US 5365524

Patent Overview: US5365524A

Title: "Establishing telecommunications call paths between clustered switching entities"

Patent number: US 5,365,524 A

Application number: US07/972,787

Inventors: Thomas L. Hiller, James J. Phelan, Meyer J. Zola

Original assignee: AT&T Bell Laboratories Inc. (later recorded as assigned to American Telephone and Telegraph Company)

Dates (from the source): Priority/filing date 1992‑11‑06; publication/grant date 1994‑11‑15; anticipated expiration 2012‑11‑06. Legal status listed as "Expired – Lifetime" (the source notes legal status is an assumption, not a legal conclusion).

Purpose and plain-language scope (based only on the supplied text):
The patent concerns establishing telecommunications call paths between clustered switching entities. Its context is the Asynchronous Transfer Mode (ATM) standard, under which communication signals are packed into cells, each 53 bytes long — a 5‑byte header plus a 48‑byte payload. Within a segment of a signal, the source says each cell may be headed for a separate destination, with that destination identified in the header. The stated motivation is that "no sound economic proposal has been made for the economic use of ATM for achieving a very high capacity large switching system or a large highly interconnected cluster of smaller switching systems." The excerpt lists prior-art keywords — atm, cells, cell, atmu, signals — and mentions permanent virtual circuits, but the claim language and detailed operation are not reproduced here.

Classifications in the source include packet switching elements, ATM switching fabrics/elements (including space switching such as crossbar or matrix), routing/path finding using connection establishment between ports, hybrid switching systems, and broadband ISDN provisions, among others.

Source cited: https://patents.google.com/patent/US5365524/en (fetched 2026‑09‑23; the supplied text is marked as an excerpt only).

What the excerpt does not establish: The specific claims and their exact scope; the detailed embodiments, figures, and terminology (e.g., what "atmu" denotes) are absent. The excerpt also does not support any findings on prior-art comparisons, litigation, validity, enforceability, ownership transfers, or current assignee accuracy — the source itself cautions that listed assignees "may be inaccurate."