A first wireless unit engages in contemporaneous participation in a plurality of wireless networks. A connection is established with a second wireless unit in a first wireless network. Then, a hold time-out period is determined, and the first wireless unit enters a hold mode with respect to the first...http://www.google.com.hk/patents/US6026297?utm_source=gb-gplus-share專利 US6026297 - Contemporaneous connectivity to multiple piconets
