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公开(公告)号：GB2314487A
公开(公告)日：1997-12-24
申请号：GB9712244
申请日：1997-06-13
Applicant: IBM
Inventor： GFELLER FRITZ RUDOLF , HORTENSIUS PETER DIRK , KAM PATRICK K , KERMANI PARVIZ , MCKAY DANNY M , NAGHSHINEH MAHMOUD , OLSEN CLAUS MICHAEL , REZVANI BABAK
IPC: H04L1/00 , H04L1/08 , H04L12/413
Abstract: A method of wireless communications in a network having a plurality of terminals comprises transmitting media access coordination information at a first repetition rate and other information at a second repetition rate lower than said first repetition rate. A Media Access and contention resolution scheme for using multirate wireless,/infrared communication is described. In such an environment, each physical layer frame is broken into two portions: (1) the robust header portion which contains all svmbols important to the MAC protocol and media coordination and is sent with a repetition rate Rmax where Rmax is selected in such a way that all stations within the interference environment can decode the reservation symbols with a desired probability; and (2) data symbols which are sent with a repetition rate R where R can be less than Rmax. Here R depends on the channel conditions at any destination with respect to the source station transmitting such data symbols.
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12.发明专利
公开(公告)号：CA2219045C
公开(公告)日：2001-05-29
申请号：CA2219045
申请日：1997-07-08
Applicant: IBM
Inventor： MCKAY DANNY NEIL , HORTENSIUS PETER D , REZVANI BABAK , OLSEN CLAUS M , NAGHSHINEH MAHMOUD , KERMANI PARVIZ
IPC: H04L29/06
Abstract: In a communication network having a plurality of nodes and using a collision avoidance media access protocol; using a shared common channel medium, where channel a ccess resulting in a successful reservation, where the reservation requester is th e primary station and subject target in the secondary station, where the primary station coord inates the channel data communication to the secondary station, where the secondary sta tionacknowledges the data with Acknowledgment (ACK) cont rol frame, where the primarystation controls the reservation termination bas ed on transmission of an End-Of-Burst (EOB) control frame, where the secondary station responds with an End-Of-Bur st-Confirm (EOBC) control signal; the method comprising combining the data with the EOB control frame and transmitting them together and combining the ACK control frame and the EOBC frame and transmitting them together.
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13.发明专利
公开(公告)号：CA2218905C
公开(公告)日：2001-02-13
申请号：CA2218905
申请日：1997-07-08
Applicant: IBM
Inventor： MCKAY DANNY NEIL , KERMANI PARVIZ , HORTENSIUS PETER D , REZVANI BABAK , OLSEN CLAUS M , NAGHSHINEH MAHMOUD
Abstract: In a communications network having a plurality of stations and a shared common communications medium using a collision avoidance media access protocol for communication between the stations; in which medium access is granted to a pair of stations obtaining a successful reservation of the medium; the pair of stations comprising a requester station and a target station, the requester station comprises a primary station, and the target station comprises a secondary station; wherein the primary station coordinates communication to the secondary station; a method of maintaining thereservation in the event a transmission of a frame of data is received from a third station not participating in the reservation comprising: each station participating in the reservation examining all received frames to determine the transmitter address thereof; ignoring frames transmitted from a non-participating station continuing with the reservation.
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公开(公告)号：GB2314487B
公开(公告)日：2001-01-10
申请号：GB9712244
申请日：1997-06-13
Applicant: IBM
Inventor： GFELLER FRITZ RUDOLF , HORTENSIUS PETER DIRK , KAM PATRICK K , KERMANI PARVIZ , MCKAY DANNY M , NAGHSHINEH MAHMOUD , OLSEN CLAUS MICHAEL , REZVANI BABAK
IPC: H04L1/00 , H04L1/08 , H04L12/413
Abstract: In a wireless multi-rate communications system, a method for extending the range of communications in the system by dividing the physical layer frame into two portions: a robust header portion and a body, where the repetition rate of the data symbols in the header portion is greater than or equal to the repetition rate of the data symbols in the body of the frame. In this way the header can be received and decoded by all stations in the system with a high probability, while the body of the frame need only be received and decoded by the destination station to which the body of the frame is intended to be received and decoded.
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公开(公告)号：DE3876776D1
公开(公告)日：1993-01-28
申请号：DE3876776
申请日：1988-01-22
Applicant: IBM
Inventor： BUX WERNER KLAUS , KLEINOEDER WOLFGANG B , KERMANI PARVIZ
Abstract: In the Checkpoint Mode Protocol (CPM), checkpoint frames are transmitted at regular intervals for acknowledging received information frames and individually requesting retransmission of missing information frames. The disclosed invention reduces the flow of checkpoint frames in situations where their information is not required. This is achieved by either sending a Stop Checkpointing frame from sender to receiver in particular situations, or by inserting, in the case of duplex transmission (i.e. both stations are sending and receiving), Request-Reply bits into normal checkpoint frames for suppressing the flow of checkpoint frames when they are not necessary. In each case, provisions are made to resume the transmission of checkpoint frames as soon as they are required again.
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Patent Agency Ranking
公开(公告)号：DE69732064T2
公开(公告)日：2005-12-08
申请号：DE69732064
申请日：1997-06-25
Applicant: IBM
Inventor： MCKAY DANNY NEIL , NAGSHINEH MAHMOUD , OLSEN CLAUS MICHAEL , REZVANI BABAK , KERMANI PARVIZ
IPC: H04B7/26 , H04L12/28 , H04L12/413 , H04L12/56 , H04L29/02
Abstract: A communication network and method improves the performance (measured e.g. in terms of throughput) of a RTS/CTS based distributed media access control protocol. The medium reservation is done in a hierarchical fashion where first the shared medium is reserved for two stations called the participants. All other stations called observers stay quiet during the time reserved for the participants. In this fashion, a shared medium can be reserved for a subset of the plurality of devices. During this period called the reserved period, a master (or primary), and a slave (or secondary) station attribute can be given to the participating devices and the medium can be shared using another medium coordination algorithm which is not necessarily the same as the one used to reserve the medium for a reserved period in the first place. After the medium is reserved, the participating devices can establish a conventional point-to-point connection within the reserved time period between participating devices for a predefined period of time. Specifically, the primary attribute can be exchanges with a secondary attribute which in effect gives the control of the shared medium during the reserved period to another station different from the one that originally was assigned the primary attribute. During the reserved time, the secondary can signal the primary station that it has data to send to the primary station and request that the primary and secondary roles or attributes to be exchanged. In the case that a role exchange takes place, the control of the medium is transferred from one station to another and data transfer in an opposite direction can take place without requiring another reservation attempt.
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公开(公告)号：DE69732064D1
公开(公告)日：2005-02-03
申请号：DE69732064
申请日：1997-06-25
Applicant: IBM
Inventor： MCKAY DANNY NEIL , NAGSHINEH MAHMOUD , OLSEN CLAUS MICHAEL , REZVANI BABAK , KERMANI PARVIZ
IPC: H04B7/26 , H04L12/28 , H04L12/413 , H04L12/56 , H04L29/02
Abstract: A communication network and method improves the performance (measured e.g. in terms of throughput) of a RTS/CTS based distributed media access control protocol. The medium reservation is done in a hierarchical fashion where first the shared medium is reserved for two stations called the participants. All other stations called observers stay quiet during the time reserved for the participants. In this fashion, a shared medium can be reserved for a subset of the plurality of devices. During this period called the reserved period, a master (or primary), and a slave (or secondary) station attribute can be given to the participating devices and the medium can be shared using another medium coordination algorithm which is not necessarily the same as the one used to reserve the medium for a reserved period in the first place. After the medium is reserved, the participating devices can establish a conventional point-to-point connection within the reserved time period between participating devices for a predefined period of time. Specifically, the primary attribute can be exchanges with a secondary attribute which in effect gives the control of the shared medium during the reserved period to another station different from the one that originally was assigned the primary attribute. During the reserved time, the secondary can signal the primary station that it has data to send to the primary station and request that the primary and secondary roles or attributes to be exchanged. In the case that a role exchange takes place, the control of the medium is transferred from one station to another and data transfer in an opposite direction can take place without requiring another reservation attempt.
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18.发明专利
公开(公告)号：CA2218905A1
公开(公告)日：1998-01-09
申请号：CA2218905
申请日：1997-07-08
Applicant: IBM
Inventor： HORTENSIUS PETER D , OLSEN CLAUS M , KERMANI PARVIZ , MCKAY DANNY NEIL , NAGHSHINEH MAHMOUD , REZVANI BABAK
Abstract: In a communications network having a plurality of stations and a shared comm on communications medium using a collision avoidance media access protocol for communication between the stations; in which medium access is granted to a p air of stations obtaining a successful reservation of the medium; the pair of stati ons comprising a requester station and a target station, the requester station comprises a primary station, and the target station comprises a secondary station; wherein the primary st ation coordinates communication to the secondary station; a method of maintaining thereservation in the event a transmission of a frame o f data is received from a third station not participating in the reservation comprising: each station participating in the reservation examining all received frames to determine the transmitter address thereof; ignoring frames transmitted from a non-participating station continuing with the rese rvation.
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公开(公告)号：CA2210030A1
公开(公告)日：1998-01-09
申请号：CA2210030
申请日：1997-07-08
Applicant: IBM
Inventor： REZVANI BABAK , MCKAY DANNY NEIL , KERMANI PARVIZ , NAGHSHINEH MAHMOUD , OLSEN CLAUS M , HORTENSIUS PETER D
Abstract: A communication network and method improves the performance (measured e.g. in terms of throughput) of a RTS/CTS based distributed media access control protocol. The medium reservation is done in a hierarchical fashion where first the shared medium is reserved for two stations called the participants. All other stations called observers stay quiet during the time reserved for the participants. In this fashion, a shared medium can be reserved for a subset of the plurality of devices. During this period called the reserved period, a master (or primary), and a slave (or secondary) station attribute can be given to the participating devices and the medium can be shared using another medium coordination algorithm which is not necessarily the same as the one used to reserve the medium for a reserved period in the first place. After the medium is reserved, the participating devices can establish a conventional point-to-point connection within the reserved time period between participating devices for a predefined period of time. Specifically, the primary attribute can be exchanges with a secondary attribute which in effect gives the control of the shared medium during the reserved period to another station different from the one that originally was assigned the primary attribute. During the reserved time, the secondary can signal the primary station that it has data to send to the primary station and request that the primary and secondary roles or attributes to be exchanged. In the case that a role exchange takes place, the control of the medium is transferred from one station to another and data transfer in an opposite direction can take place without requiring another reservation attempt.
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公开(公告)号：DE3876776T2
公开(公告)日：1993-07-01
申请号：DE3876776
申请日：1988-01-22
Applicant: IBM
Inventor： BUX WERNER KLAUS , KLEINOEDER WOLFGANG B , KERMANI PARVIZ
Abstract: In the Checkpoint Mode Protocol (CPM), checkpoint frames are transmitted at regular intervals for acknowledging received information frames and individually requesting retransmission of missing information frames. The disclosed invention reduces the flow of checkpoint frames in situations where their information is not required. This is achieved by either sending a Stop Checkpointing frame from sender to receiver in particular situations, or by inserting, in the case of duplex transmission (i.e. both stations are sending and receiving), Request-Reply bits into normal checkpoint frames for suppressing the flow of checkpoint frames when they are not necessary. In each case, provisions are made to resume the transmission of checkpoint frames as soon as they are required again.
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