Abstract: A number of features for enhancing the performance of a communication system, in which data is transmitted between a base station and a plurality of subscriber stations located different distances from the base station, are presented. The power transmission level, slot timing, and equalization of the subscriber stations are set by a ranging process. Data is transmitted by the subscriber stations in fragmented form. Various measures are taken to make transmission from the subscriber stations robust. The uplink data transmission is controlled to permit multiple access from the subscriber stations.

Abstract: A system and method is presented that uses hardware at a central node to determine if bandwidth being provided to a remote node in accordance with an unsolicited grant service (UGS) flow requires adjustment. In one embodiment, the hardware performs this function by comparing information in two consecutively-received UGS extended headers from the same remote device. If the information in the current and previous UGS extended headers differ, then an indication is provided to software of the central node that the bandwidth being provided to the remote node requires adjustment.

Abstract: A system and method is presented that uses hardware at a central node to determine if bandwidth being provided to a remote node in accordance with an unsolicited grant service (UGS) flow requires adjustment. In one embodiment, the hardware performs this function by comparing information in two consecutively-received UGS extended headers from the same remote device. If the information in the current and previous UGS extended headers differ, then an indication is provided to software of the central node that the bandwidth being provided to the remote node requires adjustment.

Abstract: A plurality of CMTS devices are linked together and synchronized to facilitate communication between the respective CMTS devices and respective downstream cable modems. According to one embodiment of the invention, one of the CMTS devices is designated as a master device, and the other CMTS devices are designated as slave devices. The respective CMTS devices are connected to each other by means of a synchronization bus. The master CMTS device then generates and broadcasts a future time stamp value, which is received by the respective slave CMTS devices. When the time stamp counter in the master CMTS device reaches the transmitted value, a control signal is broadcast over the synchronization bus. The slave CMTS devices then retrieve the time stamp value and reset their respective local time stamp counters to the received value. In this manner, the CMTS devices are synchronized.

Abstract: A method for increasing upstream bandwidth per cable modem user in a cable communications system that includes a cable modem termination system (CMTS) and a plurality of cable modems is provided. The method permits a cable modem to transmit data to the CMTS on multiple upstream channels simultaneously using a technique called “channel bonding.” Channel bonding allows smaller bandwidth upstream channels to be bonded together to create a larger bandwidth pipe.

Abstract: A method for increasing upstream bandwidth per cable modem user in a cable communications system that includes a cable modem termination system (CMTS) and a plurality of cable modems is provided. The method permits a cable modem to transmit data to the CMTS on multiple upstream channels simultaneously using a technique called “channel bonding.” Channel bonding allows smaller bandwidth upstream channels to be bonded together to create a larger bandwidth pipe.

Abstract: A method for increasing upstream bandwidth per cable modem user in a cable communications system that includes a cable modem termination system (CMTS) and a plurality of cable modems is provided. The method permits a cable modem to transmit data to the CMTS on multiple upstream channels simultaneously using a technique called “channel bonding.” Channel bonding allows smaller bandwidth upstream channels to be bonded together to create a larger bandwidth pipe.

Abstract: A method and system for allocating an initial maintenance request (IMR) for an upstream channel in a communications system, wherein the communication system includes a headend and at least one remote device associated with the channel. A first propagation delay from the headend to the remote device having the greatest delay is determined. Likewise, a second propagation delay from the headend to the remote device experiencing the least delay is determined. The IMR is then defined to be shorter than the first propagation delay and at least as long as the difference between the two propagation delays. The starting point of the IMR is established by modifying the clock output of the headend. A modification value is added to the headend clock output. The modification value corresponds to a time interval that can be as long as the propagation delay from the headend to the remote having the shortest delay.

Abstract: A number of features for enhancing the performance of a cable transmission system, in which data is transmitted between a cable modem termination system at a headend and a plurality of cable modems located different distances from the headend, are presented. The power transmission level, slot timing, and equalization of the cable modems are set by a ranging process. Data is transmitted by the modems in fragmented form. Various measures are taken to make transmission from the cable modems robust. The upstream data transmission is controlled to permit multiple access from the cable modems.

Abstract: A method and apparatus are provided for establishing communication between entities in a communication system. The time required to establish network connectivity for CPE devices can be reduced by prioritizing and/or reducing contention between the CPE devices. The CPE devices can be divided into acquisition groups and assigned specific upstream channels on which to range. The CPE devices can randomly or pseudo-randomly range on upstream channels.

Abstract: Upstream requests such a bandwidth requests, are processed by CMTS out of order on a priority basis to reduce latency in responding to the request. Specifically, a cable modem termination system (CMTS) is connected to a plurality of cable modems by a cable plant. The CMTS has a burst receiver adapted to be connected to the cable plant to process upstream data packet units and bandwidth requests transmitted by the cable modems. Each packet includes a header that uniquely distinguishes the bandwidth requests from other data types. Packet data units are arranged in a first memory queue. Bandwidth requests are arranged in a second memory queue. The headers of the packets processed by the burst receiver are inspected as they arrive at the CMTS to determine if the packets are packet data units or bandwidth requests. Packet data units are routed to the first memory queue. Bandwidth requests are routed to the second memory queue.

Abstract: A method for synchronizing clocks in a packet transport network. The method comprises, receiving an external network clock at a central packet network node and transmitting timing information to a plurality of packet network devices, the timing information based upon the external network clock. The method further comprises, transmitting and receiving data that is synchronized to the timing information to a plurality of connected packet network devices. And finally, delivery of packets to an external interface via a packet network that contains data synchronized to the external network clock.

Abstract: A supervisory communications device, such as a headend device within a cable communications network, monitors and controls communications with a plurality of remote communications devices, such as cable modems, throughout a widely distributed network. The supervisory device allocates bandwidth on the upstream channels by sending MAP messages over its downstream channel. A master-slave interface permits a second supervisory device to be connected to increase the number of available upstream channels. When one device operates as the slave device to the other, the slave device is programmable to select MAP messages from either of the master device or the slave device. A primary filter and a slave filter are provided to specify which downstream channel(s) has the authority to issue MAP messages for each available upstream channel. The filters utilizes registers to authenticate the source of the MAP messages.

Abstract: A traffic prioritization system performs a coarse classification of upstream bursts at the physical interface of a headend communications device. The headend device monitors and controls communications with a plurality of remote communications devices throughout a widely distributed network, including the Internet. The traffic prioritization system includes a burst receiver that receives and sends the upstream bursts to a classifier. At an appropriate time, the classifier receives the upstream bursts and queries a priority lookup table (LUT) to determine a priority classification. The priority classification is used to separate the bursts into two or more priority levels. The higher priority level is used to designate services having a low tolerance for delay, such as telephony. Upon classification, the upstream bursts are forwarded to one of several priority queues. Each priority queue corresponds to at least one priority level.

Abstract: A system and method is presented to utilize hardware instead of software to compare for bandwidth request changes between two consecutively received unsolicited grant service (UGS) extended headers for the same service identifier (SID), obtains significant savings in CPU cycles for the CMTS software. The system determines whether adequate bandwidth is being provided from a cable modem termination system to a data provider during a unsolicited grant service flow. The system includes a means for receiving a current voice packet in the unsolicited grant service flow at the cable modem termination system from the data provider, where the current voice packet comprises a unsolicited grant service extended header. The system further includes means for comparing the current unsolicited grant service extended header with a previous unsolicited grant service extended header.