Abstract: In a slotted ring network, a node may transmit a non-renewable slot reservation with any unreserved slot. The reservation restricts other nodes from transmitting a new packet in the slot. When the slot returns around the ring to the reserving node, the slot will be available. Preferably, reservation is made responsive to a starvation condition in the reserving node, which may be detected in any of various ways. In an optional enhancement, a reservation identifies the reserving node, and another node on the ring is free to transmit a new packet in the reserved slot if the new packet will reach its destination at or before the reserving node, and thus will not interfere with the reservation.

Abstract: This invention provides a new architecture for a communication system between head-ends and end-users which expands bandwidth and reliability of the communication system. A mux-node receives communication signals from a head-end and forwards the received communication signals to one or more mini-fiber nodes. The connection to the head-end is via a small number of optical fibers and the connections to each of the mini-fiber nodes may be via one or more optical fibers that may provide full duplex communication. The head-end may communicate with the mux-node using digital or digital and analog signals. The mini-fiber nodes may combine the signals received from the head-end with loop-back signals used for local media access control prior to forwarding the signals to the end-users. Upstream data are received by the mini-fiber nodes and transmitted to the mux-node.

Abstract: Methods and apparatus for performing registration on behalf of a session associated with a mobile node are disclosed. The mobile node composes a registration request including a NAI identifying a userID and a sub-NAI that uniquely identifies a session associated with the NAI. The mobile node then sends the registration request. When the Home Agent authenticates the mobile node, the Home Agent returns an IP address associated with the session. The NAI and sub-NAI may then be mapped to this IP address in a mobility binding table associated with the Home Agent as well as a visitor table associated with the Foreign Agent to which the mobile node has roamed.

Abstract: An apparatus and method is disclosed to manage storage coherency in a symmetric multiprocessing environment having a plurality of nodes, each of which contain a multitude of processors, I/O adapters, main memory and a system controller comprising an integrated switch with a top level cache. The nodes are interconnected by a dual concentric ring topology. Local controllers on any given node initiate bus operations on behalf of said processors and I/O adapters on that node. Snoop requests are launched onto the ring topology simultaneously in both directions. As the messages traverse the nodes on the ring, they trigger remote controllers to perform coherent actions such as cache accesses or directory updates. Messages arriving on each node from both directions are combined with each other and with locally generated responses to form cumulative final responses. Additionally, controllers on the requesting node may perform local coherent actions based on the information conveyed by the returning final responses.

Abstract: This invention provides a new architecture for a communication system between head-ends and end-users which expands bandwidth and reliability of the communication system. A mux-node receives communication signals from a head-end and forwards the received communication signals to one or more mini-fiber nodes. The connection to the head-end is via a small number of optical fibers and the connections to each of the mini-fiber nodes may be via one or more optical fibers that may provide full duplex communication. The head-end may communicate with the mux-node using digital or digital and analog signals. The mini-fiber nodes may combine the signals received from the head-end with loop-back signals used for local media access control prior to forwarding the signals to the end-users. Upstream data are received by the mini-fiber nodes and transmitted to the mux-node.

Abstract: In a communication network that includes a plurality of nodes interconnected by links, a method for routing a data flow includes receiving a request to allocate one or more resources in the network so as to carry the data flow between first and second ones of the nodes over one of a plurality of paths therebetween, each such path including a respective sequence of the links. For the links included in each of the paths, respective levels of use of the requested resources due to communications in process over the network are determined. The path that is to carry the data flow is selected responsive to the determined levels of use of the requested resources on the links included in each of the paths.

Abstract: A method is described for communication among equal-access stations of a ring-shaped, serial fiber-optic bus and to a device for carrying out this communications method. One station, during a bus cycle, generates container messages in a strictly time-cyclical manner, addresses them, and provides them to the serial bus, and it transmits a synchronization message at the end of the bus cycle time, each station writing its data into container messages that are addressed to it, and each station, depending on its read authorization, reading the container messages of the serial bus, all the data that have been read in the stations being imported with the assistance of the synchronization message. Thus, equal-access stations of a ring-shaped, serial fiber-optic bus can exchange data, in direct-access, extremely quickly and in a strictly time-cyclical manner.

Abstract: A network (4) includes optical routers (19), which route information in fibers (10). Each fiber carries a plurality of data channels (16), carrying data in data bursts (28) and a control channel, carrying control information in burst header packets (32). A burst header packet includes routing information for an associated data burst (28) and precedes its associated data burst. Information on the data channels and control channel is organized in synchronized slots. Multiple burst header packets occupy portions of a slot, referred to as micro-slots. When the burst header packets are received, an egress processor (52) schedules the routing of their associated bursts. The egress processor (52) determines a time at which a data burst can be scheduled for passing through an optical matrix (40) to the desired output channel group (the burst can be delayed via fiber delay lines (46) if necessary).

Abstract: A method and apparatus is provided for managing bandwidth and prioritizing different forms of data to be transmitted from a central hub or node to a plurality of ground stations. All data of all types including image data and text data is processed into frames of TCP formatted data at the central hub or node and passed through a bandwidth flow control system which imposes flow control on the data. Some of the TCP formatted data has inserted therein a conversion flag which denotes a desire to convert the TCP formatted data into UDP formatted data. A computer or controller/converter reads the conversion flags and converts TCP formatted data into UDP formatted data for multi-broadcasting simultaneously to a plurality of ground stations which reduces bandwidth.

Abstract: A method for connecting two or more devices via a wireless communication channel is provided. In one embodiment, a method of connecting a first device to a second device includes the steps of arbitrarily assigning one of two possible states to each device, wherein in a first state, a device seeks to establish a connection with another device, and in a second state, the device renders itself available for connection with the other device; and alternating a present state of each device between the first state and the second state in accordance with a predefined probability distribution until either a predetermined timeout period has expired or a connection between the devices has been established, the length of time that each device remains in the first and second states being controlled by the probability distribution. In a second embodiment, a method of forming a scatternet between a plurality of devices or nodes in an ad hoc wireless communication network is provided.

Abstract: Examples of local communication systems are disclosed, based on a ring of point-to-point links, providing for transport of fixed rate synchronous, fixed rate asynchronous data and variable rate data in a flexible format. Different segments of the ring network can carry data at different bit rates, while remaining synchronized to a common frame rate and having a common control channel structure, for compatibility with earlier systems. Parallel channels are provided, either permanently or when required, for signalling errors of source data, data validity/padding, flow control. Parallel variable width channels are defined with free content (stream or packet). Null data symbols are defined for padding on a byte-by-byte basis. The allocation of capacity among variable width channels is revised block by block, and a transition period is defined to allow for ring latency.

Abstract: An apparatus and method for controlling mode transition in a traffic channel substate in a mobile communication system. If a control hold mode should be transited to an active mode a BSC sets a transmission rate on a DCCH in use to a continuous rate and transmits the continuous rate information to a BTS that an MS is within the coverage area of the BTS. Then, the BSC allocates an additional required channel besides the DCCH. If an active mode should be transited to a control hold mode, a BSC sets a transmission rate on a DCCH in use to a predetermined gating rate and transmits the gating rate information to a BTS that an MS is within the coverage area of the BTS. Then, the BSC releases an additional required channel besides the DCCH.

Abstract: Systems and methods consistent with this invention allow for each node within one or more rings to obtain connection and topology information from other nodes within these rings. In such a system, each node is able to maintain connection table and topology tables for each node and each ring within a ring network. In particular, such information can be kept current because this scheme allows for dynamic updating of connection and topology information in real time. With such current information, a node is able to utilize this information to execute such operations as squelching connections on a protect line and timeslot interchange. In addition, by supporting timeslot interchange, the ring can be managed as more than a single logical entity as well as can have better bandwidth management utilization.

Abstract: Various method and apparatus provides for matching revision levels used by a mobile station (102-104) and a base station (101, 160) for establishing a communication link. The mobile station repeats, for a number of times, the transmission of a request for establishing a communication link between the mobile station and the base station. The mobile station detects failure of establishing the communication link with the first revision level based on repeating the request for the number of times. The mobile station changes the first revision level to the second revision level at the mobile station for establishing the communication link.

Abstract: There is disclosed, for use in communication network, a network communications manager capable of controlling data transfers among a server and a plurality of client nodes coupled by a network ring. The network communications manager comprises a time quanta controller capable of dividing a time frame on the network ring into distinct time quanta and assigning to each of the plurality of client nodes a predetermined time quantum during which the each of the plurality of client nodes may transmit data.

Abstract: An access point for interfacing a mobile station having a wireless local area network interface to a wireless telecommunications network. The access point comprises a wireless local area network interface, a processor, and a mobile telephony interface. The wireless local area network interface is operable to receive a packetized data stream from the interface of the mobile station.

Abstract: A control network comprises multiple master nodes and multiple slave nodes, connected together in a loop configuration by at least one fiber optic cable. The master nodes share concurrent control over the network nodes by time multiplexing or other techniques. The control network may include two fiber optic rings which carry the same data simultaneously in opposite directions around the loop. A polling scheme may be used by the master nodes such that only one node transmits at a given time in both directions around the loop. The receiving node(s) propagate the transmissions and select between the transmissions based on time, error rate, or other factors. A hierarchical control network may be constructed with upper tier and lower tier fiber optic rings. Multiple master nodes may be used at any level of the ring, and some or all of the rings may include two fiber optics for bidirectional, redundant communication within the network.

Abstract: A control network comprises multiple master nodes and multiple slave nodes, connected together in a loop configuration by at least one fiber optic cable. The master nodes share concurrent control over the network nodes by time multiplexing or other techniques. The control network may include two fiber optic rings which carry the same data simultaneously in opposite directions around the loop. A polling scheme may be used by the master nodes such that only one node transmits at a given time in both directions around the loop. The receiving node(s) propagate the transmissions and select between the transmissions based on time, error rate, or other factors. A hierarchical control network may be constructed with upper tier and lower tier fiber optic rings. Multiple master nodes may be used at any level of the ring, and some or all of the rings may include two fiber optics for bidirectional, redundant communication within the network.

Abstract: A control network comprises multiple master nodes and multiple slave nodes, connected together in a loop configuration by at least one fiber optic cable. The master nodes share concurrent control over the network nodes by time multiplexing or other techniques. The control network may include two fiber optic rings which carry the same data simultaneously in opposite directions around the loop. A polling scheme may be used by the master nodes such that only one node transmits at a given time in both directions around the loop. The receiving node(s) propagate the transmissions and select between the transmissions based on time, error rate, or other factors. A hierarchical control network may be constructed with upper tier and lower tier fiber optic rings. Multiple master nodes may be used at any level of the ring, and some or all of the rings may include two fiber optics for bidirectional, redundant communication within the network.

Abstract: A packet switching fabric includes means forming a data ring, means forming a control ring, and means forming a plurality of data communication network links each having at least one network node coupled thereto. The fabric further includes a plurality of output queuing controlled switching devices coupled together by the data ring means and the control ring means so that the network links can be selectively communicatively coupled. Each of the output queuing controlled switching devices includes control ring processing means operative to develop, transmit and receive control messages to and from adjacent ones of the devices via the control ring means.

Abstract: A communication system between head-ends and end-users is provided which expands bandwidth and reliability. A concentrator receives communication signals from a head-end and forwards the received communication signals to one or more fiber nodes and/or one or more mini-fiber nodes. The concentrator demultiplexes/splits received signals for the mini-fiber nodes and the fiber nodes and forwards demultiplexed/split signals respectively. The mini-fiber nodes may combine signals received from the head-end with loop-back signals used for local medium access control prior to forwarding the signals to the end-users. Upstream data are received by the mini-fiber nodes and/or fiber node and transmitted to the concentrator. The concentrator multiplexes/couples the mini-fiber node and the fiber node upstream signals and forwards multiplexed/coupled signals to the head-end.

Abstract: A method and apparatus for reserving bandwidth in a network includes a series of elements. A demand matrix is calculated, for bandwidth requirements based upon communication needs among a plurality of nodes on the network. An integer number of time slots is provided, aligned around the network. Bandwidth is reserved for node-to-node communication based upon the demand matrix. The reserving of bandwidth reserves bandwidth between two nodes based upon time-slot alignment. Transmission is scheduled between the two nodes by reservation of wavelengths and time slots.

Abstract: The device for data transmission has a main station (3) and a number of terminals (1) and is provided with a device for coordinating operation in respective signaling data phases for downlink (42) and uplink (52) and corresponding useful signal data phases (41, 51). Each transmission frame (5) has a first data field (4211) that is fixed in length and is for required, time-critical, data and at least one other data field (4212) which is flexible in length and for only sporadically required data using various information elements (6), such as announcements of frequency changes, status information, additions to manufacture-specific information, warnings and/or information regarding the capabilities of the main station.

Abstract: A ring interface is coupled to a current node in a ring network having a plurality of nodes and corresponding ring interface for each of said nodes. The ring interface includes a ring input port operative to conduct upstream message packets from a previous node to the ring interface, a ring output port operative to conduct message packets to a next node of the ring network, and a bypass queue operative to buffer message packets. A receive queue buffers message packets before passing them on to the current node. An address filter is coupled to the ring input port to receive the upstream message packets, read their destination addresses and pass them to the bypass queue if the addresses correspond to another node and pass them to the receive queue if their addresses are that of the current node.

Abstract: A hub port in a loop network is disclosed. The hub port includes a hub data source, first and second detect circuits, and a processor. The hub data source supplies data to the hub port from the loop network. The first detect circuit is configured to detect a first sequence from an attached node port establishing a loop circuit. The second sequence from the attached node port indicates to terminate the loop circuit. The processor is configured to receive the first sequence from the first detect circuit. Further, the processor operates to close a detect window and to increment a sequence origination count, if the detect window is open. The second detect circuit is configured to detect the second sequence from the hub data source confirming the termination of the loop circuit.

Abstract: In a communication network that includes a plurality of nodes interconnected by links, a method for routing a data flow includes receiving a request to allocate one or more resources in the network so as to carry the data flow between first and second ones of the nodes over one of a plurality of paths therebetween, each such path including a respective sequence of the links. For the links included in each of the paths, respective levels of use of the requested resources due to communications in process over the network are determined. The path that is to carry the data flow is selected responsive to the determined levels of use of the requested resources on the links included in each of the paths.

Abstract: A communications system includes a plurality of network nodes including a first node having an interface unit. The interface unit includes a scheduler operable to schedule periodic transmission of a plurality of frames at respective designated times. Each of the plurality of frames includes a plurality of slots. The interface unit also includes an access system operable to designate which of the plurality of slots of a frame are accessible by each of the plurality of nodes and to access the designated slots.

Abstract: A ring configuring method configures a network in which a plurality of nodes are connected linearly, and performs topology construction for the ring by circulating topology data through the respective nodes and collecting connection information of the respective nodes. The method includes the steps of providing in the topology data a flag indicating whether the connection information is collected in each node; inverting the flag at a terminal station which is an end node of the open ring, and turning the topology data there; causing the topology data to passing through a node other than any terminal station as it is; and adding the connection information to the topology data in each node according to the flag, and performing topology construction.

Abstract: A digital transmission network comprises a plurality of transmission terminals and receiving terminals, which are all connected with each other by a transmission line of a metal cable or optical fiber cable in the form of loop. Signals are transmitted by timeshare multiplexing in one direction. An individual time slot which is defined for each transmission terminal by time sharing multiplexing is allocated to each of all transmitted signals. A timing device is inserted into the loop for retransmitting a signal so that the delay time is corrected to the delay time of one frame including the delay time caused by the transmission line, cable and the like so that the consecutive frames are continuous. The transmission line is in single or dual loop. In case of the single loop, the transmission terminal includes a bypass circuit for bypassing a signal input to the transmission line if necessary.

Abstract: A network for interconnecting network equipment units via a ring optimizes access to the ring by the equipment units in that the capacity of the ring is permanently shared between the various equipment units. An information signal, representing the unused part of the capacity of the ring, is forwarded on the ring. The equipment units insert into a transport frame a number of data units corresponding to a minimum transmission right guaranteed to each equipment unit. The unused capacity of the ring is then subdivided between the equipment units.

Abstract: An improved access system for use in a Fiber-In-The-Loop (FITL) communications network is disclosed. The access system comprises a host digital terminal (HDT) and a plurality of subtending optical network units (ONUs). The digital signal processing (DSP) functions traditionally executed by line interface units (LIUs) within the ONUs are migrated to the HDT, rendering the individual ONUs simpler, cheaper and more reliable. This is made possible by the provision in each ONU of an oversampling codec for sampling (and conversion) of upstream and downstream data at a very high bit rate. The large bandwidths of the data communicated between the ONUs and the HDT are easily handled by the fiber optic medium therebetween. In the HDT, DSP functions are executed by a common pool, or bank, of DSP ASICs. Decimators are provided in the HDT in order to properly format the data for processing by the DSPs.

Abstract: A method for transmitting digital data over data lines between subscribers forming data sources and data sinks and being disposed in a network having a ring structure and connecting a plurality of subscribers to one another with network segments each being formed between two adjacent subscribers, includes transmitting the data in the network in a format specifying a clocked sequence of individual bit groups of equal length, each including at least one partial bit group forming a data channel to be assigned temporarily to two subscribers in the network for a data transmission. A temporary allocation of the data channels for a data transmission between two subscribers takes place segmentally in the network, for optimal utilization of the data transmission capacity of the network only those network segments that are located between the applicable data source and the associated data sink are occupied for the particular data transmission.

Abstract: A device-implemented method of data communications in a communications network is provided. A particular node which has data information to send is granted a turn when an incoming request signal is in an "off" state. An empty frame is captured and a frame of data information is sent in a downstream direction on the communication network when the particular node is granted a turn. An outgoing request signal is set in an "off" state when the empty frame is captured. The outgoing request signal is set in an "on" state when the empty frame is not captured and a turn has been granted. The outgoing request signal is set in an "on" state when the incoming request signal is in an "on" state and an incoming frame is not empty. The outgoing request signal preferably is sent in an upstream direction on the communication network where the upstream direction is different from the downstream direction on the communication network.

Abstract: An optical ring network with a plurality of network elements (#1, . . . , #N) is disclosed which contains only a single laser diode (2). This laser diode (2) is controlled to produce optical pulses of constant repetition frequency. Each network element (#1, . . . , #N) includes an add-drop facility by which the optical pulses (data bits) are selectively added to or extracted from an optical data stream.

Abstract: An adaptive burst multiplexing system using dynamic deadline computation serializes data from source units. It comprises interface circuits for accumulating in a buffer memory a quantity of data from a corresponding source unit. An empty frame generator circulates a series of frames around a ring through the interface circuit. Each interface circuit computes a deadline beyond which its buffer memory may become saturated and places this deadline in a passing empty frame. When this frame returns to the frame generator it contains the identifier of the interface circuit that put in it the earliest deadline. The generator transmits an empty frame over the ring with the identifier of this interface circuit which then recognizes its authorization to transfer data accumulated in its memory.

Abstract: A node for an access control system for a multi-channel data transmission ring is disclosed. Access to a channel is controlled exclusively by one node, which is the only data receiving node connected to that channel. The receiving node generates slots so that other connected nodes can transfer data to the receiving node. The receiving node can provide balanced access to the channel by all connected nodes. Further embodiments feature prevention of congestion in the buffer of the receiving node. The invention is particularly useful for wavelength division multiplexed (WDM) optical rings.

Abstract: A communication system having communicating devices coupled to a closed loop bus substantially reduces interconnect distances and corresponding signal propagation delays between the devices. Particular devices possess switchable impedance elements that can be selectively actuated to produce an effective terminating impedance substantially at a midpoint position along the closed loop from the coupling point of a transmission device. In such an arrangement, the produced effective terminating impedance would cause the signal transmitted by the transmission device to propagate to a destination device substantially without signal degradation due to signal reflections.

Abstract: In a token ring network a periodic recirculating frame having a plurality of information carrying slots and a header section is used for enabling a plurality of telephone stations to exchange information carrying signals. The header is provided with a token which can assume one of three states. In the first state FF, a telephone station wanting to make a call, changes the token to the second state 00 and inserts call establishment information in the header. A server station also connected in the ring detects the second state as a request to establish a connection from and to a station specified in the header. The server changes the token to the third state AA and inserts a slot assignment in the header. All stations receiving a frame with a token in the third state examine the header. The calling station implies confirmation of the requested connection and the called station is made aware of the call and the identity of the caller.

Abstract: An advanced data server including an I/O ring coupled to at least one I/O access channel which provides data to the I/O ring or reads data out from the I/O ring; a disc array ring coupled to least two disc arrays which store therein data received from the disc array ring or retrieve therefrom data for receipt by the disc array ring, the disc array ring also being coupled to the I/O ring so that data can flow between those rings; and a server controller coupled to the I/O ring and the disc array ring for controlling the operations thereof. The I/O ring includes a first ring controller which controls receipt of data from the I/O access channel and transfer of that data to the disc array ring, or receipt of data from the disc array ring and transfer of that data to the I/O access channel.

Abstract: A deterministic network protocol for connecting critical sensors, actuators and computing elements on a bi-directional, time-multiplexed, fiber optic or other media data bus, such that critical messages have concisely bounded latency and non-critical messages may be sent without impacting critical messages. It is a unique combination of a time-slot allocation protocol and a contention-based protocol in which global synchronization information is passed on the data media via a synchronization beacon.

Abstract: A system and method for passively measuring and correcting ring latency on a token or FDDI ring includes generating bits and token frames in a defined pattern according to the token ring protocol. A passive device coupled to the token ring measures CMIN, the minimum spacing, CMAX, the maximum spacing in bits and calculates Fi the frequency of changes in Cmin and Cmax between successive tokens or a token and a frame on the ring. A latency event vector Li is generated by the passive device. A controller responsive to the latency vector Li corrects the spacing between successive tokens or a token and frame to achieve a constant ring latency regardless of electrical or operational changes on the token ring.

Abstract: In a communications network, first information items are transmitted synchronously and second information items asynchronously. The second information items are overlaid on the synchronously transmitted first information items. A bandwidth accessible on transmission can be variably distributed between the first and second information items and, with the desired variable distribution, transmitting and receiving units become synchronized by synchronization information which is transmitted via a channel established for asynchronous transmission between the transmitting and receiving units.

Abstract: A communications network, having an SDH transmission line with four main channels, is provided, at four different tributary connection nodes, with respective add/drop multiplexer units for permitting interchange of information signals between the main channels and tributary channels of the network connected to respective tributary ports. Each add/drop multiplexer unit includes a time slot interchange unit through which a pair of the main channels pass but which bypass the other two main channels. Because different pairs of the main channels pass through the different time slot interchange units, signal interchange is possible between any one of the main channels and any one of the tributary channels, even though the time slot interchange unit at each node need not have an interchange capability sufficient to enable signal interchange between each tributary channel at the node concerned and any one of the main channels. The add/drop multiplexer units can be located together at a single node, if required.