Abstract: The invention features a computer-implemented method for playing back an announcement message to a user device. The method includes initiating, by a computing device, an announcement session in response to a user device establishing communication with the computing device and determining, by the computing device, the announcement message to be played back to the user device. The method includes loading, by the computing device, into a queue associated with the announcement session, a descriptor referencing a memory buffer on the computing device. The memory buffer includes a plurality of memory partitions, each memory partition storing at least one portion of the announcement message encoded at a different rate. The method includes the computing device scheduling play back of the announcement message, playing the announcement message to the user device at a first rate and receiving a request from the user device for playback at a second rate.

Abstract: The invention features a computer-implemented method for playing back an announcement message to a user device. The method includes initiating, by a computing device, an announcement session in response to a user device establishing communication with the computing device and determining, by the computing device, the announcement message to be played back to the user device. The method includes loading, by the computing device, into a queue associated with the announcement session, a descriptor referencing a memory buffer on the computing device. The memory buffer includes a plurality of memory partitions, each memory partition storing at least one portion of the announcement message encoded at a different rate. The method includes the computing device scheduling play back of the announcement message, playing the announcement message to the user device at a first rate and receiving a request from the user device for playback at a second rate.

Abstract: The invention features a computer-implemented method for playing back an announcement message to a user device. The method includes initiating, by a computing device, an announcement session in response to a user device establishing communication with the computing device and determining, by the computing device, the announcement message to be played back to the user device. The method includes loading, by the computing device, into a queue associated with the announcement session, a descriptor referencing a memory buffer on the computing device. The memory buffer includes a plurality of memory partitions, each memory partition storing at least one portion of the announcement message encoded at a different rate. The method includes the computing device scheduling play back of the announcement message, playing the announcement message to the user device at a first rate and receiving a request from the user device for playback at a second rate.

Abstract: Effecting the transmission of video data across a network of resources that includes incompatible resources is disclosed. Information indicating a source device and a destination device is received. The source device originates the video data and the destination device is to receive the video data. A plurality of paths between the source device and the destination device is identified. Each path is defined by a set of resources, the set of resources including resources needed to transmit the video data across any incompatible resources in the path. From the plurality of paths, a best path for transmission of the video data is determined based on the set of resources for that path, a distance between the source device and the destination device along that path, and a quality of the video data maintained by that path. The transmission of the video data is then effected across the determined best path.

Abstract: The invention features a computer-implemented method for playing back an announcement message to a user device. The method includes initiating, by a computing device, an announcement session in response to a user device establishing communication with the computing device and determining, by the computing device, the announcement message to be played back to the user device. The method includes loading, by the computing device, into a queue associated with the announcement session, a descriptor referencing a memory buffer on the computing device. The memory buffer includes a plurality of memory partitions, each memory partition storing at least one portion of the announcement message encoded at a different rate. The method includes the computing device scheduling play back of the announcement message, playing the announcement message to the user device at a first rate and receiving a request from the user device for playback at a second rate.

Abstract: Effecting the transmission of video data across a network of resources that includes incompatible resources is disclosed. Information indicating a source device and a destination device is received. The source device originates the video data and the destination device is to receive the video data. A plurality of paths between the source device and the destination device is identified. Each path is defined by a set of resources, the set of resources including resources needed to transmit the video data across any incompatible resources in the path. From the plurality of paths, a best path for transmission of the video data is determined based on the set of resources for that path, a distance between the source device and the destination device along that path, and a quality of the video data maintained by that path. The transmission of the video data is then effected across the determined best path.

Abstract: Three-dimensional photovoltaic devices and power conversion structures associated therewith are provided.

Abstract: Described are computer-based methods and apparatuses, including computer program products, for identifying attackers on a network. A data packet is filtered by a multi-tiered filtering and transmission system. Data packets matching the first tier filter are discarded. Data packets matching the second tier filter are transmitted to an output module based on a criterion. Data packets in the third tier filter are hashed into bins and data packets matching an entry in the bin are transmitted to the output module based on a criterion for the bin. Data packets in the fourth tier transmission system are transmitted to the output module based on a criterion. Data packets that do not meet the criterion for transmission to the output module are transmitted to an attack identification module which analyzes the data packets to identify attacks.

Abstract: Described are computer-based methods and apparatuses, including computer program products, for filtering and policing for defending against denial of service attacks on a network. A data packet is filtered by a multi-tiered filtering and transmission system. Data packets matching the first tier filter are discarded. Data packets matching the second tier filter are transmitted to an output module based on a criterion. Data packets in the third tier filter are hashed into bins and data packets matching an entry in the bin are transmitted to the output module based on a criterion for the bin. Data packets in the fourth tier transmission system are transmitted to the output module based on a criterion. Data packets that do not meet the criterion for transmission to the output module are transmitted to an attack identification module which analyzes the data packets to identify attacks.

Abstract: Described are computer-based methods and apparatuses, including computer program products, for identifying attackers on a network. A data packet is filtered by a multi-tiered filtering and transmission system. Data packets matching the first tier filter are discarded. Data packets matching the second tier filter are transmitted to an output module based on a criterion. Data packets in the third tier filter are hashed into bins and data packets matching an entry in the bin are transmitted to the output module based on a criterion for the bin. Data packets in the fourth tier transmission system are transmitted to the output module based on a criterion. Data packets that do not meet the criterion for transmission to the output module are transmitted to an attack identification module which analyzes the data packets to identify attacks.

Abstract: Described are computer-based methods and apparatuses, including computer program products, for filtering and policing for defending against denial of service attacks on a network. A data packet is filtered by a multi-tiered filtering and transmission system. Data packets matching the first tier filter are discarded. Data packets matching the second tier filter are transmitted to an output module based on a criterion. Data packets in the third tier filter are hashed into bins and data packets matching an entry in the bin are transmitted to the output module based on a criterion for the bin. Data packets in the fourth tier transmission system are transmitted to the output module based on a criterion. Data packets that do not meet the criterion for transmission to the output module are transmitted to an attack identification module which analyzes the data packets to identify attacks.

Abstract: The apparatus (101) and method for spectrum management in a multipoint communication system controls upstream channel usage for secondary stations (110) transmitting information to a primary station (101) and downstream channel usage for secondary stations (110) receiving information from a primary station (101). The preferred apparatus (101) embodiment includes a processor arrangement (120) having a master controller (121) and a plurality of processors (130), with the processor arrangement connected to a channel interface (125). The apparatus (101) and method controls channel load balancing, channel congestion, and channel assignment in a multipoint communication system, and controls upstream channels independently from downstream channels. Factors and parameters utilized in such channel control and allocation include error parameters, channel noise parameters, transmit and receive loading factors, and congestion parameters.

Abstract: A system, device, and method for improving access in a hybrid contention/polling protocol maintains a list of active users, a list of recently active users, and a list of inactive users. An active user that becomes inactive is moved into the list of recently active users, and a recently active user that remains inactive is moved into the list of inactive users. A limited contention poll addressed to a number of inactive users and at least one recently active user authorizes any of the addressed users to contend for access to the shared channel. Upon detection of a collision, addressed users that are in the list of recently active users are polled individually, while the inactive users are sent a collision resolution poll which forces the inactive users to contend again for access. Users that become active are moved into the list of active users.

Abstract: An apparatus and method to implement a hybrid contention and polling protocol for a communications or computer network is disclosed. Various apparatus and method embodiments of the invention employ specific polls from a primary station for polling identified secondary stations of the network which may be in an active state, general polls to any of a plurality of secondary stations of the network which may be in an unresponsive state to initiate contention access to the network, and general polls for collision resolution in the event that a plurality of secondary stations may simultaneously contend for network access. Various embodiments may also include frequency channel allocation for transmission and reception of data and other information within the network. The various procedures and apparatus disclosed may also be used to apply various polling parameters to optimize network performance.

Abstract: An apparatus (101, 110) and method for channel acquisition in a communication system (100) provides for selecting a channel, from a multiplicity of available channels (205), and determining whether the selected channel is the properly assigned channel for data and other information to be received by the apparatus (101, 110). The selected channel is monitored for a predetermined or adaptive energy level (210), a predetermined modulation mode (215), for a protocol signal, and for a protocol signal having an identification specifying the particular apparatus (225), such as a protocol frame containing a serial number corresponding to the apparatus. When a protocol signal having an identification specifying the particular apparatus (225) is received, the selected channel is acquired (250) for reception of data and other information.

Abstract: A control station (8) is coupled to a plurality of tributary devices (20, 16, 18) by way of at least one high speed broadcast downstream data channel and more than one shared lower speed upstream data channels. The control station (8) broadcasts data to all the tributary devices (20, 16, 18) and selects a channel for a specific tributary device (20, 16, 18) to respond to a poll. After polling, the tributary device (20, 16, 18) changes the tributary device transmitter (42) to the frequency of the selected channel. The tributary device (20, 16, 18) either sends data to send to the control station (8) or sends a negative acknowledge to the control station (8). If a negative acknowledgment was transmitted, the control station (8) notifies the control station transmitter that the channel is idle.

Abstract: A plurality of secondary stations (10.sub.a through 10.sub.n) are coupled to a primary station (8) by way of a shared communication medium (15, 16). The secondary stations (10.sub.a through 10.sub.n) sends information to the primary channel on the upstream channel. The primary station sending information to the secondary stations (10.sub.a through 10.sub.n) on a downstream channel. The power level of a secondary station (10.sub.n) is set at the power level stored in secondary station memory (55). The secondary station (10.sub.n) transmits a message to the primary station on the upstream channel. The primary station (8) receives the message, determines the power level of the received message, and sets the power level of the secondary device to the nominal power level.

Abstract: An apparatus and method to implement a hybrid contention and polling protocol for a communications or computer network is disclosed.

Abstract: An apparatus (110, 101), method, system (100) and system method provide for distributed internetwork routing of information in a communication system (100). The communication system (100) is characterized by a topology having a primary node connected to a first network, such as the Internet, and connected via an intermediate network to a mulitplicity of secondary nodes, which are further connected via a secondary network to a plurality of terminals, such as personal computers. The apparatus (110, 101), method, system and system method provide for routing of information between the primary node and the terminals independently of and transparently to any internetwork address of a secondary node. The apparatus (110, 101), method, system and system method conserve internetwork addresses by utilizing internetwork addresses only for a primary node and for terminals.

Abstract: An apparatus (101, 110) and method provide for memory utilization and management which may expand the number of write operations for limited write memories, such as non-volatile memory, to provide for more optimal performance of systems such as computer or communication systems. Such memory utilization, in accordance with the present invention, includes allocating portions of the limited write memory, as a memory structure, for an ordinal or parameter designation. Upon system initialization or start up, comparison of adjacent ordinal designations may then be utilized to precisely locate the area of memory into which data or other information was previously written, indicating the current memory locations for current read operations, and to precisely locate the area of memory into which data or other information is to be written next, in order to provide the proper memory location for a subsequent write operation.