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1.发明授权公开(公告)号：US06574797B1
公开(公告)日：2003-06-03
申请号：US09227991
申请日：1999-01-08
IPC分类号： H04N7173
CPC分类号： H04N17/00 , H04N7/17309
摘要： Apparatus, methods, and computer program products for utilizing a frequency channel determined to be unacceptably noisy by finding a cleaner, narrower bandwidth within the frequency channel. Initially data is received on a frequency channel at a CMTS, specifically an upstream receiver, and by a narrow bandwidth detector, connected to a processor also used by components in the CMTS. The narrow bandwidth detector performs a Fast Fourier Transform (FFT) on the frequency channel thereby creating multiple FFT points within the frequency channel. A clean bandwidth for transmitting data within the frequency channel is identified where the clean bandwidth is derived from a subset of FFT points from the full set of FFT points. The subset of FFT points are contiguous points that have a noise level below a predetermined noise threshold.
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2.发明授权Method and apparatus for locating a cleaner bandwidth in a frequency channel for data transmission 有权用于在数据传输的频道中定位更清洁带宽的方法和装置公开(公告)号：US07509670B1
公开(公告)日：2009-03-24
申请号：US10407345
申请日：2003-04-03
IPC分类号： H04N7/173
CPC分类号： H04N17/00 , H04N7/17309
摘要： Apparatus, methods, and computer program products for utilizing a frequency channel determined to be unacceptably noisy by finding a cleaner, narrower bandwidth within the frequency channel. Initially data is received on a frequency channel at a CMTS, specifically an upstream receiver, and by a narrow bandwidth detector, connected to a processor also used by components in the CMTS. The narrow bandwidth detector performs a Fast Fourier Transform (FFT) on the frequency channel thereby creating multiple FFT points within the frequency channel. A clean bandwidth for transmitting data within the frequency channel is identified where the clean bandwidth is derived from a subset of FFT points from the full set of FFT points. The subset of FFT points are contiguous points that have a noise level below a predetermined noise threshold.
摘要翻译： 用于通过在频道内找到更清洁，更窄的带宽来确定被确定为不可接受的噪声的频道的装置，方法和计算机程序产品。 最初，数据在CMTS的频道上，特别是上游接收机，以及连接到也由CMTS中的组件使用的处理器的窄带宽检测器接收。 窄带宽检测器在频率信道上执行快速傅里叶变换（FFT），从而在频道内创建多个FFT点。 识别在频道内发送数据的干净带宽，其中干净带宽是从全集FFT点的FFT点子集导出的。 FFT点的子集是具有低于预定噪声阈值的噪声电平的连续点。
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公开(公告)号：US06385773B1
公开(公告)日：2002-05-07
申请号：US09227060
申请日：1999-01-07
IPC分类号： H04N7173
CPC分类号： H04N7/17309 , H04L12/2801
摘要： Transitions among different upstream frequency channels in a cable television plant in order to transmit data occur while considering the noise level of the upstream frequency channel presently being used to transmit data. By taking into account the noise level of the presently used upstream frequency channel, the CMTS in a cable plant can make a more intelligent decision as to whether it is worthwhile changing the upstream frequency channel for a group of cable modems. A spectrum analyzer determines the noise level of a presently used frequency channel. A bit error rate for the present frequency channel is detected. The spectrum analyzer then determines whether the bit error rate exceeds a threshold value. Is so, it is then determined whether the noise level of the present frequency channel is greater than or less than the noise level of another frequency channel having the lowest noise level plus a buffer noise value. If the present noise level is greater, a transition is made to the other frequency channel with the lower noise level. If not, the cable plant continues using the present frequency channel. The noise level of the presently used frequency channel is measured at the CMTS upon receipt of an empty data packet arriving at a known timing mark.
摘要翻译： 在考虑目前用于发送数据的上行频道的噪声电平的同时，在有线电视设备中的不同上行频道之间的转换以发送数据。 通过考虑目前使用的上行频道的噪声水平，电缆设备中的CMTS可以更准确地决定是否值得改变一组电缆调制解调器的上行频道。 频谱分析仪确定当前使用的频道的噪声电平。 检测当前频道的误码率。 然后，频谱分析仪确定误码率是否超过阈值。 这样，然后确定当前频道的噪声电平是否大于或小于具有最低噪声电平加上缓冲器噪声值的另一频道的噪声电平。 如果当前噪声电平较大，则对具有较低噪声电平的另一频道进行转换。 如果没有，电缆厂继续使用当前的频道。 当接收到到达已知定时标记的空数据分组时，在CMTS测量当前使用的频道的噪声电平。
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公开(公告)号：US5796795A
公开(公告)日：1998-08-18
申请号：US347618
申请日：1994-11-30
CPC分类号： H04J3/0685 , H04L7/0337
摘要： A network (10) includes a broadband customer service module (B-CSM) (20). The B-CSM (20) includes a plurality of feeder interface cards (FICs) (36) and optical line cards (OLCS) (38) which are coupled together through a midplane assembly (34) so that each FIC (36) couples to all OLCs (38) and each OLC (38) couples to all FICs (36) through junctor groups (68). The B-CSM (20) interfaces many OC-12 SONET feeders to many OC-12 SONET lines. Within the B-CSM (20) circuit switching is performed electrically at an STS-1 rate. A reference clock which oscillates at a frequency lower than the data rate is routed with payload data so that it receives delays similar to those imposed on the payload data due to processing. At second stage switching fabrics (50) where data need to be extracted from signals flowing within the B-CSM (20), a clock regeneration circuit (32) generates a master clock signal oscillating at twice the data rate and phase synchronized to a delayed reference clock. A geometric compensation scheme corrects for timing skew which occurs when clocks and data are distributed to points or small areas from widely dispersed locations, and when clocks and data are distributed from points or small areas to widely dispersed locations.
摘要翻译： 网络（10）包括宽带客户服务模块（B-CSM）（20）。 B-CSM（20）包括多个馈线接口卡（FIC）（36）和光线路卡（OLCS）（38），它们通过中平面组件（34）耦合在一起，使得每个FIC（36）耦合到 所有OLC（38）和每个OLC（38）通过连接器组（68）耦合到所有FIC（36）。 B-CSM（20）将许多OC-12 SONET馈线连接到许多OC-12 SONET线路。 在B-CSM（20）中，电路以STS-1速率进行电路切换。 以低于数据速率的频率振荡的参考时钟用有效载荷数据进行路由，使得其接收与由于处理而对有效载荷数据施加的延迟相似的延迟。 在第二级交换结构（50），其中需要从在B-CSM（20）内流动的信号中提取数据，时钟再生电路（32）产生以两倍数据速率振荡的主时钟信号，同步于延迟 参考时钟。 当时钟和数据被分散到从广泛分散的位置的点或小区域以及时钟和数据从点或小区域分布到广泛分散的位置时，几何补偿方案校正了定时偏移。
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公开(公告)号：US4999832A
公开(公告)日：1991-03-12
申请号：US441794
申请日：1989-11-27
CPC分类号： H04J3/08 , H04L12/43 , H04L12/4637 , H04Q11/0478 , H04J2203/0003 , H04J2203/0039
摘要： A broadband ISDN communication system (10) comprises a plurality of bit-serial synchronous time-division multiplexed ring networks (15) interconnected by a circuit switch (11). In each network, terminal equipment (14) is interfaced to a fiber-optic ring bus (12) by add/drop multiplexers (13). Single time slots (201) on the ring function as independently-assignable channels. Each time slot carries one bit at an 8 Kbps rate. Ring bandwidth is 45 Mbps. The circuit switch is a time-division multiplexed time-space switch. The time stage (301) comprises a plurality of time slot interchangers (TSI 303), one for each switch output port (306). Each TSI unit is connected to all switch input ports (305) and through the space stage to its corresponding output port. The space stage (302) is a time-multiplexed space stage. The switch is fully non-blocking and has broadcast capability. System bandwidth is dynamically allocated to users in single time slot (8 Kbps) increments, under control of a network manager (16).
摘要翻译： 宽带ISDN通信系统（10）包括由电路交换机（11）互连的多个位串行同步时分复用环网（15）。 在每个网络中，终端设备（14）通过分插复用器（13）与光纤环总线（12）接口。 环上的单个时隙（201）作为独立分配的信道。 每个时隙以8 Kbps速率承载一位。 环带宽为45Mbps。 电路开关是时分复用的时空开关。 时间段（301）包括多个时隙交换器（TSI 303），一个用于每个开关输出端口（306）。 每个TSI单元连接到所有开关输入端口（305），并通过空间级连接到其相应的输出端口。 空间级（302）是时分复用空间级。 交换机完全无阻塞，具有广播功能。 在网络管理器（16）的控制下，系统带宽以单个时隙（8 Kbps）的增量动态分配给用户。
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公开(公告)号：US06188687B1
公开(公告)日：2001-02-13
申请号：US09000908
申请日：1997-12-30
IPC分类号： H04L1264
CPC分类号： H04J3/0685 , H04L7/0337
摘要： A network (10) includes a broadband customer service module (B-CSM) (20). The B-CSM (20) includes a plurality of feeder interface cards (FICs) (36) and optical line cards (OLCs) (38) which are coupled together through a midplane assembly (34) so that each FIC (36) couples to all OLCs (38) and each OLC (38) couples to all FICs (36) through junctor groups (68). A reference clock which oscillates at a frequency slower than the data rate is routed with payload data so that it receives delays similar to those imposed on the payload data due to processing. At second stage switching fabrics (50) where data need to be extracted from signals flowing within the B-CSM (20), a clock regeneration circuit (32) generates a master clock signal oscillating at twice the data rate and phase synchronized to a delayed reference clock. A geometric compensation scheme corrects for timing skew which occurs when clocks and data are distributed to points or small areas from widely dispersed locations, and when clocks and data are distributed from points or small areas to widely dispersed locations. The B-CSM (20) ranks the junctor groups (68) according to signal occupancy and manages signal traffic to efficiently utilize the FICs (36) and to reduce the probability of signal blocking. The junctor groups (68) can include a number of bidirectional junctors. The bidirectional junctors are configured to carry upstream or downstream signals according to current upstream and downstream signal traffic volume.
摘要翻译： 网络（10）包括宽带客户服务模块（B-CSM）（20）。 B-CSM（20）包括通过中平面组件（34）耦合在一起的多个馈线接口卡（FIC）（36）和光线路卡（OLC）（38），使得每个FIC（36）耦合到 所有OLC（38）和每个OLC（38）通过连接器组（68）耦合到所有FIC（36）。 以比数据速率慢的频率振荡的参考时钟用有效载荷数据进行路由，使得其接收与由于处理而对有效载荷数据施加的延迟相似的延迟。 在第二级交换结构（50），其中需要从在B-CSM（20）内流动的信号中提取数据，时钟再生电路（32）产生以两倍数据速率振荡的主时钟信号，同步于延迟 参考时钟。 当时钟和数据被分散到从广泛分散的位置的点或小区域以及时钟和数据从点或小区域分布到广泛分散的位置时，几何补偿方案校正了定时偏移。 B-CSM（20）根据信号占有率对丛组（68）进行排序，并管理信号流量以有效利用FIC（36）并降低信号阻塞的可能性。 连接器组（68）可以包括多个双向接头。 双向总线被配置为根据当前的上行和下行信号流量承载上行或下行信号。
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