Unified micro-cellular network with Pico-cells to avoid local congestion

Micro-cellular networks have advantage of the radio band reusability over macro-cellular networks though they have drawbacks; frequent handovers disturbing smooth packet transfer and local congestion closed in micro-cells. MM-MAN (mobile multimedia metropolitan area network) the authors have been studying is a unified micro-cellular network in which micro-cells for fast terminals are deployed along major roads in metropolitan area. This paper presents how the MM-MAN solves two major drawbacks of micro-cellular network. To avoid frequent handover, polling is emitted to each micro-cell in an LMC (logical macro-cell) consisting of several adjacent cells, and packet transfer is conducted in one of micro-cells to which polling response comes. The LMC switched-over is triggered when the terminal move to the next cell is detected by the network side. The local congestion which can typically happen around cross-sections can be released with a small double tier, micro-cells with pico-cell. The capacity of the unified micro-cellular network can be much larger than that of the conventional double tier network