The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 03, 1995
Filed:
Dec. 29, 1992
Louis P Herzberg, Monsey, NY (US);
Antonio Ruiz, Yorktown Heights, NY (US);
Marc H Willebeek-LeMair, Mt. Kisco, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A rights controlling concentrator (RCC) is an apparatus for separating and controlling 'rights of receiving' and 'rights of transmitting' of a group of stations or groups of stations on a ring-of-trees local area network. RCC elements perform collectively to separately control, limit and/or make available the 'rights of receiving' and the 'rights of transmitting' of a group of stations or groups of stations. Control of the 'rights of receiving' ensures that its membership is only forwarded frames transmitted by an external station which has a destination within the membership, and that the external stations only be forwarded frames transmitted by the membership which have a destination within the external stations. Frames that are transmitted to a destination in one group traverse only stations within that group. Frames that are deemed by the RCC not to be of interest to any group of stations are withheld from that group by the RCC controlling both frame receiving and transmitting rights. This significantly reduces the workload of groups of stations, because frames are not passed through station groups that are not necessary for the frames to reach their destination. Furthermore, since data frames are handled by fewer stations, the reliability of the main ring is increased. Control of the 'rights of transmitting' ensures that the token is, or can be, withheld from stations that are 'listen only' and need not be given the rights to transmit. This reduces the travel time of the token around the ring (and the Token Target Rotation Time (TTRT)), providing faster repeating opportunities for the transmitting stations to transmit.