Abstract:
A method of distributed control of a wireless mesh network without knowledge of global topology. The method includes: a station joining the network with any current member by propagating the join-request, or two meshes merging using the steps of: one mesh joining the other as a whole and then re- synchronizing its timing. The method further includes: first, each station periodically transmits a beacon; second, in response to a beacon being no longer detected, a station transmitting a bitmap of stations that it can still receive; third, each station responds by adding stations that it can receive with all of the bitmaps received from other members, and retransmitting the updated bitmap; fourth, after time for all stations to respond, all stations base current membership on the bitmap. The method further includes: determining sharable time slots that will not interfere with neighbors or other slot sharers, using and then releasing those slots.
Abstract:
Vorrichtung zur Synchronisation wenigstens zweier Bussysteme mit einem ersten Kommunikationsbaustein für ein erstes Bussystem und einem zweiten Kommunikationsbaustein für ein zweites Bussystem, wobei in dem ersten Kommunikationsbaustein eine erste Triggerinformation (TMI1) vorliegt, durch welche im ersten Bussystem ein Triggersignal (TS) ausgelöst wird, dadurch gekennzeichnet, dass die Vorrichtung derart ausgebildet ist, dass der erste und der zweite Kommunikationsbaustein in Verbindung stehen und dass die erste Triggerinformation (TMI1) an den zweiten Kommunikationsbaustein übertragen wird, und der zweite Kommunikationsbaustein derart ausgebildet ist, dass aus der ersten Triggerinformation (TMI1) ein Zeitinformationswert (CT2Mess) ermittelt wird und dieser Zeitinformationswert (CT2Mess) mit einer zweiten Zeitmarke (TM2) des zweiten Bussystems verglichen wird, wobei ein Zeitunterschied (TD) ermittelt wird und die nächste Referenznachricht (RN) im zweiten Bussystem abhängig von der zweiten Zeitmarke (TM2) und dem Zeitunterschied (TD) ausgelöst wird.
Abstract:
A grouped polling method based on guarantee strategy of fixed quality of service (QoS) in the wireless local area network includes: determine the grouped polling strategy according to the priority of the traffic type and perform the circular polling to the groups according to said strategy, one grouped polling of said circular polling is for all the groups or part of the groups, the content of the each grouped polling can be different, the stations respond the grouped polling according to the priority of the data traffic type to be transmitted, the stations that comply with the polling terms transmit the data to the destination station and the destination station receives the response. The invention enables the interval between frames when transmitting the traffic type with different priority and the retreating window to be set as same or different. The interval between frames when transmitting the traffic type with low priority is not very large. The invention doesn't have the unnecessary transmission delay, increases the network throughput and enhances the network performance.
Abstract:
A fixed and/or moveable system, for example associated with or able to be connected to cars (lorries), effects monitoring of functions carried out by two or more units (E1, E2) comprised in the system. The execution of the functions (F-F5) is arranged to be able to be detected and determined by means of one or more time-perceiving devices, for example clocks, and/or devices that indicate events that are comprised in one or more of the said units that constitute module units in the system. This can consist of or comprise one or more serial, distributed and protocol-utilizing systems. The respective determination is arranged to form the basis for or to invoke functionality in the system. By means of the invention, it is possible to simplify considerably hardware comprised in the respective systems, to use less bandwidth or utilize it better for efficient transmission of information. In addition, the system’s hardware can be simplified.
Abstract:
A network loop monitor (10) is disclosed which comprises an RS485 port (16) for connection to a host which receives and transmits data. The port (16) comprises termination jumpers (14), a transmitter/receiver (34) and an isolator (36). The monitor (10) includes two further RS485 ports (18, 20) each of which has a termination (26, 28), a transmitter/receiver (42, 44) and an isolator (38, 40). A relay (22) controls contacts (24) in the line pair (12). Router logic (32) controlled by a microprocessor (30) determines the status of the loop monitor.
Abstract:
In one embodiment, a node (102) comprises a first network interface (112) and a second network interface (112). The node further comprises a first bus guardian that asserts a first bus guardian (130) signal when the second network interface is allowed to transmit and a second bus guardian (130) that asserts a second bus guardian signal when the first network interface is allowed to transmit. The first network interface is not allowed to transmit unless the second bus guardian asserts the second bus guardian signal. The second network interface is not allowed to transmit unless the first bus guardian asserts the first bus guardian signal.
Abstract:
Bei dem Verfahren zur seriellen Vergabe von Adressen und zur Überprüfung der Adressvergabe in einem Bussystem, das einen Bus aufweist, an den eine Steuereinheit und mehrere zu adressierende Teilnehmer angeschlossen sind, ordnet die Steuereinheit (12) innerhalb jeweils eines Adressvergabezyklus einem zu adressierenden Teilnehmer (16-22) eine Adresse zu, wobei die Steuereinheit (12) zu Beginn eines jeden Adressvergabezyklus ein Startsignal ausgibt. Jeder noch zu adressierende Teilnehmer (16-22) erfasst bis zu seiner Adressierung die Anzahl an empfangenen Startsignalen und speichert innerhalb desjenigen Adressvergabezyklus, in dem ihm von der Steuereinheit (12) eine Adresse zugeordnet wird, einen der Anzahl an bis dahin empfangenen Startsignalen entsprechenden Zahlenwert. Die Steuereinheit (12) fragt nach Adressierung des letzten noch nicht adressierten Teilnehmers (16-22) oder nach Ablauf einer der Anzahl von Teilnehmern (16-22) gleichenden Anzahl von Adressvergabezyklen die gespeicherten Zählerwerte der adressierten Teilnehmer (16-22) ab und überprüft anhand dieser Abfrage die Adressvergabe auf ihre Plausibilität hin.
Abstract:
A method of controlling and sharing access to a wireless network wherein some stations of the network may be out of range of other stations of the network (Fig. 2, 4, 5). The method includes the steps of: first, each station periodically transmits a beacon containing a bit map having a bit location for every station on the network and monitoring the beacons of stations within its range (fig. 2); second, in response to a beacon being no longer detected, each station transmits a bit map containing an indication of only the stations that it can still receive; third, on receiving a bit map with not all stations indicated, each station responds by adding stations that it can receive to the received bit map and transmitting the updated bit map; fourth, each station repeats the third step until the updated bit map indicates that all stations are still in the network or that a station is missing from the network; and finally, if a station is indicated to be missing from the network, each station updates the bit map. Through the application of these steps, the invention controls access to the network without a global master. The present invention has the advantage of controlling a network without the need for a central master station, and does not require continuous global knowledge of the topology of the network (fig. 2, 4).
Abstract:
In one embodiment, a method for deterministic registration for communication networks comprises transmitting a node register command over a network, the node register command comprising a first plurality of bits and a second plurality of bits, the first and second plurality of bits addressing a range of nodes that should respond to the node register command, and a plurality of time slot delays, during each of the plurality of time slot delays, listening to the network for a response from a node in the range of nodes (1020), the node determined by each of the plurality of time slot delays, and responsive to detecting a response (1014, 1024), determining a responding node corresponding to the response (1012) and designating the responding node as registered (1018).
Abstract:
A system and method for enabling computers associated with a communications network to remotely locate each other and establish a master-slave relationship.