Definition and evaluation of the data link layer of PACnet

Abstract

PACnet is a 200-500 Mbps dual-ring fiber optic network designed to implement a Picture Archiving and Communication System (PACS) in a hospital environment. The network consists of three channels: image transfer channel, command and control channel and real-time data channel. An initial network interface unit (NIU) design for PACnet consisted of a functional description of the protocols and NIU major components. Using the International Organization for standards/Open Systems Interconnection (ISO/OSI) reference model as a guide, we extend the definition of the data link layer. This definition covers interface service specifications for the sublayers: logical link control (LLC) and medium access control (MAC). It describes procedures for data transfer, mechanisms of error detection and fault recovery. A performance evaluation study was made to determine the network performance under various scenarios, using stochastic activity networks. The results demonstrate the feasibility of PACnet as an integrated image, data, and voice network for PACS.