公开(公告)号：CA2194026A1

公开(公告)日：1998-06-24

申请号：CA2194026

申请日：1996-12-24

Applicant: IBM CANADA

Inventor： TAGLIONE JOHN V ,  KAM PATRICK K

IPC: G06F13/28 ,  G06F15/17 ,  H04L12/46

Abstract: The invention provides a data processing system comprising: a CPU; a system memory; a plurality of network interfaces; a CPU bus connected to the system memory an d to each of the network interface for initialization and control of the network interfac es by the CPU; an individual DMA bus connected to each of corresponding network interfaces and to the system memory; each of the network interfaces is connectable to an external network, whereby data can be transferred by the data processing system from one netwo rk to another using system memory.

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.

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.