Abstract: The invention relates to a network comprising at least one first client and at least two second clients connected to the first client by a message transmission device, wherein the network is configured such that there is communication between the first client and the second clients in a communication time slot and data can be transmitted between the first client and the second clients in the communication time slot, said communication time slot having at least one first message time slot and one second message time slot, wherein the first message time slot can be used by a selected second client to transmit a message to the first client and the second message time slot can be used by a plurality of second clients to transmit a message to the first client.

Abstract: A network switch transfers data, which are to be transferred between nodes, in a time-division multiplex manner after allocating the data to slots, which are created by dividing a unit of time into a plurality of sections. An input unit includes a selection unit that selects a buffer unit according to an input slot in order to transfer the data input from the input port to the buffer unit, an input slot correspondence management table that stores a correspondence relationship between the input slots and the buffer units, and input port management information used to control a communication bandwidth of the input port.

Abstract: Various techniques can be used to handle frames within multi-stage switching fabric. For example, in one method, a frame and an associated frame header are received at a switching fabric stage. The associated frame header includes a first field and a second field. The method selects one or more fabric points of exit within the switching fabric stage, based on the second field. The first field is used to select one or more other fabric points of exit within another switching fabric stage, and thus two different fields within the associated frame header specify fabric points of exit. The method then sends the frame to the selected fabric points of exit within the switching fabric stage.

Abstract: Certain aspects of the present disclosure propose techniques for resolving paging interval conflicts between two different radio access technology (RAT) paging intervals and for avoiding missing paging messages for a multimode terminal (MMT). Certain aspects provide a method for detecting messages associated with paging, by an MMT supporting multiple-input multiple-output (MIMO), from first and second networks using first and second RATs, such as Time Division Synchronous Code Division Multiple Access (TD-SCDMA) and Code Division Multiple Access (CDMA) IxRTT (Radio Transmission Technology), Evolution-Data Optimized (EVDO), or Wideband CDMA (WCDMA). The method generally includes using a first MIMO receive chain of the MMT to detect a first message associated with paging from the first network and simultaneously using a second MIMO receive chain of the MMT, different from the first receive chain, to detect a second message associated with paging from the second network.

Abstract: A flexible OFDM/OFDMA frame structure technology for communication systems is disclosed. The OFDM frame structure technology comprises a configurable-length frame which contains a variable length subframe structure to effectively utilize OFDM bandwidth. Furthermore, the frame structure facilitates spectrum sharing between multiple communication systems.

Abstract: The present invention relates to a method and a radio base station (700) for allocating resources to a UE such that the UE can transmit at least channel feedback information to the radio base station (700). According to exemplary embodiments of the present invention, the radio base station (700) is configured to take the possibility of a scheduling request transmission from the UE into account when allocating the channel feedback information resources in order to avoid wasting of uplink resources.

Abstract: A process for scheduling reservation requests among a plurality of nodes on a network, includes examining a level of network communication activity of a first node to determine whether the first node is active; allocating a reservation request to the first node, but only if the first node is determined to be active; and repeating the process of examining and allocating for one or more subsequent nodes on the network. In one embodiment, the process can utilize thresholds to determine whether a network device is active and the thresholds can be based on, for example, recent network activity for the node being evaluated.

Abstract: A method of allocating resources in a communication system and a station for the communication system is disclosed. The communication system is such that a plurality of user equipment can communicate data on a dedicated channel. In the method a request for communication resources may be sent from a user equipment to the station on a first protocol layer. Priority information is obtained at the station from a data flow on a second protocol layer. Communication resources may then at least partially be allocated based on said priority information.

Abstract: The teachings herein disclose methods (600, 700) and apparatuses (36, 50) for dynamically rescheduling retransmissions from a selected Hybrid Automatic Repeat reQuest, “HARQ”, process, based on temporarily remapping the selected HARQ process to one or more subframes (12) that are by default scheduled for another HARQ process running synchronously with the first HARQ process. One advantage of dynamic rescheduling is that a retransmission for a given HARQ process can be accelerated in time, as compared to when the retransmission would occur absent the remapping. In another advantageous aspect, in at least some embodiments, the control signalling (20) for dynamic rescheduling is included in the Downlink Control Information, “DCI”, used to send scheduling grants for the HARQ processes, such that dynamic rescheduling uses control signalling (20) that is compatible with existing scheduling grant signalling.

Abstract: More than one communication device that is to simultaneously transmit identical data through multiple data transmissions using different radio wave multiplex types is determined based on the link qualities of a plurality of communication devices. Then the multiple data transmissions are made by transmitting the identical data with synchronized timings at the determined communication apparatuses. The link qualities are determined by measuring received signal intensities, bit error rates, or frame error rates at the respective communication devices at the time of the multiple data transmissions using two radio wave multiplex types orthogonal to each other.

Abstract: A wireless communication system includes a mobile terminal, a controller, and at least one base station. A mobile terminal has an array antenna and searches for neighbor base stations. The controller determines an active set for multi-cooperative transmission/reception with respect to the mobile terminal among searched neighbor base stations, and schedules beam transmission of each base station included in the determined active set. The at least one base station performs transmission/reception with the mobile terminal using beam-forming in an ultra high frequency band, and provides resource information regarding uplink/downlink of each base station included in the active set to the mobile terminal based on the scheduling by the controller.

Abstract: Each station makes a transition to a power saving state autonomously in response to the reception of signals from the other stations in the same group and the transmission of its own signal. Each station sets its transmission timing such that it does not overlap the transmission timing of the other stations, by referring to data elements included in a beacon signal. The transmission timing in the stations is determined for each transmission.

Abstract: A network device or user equipment (UE) may manage the transmission and retransmission of radio link control (RLC) data protocol data units (PDUs). An indication is received that an RLC data PDU was not successfully received by a receiving device. The RLC data PDU, that was not successfully received, is retransmitted, and prioritized over non-retransmitted RLC data PDUs. A number of times that the RLC data PDU was retransmitted is determined.

Abstract: Device, system, and method of phone call placement. A method of placing a phone call from a mobile phone includes: receiving a user command to initiate a phone call from said mobile phone using a cellular network; diverting said phone call to be carried by a detected network element of a non-cellular wireless network, instead of by said cellular network; wherein the diverting is based on at least one of: a Media Access Control (MAC) address of a detected network element of said non-cellular wireless network, an Organizationally Unique Identifier (OUI) of a detected network element of said non-cellular wireless network, or a Session Initiation Protocol (SIP) account configuration data of a detected network element of said non-cellular wireless network.

Abstract: Method and apparatus for decoding is provided. A decoding channel IDentity (ID) of a Dedicated Physical Control Channel (DPCCH) and a decoding channel ID of an Enhanced DPCCH (E-DPCCH) of a user are acquired according to a user ID of the user; Transport Format Combination Indicator (TFCI) symbols in the DPCCH and Enhanced TFCI (E-TFCI) symbols in the E-DPCCH are de-mapped, and the de-mapped symbols are stored according to the decoding channel ID; and a symbol queue to be decoded is selected according to priorities of symbol queues of the DPCCH and the E-DPCCH, symbols corresponding to the selected symbol queue from the de-mapped symbols, and decoding the read symbols are read out.

Abstract: Techniques for supporting MIMO transmission are described. User equipments (UEs) are classified into a first group of UEs to be scheduled individually and a second group of UEs that can be scheduled together. The classification may be based upon the number of transmit and receive antennas, sector loading, data requirements, long-term channel statistics, the number of UEs, etc. Channel quality indicator (CQI) information received from the UEs is interpreted in different manners depending on the groups to which the UEs belong. A single UE may be selected at a time from the first group or multiple UEs may be selected at a time from the second group for MIMO transmission. A MIMO transmission may be sent to a single UE in the first group or multiple UEs in the second group at rates selected based upon the CQI information.

Abstract: In a method of providing downlink retransmissions to a mobile station in a wireless communication network, the wireless communication network comprising a base station communicatively linked to a transparent relay station, the base station receives a request for a retransmission from the mobile station; schedules resources for the retransmission; signals scheduling information for the retransmission to the transparent relay station via a control link; and the transparent relay station receives the scheduling information for the retransmission on the control link; and sends the retransmission to the mobile station in a retransmit subframe on a retransmit frequency band.

Abstract: There is provided a method of scheduling requests from a plurality of services to at least one data storage resource. The method comprises receiving, on a computer system, service requests from said plurality of services. The service requests comprise metadata specifying a service ID and a data size of payload data associated with said service request, and at least some of said service IDs have service throughput metadata specifying a required service throughput associated therewith. The method further includes arranging, in a computer system, said requests into FIFO throttled queues based on said service ID and then setting a deadline for processing of a request in a throttled queue. The deadline is selected in dependence upon the size of the request and the required service throughput associated therewith. Then, the deadline of each throttled queue is monitored and, if a request in a throttled queue has reached or exceeded the deadline the request is processed in a data storage resource.

Abstract: Various methods and apparatuses for prioritizing operation of Relay Node are disclosed. A method for prioritizing the transmission and receipt of uplink signals in a relay node of a wireless communication system is presented. The method comprises determining radio resource requirements for receiving one or more access link signals and/or transmitting one or more backhaul link signal, determining the signal type of the one or more access link signals and/or determining the signal type of the one or more backhaul link signals, and selecting one of a transmitting mode operation and a receiving mode operation based on the radio resource requirements for receiving the one or more access link signals and/or transmitting the one or more backhaul link signals, and based on the signal type of the one or more access link signals and/or the signal type of the one or more backhaul link signals.

Abstract: An apparatus and method for scheduling within a switch is described. A set of input signals is received from input ports. The set of input signals is associated with a set of packets at the input ports. A request for each packet from the set of packets is generated based on the set of input signals. Each request has an input-port indicator, an output-port indicator and a service-level indicator. The packets are scheduled based on the service-level indicator.

Abstract: Translating between an Ethernet protocol used by a first network component and a Converged Enhanced Ethernet (CEE) protocol used by a second network component, the first and second components coupled through a CEE Converter that translates by: for data flow from the first network component to the second network component: receiving, by the CEE converter, traffic flow definition parameters for a single CEE protocol data flow; calculating, by a credit manager, available buffer space in an outbound frame buffer of the CEE converter for the data flow; communicating, by the credit manager to a CEE credit driver of the first component, the calculated size of the buffer space together with a start sequence number and a flow identifier; and responding, by the CEE credit driver to the CEE converter, with Ethernet frames comprising a private header that includes the flow identifier and a sequence number.

Abstract: Techniques are provided for scheduled and non-scheduled delivery of messages. A message directed to at least one consumer is received at a message entity. The message is determined to include a scheduled delivery time. The received message is stored in a scheduled sub-queue of the message entity. Activation metadata is retrieved and stored for any messages stored in the scheduled sub-queue that include a scheduled delivery time within a predetermined upcoming time period. If when the message is received, the scheduled delivery time of the message is within a current activation window, the activation metadata for the message may be extracted and stored immediately. The stored activation metadata is analyzed to determine a batch of messages in the scheduled sub-queue ready for delivery. The determined batch of messages is stored in an active sub-queue of the message entity, to be ready for delivery at the request of a consumer.

Abstract: Assigning slots to nodes in a mesh network. Slot numbers are assigned to nodes in a wireless mesh network using a depth-first search combined with information on 2-hop neighborhoods for each node. Assigning slots using 2-hop neighborhood information allows slots to be safely reused. The slot assignment process may take process in parallel using different wireless channels for different subtrees rooted to a controller. Slot assignment may be repeated when the mesh topology changes. Reporting using the slot numbers allows for information from child nodes to be aggregated or filtered at parent nodes.

Abstract: The present invention provides a method of scheduling asynchronous transmissions for a plurality of subscriber units. The method includes receiving information associated with a plurality of subscriber units that have uplink data to transmit, the information including uplink timing offset information associated with each of the subscriber units. Two or more subscriber units are then selected from a set of subscriber units having a timing offset differential, that is below a predetermined threshold, where the timing offset differential is the difference between the timing offset of a first subscriber unit and the timing offset of a second subscriber unit further selectively offset by a multiple of the transmission segment size, which minimizes the difference.

Abstract: Methods for scheduling downlink (DL) data on a downlink subframe from a base station directed to at least one wireless terminal in a wireless network are provided. The methods include selecting a control channel element (CCE) region for a physical downlink control channel (PDCCH) carried in a control region of the downlink subframe; determining whether a DL assignment corresponding to the DL data can be allocated on the selected CCE region based on a load imposed on a corresponding physical resource block (PRB) of a physical uplink control channel (PUCCH) of a future uplink subframe that will carry an ACK/NACK response corresponding to the DL assignment; and allocating the DL assignment on the selected CCE region when it is determined that the DL assignment can be allocated.

Abstract: A relay node and a method thereof for transmitting data are provided in the present invention, which relates to the field of wireless communication technology. The method in the present invention includes: the relay node receiving data on multiple corresponding continuous or discontinuous downlink backhaul subframes according to the obtained scheduling information of downlink multiple subframes scheduling, and sending data on multiple corresponding continuous or discontinuous uplink backhaul subframes according to the obtained scheduling information of uplink multiple subframes scheduling. The technical solution of the present invention solves a problem of scheduling resources of multiple subframes for the relay node. Compared to a dynamic scheduling and semi-persistent scheduling method in the prior art, the technical solution of the present invention can more flexibly configure and use resources to ensure transmission of the backhaul link between a base station and the relay node.

Abstract: A system and method for packing data over User Packets and packing the User Packets over DVB-S2 Frames, using the DVB-S2-ACM satellite transmission standard.

Abstract: The path management controller 1 refers to resource information 131 including reservation statuses of working paths and advance reserved paths that are set in every link, so as to calculate a route for setting a new path and set this path in this calculated route. If the route for setting this new path cannot be obtained (1) because of a shortage of residual bandwidth of a link of interest, the path management controller 1 refers to the resource reservation information 131 of working paths and advance reserved paths and calculates an alternative route for another existing path used in the link of interest, and moves this path to the calculated alternative route.

Abstract: A method of transmitting signals from a base station towards user terminals in a cellular communication system. The method includes generating diversity signals, wherein at least one of the diversity signals is subjected to a selectively variable RF phase shift. Specifically, a set of radio link quality indicators is determined at the base station, wherein each radio link quality indicator is representative of the quality of the radio link between the base station and a respective one of the user terminals. The set of radio link quality indicators is used to generate an aggregated radio quality indicator, which in turn is used to selectively vary the variable RF phase shift. For example, the phase shift may be selected, which optimizes the aggregated radio quality indicator.

Abstract: Methods, devices, and machine readable media are provided for transmission in a network with active and sleeping clients. Some examples can include transmitting a first multicast stream of data in response to an active wireless client being associated with the wireless network device at a particular time. The method can include transmitting a second multicast stream of the data after the first multicast stream in response to a sleeping wireless client being associated with the wireless network device at the particular time and in response to a delivery traffic indication message count expiring. The first and/or second multicast streams of the data can be retransmitted a number of times (e.g., at different data rates). An active/sleep status can be maintained for the wireless clients. A unicast stream can be transmitted when the number of clients does not exceed a threshold.

Abstract: Provided is a allocation controlling method of a radio resource for a radio resource allocation request in a base station which allocates, to a terminal, in response to the radio resource allocation request received from the terminal, a radio resource for transmitting retention data in a transmission buffer of the terminal to the base station, and which transmits to the terminal a radio resource allocation notification indicating a result of the allocation. When an amount of retention data in the transmission buffer received from the terminal is not zero, a transmission cycle that is suited to the retention amount is determined as a transmission cycle of the notification of radio resource allocation for transmitting the retention data in the transmission buffer and, during cyclic transmission of the radio resource allocation notification, the allocation of a radio resource for the radio resource allocation request is stopped.

Abstract: An apparatus for interconnecting a fiber-optic network and a coax network comprising a coax line terminal (CLT) configured to couple to an optical line terminal (OLT) at the fiber-optic network and a plurality of coax network units (CNUs) at the coax network and to cache data received from the CNUs and forward the cached data to the OLT upon receiving a message from the OLT that assigns a transmission cycle for a specified CNU, wherein the CLT forwards the cached data to the OLT upon receiving the message regardless of whether the cached data corresponds to the specified CNU.

Abstract: Certain aspects of the present disclosure support techniques for cooperative beamforming based on inter-cell coordination. Signaling design allows coordinated downlink transmissions with reduced inter-cell interference.

Abstract: The disclosure provides a method and device for enhancing Quality of Service (QoS) in a Wireless Local Area Network (WLAN). The method for enhancing QoS in the WLAN includes the steps of: adding a message category in a wireless access point (S10); adding a QoS priority transmission queue according to the added message category and setting queue attributes (S11); performing QoS scheduling by using the added transmission queue and performing data transmission (S12). The device for enhancing QoS in the WLAN can ensure that a wireless full service is carried out normally according to requirements of users by expanding the message categories in Enhanced Distributed Channel Access (EDCA) QoS, adding a wireless priority queue correspondingly, and using a policy of discarding a message intelligently and the like, thereby enhancing QoS to improve the user experience.

Abstract: Multicasting network packets is disclosed. A total number of copies of a frame, t, to be sent is determined. A number of copies of the frame, m, which is less than a total number of copies of the frame, t, to be made during a current iteration is determined. M copies of the frame are made. The m copies of the frame are then sent to their destinations. The original input frame is provided as output with an indication that the frame should be returned for further processing. Processing of the frame is discontinued during an interval in which other frames are processed. The process is repeated until t copies have been sent.

Abstract: Techniques for efficiently assigning resources for spurts of traffic in a wireless communication system are described. The system may support semi-persistent and non-persistent resource assignments. A semi-persistent resource assignment is valid for as long as more data is sent within a predetermined time period of last sent data and expires if no data is sent within the predetermined time period. A non-persistent resource assignment is valid for a predetermined duration or a specific transmission. A semi-persistent resource assignment may be granted for an expected spurt of data to send via the communication link. For Voice-over-Internet Protocol (VoIP), a semi-persistent resource assignment may be granted for a voice frame in anticipation of a spurt of voice activity, and a non-persistent resource assignment may be granted for a silence descriptor (SID) frame during a period of silence.

Abstract: The present disclosure provides a fabric ingress scheduler and method that distributes ingress packet traffic in a time division multiplex (TDM) system, both fabric interface aggregate and per connection, deterministically across fabric paths. Advantageously, the fabric ingress scheduler and method minimizes fabric latency and prevents fabric interface head-of-line blocking. The fabric ingress scheduler and method utilizes the fact that each connection flow has a known maximum rate which must be reserved through the fabric for prevention of data loss (essentially circuit switching using a packet fabric). In exemplary embodiments, the fabric interface supports per packet fabric path selection. Generally, the fabric ingress scheduler and method generally provides a deterministic scheduling of ingress packets to fabric paths.

Abstract: In one or more embodiments of the disclosed technology, an Access Point (AP) schedules communication traffic flows or service tasks between an Access Point (AP) and one or more member stations in a Wireless Local Area Network (WLAN). The communication traffic flows or service tasks may include both control and management flows and data traffic flows. The communication traffic flows or service tasks may include traffic flows or streams of different types, each of which may have different service intervals. The order of service tasks can be changed from cycle to cycle, randomly, by rotation, or based on historical delay records.

Abstract: Described herein are various technologies pertaining to scheduling data transfer between a mobile computing device and a base station in a cellular network. A signal quality value for a signal over which data is to be transferred is computed, and transfer of data is scheduled based upon the signal quality value. If the signal quality value is above a threshold, a wireless radio of the mobile computing device is caused to commence data transfer or continue data transfer. If the signal quality value is below the threshold, and the data need not be immediately transferred, then the wireless radio is caused to transition to an idle state or remain in an idle state.

Abstract: An apparatus comprising an ingress controller configured to receive a data frame comprising a high priority data and a low priority data, and an ingress buffer coupled to the ingress controller and configured to buffer the low priority data, wherein the high priority data is not buffered. Also disclosed is a network component, comprising an ingress controller configured to receive a data stream comprising high priority data and low priority data, and an ingress buffer coupled to the ingress controller and configured to receive, buffer, and send the low priority data, and further configured to receive a flow control indication, wherein the ingress buffer varies an amount of the low priority data sent from the ingress buffer in accordance with the flow control indication.

Abstract: Method and apparatus for managing connections and state transitions between a mobile wireless device and a wireless network are described. The mobile wireless device measures network characteristics of radio sectors in the wireless network and saves the measured network characteristics in a database, later retrieving the network characteristics and determining data inactivity timeout values for the radio sector. The mobile wireless device manages connections and state transitions based on the determined data inactivity timeout values. The database of network characteristics is organized by geographic location.

Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for generating a schedule to transmit data on a network. The method includes accessing information that identifies a quantity of data that a particular client device has designated for transmission. The method includes determining, using the information that identifies the quantity of data for each of multiple client devices, a first schedule that identifies a subset of packet time segments, from a frame that includes packet time segments, during which a first client device is permitted to transmit data to the computing system. The first client device is one of the multiple client devices. The information includes transmitting the first schedule. The schedule includes receiving a transmission of data from the first client device during the identified subset of packet time segments in accordance with the schedule.

Abstract: In a wireless mobile communications system, a method for processing control information allows the operations of a mobile terminal to be simplified and permits efficient use of resources for the mobile terminal. The network instructs in advance, the transmission of control information, such as system information and the like, via a single indicator channel. The mobile terminal receives this single indicator channel and uses the indicator information that was transmitted via the indicator channel in order to receive the control information.

Abstract: In one embodiment, a receiving node in a computer network may detect congestion, and also identifies a set (e.g., subset) of its neighbor nodes. In response to the congestion, the receiving node may assign a transmission timeslot to each neighbor node of the set based on the congestion, where each neighbor is allowed to transmit (synchronously) only during its respective timeslot. The assigned timeslots may then be transmitted to the set of neighbor nodes. In another embodiment, a transmitting node (e.g., a neighbor node of the receiving node) may receive a scheduling packet from the receiving node. Accordingly, the transmitting node may determine its assigned transmission timeslot during which the transmitting node is allowed to transmit. As such, the transmitting node may then transmit packets only during the assigned timeslot (e.g., for a given time). In this manner, congestion at the receiving node may be reduced.

Abstract: A system for managing parallel processing of network packets is also provided. A wireless access device that includes multiple transceivers and multiple processing units receives network packets. A media access controller determines which transceiver a received network packet is associated with. A tagging module determines whether the transceiver associated with the received network packet is bound to one of the processing units. In response to a determination that the transceiver is bound, a scheduler assigns the received packet to the processing unit the transceiver is bound to. In response to a determination that the transceiver is not bound, the tagging module binds the transceiver to a processing unit such that the processing unit processes network packets associated with the transceiver while the transceiver is bound to the processing unit, and the scheduler assigns the received network packet to the processing unit the transceiver is bound to.

Abstract: An data transmission adjustment system that comprises a server and a plurality of data transmission devices within a sensing region. The server adapts to receive a sensed data from at least one data transmission device, define a timeline, divide the timeline into a plurality of monitoring periods, calculate a ratio of the number of the monitoring periods that have received the sensing data from the data transmission device within the sensing region or not to the number of all the monitoring periods, and broadcast at least one message to the data transmission devices within the sensing region according to said ratio.

Abstract: A system and method for collision detection and avoidance that converts a probabilistic, packet based communications system into a deterministic packet based communications system. The system and method operates in packet, frame, or datagram based network environments that support different levels of forwarding priority, for example, IP networks and Ethernet networks.

Abstract: A networking system is discussed. The system may be used for industrial networks, where deterministic behavior is often valued. Bounded message travel times may be achieved for a first set of network traffic. Additional traffic may be routed over the networking system without interfering with the message travel times associated with the first set of network traffic. Systems and methods for assigning priority to various sets of network traffic are discussed.

Abstract: An industrial network with bidirectional communication for real time control includes nodes selectively operable in either a switch mode or a serial shifting mode. Nodes operating in the switch mode are capable of initiating data frames for transmission on the network and receiving data frames from the network. Nodes operating in either the switch mode or the serial shifting mode are capable of extracting and/or inserting data into a data frame as it is transmitted through that node. An initialization procedure determines end nodes and intermediate nodes within the network. The end nodes are configured to initially operate in the switch mode and the intermediate nodes are configured to initially operate in the serial shifting mode. The intermediate nodes are additionally operable to selectively toggle between operation in switch mode and serial shift mode and may operate in both modes during a single I/O scan cycle.

Abstract: A method of allocating radio resources in a wireless communication system is disclosed. A method of allocating radio resources from a network of a wireless communication system in accordance with a plurality of scheduling modes comprises transmitting first scheduling information to a user equipment to allocate radio resources to the user equipment in accordance with a first scheduling mode, the first scheduling information including a first user equipment identifier, and transmitting second scheduling information to the user equipment to allocate radio resources to the user equipment in accordance with a second scheduling mode, the second scheduling information including a second user equipment identifier.