Abstract:
A transport stream encoder comprises a plurality of component signal sources (5). One of the component signals sources is a source (7) of an opportunistic data component signal carrying a block of data having a predetermined size to be transferred within a predetermined period of time. A packet generator (10) is coupled to the plurality of component signal sources, and produces a composite packet stream, partitioned into successive groups containing a plurality of packet slots. A memory (20) stores a plurality of priority lists respectively associated with the plurality of packet slots. Each priority list contains a plurality of entries, and each entry contains data representing a respective one of the plurality of component signal sources. A scheduler (30) is responsive to the entries in the plurality of priority lists and conditions the packet generator to generate a packet for each one of the packet slots. The generated packet contains data from a component signal source selected from among the component signal sources having representative data in the entries in the priority list associated with that packet slot. A processor (50) modifies the entries in the plurality of priority lists in such a manner as to ensure that a packet containing data from the opportunistic data component signal source is generated with sufficient time regularity to guarantee that the block of data is transferred within the predetermined time period.
Abstract:
The present invention provides a novel scheme for automatically increasing data throughput in a communication system by having data compression with delay minimization done with a modem. A high speed modem includes a logical link negotiation unit (102) for probing and determining data compression parameters (DCPs) for a synchronous data compression link with a remote modem and for inserting the DCPs and predetermined instructions into compressed data. The modem also includes a physical layer connection unit (104) coupled to synchronous data terminal equipment to provide a delay minimizing scheme that adjustably accommodates data delivery delay to the receiving modem. A method and system incorporate the functions of the high speed modem.
Abstract:
A communication resource is subdivided as a function of time into a plurality of time slots (210), which may then be further subdivided on a non-periodic basis into a number of sub-slots (220). In a slot or sub-slot, communication units (101) may utilize the communication resource according to a specific set of access methods defined for that slot or sub-slot. In one embodiment the time slots are subdivided on a non-periodic basis into at least two random access sub-slots, during which communication units may either request one or more reserved time slots, or send unreserved data packets (240). In response to requests for reserved time slots from a requesting communication unit, one or more reserved time slots are provided for the use of the requesting communication unit.
Abstract:
In this invention a hierarchical addressing technique is employed in a packet communications system to enhance flexibility in handling packet information. This method permits packet message data (Fig. 3) and certain packet control data (Fig. 3) to be stored in memory locations (32, 34) without having to be duplicated at a different memory location prior to transmission of the packet. This method is preferably employed in a ring configuration in which a series of packets have addressing mechanisms which points sequentially to each other to form a ring of packets.
Abstract:
A congestion control strategy for a packet switching network (10) comprises an admission policy which controls the admission of packets into the network (10) and a stop-and-go queuing strategy (50) at the network nodes (n'''). The congestion control strategy utilizes multiple frame sizes (Fig. 6A) so that certain types of connections can be provided with small queuing delays while other types of connections can be allocated bandwith using small incremmental bandwidth units.
Abstract:
The invention reduces information loss in a communications network (10). A plurality of virtual connections are sent over a first link from a first node in the communications network (10) to a second node. The nodes comprise a plurality of input queues coupled to a switching network, which is coupled to a plurality of output queues. Each virtual connection is associated with a first output queue in the first node, a second input queue in the second node, and a second output queue in the second node. A connection feedback signal is provided from the second node to the first node with status of the second input queue so as to control the flow of information between the nodes. A switch feedback signal is provided between from the second output queue to the second input queue with status of the second output queue to control the flow of information through the switch of the second mode.
Abstract:
A method for providing access by secondary stations (12, 14, 16) to a shared transmission medium, maintains a list of secondary stations (12, 14, 16). A poll is transmitted by a primary station (10) to one of the secondary stations (12, 14, 16). The secondary station (12, 14, 16) waits for a poll, examines the transmission allocation, determines if there is congestion and transmits, along with the data in response to the poll, information regarding congestion. A system for providing such access includes a primary station (10) and a plurality of secondary stations (12, 14, 16). The primary station includes a polling controller (30), a receiver (32), a transmitter (34), a summer (36), a secondary station poll list database (38) and a data traffic controller (40).
Abstract:
A large data file is distributed to a number of nodes (O - Z) in a data communication network by a process of distributed downloading. Destination nodes are informed of the location in the network of the large data file and are directed to receive the large data file by requesting that blocks (S2) of data containing the file be transmitted to them from the designated source node. The destination nodes control the file transfer. The large data file may contain program code for updating network software.
Abstract:
The method (100, 200) and data communication equipment (300, 400) utilizing the method to substantially eliminate duplicate synchronous data frames thus limiting delay for a synchronous data system having error correcting protocol. Duplicate synchronous data frames are eliminated for timeouts where a communication channel becomes unusable for timeout that exceeds a preselected value.
Abstract:
A selective call receiver (106) receives one or more message packets of a transmitted fragmented message, where each of the one or more message packets includes an address (1605) and message data (1610), and the message data (1610) includes an indication (1702) of whether more message packets are to be received for the fragmented message. The selective call receiver (106) receives an address of each message packet, and then correlates (2908) the address to one or more predetermined addresses. After a successful correlation (2908), the selective call receiver (106) decodes the message data (1610) of each message packet, and then successively stores (2928, 2936, 2942) the decoded message data (1610) to reconstruct the fragmented message. The selective call receiver (106) determines that the fragmented message is completely reconstructed after detection (2918) in the decoded message data (1610) an indication (1702) that no more message packets are to be received for the fragmented message.