Wei Zhuang Yung-Sze Gan Qing Gao Kok Jeng Loh Kee Chaing Chua Multi-domain policy architecture for IP multimedia subsystem in UMTS. 27-38 2002 conf/ifip6-2/2002 Net-Con db/conf/ifip6-2/ifip6-2-2002.html#ZhuangGGLC02