and analyzing the fault; an alternate route defining means for previously defining a plurality of alternate routes for the PVC route; and an alternate route processing means for switching a faulty route to one of the plurality of alternate routes defined by the alternate route defining means when the fault occurs at any one of network elements. 16. A network management system as claimed in claim 15, wherein the alternate route defining means comprises and alternate route selecting unit and a faulty PVC route switching table, wherein the alternate route selecting unit selects any one of PVC routes from the faulty PVC route switching table, and the faulty PVC route switching table is formed by a plurality of faulty element containing PVC routes and a plurality of changeable PVC routes each corresponding to each faulty element containing PVC route. 17. A network management system as claimed in claim 15, further comprising a PVC relief order determining means connected between the faulty event analyzing means and the alternate route defining means, for determining an order of relief for the PVC route based on information of importance which is previously held in each PVC rou