| It may be envisioned that future wireless networks would be All-IP based and consist of QoS capable and mobility enhanced IP routers which handle both real-time and best-effort data traffics. In population dense areas (traffic hot spots), pico-cells with radius of hundreds of meters are deployed to efficiently reuse the precious radio spectrum and meet the high demand for radio based broadband access. To avoid the high cost of connecting a large number of pico-cells to the backbone network, the pico-cells are inter-connected via short highly focused free-space optic links or microwave links in a multi-hop mesh fashion (called UniNet). Traffic generated within (or delivered to) any pico-cell would, in general, be relayed among a sequence of pico-cells in a multi-hop arrangement, eventually entering (or leaving) the wireless IP network at a local end office.; Mobility management is one of the main challenges presented by the development of IP-centric mobile telecommunication networks and the focus of this dissertation. There are three types of mobilities in the network described above: macro-mobility between mobile domains, micro-mobility between the regular cells within a mobile domain, and pico-mobility between the pico-cells in UniNet. In this dissertation, we look at hierarchical mobility management schemes that differentiate the three types of mobilities. We assume the macro-mobility is handled by Mobile IP due to its scalability for global mobility and therefore focus on the micro-mobility and pico-mobility management. Because of the unique nature of UniNet, we further differentiate the pico-mobility in UniNet from the micro-mobility: for the pico-mobility within UniNet, a simple and efficient connection tree sharing based scheme is proposed that works on link layer and is able to handle both the call routing and handoff within UniNet; for the micro-mobility within the IP mobile domain, a connection tree based scheme is proposed that works on IP layer and supports such critical features as IP QoS, fast location update and handoff, and soft handoff. |
