Oodan, Antony P.; Ward, Keith E.; Savolaine, Catherine G.; Daneshmand, Mahmoud; Hoath, Peter: 'Telecommunications Quality of Service Management' (Telecommunications, 2003) DOI: IET Digital Library, https://digital-library.theiet.org/;jsessionid=m7v7b38vvq1r.x-iet-live-01content/books/te/pbte048e