Browse Prior Art Database

Logical Communications Support: Interface and Subsystem

IP.com Disclosure Number: IPCOM000108301D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 3 page(s) / 123K

Publishing Venue

IBM

Related People

Reider, RS: AUTHOR [+2]

Abstract

Disclosed is an interface and subsystem architecture that allows application programs, compliant with the evolving "Logical ACR-NEMA" standard, to communicate over heterogeneous networks independent of network-specific considerations, and across multiple platforms.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Logical Communications Support: Interface and Subsystem

       Disclosed is an interface and subsystem architecture that
allows application programs, compliant with the evolving "Logical
ACR-NEMA" standard, to communicate over heterogeneous networks
independent of network-specific considerations, and across multiple
platforms.

      "Logical ACR-NEMA" refers to the emerging Application Layer and
Presentation Layer specifications from the National Electrical
Manufacture's of America's (NEMA) "ACR-NEMA 300-1988" specification
(1).  Based on the International Organization for Standardization's
(OSI) basic reference model (2), Logical ACR-NEMA specifies
application layer commands and presentation layer formats to be used
between radiological devices (e.g., X-ray machines, CT scanners,
image review stations, image archival devices).

      The Logical Communications Support (LCS) interface defines the
following:
1.   An LCS Service Access Point (SAP) situated beneath the ACR-NEMA-
defined Presentation Layer.  Note that the layer beneath the LCS
interface is not necessarily comparable to an OSI session layer. For
instance, a future implementation may directly map the transport
layer service primitives of TCP/IP to the LCS session layer service
primitives.
2.   Two LCS service primitives are specified for transferring data:
one for sending data, one for receiving.  These primitives include:
      a. a remote application level ACR-NEMA logical address
      b. a file stored or buffer stored Logical ACR-NEMA message
      c. optional acknowledgment mechanisms
3.   A single LCS "initialization" service primitive which includes:
     a. a list of ACR-NEMA specific remote logical addresses (RLAs)
     b. owner-specific information associated with an RLA, for in
stance, phone number, name, address.
     c. common network wide parameters, such as retries and timeouts
     d. network-specific parameters, such as physical addresses and
session level names.

      Additionally, the LCS definition includes a specific subset of
existing protocol standards to ensure compatibility across different
implementations.  Thus, for instance, in making use of APPC
communications, LCS compliant nodes must allocate two bidirectional
simplex sessions to allow for full-duplex asynchronous
communications.

      The advantages of Logical-ACR-NEMA application's conforming to
the architecture and the implementations of LCS include:
      1.   A simplification of communications handling.
      2.   Ability to use new communications supported by an LCS
subsystem with no modifi...