Abstract: A light beam emitted from a light source is focused by an objective lens onto an information recording surface of an optical information recording medium. The objective lens has a substantially truncated-cone-shaped portion on its surface on the side of the optical information recording medium. This makes it possible to prevent interference with a DVD-RAM cartridge and ensure optical compatibility with a BD and a DVD.

Abstract: An objective lens for use in an optical pickup apparatus for conducting recording and/or reproducing information for an optical information recording medium, has a lens section shaped in an approximate circle and including a flange section; and a connecting section integrally provided to the lens section.

Abstract: An optical pickup is provided which includes a light source, an optical system for converging a laser beam emitted from the light source, and an optical element having a function of increasing a numerical aperture of the optical system, wherein recording and/or reproducing information on a recording medium is performed by using the laser beam from the light source while the optical element is brought in contact with or in close to the recording medium, and the optical element has a contamination-preventing structure.

Abstract: While supporting an optical disc having a recording density that is higher than conventional optical discs by shortening the wavelength of the emitted light and increasing the numerical aperture (NA) of an objective lens, a reduction in the size of an optical pickup apparatus relative to the size of a disc cartridge that houses the optical disc is achieved. The present invention includes a fixed optical system having a built-in light source, and a movable optical system having an objective lens. A parallel light beam that enters the movable optical system from the fixed optical system enters the movable optical system via a light path that is parallel to the direction in which the objective lens is movable and from the side on which a spindle motor is provided.

Abstract: An electromagnetically controlled drive system for accessing a data storage medium comprises an optical signal generator and a reflector element adapted to receive an optical signal from the optical signal generator. The reflector element is also adapted to direct the optical signal toward the data storage medium. The system also comprises an electromagnetic element adapted to generate an electromagnetic field proximate to the reflector element. The reflector element is adapted to respond to the electromagnetic field to move the optical signal relative to the data storage medium in response to a change in the electromagnetic field.

Abstract: An optical pickup includes a diffraction grating partitioned into three areas, in which the phase of periodic grating groove structure in an area is successively shifted from that in the adjacent area by 90°. In the generation of a differential push-pull signal, an amplification factor K for sub push-pull signals is varied depending on the type of the optical disk. By such composition of the optical pickup, amplitude deterioration of the tracking error signal accompanying displacement of the object lens is reduced.

Abstract: In a biaxial actuator for an optical pickup, rising pieces are bend-formed on a base member on which a lens holder having an objective lens is placed in such a way as to be able to displace in a focusing direction and in a tracking direction. The strength of the base member is increased by setting the width of the bend-formed portion at the root of each of the rising pieces in such a way as to be larger than the width of any other part of the associated rising piece. Preferably, the shape of a side elevation section of each of the rising pieces is set to be a trapezoid.

Abstract: A turntable that has a platter that can be vertically positioned so that the VTA between the stylus of the cartridge and the record can be easily adjusted without tweaking or touching the tone arm. The turntable includes a base, a platter, a spindle assembly configured to position the platter above the base, and a spindle adjustment mechanism configured to selectively position the vertical position of the platter with respect to the base. In one embodiment, the spindle adjustment mechanism includes a drive shaft that is configured to engage the spindle assembly and to selectively drive the spindle assembly up or down. As the spindle assembly is moved up and down, the platter moves up and down with respect to the base. In another embodiment, the spindle assembly includes a spindle shaft configured to rotate inside a chamber of the spindle assembly. A bolt which attached to the spindle shaft is configured to move up and down when the spindle shaft is rotated.

Abstract: A recording medium having a spare area for defect management and the management information of the spare area, a spare area allocation method, and a defect management method. When a primary spare area is allocated for slipping replacement and linear replacement upon initialization, and a remaining portion of the primary spare area after slipping replacement and allocated for linear replacement after initialization are insufficient, a supplementary spare area is allocated.

Abstract: The present invention separates MTF into a plus frequency region and a minus frequency region and uses the plus frequency region and the minus frequency region to thereby enable an effectively usable frequency region to be doubled in effect. Digital information to be recorded on an optical disk medium is recorded as independent signals of, respectively, a light beam reflected or diffracted forward and a light beam reflected or diffracted backward with respect to a direction of traveling of a track on the optical disk medium. At the time of producing an optical disk medium, digital information is divided into two pieces, a complex modulating signal is generated by changing a plus frequency component and a minus frequency component according to the pieces of the divided digital information, and a laser beam is modulated on the basis of the complex modulating signal.

Abstract: An optical information-recording medium comprising a substrate which is formed with a plurality of lands and grooves, and a recording layer and a reflective layer which are provided on the substrate, is provided. The grooves include a first groove, a second groove which is formed with pits, and a third groove which is formed with pits having widths narrower than those of the pits of the second groove, wherein the third groove is arranged between the first groove and the second groove. With the optical information-recording medium based on the use of the substrate as described above, even when the tracking is performed to span the boundary between the area in which the in-groove pits are formed and the area in which only the groove is formed, then the radial push-pull signal is scarcely disturbed, and it is possible to perform the stable tracking.

Abstract: This invention is a technical inprovement of the CD & DVD medium. It involves the addition of a protective ring on the outside border of a CD & DVD to prevent the face of the CD & DVD containing the data from touching a surface where it may be placed on.

Abstract: A digital data storage assembly (2), e.g., a flexible thin film compact disc, is described. Digital data storage assembly (2) includes, (a) a thin film data storage carrier (11), having substantially opposed first (14) and second (17) surfaces, a cruciform aperture (20) defined in part by a pair of substantially opposed arcuate sides (97, 97′) and a pair of substantially opposed substantially straight sides (94, 94′), and at least one tab (23, 26) extending partially into aperture (20). The assembly (2) also includes, (b) a rigid support (29) having substantially opposed first (32) and second (35) surfaces, and an aperture (38). The assembly (2) further includes, (c) a locking device (41) positioned at least partially around aperture (38) of rigid support (29). Locking device (41) includes at least one shelf (44, 47) extending out over a portion of the first surface (32) of rigid support (29). The shelf (e.g., 44) and a portion (e.g.

Abstract: A digital data storage assembly (2), e.g., a flexible thin film compact disc, is described. Digital data storage assembly (2) includes, (a) a thin film data storage carrier (11), having substantially opposed first (14) and second (17) surfaces, an aperture (20), and at least one tab (23, 26) extending partially into aperture (20). The assembly (2) also includes, (b) a rigid support (29) having substantially opposed first (32) and second (35) surfaces, and an aperture (38). The assembly (2) further includes, (c) a locking device (41) positioned at least partially around aperture (38) of rigid support (29). Locking device (41) includes at least one shelf (44, 47) extending out over a portion of the first surface (32) of rigid support (29). The shelf (e.g., 44) and a portion (e.g., 53) of the first surface (32) of rigid support (29) residing thereunder together define a tapered slot (e.g., 62), having an open end (59) and a closed end (56).

Abstract: For transmit diversity in a multi-antenna OFDM system, a transmitter encodes, interleaves, and symbol maps traffic data to obtain data symbols. The transmitter processes each pair of data symbols to obtain two pairs of transmit symbols for transmission from a pair of antennas either (1) in two OFDM symbol periods for space-time transmit diversity or (2) on two subbands for space-frequency transmit diversity. NT·(NT−1)/2 different antenna pairs are used for data transmission, with different antenna pairs being used for adjacent subbands, where NT is the number of antennas. The system may support multiple OFDM symbol sizes. The same coding, interleaving, and modulation schemes are used for different OFDM symbol sizes to simplify the transmitter and receiver processing. The transmitter performs OFDM modulation on the transmit symbol stream for each antenna in accordance with the selected OFDM symbol size. The receiver performs the complementary processing.

Abstract: This invention generally relates to apparatus, methods and computer program code for decoding a received signal where the signal is received by a received antenna from a plurality of transmit antennas. The invention addresses the further difficulties which arise when only limited or known information for deriving an estimate of the responses of the channels between the transmit antennas and the receive antenna is available.

Abstract: A code-modulation adaptive and variable multiplexing transmission apparatus. Dividing circuit divides transmission information data into plural transmission sub-channel signals. Coder performs error-correction coding by coding scheme and coding ratio selected from plural schemes and plural ratios for each sub-channel. Modulator performs primary modulation by selecting a multi-level modulation scheme from plural schemes for each sub-channel. Another modulator performs band-broadening by selecting a band-broadening scheme from plural schemes for each sub-channel. Adding circuit adds transmission-condition identifying information including coding scheme and coding ratio, multi-level modulation scheme in the primary modulation, band-broadening scheme in the secondary modulation on each sub-channel, and the number of the sub-channels. Multiplexing circuit frequency-multiplexes plural modulated outputs, so that they are frequency-multiplexed and transmitted.

Abstract: Data carrier duplication (DCD) is used to implement power control in multipoint-to-point OFDM systems. In DCD, data on several carriers (i.e., frequencies) is utilized in order to increase the power of a channel. Data carrier duplication not only provides power control capabilities, but it also mitigates selective fading problems. In a “closed loop power control” (CLPC) scheme, a hub is provided with certain intelligence which allows it to provide optimal distribution of carriers among nodes. In an “open loop power control” (OLPC) scheme, the nodes are provided with more intelligence to allow them to determine the number of additional carriers they require for transmitting data.

Abstract: A method for constructing orthogonal codes of length N for use in a network utilizing quasi-synchronous code division multiple access combined with time division duplexing. The method determines the balanced vectors of length N, being all possible cross-correlation vectors resulting from zero cross-correlation of codes of length N. An arbitrary code of length N is utilized, and a bitwise XOR-ing is performed with all the balanced vectors to produce a set of codes with which the arbitrary code is orthogonal. A bitwise XOR-ing of the original balanced vectors is performed and the code is added to a set of orthogonal codes if the result of the bitwise XOR-ing of the original balanced vectors is balanced. The method is repeated until the set of orthogonal codes is complete.

Abstract: A system and a method for the transmission and reception of digital data wirelessly using acoustic tones comprises a device having an encoder, a modulator system, a demodulator system, and a decoder. The modulator system uses dual tone multiple frequency (DTMF) tones that are amplitude modulated. The received signal is demodulated and detected by Fourier analysis. An expanded Hamming code based decoder is used for correcting errors occurring during transmission.

Abstract: The invention refers to a method for monitoring a communication media access schedule of a communication controller (5) of a communication system (1) by means of a bus guardian (6). The communication system (1) comprises a communication media (2) and nodes (3) connected to the communication media (2). Each node (3) comprises a communication controller (5) and a bus guardian (6) assigned to the communication controller (5). Messages are transmitted among the nodes (3) across the communication media (2) based on a cyclic time triggered communication media access scheme.

Abstract: There is disclosed, for use in a CDMA wireless network, a channel resource allocator for reallocating a data traffic channel in a soft handoff state to handle incoming calls from new mobile stations. The channel resource allocator includes an overhead channel controller for reconfiguring a data traffic channel as an overhead channel upon failure of an overhead channel element in a base transceiver station (BTS). The channel resource allocator determines if all data traffic channels of the BTS are in use. If so, the channel resource allocator determines whether any of the existing calls being serviced by the data traffic channels are in a soft handoff state in which the call is connected simultaneously to two or more base transceiver stations. If so, the channel resource allocator drops the connection to the BTS in which the overhead channel failure occurred, thereby freeing up the data traffic channel.

Abstract: Described is a packet switching mechanism for packet data transmission systems in a multi-channel radio arrangement. The method comprises the steps of receiving a plurality of data packets (A, B, C, . . . ) to be transmitted; and providing a number (n+p) of radio channels (VC-X#1, VC#X-2, . . . ) for performing the transmission. The method is characterized by the steps of assigning the entire transport of each data packet (A, B, C, . . . ) to one radio channel (VC-X#1, VC#X-2, . . . ) and, in absence of failures, by performing the transmission by using all the available working and protection channels.

Abstract: Systems and methods for performing error recovery in a system utilizing redundant communication links. In one embodiment, a host device is coupled to a sequential device such as a tape drive by a pair of Fibre Channel links. The host is configured to associate an identifier with each command. Upon detecting a failure of the transmission of the command via the first link, the host re-transmits the command via the second link. When the link failure is detected, the status of the last command transmitted before the failure is requested. After receiving the status of the command, a request that recovery start (possibly at a point indicated by the status information) is transmitted to the sequential device. If the recovery request is accepted, performance of the command is completed.

Abstract: A fast ring switchover is enabled in packet level processing at the time of ring configuration, and as a result, a system switchover function can be implemented in an Ethernet switch or the like by a ring switchover method in a network constituted of layer 2 switches connected in a ring shape, each layer 2 switch having a path control function and a failure detection function. The ring switchover method includes the steps of providing in each layer 2 switch an address learning table in which a Media Access Control (MAC) address and a corresponding port are stored; on detection of a link failure between mutually neighboring layer 2 switches, transmitting a failure notification frame packet from each neighboring layer 2 switch; and in the layer 2 switch having received the failure notification frame, recording a Media Access Control (MAC) address of said layer 2 switch into the failure notification frame, and transferring the failure notification frame to a neighboring layer 2 switch.

Abstract: A digital information distribution system having a plurality of nodes that are connected to one another by counter-rotating data paths. Each node comprises a ring terminal that selects data packets from the data paths for use by the node and passes the remaining data packets to neighboring nodes. The data paths communicate data using asynchronous serial interface packets that transport video data or IP data.

Abstract: A telecommunication network with fast-reroute features wherein a method is used to release, by means of a “Path_Tear Message”, a Label Switched Path [LSP] established between linked routers (A, B, C, D, E). The routers are linked in cascade according to a Main Path (AB, BC, CD, DE) and are further linked in another order according to at least one Detour Path (ac, ce; bd). The Path_Tear Message includes a tag indicating, in each router, whether this Path_Tear Message should be immediately forwarded towards a downstream-located router or not. It is thereby possible to obtain a faster release of any unused Label Switched Path [LSP] than waiting for a timeout of 1 to 2 minutes, as it is currently the case.

Abstract: The invention relates to a method of protecting a data link (1-10, 1-20) established via an access point (GGSN1, GGSN2, ROUTER1, ROUTER2) to a mobile subscriber node (MN). The invention further includes the steps in which: (i) a monitoring network element (HA) observes the operation of the data link (1-10, 1-20); and (ii) in case the operation of the data link (1-10, 1-20) becomes unsuitable for communication, the monitoring network element (HA) starts to set up an alternative data link (1-10, 1-20) via an alternative access point (GGSN1, GGSN2, ROUTER1, ROUTER2).

Abstract: A method, apparatus and program storage device for verifying existence of a redundant Fibre Channel path is disclosed. The present invention verifies that a redundant path exists prior to moving the WWNN and WWPN. Thus, if the path being used for Fibre Channel communication is lost, connectivity can be restored when the source of the original connection can access the physical interface where the WWNN and WWPN have been moved.

Abstract: Disclosed are data transfer systems, methods, and programs. One example data transfer method includes determining whether a present time is acceptable to a recipient for transmission of data to the recipient over the telephone line, transmitting the data to a data receiving device of the recipient over the telephone line if the time is acceptable, and delaying transmission of the data if the time is not acceptable. One example data transfer program includes logic configured to determine what time is acceptable to a recipient for transmitting data to a data receiving device of the recipient, logic configured to determine what time is acceptable to a sender for transmitting data to the data receiving device, logic configured to determine a time that is mutually acceptable to the recipient and the sender, and logic configured to facilitate data transmission during the mutually acceptable time.

Abstract: A method of transmitting data in a centralized network is disclosed. The method establishes a traffic channel. A source device transmits data to a group of destination devices over the traffic channel. The source device then waits for an acknowledgement of reception of the data from at least one source device.

Abstract: The present invention relates to a congestion controller, which suppress transmission traffic based on a traffic attribute in the event of congestion especially in a circumstance in which a plurality of Ethernet switches are connected. The congestion controller in the Ethernet switch comprises a plurality of transmission queues having different priority each other, a receiving unit for receiving a PAUSE frame, and a restriction unit to restrict transmission traffic from the transmission queue by the received PAUSE frame, wherein the restriction unit restricts the transmission traffic from a transmission queue of lowest priority by a PAUSE frame received at a time other than a PAUSE time and suppresses transmission traffic from a transmission queue of highest priority by a PAUSE frame received during the PAUSE time.

Abstract: In one embodiment, a method comprises recursively selecting a child node of a previously selected node of a port tree and having a highest priority among nodes of a same level within the port tree, until the selected node has associated egress queues of an egress port. The method also includes outputting a number of packets from the associated egress queues of the selected node in a current processing cycle. The number of packets outputted is based on an allocated bandwidth for the associated egress queues, in which the allocated bandwidth accounts for a deficit from a previous processing cycle.

Abstract: The present invention provides an admission control method in an Internet differentiated service network, for dividing an admission control function executed at an ingress edge node into a path level and a link level, performing a path level admission control function at an ingress edge node without communication with a bandwidth broker by enabling the path level to use a specific bandwidth being initially allocated to a corresponding path by a bandwidth broker, and performing a link level admission control function through the use of a measurement based admission control method by enabling the link level to be allocated a bandwidth of an unused other service using a movable boundary method when the initially allocated path level bandwidth is completely used.

Abstract: A flexible, policy-based, mechanism for managing, monitoring, and prioritizing traffic within a network and allocating bandwidth to achieve true quality of service (QoS) is provided. According to one aspect of the present invention, a method is provided for managing bandwidth allocation in a network that employs a non-deterministic access protocol, such as an Ethernet network. A packet forwarding device receives information indicative of a set of traffic groups, such as: a MAC address, or IEEE 802.1p priority indicator or 802.1Q frame tag, if the QoS policy is based upon individual station applications; or a physical port if the QoS policy is based purely upon topology. The packet forwarding device additionally receives bandwidth parameters corresponding to the traffic groups.

Abstract: A method and system for initiating selective flow control within a network multiplexer. Each port of a network multiplexer is associated with high and low threshold values, as well as a list of indications of ports that have requested the port to initiate flow control and a list of indications of ports which the port has requested to initiate flow control. A port that, by queuing a message descriptor to the transmit queue of a destination port, causes the number of message descriptors queued to the transmit queue of a destination port to equal or exceed its high threshold, is flow controlled by the destination port. When the number of message descriptors queued to the transmit queue of a destination port that previously equaled or exceeded the high threshold falls below the low threshold, all ports flow controlled by the destination ports are released from flow control.

Abstract: A policing mechanism 100 for a resource limited wireless MAC processor. The policing function is enforced at both the host software and embedded firmware. The responsibility of the policer on the host prevents ill behaved flows from flooding the firmware and thus blocking other flows. The policer on the firmware prevents users with bad channels from occupying the channel with low rate transmissions/retransmissions and thus blocking others from transmission.

Abstract: A device for converting between the trunked and untrunked transmission of Fibre Channel frame data and for providing connections using longer distance links is described. During conversion, the device manages the flow of frame data in both the egress (from Fibre Channel ports to a non-Fibre Channel port) and ingress (from a non-Fibre Channel port to Fibre Channel ports) directions. In the egress direction, the device operates as a FIFO to transmit all frames received from the Fibre Channel ports to the non-Fibre Channel ports. In the ingress direction, every frame received by the non-Fibre Channel port is stored in one of up to four storage segments based on the frame data's virtual circuit and path number identifiers. Frames are transmitted out of each storage segment in the order in which they are received therein. The device may be a stand-alone device. The device may also be incorporated into a Fibre Channel switch or other apparatus that connects to a Fibre Channel network or switch.

Abstract: A method and apparatus for detecting discontinued transmission (DTX) frames in data frames received over a link or channel, is described, where a DTX frame is a frame that does not carry data and which is transmitted with zero power over the link or channel. The method calculates a data rate of a channel over which data frames are being transmitted, sets a threshold based on the data rate, and determines whether a received data frame is a DTX frame based on the threshold. The apparatus can effectively discriminate a case where a data frame is received as an erasure (e.g., data frame received with errors), and a case where a transmitted data frame is received as a DTX frame.

Abstract: A resource reservation protocol substitute reply router is provided for enabling execution of RSVP procedure as substitute by automatically detecting that a reception host does not support RSVP. A Path message storage portion stores a Path message handled by an RSVP control portion. An ICMP detecting portion monitors data packet input to a routing portion. When “message of Destination Unreachable” is found in the packet, an IP header information contained in the ICMP message and a stored value of the Path message storage portion are compared. If matched one is present, the ICMP message is disposed, and in place, it is requested to the substitute RSVP control portion to execute the procedure of RSVP on behalf of the reception host. The substitute RSVP control portion executes the procedure of RSVP on behalf of the original reception host.

Abstract: An identification system and method for recognizing a device as one of a plurality of different types of devices connected to at least one terminal of an information handling system includes supplying a test signal to a device in a test mode; measuring an electrical characteristic of the device in response to the test signal being applied to the device in the test mode; and matching a representation of the electrical characteristic of the device with representations of the electrical characteristics of the plurality of devices for recognizing the device connected to the terminal as one of the plurality of different devices.

Abstract: Tandem-free vocoder operations (TFO) between non-compatible communication systems may be enabled through hardware modifications at communication elements within each system. In one aspect, each infrastructure entity in System 1 comprises an intra-system TFO Frame Generator G1, an intra-system TFO Frame Extractor E1, and a TFO Frame Extractor E2 of System 2, which is non-compatible to System 1. Each infrastructure entity in System 2 comprises an intra-system TFO Frame Generator G2, an intra-system TFO Frame Extractor E2, and a TFO Frame Extractor E1 of System 1.

Abstract: The practice and need for active network measurement is well established, however, current tools are not well suited to this task, mostly because the protocols which they employ have not been designed for measurement of the modem Internet. The IP Measurement Protocol (IPMP) is based on packet-probes, and is designed to allow routers to participate in measurements by the insertion of path information as the probe passes between a pair of hosts.

Abstract: The practice and need for active network measurement is well established, however, current tools are not well suited to this task, mostly because the protocols which they employ have not been designed for measurement of the modern Internet. The IP Measurement Protocol (IPMP) is based on packet-probes, and is designed to allow routers to participate in measurements by the insertion of path information as the probe passes between a pair of hosts.

Abstract: A method for rate matching in equipment used as part of, or in communication with, a radio access network implementing FLO (Flexible Layer One) so as to provide retransmission with incremental redundancy, the method using a rate-matching algorithm based on determining a starting parameter eini, the method characterized by: a step (21) of providing a retransmission parameter R controlled by the RLC protocol layer and having typically a value of one for a first retransmission and a next higher value for each subsequent transmission; a step (24) of determining a characteristic distance D related to the average distance between either punctured bits or between transmitted bits, depending on the value of the average distance between punctured bits; and a step (25) of determining a new value of eini based on a cycling term having a value depending on R but modulated by D so as to never exceed D−1.

Abstract: Network switches of an information handling system are automatically configured by a PXE agent associated with each network switch, such as a PXE agent embedded in firmware of each network switch. The PXE agent automatically requests a configuration image during boot of the network switch and re-configures the network switch with the configuration image. For instance, the PXE agent requests configuration service from a PXE server, which directs a TFTP server to download the configuration image to the network switch. In one embodiment, a blade server has plural server blades supported in plural chassis with each chassis having one or more switches. Each switch has a PXE agent so that the switches of the blade server are automatically configured with the same configuration image. Alternatively, selected configuration factors, such as a static IP address, are individually configured by reference to a unique identification, such as a universal unique identifier.

Abstract: A layered network node of which a network it belongs is divided up into cells which are constituted by a plurality of nodes; the cells are defined as virtual nodes; if links exist which connect the interiors of the virtual nodes and the exterior, contact points between them are defined as interfaces of the virtual nodes; the virtual network constituted by the virtual nodes is further divided up into cells and making them into virtual nodes; said virtual network is defined as a network of a higher level with respect to the initial virtual network; by performing said operation of division into cells and making into virtual nodes once or a plurality of times, the layered network is constituted; path computation is performed from the source node to a destination node in a stepwise manner by dispersing it over the various layers.

Abstract: In the present invention, the available delay budget for a full-duplex communication is distributed between the links depending on their activity, present and near history. By keeping track on if a link in a full-duplex communication system is active or inactive, i.e. knowing the information value of the transferred data, coding procedures having larger coding delays than normally accepted can be used for active links, if the opposite link simultaneously is inactive. Since the user sensibility for delays is as largest at the moment a link becomes active, coding procedures having smaller coding delays than normally used are assigned at the moment a link becomes active. The coding delay is subsequently increased. Preferably, the round-trip delay is controlled to be kept smaller than a requested maximum value.

Abstract: The invention is a system for providing virtual connections through an ATM interworking multiplexer on a call-by-call basis. A signaling processor receives signaling for a call and selects the virtual connection for the call. The signaling processor generates new signaling that identifies the selection and transfers the new signaling to the ATM interworking multiplexer that accepted the access connection for the call. The multiplexer converts user information from the access connection into ATM cells for transmission over the virtual connection in accord with the new signaling.

Abstract: Methods and apparatus for performing arbitration to coordinate the sending of a plurality of packets or frames received at one or more input ports for transmission by one or more output ports are disclosed. One or more request messages are received from one or more of the input ports, each of the request messages indicating a request to send one or more packets or frames via one of the output ports. The arbitrator then determines whether the one of the output ports is capable of receiving the one or more packets or frames. A grant message is generated or sent when it is determined that the one of the output ports is capable of receiving the one or more packets or frames, the grant message indicating that the one of the output ports is capable of receiving the one or more packets or frames.