摘要:
A method and apparatus for time synchronization (TS) method using GPS information in a communication system synchronizing the time of slave nodes, which do not have a GPS receiver, by using GPS information of a node having a GPS receiver. The method includes the steps of extracting 1PPS, TOD, 1PPS_en, and clocks using GPS signals by a grand master node having a GPS receiver, stabilizing the signals, generating a sync message for TS, and transmitting the sync message to a slave node; receiving the sync message by the slave node and conducting a TS operation using OFCC synchronization technology extracting 1PPS, TOD, and 1PPS_en signals using the modified TOD information by the block and delivering to a stabilization block of the slave node for stabilization; and redelivering to the TS block to update TOD information and generate a sync message for TS of a second slave node.
摘要:
Disclosed is an apparatus and a method for performing time synchronization by using Global Positioning System (GPS) information in a communication system. The apparatus comprises a grand-master node having a GPS receiver, for generating a synchronizing message required to synchronize time on slave nodes by using Time Of Day (TOD) information received from the GPS receiver and at least one slave node for receiving the synchronizing message required to synchronize time from the grand-master node or from another slave node, for carrying out time synchronization operation by using an Offset and Frequency Compensation Clock (OFCC) synchronization process supporting time offset and frequency separation compensation, and for generating a synchronizing message required to synchronize time on other slave nodes.
摘要:
Disclosed is an apparatus and a method for performing time synchronization by using Global Positioning System (GPS) information in a communication system. The apparatus comprises a grand-master node having a GPS receiver, for generating a synchronizing message required to synchronize time on slave nodes by using Time Of Day (TOD) information received from the GPS receiver and at least one slave node for receiving the synchronizing message required to synchronize time from the grand-master node or from another slave node, for carrying out time synchronization operation by using an Offset and Frequency Compensation Clock (OFCC) synchronization process supporting time offset and frequency separation compensation, and for generating a synchronizing message required to synchronize time on other slave nodes.
摘要:
A radio-over-fiber (RoF) system and method for controlling a transmission time is provided. In a Time Division Duplex (TDD) wireless communication system comprising a Base Station (BS) having a donor and a remote connected thereto via am optical fiber, upstream and downstream Radio Frequency (RF) signals are transmitted and received, and by reliably transmitting a switch control signal to the remote and simultaneously compensating for a transmission time delay occurring in the optical cable, time synchronization of the upstream and downstream RF signals transmitted and received via antennas of the BS and the remote is controlled, thereby efficiently increasing the performance of a TDD wireless service system.
摘要:
A method and apparatus for ensuring QoS in a synchronous Ethernet bridge are disclosed, in which a classifier classifies an ingress packet according to a PHB mapped to a DSCP value of the packet and provides the classified packet to one of a predetermined synchronous packet queue and a predetermined asynchronous packet queue, a buffer queue with a plurality of queues mapped to priority levels buffers the classified packet, a marker marks the buffered packet as a synchronous packet or, if the buffered packet is an asynchronous packet, marks the packet in a predetermined format corresponding to a priority level of the packet, and a synchronous Ethernet scheduler schedules the marked packet.
摘要:
A method and apparatus for ensuring QoS in a synchronous Ethernet bridge are disclosed, in which a classifier classifies an ingress packet according to a PHB mapped to a DSCP value of the packet and provides the classified packet to one of a predetermined synchronous packet queue and a predetermined asynchronous packet queue, a buffer queue with a plurality of queues mapped to priority levels buffers the classified packet, a marker marks the buffered packet as a synchronous packet or, if the buffered packet is an asynchronous packet, marks the packet in a predetermined format corresponding to a priority level of the packet, and a synchronous Ethernet scheduler schedules the marked packet.
摘要:
Disclosed is a bridged portable internet system, which includes: a plurality of edge bridges entirely connected as a mesh structure to form a core network, and configured as a layer 2 switch; a plurality of Radio Access Stations (RASs) connected to one of the plurality of edge bridges to provide portable internet services to Mobile Nodes (MNs) within the range of services; and a Neighbor Discovery Server (NDS) for supporting neighbor discovery of components in the network and storing and managing configuration information of the components, wherein each of the plurality of edge bridges maintains an optimal path through a predetermined routing protocol, identifies the destination of a Media Access Control (MAC) frame transmitted by an MN connected to an edge bridge itself through a corresponding RAS by referring to the configuration information from the NDS so as to transmit a corresponding MAC frame to the MAC address of an edge bridge to which a corresponding CN is connected by performing MAC in MAC encapsulation if receiving a MAC in MAC encapsulated frame with its own MAC address as a destination, and performs MAC in MAC encapsulation with the frame to delete an outer MAC address and to transmit an original MAC frame to a corresponding MN.
摘要:
A network system for interworking a Wireless Local Area Network (W-LAN) and a 3rd-Generation (3G) mobile communication network through a Radio-over-Fiber(RoF) link and an authentication method in interworking in the network system are provided. The network system includes a 3G mobile communication network and a W-LAN system. The 3G mobile communication network includes a voice signal processing network connected to a Public Switched Telephone Network (PSTN) for voice call processing with respect to a predetermined mobile terminal, a packet data network for data communication with the predetermined mobile terminal, and a terminal device for communication with the predetermined mobile terminal. The W-LAN system is connected to the packet data network of the 3G mobile communication network to provide a W-LAN service to the predetermined mobile communication terminal. The W-LAN system is implemented in a plurality of Base Transceiver Stations (BTSs) included in the 3G mobile communication network through the RoF link.
摘要:
A duobinary optical transmission device provides duobinary optical transmission with improved quality by a technique that does not require an electrical low pass filter LPF.A duobinary optical transmission device includes at least one semiconductor optical amplifier (SOA). A light source outputs a carrier wave as an optical signal. A precoder encodes an input of a non-return-to-zero (NRZ) electrical signal. An interferometer type semiconductor optical amplification unit modulates the carrier wave according to a change of an applied bias current coupled to the encoded signal. An optical band pass filter (OBPF) receives the phase-modulated optical signal from the semiconductor optical amplification unit, filters the received phase-modulated optical signal according to a designated band, and outputs an optical duobinary signal.
摘要:
An apparatus that adaptively allocates transmission power for beam-forming combined with orthogonal space time block codes in a distributed wireless communication system, the apparatus including: sub-arrays for beam-forming, which are geographically distributed and each of which includes a plurality of distributed antennas placed in random groups. A central processing unit provides predetermined combinable power allocation schemes according to subsets in a plurality of the sub-arrays, identifying performances of the schemes by using information on large-scale fading of each of the sub-arrays fed back from a receiving party, setting a subset having best performance as an optimal subset according to the identified performances, and performing power allocation according thereto.