12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Scheduling and admission testing for jitter-con...
View graph of relations

« Back

Scheduling and admission testing for jitter-constrained periodic threads

Research output: Contribution to journalJournal article

Published

Journal publication date09/1997
JournalMultimedia Systems
Journal number5
Volume5
Number of pages10
Pages337-346
Original languageEnglish

Abstract

We present new admission tests for periodic realtime threads with explicitly stated deadlines scheduled according to the earliest deadline first (EDF) algorithm. In traditional real-time periodic scheduling, the deadline of a periodic thread is conventionally the end of the current period. In contrast, our tests support periodic threads in which the deadline may be earlier than the end of the current period. In the extreme case, the deadline may be specified as identical to the per period execution time, which results in perfectly isochronous periodic threads. The provision of such threads, which we refer to as jitter-constrained threads, helps end-systems to honour jitter as well as throughput-related QoS parameters in distributed multimedia systems. In addition, such threads can reduce end-to-end delay and buffer memory requirements as less buffering is needed to smooth excessive delay jitter.